Home

4 - SoDa Service

1. PV array disconnected when full battery Load disconnected in case of deep battery discharge Back up generator eventually running if defined in the system according to battery voltage Due to battery voltage evolution these operating conditions may change during the time step In this case the program determines the exact time when a regulator threshold condition is met evaluates the energies for this hour fraction and starts again a balance loop according to the new operating conditions Several variables 97 are computed during and after this process array running characteristics battery storage and ageing load an used energies etc Simulation process DC grid system System calculation is rather different whether a load profile is defined or not With undefined illimited load profile When the load consumption vehicle is not defined the delivery of the conventional power supplyis irrelevant The voltage at the output of the arrayis the Main Power Supply Nominal Voltage with a fixed value The treatment is easy since the array operates at this fixed voltage current and power are directly deduced from the array I V characteristics model Voltage at the user s level is decreased by the P V system line resistance voltage drop In this case the safety overvoltage regulation does not operate since the line voltage stays ata fixed value and the PV current production is supposed to be always absorbed With defined load
2. Data Projects directory Pre_Grid PSG Pre_SAlone PSS Pre_Pumping PSP Project PRuJ Project VCi Chapter 7 Technical aspects Preliminary design of grid connected systems Preliminary design of stand alone systems Preliminary design of pumping systems Central definitions of a project for full simulation and or measured data analysis includes site associated meteo file albedo data eventually altitude corrections etc Variant of a simulation version Includes all specific parameters for one simulation plane 178 179 Technical aspects T orientation PV module arrangement inverters batteries or pumps etc loss factors shadings horizon etc as well as simulation results These files have the same name as the project The last letter of the extension determines the version number running from 0 9 and A Z Project CMi Variant of a simulation measured data comparison similar to the simulation variant but including more the detailed comparison pairs in hourly or daily values Data Shadings Data Shadings directory Horizon HOR Horizon profile definition Shading_Scene SHD Complete shading scene may also include the Shading Factor Table Buildings BLD Buildings templates created in the near shading scene Shading_objects SHO Collection of shading objects which can be saved together using multiple selection Data Models Data Models directory Load LOD Load definition or p
3. AM1 5 Spectrum i e a normalised solar spectrum corresponding to the crossing of 1 5 times the normal atmosphere vertical air mass atthe sea level Transverse Incidence Angle Let us call Profile Plane the plane passing through a horizontal line perpendicular to a given azimuth and the sun We call Transversal incidence angle the angle between the normal to a tilted plane ofthis given azimuth and the corresponding profile plane This is useful for mutual shadings of sheds or sun shields calculations Chapter 9 Glossary 194 195 Glossary 9 Wind Velocity Synthetic generation Wind Velocity in synthetic generation The wind velocity values are not converted into hourly values as we don t know any general rule for doing this and we don t have any algorithm at disposal Therefore the simulation process will use the monthly value Nevertheless the wind velocity is only involved in estimating the Array Loss Factor K Kc Kv Vw W m k before determining the array temperature Therefore the wind velocity has only a very little incidence on the PV array production during the simulation process Currently we don t avail of validations of the simulation results by third parties Finally few people really perform results analysis by respect to their real data or they don t make them public This is not easy because The simulation results depend on many parameters which may be set at any value in order to get the expected r
4. In this mode the only energy loss is the difference between the Pmpp potential power and the PhomDC limit values We can see on the power distribution diagrams that even when the inverter s power is a little bit under the maximum powers attained by the array in real operation this results in very little power losses violet steps by respect to the green ones The simulation and the analysis of the overload loss is therefore a very good mean for assessing the size of an inverter Please see the power histogram in the System definitions button Show sizing For an economical optimization the final overpower losses are to be put in balance with the price difference with an inverter of higher power These considerations often lead to very undersized inverters by respect to the manufacturer s recommendations Pnom ratio of the order of 1 25 for optimal 30 south planes up to 2 2 for a south fa ade Grid Inverter sizing Please note that the inverter sizing should take into account the fact that the inverter nominal power is defined as the device output power The corresponding input power has to be increased by a factor 1 Efficiency about 4 to 8 at maximum power the array nominal power is defined at STCI19 1000 W m 25 C Under operating conditions the module temperature mismatch and other losses decrease the effective array output power of at least 15 to 20 from the given nominal power Therefore for proper
5. The user is free to choose his parameter bo or even to define any special profile shape as a function of the incidence angle The custom profile can be easily drawn on the graph with the mouse Array mismatch loss Losses due to mismatch are related to the fact that the real modules in the array do not rigorously present the same I M characteristics A graphical tool helps for visualising the realistic behaviour of such an array with a random dispersion of the characteristics of short circuit current for each module This tool allows for the quantification of power loss at the maximum power point as well as of current loss usually higher when working at fixed voltage The simulation asks for a Mismatch loss factor different for MPP or fixed voltage operation which is taken as constant during the simulation Wiring loss optimisation The aim of this tool is to optimise the wire diameters in the array given a predefined loss limit First give a look on the array usual wiring schema bypressing the Schema button This identifies the different parts of the circuits by colors The string connections between all modules ofa string up to the wiring connection box usually situated near the array The connexion between this boxes and the system inverter battery Optionally when choosing Groups of parallel string the connection between the group boxes and the global array box Secondly you have to specify the
6. 800 W m T mb 20 C gt Wind velocity 1 m s Open Circuit The NOCT factor is related to our loss factor U by the thermal balance from the expression of the top Alpha 800 Wim 1 0 Us U 1m s NOCT 20 C In the definition dialog the user may define either the U factors or the NOCT The program immediately gives the equivalence using Alpha 0 9 and Effic 10 without wind dependence Module Layout There is now a tool for defining the layout of the PV modules on the available area with geometrical constraints the cabling i e the attribution of each module to a given string defined in the system part this will lead in a next version to a detailed calculation of the electrical effect of shadings replacing for not too big systems the evaluation according to modules Available area definition In the first tab Mechanical you can define surfaces for receiving the PV modules which we will name sub field area Each sub field area is a rectangle based area in which you can include secondary rectangles of any size for defining areas forbidden for modules These secondary rectangles may be positioned on comers or anywhere in the main rectangle representing for example a window a chimney with its shaded environment etc This rectangle may also be transformed into a rectangular triangle for example for representing a four sided roof Within such an inactive secondary rectangle
7. Data anywhere on your machine If you have to put it on a network please consider your network path as a disk as PVsyst doesn t recognize the network paths Be aware that no check is performed for the simultaneous use of data Chapter 2 Licensing Licensing 2 Warning Neither the University of Geneva nor the author take on any responsibility under any form concerning the database contents the accuracy of the results or for consequences whatsoever to their use Conditions for the supply of the DRY Swiss meteorological data prepared by the Physics and Installations in Buildings Section of the EMPA Basic data are property of the ISM Swiss Institut of Meteorology and cannot be distributed The EMPA has been authorized to distribute data in a prepared format The EMPA prepares meteorological data from the ANETZ network of the ISM only for their use in software or computations in the field of Building Physics Energy Management and Building Installations Neither the ISM nor the EMPA or employees of these offices accept any form of responsibility for the accuracy the integrity or the ability to the use of these data neither for consequences of their use The delivery of prepared data to third parties is not authorized Asking for a license code Requesting an activation code can be done in two ways 1 From the software use the menu License Order and Purchase and choose the method Order by email Then p
8. Define the water needs may be yearly seasonal or in monthly values Define the pumping static depth if varying along the year may be seasonal or monthly Third step Choose a pump model taking the nominal Head into account pumps are coloured in green for suitable orange for not optimal or red for not suited devices Choose the number of pumps for reaching the required nominal power all pumps wired in parallel 744 Choose a PV module also Green Orange Red and a suitable PV array configuration proposed by PVsyst NB This last choice is dependenton the System Configuration which will be chosen during the next step You will have to come back to this step for eventual correction after your Configuration choice Fourth step press Regulation Button Choose the Regulation model7 again the Green Orange Red colours indicate the suitable choices according to the previously chosen System type Pump model and Pumps number Acollection of specific Warning messages explain the reasons of incompatibilities or poor design The chosen Regulation strategy fixes the available set of regulating devices There is a Default Regulating device corresponding to each strategy with all parameters automatically adjusted according to the system the system dependent parameters will be re evaluated just before the simulation If Battery Buffered configuration you still have to define the battery pack In a next version of the program it will be
9. Importing projects This tool dispatches all files related to a project to their proper directories Please define the source directory by choosing a project file among your external data When available the program will show all transferable projects green simulation maroon pre sizing projects The external Project s files source may be either a structure analogous to the PVsyst data or a flat list of all involved files in the same directory Only the projects are shown here not the associated files NB the external source directory may be the data structure of your old version of PVsyst when Upgrading to a new version The targetis of course your present PVsyst data structure Please select the projects you want to transfer When clicking on the transfer button the concerned files are dispatched to their corresponding subdirectories Only the not existing files are copied i e the original files of the database are preserved If you want to overwrite some files in your local data you should use the Dispatch Files option Files involved in a project A project design project involves several files which should be placed in a well defined directory structure They are in projects ProjectName PRJ Variants ProjectName VCi Eventually comparison variants ProjectName Cmi in meteo MeteoFile MET the hourly meteo file associated with the project in DataMeas lt Datameas DAM eventually if comparisons with measured
10. Only available in top side or front views Click to define a first segment and then a second one thatis you should define four points The angle is given even if the two segments don t have any common summit Nevertheless if so the complete angle will be drawn Azimuth measurement This gives the usual azimuth direction by respect to south or north in southern hemisphere Define origin first and then the extremity of the arrow In perspective view the vertical tilt angle named height is also given This allows for doing equivalences with the horizon representation on the Height Azimuth sun path diagram Tilt angle measurement Only available in front and side views Click on the origin first and then the arrow extremity NB When attached to summits these tools can help positioning the objects intuitively and with precision Near shadings Diffuse and albedo factors The sky diffuse component is also affected by the near shading obstacles For simplification we suppose that the diffuse sky irradiance is isotropic Ata given time the shading effect on the diffuse irradiance can be thought as the integral of the shading factor over the visible part of the vault of heaven thatis the spherical dihedron between the collector plane and the horizontal plane This is independent of the sun s position and therefore constant over the year The albedolisfis only visible from the collectors if no close obstacle is present till the
11. This is namely the case with AC motor pumps as PVsyst never manages the Pump input AC voltage nor its frequency Only the Pump power inputis a relevant input variable This holds indeed for any pump for which the power is specified instead of the current and voltage Flowrate f Power model Converter input The converter input corresponds either to a fixed DC voltage converter the input voltage should be defined in the controller specifications On most commercial devices this is adjustable by hardware At design time the controller dialog gives access to the Voltage Optimisation Me tool for finding the best suited voltage or to a MPPT converter the minimum and maximum tracking voltages have to be given in the Controller dialog As for other converters the Maximum and EURO efficiencies are required for establishing the efficiency curve For simplification there is no possibility for defining a customised efficiency profile Converter output As itis usually specified by the manufacturer the converter is supposed to match perfectly the input requirements of the pump Thatis it will be sufficiently well designed for being able to deliver the optimal voltage current to the pump ata given time and for the required head in order to use the available power with an optimal efficiency The simulation will take into account the power limitation due to step down technologie 1168 only when the pump s voltage behaviour is known i
12. User s Guide PVsyst Contextual Help University of Geneva 1994 2010 WARNING About this manual This is NOT a PVsyst User s Manual This document is a printed version of the contextual help of PVsyst you can call by typingF 1 in the software So itis not organized as a common manual with chapters sections and so on It only displays a serie of independent pages suited for hypertext navigation Nevertheless you can use this document for browsing the contextual help with hyperlinks or print your own hard copy This document is also available on our website www pvsyst com A User s Manual of PVsyst is in preparation Contents Chapter 1 Chapter 2 Chapter 3 Chapter 4 14 14 14 16 16 17 17 18 18 19 19 20 20 21 22 22 24 28 28 29 29 30 31 31 Overview General description of the PVsyst Software Tutorials Tips for beginners Historical evolution of the software Compatibility and Troubles Licensing License rights and activation code Asking for a license code Payment conditions Transferring the activation code on another machine Preliminary design Grid System Presizing Grid connected system preliminary design Stand alone system presizing Stand alone system preliminary design Stand alone system design Battery Voltage Choice Pumping system preliminary design Preliminary design economic evaluation Project design Project design tutorial Project definition Site and Me
13. According to the measurement s parameters available we have tested the various Chapter9 Glossary Validations 10 stages of the simulation giving special attention to those which involve the most delicate physical models Installation LESO LESO LRE LESO Sheds USSC Site Switzerland Borat En Lausanne Field type Anti noise Facade ses Tilt angle wall 90 28 Azimuth 45 S South South 25 East Installed power 104 kWc 25 6 kWc 12 kWc 7 6 kWc 3 2 kWc 3 kWc 0 45 kWc Field area 967 m2 170 m2 111 6 m2 61 5 m2 31 7 m2 28 6 m2 8 2 m2 Collectors manuf Kyocera BP Solar Solarex Arco Solar Photow att Flagsol USSC USA Type LA361 J48 BP495 MSX 60 M55 Nominal Pow er STC 48 Wc Saturn 60 Wc 53 Wc 48 Wc 250 Wc Measured Pow er STC 48 Wc 95 Wc 55 1 Wc 50 8 Wc 40 3 Wc Measurements Ispra 88 Wc TISO Ispra TISO Manufacture Technology Skpoly Ispra Sk poly Sk mono Sk poly r Skmono Skpoly Irrad transposition MBE transpos meas RMSE daily val RMSE hourly val Coll Temperature model No No No Yes No No No Wind velocity measurement 29 Wim2K 29 W m2K 29 W m2K 20 6vvent 29W m2K 13 W m2K 23 Wim2K K factor input param 0 3 C 0 5 C 0 03 C 0 8 C 0 7 C 0 2 C 0 0 C MBE simul 2 1 C 1 5 C 2 7 C 2 1 C 3 8 C 3 7 C 2 8 C measure RMSE hourly val PV Field DC energy field 3 Simul Base Plane irrad Plane irrad Plane irrad Horiz irrad Plane irrad Horiz Irrad Pla
14. All values are by respect to the Meteonorm values the PVsyst internal database Except the first green bin which shows the difference of Meteonorm by respect to the average of all other sources excluding Helioclim 2005 We can observe some trends We cannot say which source is the more representative of the reality and which reality no one is of course able to foresee the future climate Meteonorm often gives lower values than the average This means that simulations with default values in PVsyst will be rather conservative and give prudent results for the final yield of the customer s systems Except at Barcelona very little differences between Meteonorm old 1961 1990 and new 1981 2000 data PVGIS seems to be one of the more compatible with Meteonorm data Also when available the WRDC data are well representative of the Meteonorm data Satellight data seem to overestimate the average by 5 to 10 except in Berlin and Roma The Helioclim data response seems to be chaotic Especially the 2005 values Helioclim 3 hourly file are very high over the other data by a factor which is not always compatible with the 2005 irradiance see below for Geneva m Meteonorm Average OMN6 MN m WRDC MN Yearly GlobH Differences a NASA SSE MN m RetScreen MN o Satellight mn E PVGIS MN E Helioclim 85 89 MN GHelioclim 2005 MN 20 15 4 10 4 5 4 0 5
15. But in PVsyst we think that small discrepancies in the cell parameters inducing internal mismatch as well as the moderate accuracy of our basic input parameters usually from manufacturer make no sense to use it In the one diode model the two diodes are considered identical and the Gamma factor ranging theoretically from 1 to 2 defines the mix between them This model is well suited for the description of the Si crystalline modules but needs some adaptations for reproducing the thin film technologie module behaviourli41 We observed that the CIS technology obeys quite well to this standard model The main expression describing the general one diode model is written as lbh lo exp q V I Rs Nos Gamma k T 1 V I R Rsh with l Current supplied by the module A V Voltage at the terminals of the module V loh Photocurrent A proportional to the irradiance G with a correction as function of Te see below ID Diode current is the product lo exp _ 1 lo inverse saturation current depending on the temperature A see expression below Rg Series resistance ohm Rsh Shunt resistance ohm q Charge of the electron 1 602 E 19 Coulomb k Bolzmann s constant 1 381 E 23 J K Gamma Diode quality factor normally between 1 and 2 Nos Number of cells in series Te Effective temperature of the cells Kelvin The photocurrent varies with irradiance and temperatu
16. Chapter 6 Tools and databases Tools and databases 6 to better approach the amorphous and other thin film modules behaviour on the basis of the more recent knowledge and our own experimental research These involve special parameters that are not part of the manufacturer s data which have to be fixed to default values according to our experiences on 6 modules These additional parameters are The Rsh 0 parameter limit when Irrad 0 i e dark resistance which governs the exponential shunt resistance behaviour as function of irradiance For amorphous modules the d mteff recombination loss parameter Ideally these parameters as well as the Rsh STC should be part of the manufacturer s specifications in the future It should be noted that the model used for modules is an approximation sufficient for the use in the frame of the simulation but which cannot represent exactly the complex behaviour of a PV module in all conditions in particular it is established for a single cell and it can be extended to the whole module only under the condition that the cells are not rigorously identical Nevertheless the inaccuracies introduced by the model s imperfections or the approximation of some secondary parameters is widely dominated by the uncertainties coming from the variations between modules or groups of modules as well as those due to the methods of determining these parameters which give not the same parameters during standard
17. Paste in the clipboard Chapter 4 Project design Project design 4 On line graph definition Graphs of hourly and daily values have to be defined before the simulation process You can define up to 30 different plots including about ten already defined by default Procedure Four kinds of plots are proposed For each of them you have to chose Daily or Hourly values and the units Time evolution you will define the parameter to be accumulated and the time interval which may be different of the simulation period Scatterplot allows to show the dependence of one parameter on another one for example Input Output diagram You must define the parameter for each axis as well as the analysis period Values distribution will plot values as an histogram Apart from the physical parameter to be used you have to define the starting the width and the number of classes bins In the first class you may impose a threshold to eliminate for example null values at night These definitions depend on the range of values taken by the parameter which has to be known a priori In case of doubt you can confidently ask for a larger range up to 400 bins as the programme will automatically truncate the empty classes below and above The accumulation can take place either in time number of hourly or daily occurrences or in energy Ordered values are histograms in which each class accumulates all lower values and therefore give
18. Running of inverter for grid system or production of PV field in case of stand alone system Cuts according to the values of another measured variable or a simulated variable chosen from among the 70 parameters calculated by the simulation For example this last option allows for the selection of the measurement points with a strong beam or Chapter 6 Tools and databases 170 171 Tools and databases 6 pure diffuse irradiation by asking Diff Glob Ratio lt 25 resp gt 70 Then give a name to the accumulation you can use the speed button on the right for pre defined name After having defined as many comparisons as necessary the simulation is started exactly in the same way as for the usual simulation It follows the same process on the basis of the meteorological data of the measurements file instead of those of the meteo of the project At each time step and according to the specified conditions it accumulates comparison data asked for above Transformations of data files The data files produced by PVSYST are not ASCII files and have internal coherence constraints which imply that they should never be modified in a text editor But the programme proposes some useful transformations such as Linking two files of same data structure over different periods Linking is performed at a given fixed date allowing to manage transitory differences in the accumulation format For example passing from summer time to winter
19. a specific daily profile for working days and another one for week ends Each of these staying constant over the year The number of Working days in a week is user defined Probabitily profiles are designed for grid applications when the grid load is not illimited It is the probability distribution of the power which can be absorbed by the load at a given instant This is especially suited to DC grid for public transports 65 Possible power load is divided into 12 classes of given values the user specifies the probability distribution values for each hour This profile 5 1 can be defined Constant over the year the same profile all along the year Seasonal modulation one specific daily profile for each season as above Weekly modulation a specific daily profile for working days and another one for week ends Daily Household consumers is the default user s needs definition for stand alone systems It proposes a list of most usual domestic appliances with unit power and daily use duration Values 55 can be defined as Constant over the year the same daily load value all along the year Seasonal modulation one specific daily load for each season Monthly definitions a specific appliance distribution for each month NB With this tool a Weekly modulation option is independently available for each season or month but only for putting some week end days to zero or stadby This appliances definition is mainly thought as a pre
20. and in this use the quality of the different models allow us to hope for much higher precision Stand alone systems and particularly the battery model have not been validated up to now We hope to find properly measured data recorded in hourly values to further analyse the software accuracy General system simulation Frank Kreith Jan F Kreider Principles of Solar Engineering McGraw Hill Hemisphere Publishing Corporation 1978 ISBN 0 07 035476 6 John A Duffie et W A Beckman Solar Engineering of Thermal process John Wiley and Sons N Y 2nd ed 1991 P Schaub O Guisan A Mermoud GAP CUEPE Universit de Gen ve Etude de l installation photovolta que de 7 7 kW des SIG Rapport final OFEN 3003 Bern Juillet 1993 P Schaub O Guisan A Mermoud GAP CUEPE Universit de Gen ve Etude de l installation photovolta que de 2 2 kW des TPG Rapport final OFEN 3003 Bern Juin 1992 A Mermoud O Guisan Logiciels pour syst mes PV Analyse des besoins suisses cahier des charges et proposition de structure GAP CUEPE Universit de Gen ve OFEN 3003 Bern Octobre 1992 A Mermoud O Guisan Logiciels pour systemes PV Recensement et valuation des logiciels de simulation photovoltaique existants GAP CUEPE Universit de Gen ve OFEN 3003 Bern Juillet 1993 Guidelines for Assessment of Photovoltaic Plants Document A Photovoltaic System Monitoring Document B Analysis and presentation of Monitor
21. and therefore constant over the year can be calculated by integrating the shading and or IAM factors on the visible part of the vault of heaven that is the dihedron between the collector plane and the horizontal plane Domestic user s needs Domestic user s needs The domestic user s needs are defined on a daily basis These can be constant over the year or seasonally monthly modulated You can of course copy values from one season month to other ones The Week end option allows for concentrating the daily consumption on a specified number of days of the week only This option may be specified independently for each season month Stand by consumption may be extended to the non utilization days if desired When using an AC distribution with inverter please define an additional consumption of around 10 to take the inverter efficiency into account For simplifying data acquisition you can save your definitions as a model for re use in other projects Double orientation field Double orientation field Itis possible to connect fields of different orientations on a single input inverter or battery pack so long as all modules of each string are kept in the same orientation In this case the currents of different strings will be different according to the sun orientation but will mix at about the same voltage This results in negligible mismatch losses Putting modules in series in different orientations will yield complex I V characte
22. as the PV planes elements sensitive areas are treated differently in the program They should be positioned on the building only within the 3D scene In the main 3D scene choose Object New Rectangular PV plane You have to define the sizes Nb of rectangles 1 you could define several non interpenetrating rectangles in the same plane Tilt 25 Width 5 5 m Length 25 m NB There is no relation at this stage with the real size of the PV modules in your system definition The program will just check at the end of the 3D definitions that the plane sensitive area is greater that the area of the PV modules defined in the system without shape considerations Click OK The plane comes by respect to the origin in the 3D scene For positioning it again click Top view position it globally with the mouse Now you don t have rigorous references and you don t need to adjust the values but be careful not to interpenetrate the other roof And check the azimuth value should be exactly 90 Vertical positioning now your field is on the ground Click the oberver s Front View button and position your plane on the roof bydragging the red dot with the mouse Please always let some spacing between any active area and other objects minimum say 2 cm If you put the plane below the roof it will obviously be shaded permanently Completing with the silo and a tree In the main scene Object New Elementar
23. characteristics as the MEF files for Hourly meteo data but allows the user to choose the measured variables to be transcribed They also offer the possibility for automatically chaining data file reading daily or monthly files Hourly measured data file Normalised internal file made up from your ASCII files using the DAF interpreter Even if the source is in sub hourly steps the interpreter accumulates the values in hourly steps Data ComposPV directory Each component type is stored in its own subdirectory PVModules PAN Inverters OND Batteries BTR Pumps PMP Regulators RLT RegulPmp RLP Gensets GEN Sellers REV Parameters and characteristics of a PV module Inverter for grid connection operating limits efficiency profile Characteristics of a batteriy Characteristics of a pump device Charge discharge regulator and possible back up ON OFF operating according to threshold levels of battery voltage Pumping system controller includes the regulation strategy may include power converter or battery regulator Back up generator Genset for the battery recharge Addresses of manufacturers or other reseller NB From version 5 0 the original database for PV modules and Inverters is stored in the files PVModuleDB CSV and InverterDB CSV located in the directory DataRO This directory will hold the files that you create or modify by yourself Data Projects
24. detailed parameter Some data sheets specify nominal values and maximal ones only for exceptional conditions NB These voltage and power values are related to the pump motor itself in absence of converter but to the converter inputs if present if present Hydraulic side You have to define Chapter 6 Tools and databases 158 159 Tools and databases 6 The pump technology especially whether centrifugal or positive displacement The pump Layout The Minimum head usually the minimum head for which the manufacturer specifies data NB Anull Head at the pump with positive flowrate doesn t make much sense it would mean that the flowrate is driven by other external forces In this case the efficiencyis null The Maximum head usually the maximum head for which the manufacturer specifies data This doesn t act as an absolute limit if the system operating conditions require higher heads the model results will extend to the required value The Nominal head this value is not well determined It should correspond to the best suited head when using this pump With centrifugal pumps it could be chosen as the head with maximum efficiency Otherwise it can be an intermediate value rather toward higher values between Min and Max Heads When the model will be fully defined the dialog will display the flowrates and efficiencies corresponding to these heads and their corresponding Nominal Power as defined on the left Electrical
25. files of the PVsyst database were constructed from the ANETZ measuring network according to a procedure elaborated by the International Energy Agency IEA task 9 sub task E For other European locations DRY may sometimes be obtained at the addresses given below These data are not necessarily prepared according to the same standards some of them are referenced as Test Reference Years TRY and follow a similar method approved by the European Communities German data are specified by the Free University of Berlin The 1035 TMY3 files for the USA were prepared by the NREL Here is a list of institutions where hourly meteo data may eventually be available state 1994 Belgium Institut Royal M t orologique 3 av Circulaire B 1180 Bruxelles Denmark Cenergia ApS Sct Jacobsvej 4DK 2750 Ballerup France Direction de la M t orologie 2 avenue Rapp F 75340 Paris Cedex 07 Germany Berlin University University of Berlin Ireland Meteorological Service Glasnevin Hill IRL Dublin 9 Italy National Research Council Via Nizza 123 1 00198 Roma The Netherlands KNMI P O Box 201 NL 3730 AE De Bilt Chapter 5 Geographical and Meteorological data Geographical and Meteorological data 5 Portugal INMG Rua C Aeroporta P 1700 Lisboa Slovakia Katedre KPS Stavebena Technika Universita SL 813 68 Bratslava Switzerland MPA Ueberlandstrasse 129 CH 8600 D bendorf Turkey T bitak Building Research Inst 221 Ataturk Bulvari Ankara Unit
26. meteo data from many sources Press F1 for obtaining a detailed description of all available meteo data After choosing a given source pressing F1 will open the detailed procedure for importing the concerned data Please carefully follow it in detail and pay attention on the advices written in red at the top of the screen during your progress These data are not always completely comparable The Help includes a comparisonlt1A of these data for 12 sites from the north to the south of Europe Importing monthly meteo values In the Site definition dialog you can import monthly data from an external list of values with any separator for example from an EXCEL column or line Choose here the units of your source list Go to the external software and Copy CtI C a list of 12 values lIrradiations Temperatures or Wind velocities Chapter 5 Geographical and Meteorological data 108 109 Geographical and Meteorological data 5 Paste them in the corresponding column Checking the imported meteo data time The synchronisation of the meteo data with the solar time is of great importance for solar geometry calculations especially when using the transposition model To check it please use the Tables and Graphs tool for meteo or measured data Ask for daily plots of horizontal global irradiation and choose Clear sky model in the menu you will see a superimposed clear sky model curve on your data When choosing a good d
27. modules in the DB 2 Loss diagram still an error in the GlobShd evaluation but doesn t affect the final results 3 Meteonorm import tolerant to another not yet registred file format Version 4 32 July 2008 by respect to Version 4 31 June 2008 1 Database Inverters update from Photon Magazine 2008 2 Loss diagram incoherences in the shading and IAM relative losses onlydisplayin this diagram simulation results were correct 3 Ascii Meteo importing tool Date management improvement Site names beginning by New are now possible 4 Search Edit for easier choice in big componentlists 5 Print Preview easier navigation through pages Version 4 31 June 2008 by respect to Version 4 3 March 2008 Some bugs fixed 1 Satellight data import Temperatures were not well imported 2 PVGIS import copy paste did not work with some internet browsers 3 Site Meteo choice for Projects generated erroneous meteo files 4 Simulation report erroneous tables overwrited parameters namely IAM 5 Import of Meteo ASCII files improvements for daily data and date formats 6 Long component s lists edit box for direct access to a given item Version 4 3 March 2008 by respect to Version 4 21 Import of meteo data from multiple popular sources NASA WRDC PVGIS RetScreen Helioclim Comparison between several Meteo Data sources Developments and results in the Help Import Export of Site monthly data from to EXCEL
28. panel NB One of the reasons for introducing the Nominal Head is to determine a more refined function for the Nominal Power as a function of any Head useful in the model With HeadMin and HeadMax it would be a straight line between these two values this adds an intermediate point Pump data performance curves This sheetis for the entry of the operating points defining the pump modelli6d You may first choose the units of Head and Flowrate according to your original data Then for each curve you should choose the Parameter Voltage or Head Curve modifications acton the highlighted curve chosen by the Set curve box red points For constructing a curve you are advised to put the data points at their approximate position using right clicks of the mouse and then specify their exact values in the editing boxes As the curves are rather linear and due to cubic interpolations multiplying the data points doesn t bring more accuracy Usually 4 or 5 points curve and 3 or 4 curves are quite sufficient In some cases Power thresholds for flow production are naturally defined by extrapolation of the data curve for ex in Flowrate f Power curves In other cases they are rather defined through the voltage threshold and the I f U characteristics The thresholds determination and behaviour around them is one of the more difficult features of the pump model NB After this definition please have a look on the graphs for checking the
29. shadings it corresponds to the total sun energy intercepted for this given sun direction by the field area seen by the sun Therefore a simulation with Linear shadings not electrically realistic and another one with backtracking should give the same results if we neglect the IAM losses unavoidable with the Backtracking The backtracking calculations are of course dependent on the mutual disposition of the trackers For a given sun position the tracker orientation should be determined using the pitch and the width of the frames collectors Therefore for defining backtracking we need the same parameters as for the shed calculations i e Pitch between trackers Collector width sensitive area Left and right inactive bands of frames These parameter are defined geometrically in the 3D scene but should also be included in the Orientation parameters This is the reason why we can define backtracking only in the framework of equidistant tracker systems NB As there are no shadings except when the sun is behind the plane the 3D construction is not really necessary The Orientation dialog is sufficient for fully defining a Backtracking system for the simulation The backtracking calculations are specific for each kind of tracking planes Two axis the tracking mechanism is supposed to be a rotation around the vertical axis and a variable tilt of the plane In Backtracking conditions the tilt is facing the sun 90 su
30. usually probability load profile In this case the simulation has to resolve a balance current at the user s level User s consumption is determined by the load profile definition requirement Available solar current is coming from the PV array the rest being delivered by the conventional power supply Available solar current has to be determined from the I V array characteristics taking both line resistances PV to user and conventional supply to user into account Two cases can arise Chapter 4 Project design 90 91 Project design 4 Either the PV production is not sufficient in this case the line voltage at the array output will stay around the supply nominal value only influenced by the line ohmic voltage drops Or the PV production covers the user s needs so that the conventional supply current drops to zero In this case the line voltage follows the PV array IM characteristics and can raise up to the Voc value when the user s needs drop to zero In this case the regulation overvoltage safety should apply if the allowable maximum voltage is reached Several variables i0h are computed during and after this process Simulation process pumping system See also Simulation Process 88 irradiance and PV array Once the Incident Global Effective irradiation and the MPP running conditions are determined the system simulation is dependent on the Pumping System Typel6M and Configuration 7A In any case and for any running
31. 4 10 15 Hamburg Berlin Caen Paris Geneva Lyon Toulouse Marseille Roma Barcelona Madrid Sevilla Climate evolution We avail of a homogeneous sample of continuous measurements from the same source ISM Swiss Institute for Meteorology for Geneva from 1981 to 2007 This shows that at Geneva the annual dispersion stayed far below 5 with only 3 4 exceptions during 20 Chapter 5 Geographical and Meteorological data Geographical and Meteorological data 5 years but increased significantly since 2003 This is of course not necessary valid for other sites in Europe Geneva ISM measurements meteo data evolution 15 10 5 5 By respect to Meteonorm 81 90 1212 kWh m2 10 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2003 2005 2007 2001 Comparison with other sources These ISM data which we consider as reliable due to the fact that they are meteo standard measurements performed using calibrated pyranometers and corroborated with our own scientific measurements in Geneva since 25 years P Ineichen are compared with the Satellightl125 satellite and Helioclim 124 from terrestrial measurements data We can observe that the Satellight data overestimate the ISM data by around 5 while the Helioclim results are more chaotic over estimate the good years and underestimate the bad ones The Helioclim 2 2005 values
32. By clear days the APE diminishes shift to the red when the sun height decreases Cloudy spectrums are rather characterized by spectrums shifted to the blues more favourable for amorphous modules Amorphous modules Spectral correction The reference irradiance used for the simulation the meteo values includes the whole spectrum from 305 nm UV to 2800 nm IR Itis usually measured with pyranometers which have a practical flat response over this whole interval But each PV technologyis characterised by a spectral sensitivity curve When the Sl crystalline can use photons below 1 100 nm corresponding to E Sap 1 12 eV the photons should have a minimum energy of EJap 1 7 eV 730 nm for creating a pair in the amorphous silicium Therefore the photocurrent should be evaluated using a convolution integral between the incident spectrum and the spectral sensitivity We will call Utilisation Factor UF the value of this integral which represents the fraction of the spectrum effectively useable for generating photocurrent Nevertheless the spectral content of the solar radiation varies with the meteorological conditions and the humidity aerosols of the atmosphere etc And of course we don t avail of spectral measurements in PVsyst In order to estimate the Isc current at any instant the CREST at the University of Loughborough proposes a procedure in two phases first characterising the spectrum using a suited parameter which could be
33. EBatCh Battery Charging Energy U Batt Average battery voltage any conditions UBatCh Battery Voltage during charging operation Chapter 4 Project design Project design 4 IBatCh Battery Charging Current all currents accumulated Ah ChargON Charging duration EBatDis Battery Discharging Energy UbatDis Battery Voltage during discharge operation IBatDis Battery Discharging Current all currents accumulated Ah DischON Discharging duration ESOCBal Stored energy balance according to SOCEnd SOCBeg SOCmean Average State of Charge during the period SOC Beg State of Charge beginning of time interval SOC End State of Charge at end of time interval NB The SOC current calculations are referred to the actual capacity of the battery which is defined at nominal current but varies with the discharge current level and temperature Therefore it is not quite well determined and not reversible i e it can be different when charging and discharging EBatLss Battery global energy loss EBatCh EBatDis ESOCBal IBEffL Battery charge discharge current loss coulombic efficiency Ah IBGass Gassing Current loss electrolyte dissociation Ah IBSelf Battery Self discharge Current depends on temperature Ah EBattEff Battery energy efficiency IBEffL U Batt EBGass Gassing Current energyloss IBGass U Batt EBSelf Battery Self discharge Energy IBSelf U Batt NB The sum of the detailed battery losses contributions appearing on t
34. Energy lost when Pump stopped due to low level aspiration deep well drawdown safety ETkFull Energy lost when Pump stopped due to tank is full These two above losses are accounted only when the battery charging is OFF due to full battery EArray Effective energy at the output of the array at operating voltage Accounted only when the charging condition is ON Array Corresponding charging current instantaneous A or cumulated Ah UArray Corresponding charging voltage instantaneous or averaged V SOC_Beg State of Charge beginning of interval SOC_End State of Charge end of interval UBatt Average battery voltage IBatCh Battery charging current A or Ah IBatDis Battery discharging current Aor Ah Chapter 4 Project design 100 101 Project design 4 IBEffL Battery Charge Discharge current efficiency loss IBGass Gassing current electrolyte dissociation when full IBSelf Battery self discharge current EBatCh Battery charging energy EBatDis Battery discharging energy ESOCBal Stored energy Balance between SOCEnd and SOCBeg EBatLss Battery Overall energyloss EBatCh EBatDis ESOCBal EEffLss Battery efficiency loss EBatLss IBGass IBSelf UBatt EPmpOp Pump operating energy NB The balances of the battery energies can never be rigorous due to the very complex behaviour of the battery For example its effective capacity which strongly varies with the discharge current the temperature etc If the current balances are well
35. General treatment of low concentration systems especially 1 axis parabola or Compound Parabolic Concentrator CPC would imply a very detailed description of the optical system as well as a good knowledge of the irradiance distribution by any weather conditions and would result in inhomogeneous irradiance on the PV receiver which is very difficult to take into account when not one only cell Therefore concentration system parameters are only proposed in the 2 axis tracking dialog where you have to define The diffuse fraction to be taken into account in the simulation usually near O with high concentration The acceptance angle for a full efficiency half opening angle i e the angle between incident and optical axis The limit angle at which the efficiency falls to 0 Besides tracking errors which cannot be taken into account this will be useful when the array is reaching its tracking mechanical limits The simulation will perform a linear decrease between the acceptance and limit angles and will accumulate the corresponding tracking loss Electrical behaviour of the concentration device In a 2 axis high concentrating system the PV sensitive device is usually a single multi junction cell of some few cm2 with very high efficiency This receives a flux of the order of 500x suns 50 W cm and therefore works in a domain where our PV one diode model is not well attested We can just notice that the logarithmic behaviour of the o
36. I V curve and its range of possible variations The Rshunt resistance is the inverse of the slope at the short circuit point 0 lsc Its value is not critical at least for crystalline modules with high fill factor The value specified here is at reference conditions GRef TRef It usually has an exponential behaviour according to the irradiance see next page The user can choose the RSerie value in order to obtain a specified Gamma diode quality factor value or a required muVco value as specified by the manufacturer which is not always possible Alternatively when clicking the RSerie Default checkbox or when loading a new module the program will search itself the RSerie value corresponding to a predetermined default Gamma value Note that when at a given temperature the model results are not very sensitive to the Gamma value it significantly influences the temperature behaviour of the model From the junction theory Gamma should lie between 1 and 2 With tandem technologies it will be Chapter 6 Tools and databases 148 149 Tools and databases 6 between 2 and 4 and for triple junctions between 3 and 6 But our detailed measurements on some amorphous modules often showed higher values than expected For Crystalline modules we found that a Gamma value around 1 3 gives satisfying results Therefore a Gamma default value is proposed in PVsyst for each technology Si Mono Gamma 1 3 Sl Poly Gamma 1 35 a Si H Gamma
37. If one is to use specific data recorded in the presence of a horizon the correction is obviously not to be applied Meteo database in PVsyst Meteo database in PVsyst Monthly meteo Geographical site database Chapter 5 Geographical and Meteorological data 110 111 Geographical and Meteorological data 5 The PVSYST library includes the Geographic Site s definitions latitude longitude altitude and time zone as well as monthly data of the global irradiation temperatures and wind velocity for more than 330 sites over the world These data are issued from the database of the software Meteonorml117 versions 4 5 which summarises well established meteorological data of about 7 700 sites in the world Nevertheless only about 1 200 of these Meteonorm sites avail of irradiance measurements These are referenced as Stations in Meteonorm and hold data as monthly averages over years 1960 to 1991 Meteonorm can also get data for any unreferenced place by performing interpolations between 2 3 nearer stations taking altitude and region typology into account For the main European countries the PVsyst database includes all the available stations with irradiance measurements This represents about 10 15 Stations in each big country Data of any other site issued from Meteonorm would be obtained by interpolation You can use Tools Import Meteo data for importingh1 data from Meteonorm and many other sources in the database Hou
38. M J Kearney Test of parametric models for amorphous silicon modules and cells Chapter 11 References 204 205 References 1 1 2nd World Conference on Photovoltaic Energy Conversion Vienna 1998 J Mertens J M Asensi C Voz A V Shah R Platz J Andreu Improved equivalent circuit and Analytical Model for Amorphous Silicon Solar Cells and Modules IEEE Transactions on Electron Devices Vol 45 No 2 Feb 1998 M J Holley R Gotts chalg AD Simmons D G Infield M J Kearney Modelling the performance of a Si PV systems 16th European Photovoltaic Solar Energy Conference Glasgow May 2000 J Mertens J M Asensi C Voz J Andreu Assessing the outdoor performance of single junction and double junction amorphous silicon solar modules 16th European Photovoltaic Solar Energy Conference Glasgow May 2000 T R Betts R Gotts chalg D G Infield Spectral Irradiance Correction fo PV system Yield Calculations 19th European Photovoltaic Solar Energy Conference Paris June 2004 H Al Buflasa T R Betts R Gotts chalg D G Infield Modelling the Effects of Spectral Variations on the performance of Amorphous Silicon Solar Cells 19th European Photovoltaic Solar Energy Conference Paris June 2004 A Mermoud Conception et Dimensionnement de Syst mes Photovolta ques Introduction des modules PV en couche minces dans le logiciel PVsyst Projet SIG NER Rapport Final www cuepe unige ch Mai 2005 Inverters H Ha
39. Regulation Battery buffered configuration See also Pumping Configuration 73 previous 77 Regulation This can be understood as a regulating device like a very big capacity which operates over the time PVarray System Battery Buffered renal Regulator Controller Irad PO ee eh H meas U Array I Array gt anna ene Batt regul Level sensors Total Head Level diff k Friction losses pac Aspir level Conceptually in this operating mode the battery should not be sized for storing energy over a medium or long period the water storage in the tank is far more efficient for this task It should be meant for yielding a power complement when the sun s power doesn t reach the pump s power threshold and also absorb the excess energy when it overcomes the pump s maximum power This way the battery capacity may be reduced to a few operating hours In practice the pump is connected to the battery and operates atthe fixed battery voltage at anytime It could be regulated in the same way as any other consumer in a stand alone system i e turned OFF according to the battery discharge threshold protection But this would lead to a very intensive use of the battery in a domain low charge state where the wearing is very important It would be far better to turn the pump ON only when the sun already yields a significant power but just not sufficient for activating the pump This way the battery m
40. Specified value for muPmpp if required Parameters for the modifications of the one diode model for amorphous and CdTe technologies d mutau Specific parameter for the contribution of the recombination loss parameter The validity Spectral corr domain of this value for finding a solution to the non linear equations is strongly correlated with Rshunt and Rserie It has implications on the thermal behaviour especially of Vco To our experience with the long term measurements of several amorphous modules the value of d mutau parameter should be rather near to its maximum about 80 to 90 Parametrized correction according to Air mass and Kt Fixed correlation from University of Loughborough may be activated or not Should ne be applied with CdTe technology Characteristics of a PV Module model description To describe the operating of a PV module we use the Shockley s simple one diode model primarily designed for a single cell described for example in Beckman and al This model is based on the following equivalent circuit for decribing a PV cvell Photocourant Utilisateur lpn Chapter 6 Tools and databases 136 137 Tools and databases 6 The model was primarily developed for a single cell Its generalization to the whole module implies that all cells are considered as rigorously identical A more sophisticated model implying 2 different diodes is sometimes proposed for the very accurate modelling of a single cell
41. The available countries are grouped according to the previous Region choice Pressing Next leads to the Site selection panel If you are blocked for more than 20 30 sec here please check that you are accepting cookies If not found in the database you can also specify any location by its coordinates latitude and longitude NB GoogleEarth provides an easy mean for the determination of the geographical coordinates of your system 4 Time Period choose From Sunrise to Sunset Clock time The tool in PVsyst is designed for using legal time not solar time data All years or only specified ones PVsyst will create files for one year at a time but you will be able to choose any of the present years in this file when importing Always choose All months 5 Outdoor Solar Informations 1 Solar information Nothing to define 2 lrradiances 2 1 Surface type Horizontal 2 2 Parameters Global and Diffuse 2 3 Informations Useful for printed outputs only You have to choose at least one of these possibilities 6 Outdoor Daylight Informations Nothing to choose concerns Illuminance data for natural lighting studies 7 Submit The site will perform the calculations and send you an e mail within a few minutes for downloading your results as a zipped file SiteName tsv file or Lat_Long_ tsv After Unzipping this file can be readily imported in PVsysth2 Importing WRDC Data World Radiation Data
42. W Corresponding current 25A Inverter about lt 1kW 24V medium size with fridge and little appliances or wiring extension to more than 10 m Appliance max power lt 1000 W Corresponding current 42A Inverter about lt 5 kW 48V special industrial or agricultural use Appliance max power lt 3 kW Corresponding current 62A Inverter about lt 15 kW Higher powers require either high DC voltages special appliances or AC feeding through inverter Chapter 3 Preliminary design 20 21 Preliminary design 3 Pumping system preliminary design See also Sizing ofa pumping PVsystem 66 general considerations After defining the Location 17 the System button displays a dialog where you are asked to define On the right panel the plane orientation NB the button Show optimization opens a little tool which shows the winter yield according to the plane orientation For stand alone or pumping systems the plane orientation should usually be optimized according to the worst conditions i e for winter irradiance On the left panel The Water needs in yearly seasonal or monthly values The nominal head at which it should be pumped level difference between water outlet and source surface The diameter and length of pipes optional for eventual friction losses Apump technology centrifugal for rather low heads positive displacement for high heads An array pump coupling strategy which strongly affect
43. allowed range Itis the reason why PVsyst allows for modifying the temperature behaviour by introducing a linear variation of Chapter 6 Tools and databases Tools and databases 6 Gamma with operating Temperature Gamma Gamma0 muGamma Tmod Tref The user specifies a required muPmpp and PVsyst determines the suited mugamma correction factor The tool shows a graph of the induced variations on muVoc muVmpp and muPmpp NB This tool is made available for all modules but it is not recommended or only as a weak correction Especially with the amorphous technology the temperature coefficient is very sensitive to the D2MuTau parameter see the specific sheet Recombination loss According to our detailed measurements cumulating this correction with the recombination leads to degraded performances ofthe model that is its ability to reproduce the data in any conditions PV Module shunt resistance The shunt resistance Rsh is the inverse of the slope of the I V characteristic in the neighbourhood of the short circuit point When a measured I V curve is available itis easy to find it by fitting the data around V 0 But itis not possible to extract it from the usual manufacturer s data Therefore PVsyst has to choose a default value This is determined by calculating the virtual MPP conductance Isc lmp Vmp corresponding to the absolute minimum value for Rsh and taking a given fraction if this quantity With Si crystall
44. alos eee hae eia ee ee ees 15 Hamburg Berlin Caen Paris Geneva Lyon Toulouse Marseille Roma Barcelona Madrid Sevilla ISM hourly data in the database A meteorological hourly database of 22 stations in Switzerland is delivered with the package These data proceed from 10 years of measurements in the frame of the ANETZ meteorological stations grid of the ISM Swiss Institut for Meteorology The DRY format were prepared by the EMPA Eidgen ssische Materialprifung und Forschungsanstalt 8600 D bendorf By contract their use is reserved for building s physics and energy computations The user should commit himself not to yield these data to a third person These Design Reference Years 117 DRY were constructed according to a procedure elaborated by the International Energy Agency IEA task 9 sub task E These data are based on 10 years of measurements 1981 1990 The DRY is a juxtaposition of selected months chosen among these 10 years as function of several statistical criteria and approaching average values The DRYs files of the ISM EMPA are made up of the hourly values required for the simulation of PVSYST horizontal global and diffuse irradiances temperature and wind velocity Temperature data are slightly corrected their dynamics is enlarged in order that it includes the extreme values observed over the 10 years But these corrections preserve the internal coherence betwee
45. also provided probably with good reliability NB All these monthly data are imported as geographic site 114 files and will require the construction of Synthetic Generated hourly data files for being used in the simulation NB Monthly values are often given as averages over several years But due to the variability it doesn t make sense to average meteorological data in Daily or Hourly values Such data are always issued from real measurements at a given site or eventually from satellite photographies In the same way it is also not reliable to interpolate hourly values between different sites Chapter 5 Geographical and Meteorological data Geographical and Meteorological data 5 Meteonorm Worldwide Monthly 1 700 Terr stations 1960 1991 GlobH Software Direct averages Temp by file Interpolations V 6 0 Wind 300 stations 1995 2005 Others in PVsyst DB optional Meteonorm Worldwide Hourly Synthetic idem GH DH TA Software Direct generation VindVel by file Satellight Europe Hourly Meteosat 5 years GlobH Web Direct Any pixel of about 1996 2000 no temper free by file 5x7 km US TMY2 3 Hourly NREL 1020 stations 1991 2005 GH DH TA Web Direct Typical Meteo Years samples WindVel free by file EPW Canada Hourly CWEC 72 stations 1953 1995 GH DH TA Web Direct Typical Meteo Years samples WindVel free by file ISM EMPA Switzerland Hourly 22 stations 1981 1990 GH DH TA Included in Included in Design Ref Years
46. are 7 5 over the ISM measurements Geneva meteo data evolution and comparisons 15 S ISM measurements 40 m Helioclim red and Satellight green ee es Te o beanna ee s a ge I RG TGS Ee Se O E y eet ee A yt ped dd UL 7 i ry By respect to Meteonorm 81 90 1212 kWh m2 BO dee iae cet Abed epee O PB es ye es ong De De Se Gas Sie eye eli ag SAS eis Se ped Ge hee Beene Sek aes 15 A vy qt OONKO QAO gt A MOTH HOC RF OQOQOT AM YD OA o O O Q Q Q Q Q Q Q Q Q QOQ O O O O O O O Q O onoaondonanoaQaaaaQaaaaQaaanoennocscedscecscescescsess amp e p OO a a e U e ee a ee E E E E E a a nD Satellight data For other sites in Europe the Satellight data are always far over the Meteonorm ones with one exception in Berlin This exception is not attributable to the Meteonorm value as we can see on the global comparison plot above the Satellight data for Berlin are significantly below the other Satellight data We don t have any explanation for that Chapter 5 Geographical and Meteorological data 116 117 Geographical and Meteorological data 5 Satellight Yearly GlobH Differences by respect to Meteonorm m Average 1996 01997 m 1998 m 1999 m 2000 20 15 4 10 E 5 4 0 4 5 fe oS ewe sx Le MS ME 5 eos Hoel oe ee deme a saw tae Gee Ge hoe ew ee GeO ee ele e Gee OS ae See Ee eae Sew ke Sead oe AO se esl ele Fale seen ete leet ed eh eee Glia
47. are to be sent please perform the Paste operation immediately after the message for each page before clicking the OK button of the message NB This output feature is different from the Export Copy to clipboard tool present in all general table and graph menus where only the displayed table or graph is exported In several cases there are a few additional options when printing for instance the desired data periods Also if several items or pages are available for an output specific parts may be selected for printing Print_Head The printed forms always include a frame with the PVsyst V4 xx information in the left corner Printing date in the right corner is optional with or without hour The central first line is free for the general label of your choice company etc Chapter 7 Technical aspects 182 183 Technical aspects T You can specify a second head line if desired for example for your address telephone These customised specifications may be done either in the Print Options dialog or through the Preferences in the main menu Copying Printer pages to Clipboard Copying whole printer pages is a convenient way to store final PVSYST results in documents or to send them for example through e mail Using the Copy to Clipb oard button in the Printer dialog will store the whole printed page as an image You just have to enter another software for example MS Word Paint etc and paste the image Please
48. as a new Geographic location 119 Importing SoDa Helioclim Data SoDa Solar Data portal The SoDa Service offers an access to a large set of information relating to solar radiation and its use It builds links to other services that are located in various countries To answer a request the SoDa service invokes several resources to elaborate the appropriate answer and ensures the flow and exchange of information between the services and itself as well as with the customer It provides meteorological data from different sources mainly from the Helioclim database managed by Mines PariTech The data are computed from meterological geostationary satellite images and are Chapter 5 Geographical and Meteorological data 124 125 Geographical and Meteorological data 5 representative of real years SoDa proposes also a climatic data bank in monthly values with irradiance and temperature averaged over the years 1990 to 2004 It is provided by Mines ParisTech The following services are available from the SoDa portal HelioClim 3 data for Europe and Africa from 15 minutes time step to monthly values for the horizontal global irradiance the normal beam irradiance and the global beam and diffuse on inclined surfaces These data are available for free for the year 2005 The same components are available for pay from 2004 to the current month from a 1minute time step to monthly values MARS data this resource provides time series of d
49. average wire length for each circuit category total length i e minus and plus poles for each loop The program shows the nominal current and the resistance of one branch as well as their contribution to the whole array resistance as seen from the array connections It proposes a list of standardised wire sections beginning from the smallest wire compatible with the actual loop current The wre button allows to see the standard wire properties diameters maximum current resistivity as well as their price which you can define in order to optimise the wiring cost The maximum wire currents are given by the European Norm for isolated wires mounted in apparent or ventilated mounting ducts CEI 364 5 523 1983 Finally you can specifya maximum loss either in terms of at MPP when operating at MPP orin voltage drop when operating at fixed voltage The program will then optimise the wire sections matching these requirements either minimising the copper mass or the wiring cost providing you have defined the wire prices in the wire dialog Array ohmic wiring loss The wiring ohmic resistance induces losses R I between the power available from the modules and that at the terminals of the array These losses can be characterised by just one parameter R defined for the global array The program proposes a default global wiring loss fraction of 3 by respect to the STC 94 running conditions i e Vmpp lmpp i e a resist
50. be visualised in the results of your simulation The following table gives some usual values for the albedo Urban environment 0 14 0 22 Grass 0 15 0 25 Fresh grass 0 26 Fresh snow 0 82 Wet snow 0 55 0 75 Dry asphalt 0 09 0 15 Wet Asphalt 0 18 Concrete 0 25 0 35 Red tiles 0 33 Aluminium 0 85 Copper 0 74 New galvanised steel 0 35 Very dirty galvanised 0 08 Albedo attenuation factor Albedo attenuation factor The albedo is only visible from the collectors ifno close obstacle is present till the level of the ground This is why we have to integrate the shading factor at zero height on the virtual portion of the sphere under the horizon included between the horizontal plane and the plane of the collectors As for diffuse this factor is independent of the sun s position and therefore constant over the year Itis however to be remembered that for non vertical planes the energetic contribution of the albedo is weak in the global incident energy and that errors in its estimation will therefore only have secondary repercussions Chapter 8 Physical models used Glossary 9 Altitude corrections Altitude corrections When associating a meteo file to the project site the program can perform altitude corrections on the meteo data irradiation and temperature Itis however to be noted that these altitude corrections established for Switzerland according to Meteonorm studies in monthly values ref 6 have not really been valid
51. by editor Of course the sum should always be 100 so that at each change all other values are modified in order to match this constraint With a given range and a given probability distribution the program calculates a most probable day sum or monthly sum This is not an exact value but only the statistical average when the number of days is increasing If you are in Seasonal Modulation mode you have to define a profile for each season You have a facility to copy an already defined profile to one or several other seasons For this purpose click on Copy choose the source profile and select the target seasons The same holds for the Weekly modulation mode Chapter 4 Project design 56 57 Project design 4 User s needs daily profile definition See also User s needs l 54 When entering this daily profile definition tool please first choose the working units At the first entry all values are null You can use the operator facility to modify all hourly values at a time First choose the operator which can be Fix identical values for each month Add a given value to each month Multiply all values by a given value Renormalise all values to obtain a given yearly sum or average Then define the Operator value and click Work out You can also drag each hourly value on the graph or define a given value by editor If you are in Seasonal Modulation mode you have to define a profile for each season Y
52. by the diffuse component treatment In the Hay model the diffuse irradiance is divided into an isotropic contribution and a circumsolar proportional to the beam component Through transposition the half sphere isotropic part is reduced according to the vault of heaven s solid angle seen by the plane i e the fraction 1 cosi 2 where i is the tilt angle The circumsolar is transposed geometrically as the beam component The specifity of the Hay model is the determination of the circumsolar fraction which is chosen as the Clearness index Kb of the beam component The Perez Ineichen model introduces the horizon band as a third diffuse component It divides the sky into sectors and parametrises the transformations of the circumsolar and the horizon band according to correlations established on the basis of data of several dozen of measurement sites distributed all over the world The albedo component is evaluated in the same manner in both models as a given fraction the albedo coefficient 187 of the global weighted by the orange slice fraction defined between the horizontal and the tilted plane extension i e the half sphere complement of the seen vault of heaven which is the fraction 1 cosi 2 of the half sphere Validations During validations 9A of the software we tested these two models with the data of each site The comparison of their mean errors MBE presents a systematic difference of 1 8 to 2 2 depending on
53. case conditions occurring at a location How to import US TMY2 TMY3 data NREL TMY2 3 data can be directly and very easily imported into PVSYST First download the desired file from the web site referenced above TMY3 CSV file 1 8 MB TMY2 zipped files of 235 kB choose the DOS format and store it in a temporary directory then e xpand the file these are self extracting files of the form 12345 EXE The files are referenced as station code numbers If desired you may rename them for easier identification Returning in PVSYST choose TJools Import Meteo Data US TMY2 3 and follow the instructions on the screen The site specifications name geographic coordinates are automatically read from the TMY file Importing a TMY file will produce a PVSYST hourly meteo file met with Global and Diffuse irradiance temperature and wind velocity as well as a geographic site file sit Importing Canadian EPW data These data files of Typical Meteorological Year IMY 11 are available free on the web for 72 stations in Canada at the address http apps 1 eere energy gowbuildings energyplus cfm weather_data3 cfm region 4_north_and_central_america_wmo_region_4 country 3_canada cname CANADA Produced by Numerical Logics in collaboration with Environment Canada and the National Research Council of Canada these Canadian Weather for Energy Calculations CWEC data were derived using a methodology similar to the TMY2 CWEC
54. choice lists Data source usually refers to the main parameter measurement source most often Manufacturer may be an independent institute or your own measurements File name should have the extension PAN Nominal power is the rated power specified by the manufacturer at STCheA It could be different from the MPP model result It will be used to determine the installed power of systems which is involved namely in the normalised performance coefficients OA Tolerance is the rated limits of the Nominal power dispersion given by the manufacturer The lower Chapter 6 Tools and databases Tools and databases 6 tolerance limit could be used in the Module Quality Loss specification 9 Technology gives choice for the main technologies available on the market Except for Crystalline cells for which the standard One diode model is suitable the Advanced button allow for correcting this model in order to match the Thin films and other special behaviours The technology namely determines the value of the energy gap in the model for example 1 12 eV for crystalline silicon 1 7 eV for a Si Manufacturer Specifications or Other measurements These parameters are the main electrical module characteristics available in any manufacturer data sheets They are usually given for STCI194 but the program accepts measurements performed under other conditions to establish it s model allowing for on site measurements in external co
55. complex objects are obtained by assembling elementary objects This can be achieved in the Building Composed objects 4 dialog Chapter 4 Project design Project design 4 The Elementary object is then positioned 4 in the general scene or in a building element Defining a meaningful commentis not obligatory it will help identifying the object afterwards in the global scene Please note that internal representation of objects is built up with 3D Points and Surfaces built with these summits so that curves should be approximates by broken lines Near shadings building or composed objects See also Near shadings general organisation 37 Although elementary objects can be readily integrated in a global scene PVSYST allows to assembly several elementary objects to build a more complex one for example a complete building which will be manipulated as a whole in the global scene The construction takes place in a secondary perspective view and is quite similar to the global scene construction 40 Tools are the same a subset and the user can create and manipulate the elementary objects in the same way As with other objects the user is advised to give a meaningful description and will have to position 44 the composed objectin the global scene However building objects can be saved as models for use in other shading scenes Please note that Building objects are intended to build shading objects therefore they cannot h
56. conditioning Unit is used you should decide whether itis part of the pump definition or defined in this component This choice is automatic with Default regulators Some operational parameter for special configurations are defined here Pumps cascading 7 The irradiance threshold for switching the second or third pump ON The program Chapter 6 Tools and databases 166 167 Tools and databases 6 also gives the opportunity of defining pump Power thresholds for this purpose but itis probably more difficult to implement in the reality Array Reconfiguration 77 The irradiance threshold for commuting from parallel to series configuration Battery Buffered system 79 The irradiance threshold for turning the pump ON MPPT and DC DC Converter Define the usual parameter for power converter units thatis MPPT Minimum and Maximum MPPT voltage the voltage range for tracking DC DC Fixed input voltage which may be adjustable on most devices The dialog gives access to the Voltage Optimizing tool 168 for choosing the convenient value according to the array definition Behaviour at Maximal Power and Voltage tracking limits In the Default Regulator definition the above parameter are adjustable but all other ones are fixed according to the system before the simulation process Maximum Array Voltage and Input Current Output pump driving nominal output voltage and power maximal power NB When the converter is specifi
57. daily profile can be much more related to the global irradiance During the day temperature behaves rather like a sinusoid with amplitude related to the global daily irradiance and a phase shift of two to three hours The corresponding correlation parameters for amplitude and phase shift have been quantified from several Swiss region typologies One can accept that these can be generalised to analogous typologies for other places in the world Notes The region typology asked by the program is only used to refine these temperature daily profile parameters The dependence of PV system behaviour is not very temperature sensitive about 0 4 C Chapter 8 Physical models used 186 187 Physical models used 8 Provided that the monthly average is correct the global results of the PV production will not strongly depend on the temperature daily sequence Please be aware that these temperature synthetic data are not reliable enough to be suited for building heating or cooling studies in any climate which is not the goal of this software Some typical definitions AC ohmic loss from inverter to injection point AC ohmic loss from inverter to injection point The AC wiring losses may simply be defined by the distance between the inverter and the injection point The program will determine the minimum section of the wires and only propose suitable sections if you want to increase it Inversely you can also define a loss fraction at STC a
58. data in ComposPV Components files each kind in its own subdirectory PVModules PVModule PAN Inverters Inverter OND Batteries Battery BTR Chapter 7 Technical aspects Technical aspects T Regulators Regulator RLT Pumps Pump PMP RegulPmp PumpRegul RLP The Import or Export project options helps transferring whole project structures either from the local data or from remote data structure ensuring that all needed files for a given project are present If the target is not structured this tool creates the necessary directories with a common root usually named PVsyst_ExtData Note Preliminary design projects are made of only one file with extension PSG grid or PSS stand alone Printing PVSYST offers the opportunity for printing several types of data Preliminary design all parameters and results are summarized on one form Project design one form for complete parameters one for a results summary and other ones for additional results when necessary Any further specific table or graph can be printed independently Tables and graphs any table or graph output produced by PVSYST can be printed or exported through clipboard or file Scrolling tables like daily or hourly meteo values solar geometry can be printed for selected periods in suitable format Database components Meteorological sites or PV components PV modules Batteries Inverters Pumps Regulators etc can be outpu
59. default the program automatically chooses the Rs value corresponding to a reasonable Gamma factorh4 Please note that the gamma factor related to the dominant modes of recombination should have a physical value between 1 and 2 Fixing it s value is a priori arbitrary but it has been chosen as it seems to be the more stable of our four unknown parameters among several PV modules By the way it s exact value gives rise to very little differences on the final I V curve behaviour This way has the advantage of fixing automatically all the model parameters without any intervention of the user Nevertheless you have the opportunity of choosing any other Rs value within the authorised limits for example in order to better match your temperature factor muVoc if it is known See also the PV module parameter summary f3 for a complete description of all parameters Temperature behaviour correction In the standard one diode model h3 the temperature behaviour is essentially determined by the expression of diode saturation current lo which is exponentially dependent on the Egap and the Gamma parameters This expression fixes the muVco and muPmax temperature coefficient values which are therefore a result of the model Remember that the Gamma value is determined supposed in correlation with the Rserie choice which can vary from 0 to Rsmax But some manufacturers specify temperature coefficients muVco which are not always compatible with this Rserie
60. definition 194 i e one kWh m of irradiance should produce one kWh kWp of electricity The confusion comes from the fact that the kWh are not the same in the former case it is incident irradiance when in the latter case this is electricity Simulation variables meteo and irradiations The following variables are calculated during the simulation process 88 and available as results Meteorological data GlobHor Horizontal global irradiation as read on the meteo file DiffHor Horizontal diffuse irradiation read on the meteo file BeamHor Horizontal beam irradiation GlobHor DiffHor Tamb Ambient temperature Chapter 4 Project design 94 95 Project design read on meteo file Windvel read on meteo file monthly value or default value 1 5m s Incident energy in the collector plane GlobInc Beamlnc DiffAlnc DiffSInc Albinc Bm Gl Beam Inc GlobInc Diff Gl Difflnc GlobInc DifS GI DifSInc GlobInc Alb Gl AlbInc GlobInc Wind velocity If not present on file Incident global irradiation in the collector plane Incident beam irradiation in the collector plane Incident diffuse irradiation in the collector plane usual diffuse acception including albedo Incident diffuse irradiation from sky in the collector plane Incident albedo irradiation in the collector plane Secondary indicators Incident Beam Global ratio Incident Diffus e Global ratio Incident Sky diffus e Glob
61. density 1000 kg m and the gravitation constant g 9 81 m s And for getting bar we have to divide by 100 000 Pa bar In summary we have the following equivalences 1 Pa 1N m mksa basic unit 1 bar 100 kPa definition of the Bar 1 bar 10 19mWater passing from level difference to pressure 1 bar 33 44 ftWater Idem 1 bar 2088 Ibs ft2 Pounds Square feet 1 bar 14 504 PSI PSI Pound Square Inch 1 bar 0 987 atm 1 bar 750 1 torr or mmHg 1mWater 0 0981 Bar 1 ftWater 0 0299 Bar Chapter 4 Project design 72 73 Project design 4 1 PSI 0 069 Bar Pumping Hydraulic losses Pumping Hydraulic losses In the losses flow as shown on the Loss diagram of non battery pumping systems we have chosen to account for all electrical losses even when the pump is stopped for hydraulic reasons In this situation the ELowLev and ETkFull contributions are referred to the EPmpAv Available useful energy at pump energy An alternative way would be to refer the hydraulic ELowLev and ETkFull losses to the EArrMPP energy and to consider the system as not running during these situations In this case the hydraulic arrow losses would come upstream of the other losses with increased virtual energy hydraulic losses referred to EArrMPP The results are equivalent the account of the effective hydraulic losses being transferred from the Array and Converter to the EArrMPP quantity NB In Battery Buffered syst
62. detailed descriptions of all the PV components 11 Miscellaneous improvements or fixed bugs Projects are now sorted according to their system type in the list The Archive Projects tool has been debugged and improved Summer Winter Hour may now be taken into account when importing Meteo Data as ASCII files Some little bugs concerning the simulation especially of stand alone systems Wearing state not computed display errors etc Loss diagrams complete review some corrections for losses coherence Version 3 41 March 2006 by respect to Version 3 4 1 Automatic facility for importing satellight meteo data Satellight data are real measured meteo data available free from the web for any pixel of about 5x7 km in Europe and for years 1996 2000 Their quality becomes better than any terrestrial measured data as soon as you are far from more than 20 km of the measuring station 2 Fixsome bugs of version 3 4 concerning HIT PV modules model memoryleakages and orientations in some shading special cases transposition safety when bad meteo values orientation choice dialog meteo ASCII conversion facility Version 3 4 July 2005 by respect to Version 3 3 1 New modelling procedure for the amorphous modules This procedure was established and validated using the results of a research project performed at CUEPE funded by the SIG NER fund the SIG Services Industriels de Gen ve are the Geneva El
63. determined in the simulation process the corresponding energies involve the operating voltage which is also model dependent and varies with state of charge charge and discharge currents etc Hydraulic part for all configurations Remember that the Hydraulic Energyl7Ais the product of the Head and Volume pumped The last part of the Energy Loss diagram refers to Hydraulic energy Implicitly when it shows pumped water volumes this is under a given Head Inversely the arrows for Dynamic Head Losses express a Head loss at constant volume E Hydro Pump hydraulic energy energy to the fluid P_Effic Global pump efficiency E_Hydro E_PmpOp H_Pump Average total Head atpump During Pump_ON H_Stat Static head requirement H_Loss Friction head loss H_DrawD Well drawdown head loss Only deep well systems FlRate Average flowRate when running WPumped Water pumped volume m WStored Stored water in the tank W_Used Water drawn by the user W_Miss Missing water by respect to the user s needs Alot of further secondary variables are available for results which are not described here Simulation variables DC grid systems The following variables are calculated during the simulation process 88 and available as results Meteo and irradiation variables 94 see previous page PV array behaviour EArrMPP Array virtual energy at MPP after wiring module quality and mismatch losses Virtual calculation independent of the system state EA
64. diffuse beam and albedo components with the relation Gp Dp Bp Ap Applying the near shadingI 52 calculations shading factor on beam diffuse and albedo components either linear or according to electrical array connexions Applying the IAM 83 Incidence Angle Modifier factor this finally results in the Goff irradiance the flux effectively useable for PV conversion Haff will be the corresponding irradiation over a given time period Note we usually use G for designing irradiances flux expressed in W m and H for irradiations energies in kWh m Meteo Monthly calculations This simplified computation performs quick meteo evaluations using geographical site database only i e monthly irradiation values and evaluates horizon tilt sheds and sun shields as well IAM effects This method takes advantage of so called average months properties With real meteo data of a given month when constructing an average day by averaging separately the irradiances at each hour i e all irradiances at 8 00 9 00 10 00 etc we obtain an average profile which is very close to the Clear day model profile with amplitude reduced in such a way that the day integral matches the monthly global value This also holds for the diffuse component Therefore inversely for the middle of each month we construct a clear day with amplitude suited to the given monthly irradiation We then assume that this average day is representative of
65. distributing the water by gravity water tower principle With the Pressurized systems this requirementis of course not useful The tank characteristics are requested from the user in the Hydraulic Circuit Definition dialog The user should define The tank storage volume The tank diameter if rectangular an equivalent diameter for the same area i e Diam SQRT Length Width 4 Pi The water heightin the tank when full related to Vol and Diam The alimentation mode which may be Free output feeding by the top usual situation In this case you should define the feeding altitude by respect to the ground The outlet of the pipe is supposed without any other head loss Bottom alimentation the pumping pipe outputis atthe bottom of the tank requiring a non return valve This operation mode avoids the level drop between top and tank level and may slightly improves the system efficiency as the actual level for the head calculation is the tank level at each time The required parameter is the bottom altitude Chapter 4 Project design Project design 4 The tank volume should be sized according to the daily user s needs and the required autonomy Pumping Piping circuit Pumping Piping circuit The pipes circuit produces friction head losses which have to be kept ata reasonable value The Hydraulic Circuit Definition dialog asks for the choice of a Pipe type including diameter and a total piping lengt
66. end dates it doesn t need to read nor to write dates on files Dates read on the file If your data sequence is not very clean some holes the program should read the dates and write them on the target file This option displays a variety of date formats including the field separator as well as specific date separators for example h or for hour minutes which may all be meant as non numerical characters Dates can hold month and day numbers or day of year This option even allows to read specific measured data daily files where the day number is not included in the record but only in the file name to be used in conjunction with the Chaining facility When reading dates on the file you should specify the corresponding fields on the record The program asks for each date field and displays the corresponding labels on the columns The time base of your data will usually be Legal Time The program leaves the possibility of solar time but it is hard to imagine that someone will record data in this mode as he will have to adjust the clock periodically Finally you should pay attention to the Record Time Label 130 definition of your data If not properly defined the hourly records will be shifted of half an hour or one hour and solar geometry will not act properly especially for transposition The final result can be checked using daily profile meteo plots h73 on these plots you can ask for superimposing the clear day profil
67. evaluated from available environmental parameters and then determine a correlation between this parameter and the spectral sensitivity of the concerned technology The chosen parameter is called Average Photon Energy APE I144 and is obtained by dividing the irradiance W Chapter 6 Tools and databases Tools and databases 6 m or eV m2 sec by the photon flux density numbre of photons m sec From detailed spectral measurements over one year CREST has deduced a parametrization of this quantity according to air mass and clear day clearness index Waiting for new measurements elsewhere we can reasonably admit that this parametrization is valid at least for European climates The second phase is to determine a correlation between the UF calculated for each measured spectrum fora given technology and the APE Itis found that they are quite well correlated and lead to a simple quadratic expression The final amorphous spectral correction UF is shown on the figure Utilization Factor a Si H u 0 670 0 700 m 0 640 0 670 m 0 610 0 640 m 0 580 0 610 00 550 0 580 010 520 0 550 0 490 0 520 0 460 0 490 UF a Si KTc 16 Air Mass It varies between about 0 5 APE 1 45 to 0 065 APE 1 70 i e a range of the order of 30 It can be seen that the response of amorphous modules by clear weather decreases significantly when air mass increases winter morning and evening Butit remains rather g
68. for Stand alone and Pumping systems sizing Optional for Grid connected Constant monthly or daily profiles or custom file data PV array Choice of PV modules library Number and interconnections of modules Specification of Losses In a second step Module quality Mismatch Thermal Wiring resistance Incidence angle IAM System Grid connected Stand alone Pumping DC Grid Choice of the components and_ configuration Simulation of the system by hourly steps Results for a simulation version Complete engineer report Economical evaluation Customised Tables monthly daily and hourly graphs Detailed Loss diagram ASCII export file 23 Chapter 4 Project design Project design 4 Project design tutorial Return to the Project design 2A definitions For your introduction to the elaboration of a projectin PVsyst we will construct step by step a full project located at Marseille France The main stages which you are advised to follow for each of your future projects are Define the project which holds mainly the geographic location and the meteo file used Define a first system configuration with the minimal parameter set let PVsyst fix other parameters to default reasonable values Simulate and save this variant Define successive variants by adding progressively perturbations to this first system l e far shadings near shadings define specific loss parameters etc You can sav
69. for measured data hourly load profile values horizon profiles etc Troubles Many new features have been added in this versioon 5 0 These motivated deep changes in the internal organization of the software Although it has been tested in some relevant conditions itis impossible to check all the running possibilities after each change in the program Therefore the early version 5 0 will probably show weaknesses in the first period If you encounter some problem during the use be so kind as to report them carefully to the authors In the same way if you have some suggestions for improvements or adding some useful new feature please don t hesitate to contact the authors The Pumping part was a quite new developmentin version 4 0 Owing to its complexity it was not at the top of performances in the first version 4 0 It should be progressively improved for the future versions but we observed that as itis not used very intensively we had very few returns of users aboutits problems You can install PVsyst from our website www pvsyst com and install it It will work during 15 days without any limitations for evaluation After that it will revert in DEMO mode and you will need a licence and activation code for using it License rights and activation code License Rights For new customer we request that each company juridical entity per country hereafter named company to purchase the PVsyst license rights prior to be entitled
70. for the array thermal loss evaluation When not available for a given site an Hourly Meteo Data set can be generated 18 with synthetic hourly values obtained bya random process from any monthly data site NB By convention in PVsyst generic years lod like synthetic hourly data are always labelled as 1990 Meteorological data Tutorial The meteorological data are the starting point of the evaluation of a project But also the main source of uncertaintyh14 PVsyst holds a limited meteo internal database of about 300 sites in the world but gives an easy access to several public sources directly available from the Web Data of other providers like national meteorological offices may also be imported using a flexible importing tool Chapter 4 Project design 104 105 Geographical and Meteorological data 5 This tutorial will guide you in different options for discovering the management and organization of meteorological data in PVsyst and the import from external sources All meteo manipulations and visualizations are performed in Tools Meteo database Geographical sites Synthetic hourly data generation Import meteo data Import ASCII meteo file Meteo tables and graphs Geographical coordinates and monthly meteo data SIT files The main database is given as objects including the geographical coordinates and associated monthly meteo data These objects are stored as files with the name SIT situated in the dir
71. general model behaviour If irregularities or inconsistencies are observed itis possible that one or another points is not well defined We have sometimes observed that original data are not well defined aligned in the datasheets Pump data detailed parameter These are a complementary set of parameters Electric side Motor type reminds the choice of the preceding sheet MPPT ou DC Converter if any asks for the model name only informative this doesn refer to a device in the database Nominal Voltage reminder of the preceding sheet With DC converter input voltage In other cases the most relevant operating voltage often mentioned by the data sheets even when the Voltage characteristics is not given Other variables depend on the configuration Min Max MPPT Voltage the voltage windows for MPPT converter Abs Max Voltage Abs Max Current Abs Max Power absolute maximum ratings at the input of the device pump or converter which should never be exceeded during the simulation Corresponding protections should be specified in the Control Unit either in the simulation and in the reality Maximum and EURO efficiencies from which an efficiency profile will be constructed Hydraulic side Chapter 6 Tools and databases Tools and databases 6 Choice of the Data Set available in the data sheets This will determine the model type 7 used by PVsyst for simulating the pump behaviour and makes availa
72. ground level we have cf fig HT HG HS HF HP where HG head due to the height of the outlet pipe above the ground assuming that outlet pressure is negligible HS static head due to the depth of the water level by respect to the ground HF friction losses in the piping circuit which depend on the flowrate HP Pressurization contribution required for distribution pressur alr household Ev Ground pump close to aes pumping level Pumping level Immersed pump recommended For this system in the Pumping Hydraulic definitions dialog you will be asked to specify The source level depth by respect to the ground This may be also be given in seasonal or monthly values in the Water Needs next dialog The maximum pressure in the tank stop pumping The minimum pressure in the tank stop feeding the users The pressurization air volume at minimum pressure You will also define the Storage Tank 71 and Hydraulic circuit 7A parameters Alittle graphical tool shows the total head and its contributions as a function of the pump flowrate Pumping Storage tank Pumping Storage Tank As the solar yield is of course not constant all pumping systems include a storage tank for receiving the pumped water when available and distributing itto the final users The storage tank bottom should usually be above the ground or user s level in such a way that the static pressure is sufficient for
73. hour the simulation has to determine the Flowrate furnished by the pump as a function of the Head and the available electrical energy from PV array or eevntually battery As the head at the pump is dependent on the flowrate due to friction losses and eventually drawdown level this calculation always results of an iterative process Also at any hour night and day some water is drawn from the tank by the users this quantity is defined by the specified User s needs and supposed to be constant over the day and even over the month The simulation has to manage the situations where the tank is full limiting the pump s flow at the user s draw and stopping the pump during the rest of the hour and when the tank is empty the user s needs cannot be satisfied For obtaining a consistent balance all energies below threshold before producing flow or potential unused energies when the pump is stopped should be carefully accounted for in any running situation Along with the running losses like inefficiencies or IV mismatchs by respect to MPP these numerous energy contributions allow to construct a coherent Loss diagram 93 which is a powerful tool for identifying the system weaknesses Nevertheless this losses structure is dependent on the system types and configurations The simulation variables 9 are specific to a system layout or the order of the losses take place in a different order The final relevant results include mainly
74. identification of even the smallest misfunctioning Procedure This involves a much more complex process than the simple system simulation which includes the following steps 1 Importing the measured data 127 this is done by a programmable data interpreter which accepts almost any ASCII file provided that it holds records of hourly or sub hourly steps each one on a single ASCII line It allows to choose among the measured variables those which suit the simulation variables 2 Checking the imported data 174 In order to verify the validity of the imported data file a number of tables and graphs in hourly daily or monthly values may be drawn Further some specific graphs often used in PV data Chapter 6 Tools and databases Tools and databases 6 analysis inverter efficiency input output diagrams normalised performances parameters etc are also available allowing at this stage for using PVSYST as a complete tool for the presentation of measured data 3 Defining the system parameters 22 You have to define a project and variant parameters exactly in the same way as for usual simulation At this stage you should carefully introduce the real properties of your system 4 Comparisons between measured and simulated values 169 after performing the simulation you will obtain close comparison distributions for any measured variable According to the observed discrepancies you probably will analyse their cause and modify the i
75. import meteo hourly or daily data in almost any ASCIl format Meteo Tables and Graphs i09 powerful visualising and analysing tool for hourly meteo data files Chapter 5 Geographical and Meteorological data Tools and databases 6 PV component Database PV modules 133 Grid inverters 149 Batteries 153 Pumpslts Regulators 164 for stand alone systems Regulators Controllers h6 for pumping systems Back up generators 15 Gensets Seller listh6 Solar tool box Graph Tables of solar parameters displays solar geometry and Clear Sky irradiation on planes Electrical behaviour of PV arrays 36 reverse characteristics of PV modules mismatch array with shaded cell heterogeneous array Monthly meteo computation 18 quick meteo evaluation using geographical site database with horizon tilt sheds and sun shields IAM effects Transposition factor field orientation optimisation and evaluation tool Operating Voltage optimizationsation 62 Measured data analysis 63 Importing ASCII measured data files h2 allows to import measured hourly or sub hourly data in almost any ASCII format File transformation 17 technical tool for merging and cutting PVSYST measured data files Data tables and graphs h7 powerful tool for visualising and checking hourly measured data files Measured Data Analysis 168 parameter definition simulation and close comparisons between me
76. included in PVsyst There are many meteorological data sources available from the Web or by other means PVsyst now includes a tool for easily importing the most popular ones These are summarised in the table below and we have performed a comparison 1 between their results Sources of Meteo data in hourly values Meteonorm h hourly values are not measured but synthetic data constructed in the same way as the synthetic hourly values in PVsyst from monthly values Constructing hourly data in Meteonorm instead of PVsyst may give slightly more realistic results as the models especially for temperature have been slightly improved and wind velocities are also generated with which reliability Satellighth2 Data provides real measured data in hourly values over 5 years 1996 2000 for any pixel of 5x7 km in Europe US TMY2 3datal119 Typical Meteorological Year are compilations of measured hourly data chosen among 1961 1990 TMY2 or 1991 2005 TMY3 for 1020 locations in the US Canadian EPW datal124 Typical Meteorological Year are compilations of measured hourly data chosen among 1953 1995 for 72 locations in Canada Helioclim 3 24 provides data in hourly values measured by Meteosat since February 2004 But these data are not free Nevertheless the year 2005 is available for tests and in monthly values Meteonormh1 monthly irradiance data are available for about 1 200 stations as averages of 1960 1991 Chapter 5 Geog
77. indicating whether the value was modified and allowing for retrieving the original PVsyst default value at any time The variables are divided into the following categories Grid Connected System Pre sizing Stand alone System Pre sizing Pumping System Pre sizing Specific Pre sizing costs all systems System design parameters Detailed Simulation Verification Conditions PV modules Regulators and converters Miscellaneous The modified values can be either validated only for the present session or be permanently saved Default values and costs The pre sizing default values System efficiencies and costs are determined at the creation of the pre sizing project Pressing Edit costs allows you to modify these default values either for this session or for permanent use Values of the presently displayed pre sizing project will be updated after editing Edit costs Please be aware that at this pre design stage costs are very coarse hypothesis They can widely vary from country to country from time to time or from user to user what costs are included here customer or retailer costs which interventions on the building designer fees taxes etc The economic evaluation at the detailed simulation stage will offer a flexible and more precise tool for Chapter 7 Technical aspects Technical aspects T evaluating real costs according to the specific user s criteria Uninstall The Uninstall tool of Windows is
78. input operating voltage DCMax corresponding to the maximum power PMaxDC VinvNom The string length limitations are Minimum string length given as VinvNom VPBoutMax ex 350V 60V 5 8 or 6 PowerBoxes In practice we count at least one more module in order to ensure a good shading tolerance Maximum string length first condition is VinvNom VPBoutMin ex 350V 5V 70 power Boxes Maximum string length second condition is for the max power for the inverter PMaxDC PPBmax Maximum string length third condition is for the max output current of the PowerBox For the sizing of the PV array a good practice in PVsyst is to consider PPBmax as the maximum operating power in the real conditions of the system established according to the incidence meteo data Chapter 4 Project design Project design 4 distribution on the collector plane Power Boxes parameters definition The available Power Boxes and their parameters may be displayed in the SolarEdge inverter definition specialized inverter parameters dialog As the Power Boxes are proprietary devices of SolarEdge their parameters are not directly modifiable but only defined in the original database of PVsyst System sizing As with any usual system you are advised to start by specifying the required power for your subfield or the available area After that you have to choose a PV module When choosing a SolarEdge inverter the system sizing dialog will cha
79. inverter array ratio usually of the order of 1 0 to 1 1 But we have to notice The Pnom of the inverter is defined as the output power The corresponding input power is PnomDC PnomAC Effic i e about 4 to 6 over The Pnom array is defined for the STC But in real conditions this value is very rarely or never attained the power under 1000 W m and 25 C is equivalent to that under 1120 W m at 55 C if we take a uPmpp 0 4 C The power distribution is strongly dependent on the plane orientation Chapter 4 Project design Project design 4 But the maximum powers are not very much dependent on the latitude by clear day and perpendicular to the sun rays the irradiance is quite comparable only dependent on the air mass Most inverters accept a part of overload during short times dependent on the temperature of the device This is not taken into account in the simulation and may still reduce de calculated overload loss When over sized the inverter will operate more often in its low power range where the efficiency is decreasing If the inverter is properly designed when the Pmpp of the array overcomes its PnomDC limit it will stay at its safe nominal power by displacing the operating point in the I V curve of the PV array Therefore it will not undertake any overpower simply the potential power of the array is not produced There is no power to dissipate no overheating and therefore no supplementary ageing
80. is rarely available and leaving zero will not be a problem Specific parameters The reverse characteristics parameters are only used in the electrical behaviour of PV arrays didactic tools for the study of partial shading on cells or mismatch These definitions are not involved during the simulation process The quadratic coefficient Brev 49 of the reverse characteristic is as measured for a single cell in darkness The determination of this parameter is rough as it may fluctuate from one cell to the other and more importantly as it is strongly sensitive to temperature which obviously is highly variable in these extreme conditions of dissipation As its use is mainly qualitative the default value measured for ARCO monocrystalline cells of 100 cm will be sufficient in most cases The number of by pass diodes is often not fixed for a given module model and can vary according to customers It is usually not specified in the datasheets and given values in the database are to be checked in each case Informative parameters The maximum system voltage is an informative design constraint specified only for some modules in the database Chapter 6 Tools and databases 134 135 Tools and databases 6 See also the PV module parameter summary 134 for a complete description of all parameters PV components commercial data The commercial data especially the retailers and prices of the PV components cannot of course be define
81. level of the ground This is the reason why we integrate the shading factor at zero height over the portion of the sphere under the horizon included between the horizontal plane and the plane of the collectors below the ground It is however to be Chapter 4 Project design Project design 4 remembered that for non vertical planes the energetic contribution of the albedo is weak in the global incident energy and that errors in its estimation will therefore only have secondary repercussions Diffuse and Albedo shading factors are computed from the linear shading factor table Shadings according to module strings Spatial distribution of shadings on diffuse irradiation is smooth enough so that we can suppose that they don t affect the electrical behaviour of the field Therefore we will use the same diffuse and albedo shading factors for evaluating the shadings according to modules Near shadings Iso shading diagram The iso shading diagram is a graphical expression of the shading factor table It shows lines of some given shading factors superimposed on the sun paths Blue lines also indicate the tangential limits of the plane i e when the sun rays are parallel to the plane This diagram gives a synthetic evaluation of the shading distribution according to the season and the time of day during the year The irregular look of the lines is due to the interpolations across discrete calculation points Remember that this loss fac
82. losses along the system This is a powerful indicator of the quality of your system and will immediately indicate the big sizing errors if any Saving your simulation You should now Save this first variant for further comparisons This will be saved as Marseille_Tutorial VCO Be careful use Save As for avoiding overwriting your previous variants if any For opening previous simulations of the project click Load just above Adding further particularities of your project After this first standard simulation you can progressively add the specificities of your particular project You are advised to perform a new simulation at each step in order to check its effect and pertinence especially by analysing the Loss diagram Far shadings Horizon profile This is only suited for shading objects sufficiently far from your PV system so that the shadings may be considered global on your array The distance of the shading object should be say over about 10 times the PV system size The Horizon Profile is defined as a curve set of Height Azimuth points The Far Shadings operate in an ON OFF mode i e ata given time the sun is oris not present on the field When the sun is behind the horizon the beam component becomes null But the diffuse component supposed isotropic coming from all points of the sky vault seen bythe collectors with an identical intensity is not much affected Clicking the Horizon button will open a gra
83. measurements some users proposed when using standard meteo values such those in the US TMY2 data usually about 4 5 m sec on an average the following k values Uc 25 Wim k Uv 1 2 W m k m s Chapter 4 Project design Project design 4 By the way when the wind velocity is not present in the data as itis the case for all synthetic meteo files constructed by PVsyst PVsyst transfers the wind dependent contribution into the Uc factor assuming an average wind velocity of 1 5 m s or 5 m s in the latter case Since version 4 0 the default value is fixed for free standing arrays as Uc 29 W m k Uv 0 W m k m s If you have fully insulated arrays this should be halved Uc 15 W m k Uv 0 W m k m s Concerned people agreed that this is an acceptable choice NB our recent measurements on an horizontal array of amorphous frameless modules mounted notjointive at 8 cm above a steel roof showed a value U 18 W m k These values suppose an average wind velocity of around 1 5 m sec at the collectors level In very windy regions larger average wind velocities you can increase the values but we cannot say by which amountin a reliable way NOCT Values Some practicians and most of PV module s catalogues usually specify the NOCT coefficient Nominal Operating Collector Temperature which is the temperature attained by the PV modules without back coverage under the standard operating conditions defined as Gincid
84. min temperature 10 C by default should not overcome the maximum system voltage specified for the PV module When the desired array configuration doesn t match these requirements the system is usually not properly Chapter 4 Project design 58 59 Project design 4 sized Please see the diagram in the System definitions button Show sizing which summarizes all these constraints Design temperatures These conditions involve design temperatures which are part of your project and may be changed according to your climate in the definition of the project option Site and Meteo Next The default values for each new project may be redefined in the Hidden Parameters topic System design parameters These are Maximum cell temperature in operating conditions default 60 C Summer usual operating conditions not used for sizing constraints default 50 C Winter minimum cell temperature in operating conditions default 20 C Absolute Cell lower temperature for determining the Maximum possible voltage of the array The default is set to 10 C for most European countries best practice rule For this limit the cell temperature is considered as the ambient temperature worst case when the sun suddenly appears on the field NB these parameters are used for design only They are not involved in the simulation in any way Amorphous modules For Amorphous or other thin film modules the voltage values calcula
85. monly admitted that in a PV field all the collectors should be perfectly identical and have the same orientation This tool allows the phenomenological analysis of the effect of not observing this rule It shows the characteristic of two fields connected in parallel which can be different in orientation and collector s number Arigorous energy analysis is also possible in the framework of the simulation In Project design and Orientation parameters choose the Field type Double orientation When connecting together the outputs of 2 different arrays the resultant characteristic will depend on incident irradiances on each of the sub fields It is therefore necessary to introduce a model for the irradiance in sucha way as to be able to evaluate simultaneous irradiances under realistic conditions along the day The tool uses a clear day profile but with the possibility of modulating the global amplitude and the rate of diffuse irradiation to approach the meteorological conditions of any day The temperature of the modules is calculated according to the respective irradiances The user mayuse the scroll bar to modify the time of day in order to evaluate the dynamic behaviour during the day when the orientations are different The graph shows the respective I V characteristics of each sub field and their resultant current sum when connected in parallel The comment gives the nominal MPP value of each array as well as their common value and t
86. name and coordinates if desired In this dialog The opportunity of copying the site from a meteo file to the project or inversely to generate a synthetic hourly file from the Project s site normally performed automatically are available as soon as the location coordinates are different Ifyou need other meteo data please define them in the database using Tools Geographical site or Import meteo data When different sites the climatic distance 18 between the sites is shown Ifthe altitudes are very different altitude corrections haa may be applied to your Meteo data for matching the project s site altitude System definition The system definitions are primary aimed to define all the PV_system components necessary to fulfil the user s Chapter 4 Project design Project design 4 wishes In asecond step this part gives the possibility of modifying the PV array specific loss parameters thermal wiring resistance module quality mismatch IAM button Array losses All these parameters are initialised at typical default values so that first calculations give likely average results In stand alone systems the user s needs definition are absolutely necessary They closely condition the system design For grid systems these can be defined afterwards in order to obtain the user self consumed energy part and the energy reinjected into the grid In DC grid systems especially for public transport the inst
87. not available for PVsyst At installation PVsyst doesn t write anything outside of its own directory PVsyst5 nor in the Windows Registry At first use from V 5 2 PVsyst will define a specific area for writing its data on Window 7 or Vista c Programdata PVsyst5 Data on Windows XP and before c Documents and Settings All Users Application Data PVsyst Data When using the program you may also have copied the whole Data structure at another location of your hard disk This is especially the case when you are not administrator of your machine In this case PVsyst has created another directory PVsyst_Data in your working space as well as a little file named DataPath ini in the Documents and Settings All Users Program Files directory of your operating system Therefore when unintalling the software you should Perform the Transfer of your user s code to another machine 17 in order to preserve your user rights Export your old projectsis or eventually save your whole Data or PVsyst_Data structure as described above After that you should simply delete the whole Program Files PVsyst5 directory using the Windows explorer Delete your PVsyst5 Data structure as described above As stated above there are no additional files nor registry keys left elsewhere on your machine NB Uninstalling is not urgent Several versions of PVsyst may coexist on your machine without in
88. of the project s parameters the Orientation choice offers the opportunity of defining sheds or sun shields This will of course take the corresponding mutual shadings into account during the simulation process on beam as well as diffuse component Chapter 4 Project design Project design 4 With these tools the mutual shading of sheds or sun shields is performed using a simple geometrical computation which gives the mutual shading fraction as a function of the Transverse Incidence Angle MA or Profile angle in the shed orientation This calculation is performed assuming sheds of infinite length that is it doesn t take the edge effects into account The calculation may be performed for irradiance i e the shading factor is the shaded area fraction of the full array depends only on the pitch and tilt angle This also slightly depends on the number of sheds as the first one is notshaded This is what we call the linear shading You can also estimate the electrical effect of these shadings Remember that the current of the whole string as seen from the inverter input is limited to the current of the weakest cell i e the shaded one Therefore we suppose that the production of the bottom string becomes null regarding beam component if the bottom row of cells is fully shaded and proportional to the shaded fraction of the cells otherwise This is what we call shading according to module strings in the near shadings The
89. ohmic or transformator losses after the inverter The mono or triphased mode usually Mono for inverters smaller than about 8 kWac and Tri phased for greater ones Most grid distributors impose a limit on the phase unbalance of the order of 3 5 kW But of course you can distribute mono phased inverters on each phase The grid frequency is usually 50 Hz and 60 Hz for the US zone Many inverters are designed for accepting both frequencies making them useable on all world markets When choosing an inverter in PVsyst you can ask for a selection of only 50Hz or 60Hz suited devices The Grid Voltage parameter is also indicative in PVsyst In the reality the output voltage of the inverter will follow the grid voltage 634 at any time The device is usually equipped with securities which will disconnect when the voltage goes outside a specified voltage range But the effective Voltage thresholds specification is not part of the PVsyst parameters By the way PVsyst has no indication on the real grid voltage at a given time in the simulation process and could of course not use this information Nominal AC Power is the crucial parameter of the Inverter definition It is the power the inverter can feed continuously In PVsyst when going over this power the limiting strategy is applied displacement in the IV characteristics or cut Maximum AC Power is often specified by the manufacturers but its signification is not always clear It is usu
90. on the conditions of use average state of charge cycling depth of discharge temperature Itis therefore observed that the optimisation of a PV system is a complex problem with several criteria which has no ready made solution The preliminary design tool allows for playing with the main parameters and rapidly observe their effects on the system performance to optimise the desired characteristics by successive approximations But the accuracy of these monthly results is not guaranteed and the behaviour of the chosen system will have to be verified bya complete simulation in hourly values with real available components Battery Voltage Choice Battery Voltage Choice In a stand alone PV system with direct coupling to the user without inverter the battery voltage determines the distribution voltage As now many DC appliances can be found as well in 24V as in 12V this choice should be made according to system and or appliance power as well as the extension of the planned distribution grid to minimise the ohmic wiring losses This choice should be done from the early planning of an installation since the existing appliance voltage usually cannot be changed and voltage translators will be expensive and not 100 efficient The rated distribution values could be chosen according to the following criteria inverter supposed directly connected on the battery pack 12V little systems for lighting and TV Appliance max power lt 300
91. on the yearly global useful irradiation beam and diffuse falling onto the collectors The Chapter 4 Project design 32 33 Project design 4 curves show the pure transposition yield as if there were one only plane and the curve with mutual shadings either linear and for electrical losses This graph can be drawn with two options Either keeping the Incidence limit angle constant In this case we see thatthe collection ground ratio is very sensitive to the plane tilt Or keeping the Shed spacing i e a chosen collection ground ratio constant In both cases we see that the optimal tilt of sheds is lower than for a single plane This is still more evident with non south azimuths From these tools we can observe that With shed installations choosing a rather low tiltis often a very good solution which leads to acceptable losses of some few percent by respect to the optimum with the following advantages The installable power is much greater on a given ground area The array orientation does no more affect the performances you can install the sheds according to the building geometry special south facing arrangements are no more useful Module supports become more simple cheaper and lighter with less wind sensitivity Architectural impact can be much more acceptable Nevertheless the minimum tilt should be kept at some few degrees 2 3 for module cleaning by the rain Moreover frameless laminates sh
92. or any time in the year by clicking on the speed button Shadow drawing Solar angles or time conditions may be easily modified to see the evolution during the year After each parameter change please click on the Shadows drawing button again for updating the shadow computation NB This Linear shadow computation is a very complex process involving polygon intersection and union calculations which sometimes may fail giving erroneous results i e part of the field is over or under shaded If the program can detect the failure through it s internal checks it uses an alternative computing method by distributing a grid of points on the PV area and evaluating the shading state of each point This second method is less precise butleads always to reliable results To minimize such problems please always position PV planes with a little gap between them and their support surface If you have defined a partition of your PV field according to strings of modules the partially shadowed string rectangles will also appear in yellow The two shading factors will be displayed indicating the lower and upper limits for the shading s real effect You also have an animation of the shadows drawing over a whole day This simultaneously draws the curve of the loss factor on the beam component and calculates the overall dailyloss on beam component for a clear day Tip Try the View from sun direction speed button to deeply understand how the shadows
93. orientation of the selected object These can be edited as numbers But itis much easier to set a plane side or front view in order to drag the object in the scene with the mouse Rotate the whole scene very useful tool which allows to build the scene in its natural referential parallel to the building according to architect s plans and then rotate the whole scene according to the cardinal points Partition in module chains 46 creates a partition in module chains i e rectangles for non linear shading calculations according to module strings distribution Measurement tools 4 allow to easily get real distances and angle measurements between points of the scene Shadows drawing with completed shading scene allows to visualise the shadows on PV planes for any sun position or time of year Includes quick dialog tools for incrementing the time of day by 30 min or the day of year by 10 days You should click on the Shadow drawing button for refreshing shadows after each parameter modification Shadows animation sweeps the sun position every 15 minutes over a given day Shows the shadings and draws the shading loss evolution gives the overall loss on beam component over the whole day After completion any individual position may be reviewed in detail From sun view In order to well understand which object is involved in the shading construction you can choose to observe the scene from the sun position button in
94. related to the difference between the input and output levels The pump has to provide a total head resulting of several contributions In PVsyst we take reference to the ground level we have cf fig HT HG HS HD HF where HG head due to the height of the outlet pipe above the ground assuming that outlet pressure is negligible HS static head due to the depth of the water level in the well in absence of any pumping HD dynamic drawdown head in a borehole well the effective water level is dynamically lowered by the water flow extraction see below HF friction losses in the piping circuit which depend on the flowrate HG Storage Tank Ground level Static water level Water level when pumpin Pump inlet level Pump For this system in the Pumping Hydraulic definitions dialog you will be asked to specify The static depth This may be also be given in seasonal or monthly values in the Water Needs next dialog Chapter 4 Project design Project design 4 The maximum pumping depth corresponding to the inlet aspiration level The system will stop the pump when the dynamic level reaches this level avoiding dry running The Pump depth should be below the maximum pumping depth The borehole diameter in cm The specific drawdown expressed in m m3 h this is a characteristics of the borehole and the surrounding ground see Deep well modelling 68 You will also define the Stora
95. results which underestimate the power by about 8 to 10 when applied over all our 3 months measurements we identified 3 dominant corrections RSh exponential correction 4A On all our data including Si crystalline and CIS modules we observe an exponential increase of the Rsh when irradiance decreases This correction has a moderate effect on technologies with high Rsh but strong in amorphous This is the main contribution of our corrections Recombination losses 144 This additional current loss takes place in the intrinsic layer of the amorphous junctions The correction proposed by Mertens amp al implies a distortion of the I V curve which cannot match our I V measurements anymore but dramatically improve the Vco voltage behaviour of the model Spectral corrections 1143 Applying the spectral correction established at Loughborough UK for single amorphous modules Betts amp al improves the errors distributions bya factor of 10 to 20 Itis not clear whether this correction is quite suitable for our double and triple junctions NB PVsyst doesn t take into account the the well known initial degradation due to Staebler Wronski effects PVsyst results are supposed to apply to stabilised module performances after 2 3 months of exposition to the sun Spectral characterization Average Photon Energy APE The Average Photon Energy is aiming to the characterisation of the energetic distribution in an irradiance spectrum
96. row becomes unproductive as soon as the bottom cell is shaded Chapter 4 Project design 62 63 Project design 4 Normalised Grid voltages The electric power is distributed using a tri phased grid In such a configuration we distinguish two voltages The voltage between two phases Vpp The voltage between phase and neutral conductors Vpn which is the usual connexion for the distribution in the house for most domestic appliances The ratio between them is the square root of 3 Vpp sqr 3 Vpn In European countries the normalised low voltage in households is Vpn 230 V 6 10 i e ranging from 207 to 244V i e Vpp 400V 6 10 i e ranging from 360 to 424V In the US zone there are several standards Vpn 120 V no more very usual i e Vpp 208V some homes wired between 2 phases 7 or Vpn 236V or 240 Which range i e Vpp 408 V or 416 Which range or Vpn 277V 22 i e Vpp 480V NB Sorry we don t have precise information about the situation in other regions Stand alone system definition First step You are asked to define the user s needs 54 proposed by default as a list of domestic appliance use Second step array and battery pre sizing give the desired acceptable LOL probability ho give the requested autonomy 189 choose the battery system voltage 20 The program will then perform a system sizing in a similar manner as in the Presizing section Third
97. secured website of the Geneva University https payment datatrans biz You will have first to log in to your user account or create a new one Once logged in you can purchase PVsyst activation code s or pay an invoice using a credit card Payment by Bank transfer If not possible by credit card payment of invoice should be done by bank transfer The detailed identification of our bank account is given in the invoice Note that if you choose to pay by bank transfer a preliminary activation code allowing running the software for a time limited period usually for 3 months is returned by email Chapter 2 Licensing 16 17 Licensing 2 The definitive activation code will be sent after receipt of your payment Transferring the activation code on another machine When running with a valid code number the program provides a tool for transferring the software license to another machine Note that performing this tool will turn the software on the initial machine in Demo mode You could retum to the initial state by performing another license transfer from the second machine 1 First on the second computer the computer on which you want to transfer the license install PVsyst by downloading the program from our website www pvsyst com 2 In the main window open the menu License then Status and Activation and copy the Local Number that appear in the Registration codes panel you can use the button copy to c
98. shading effect the truth should lie between the low limit which we Call the Linear shading representing the irradiance deficit and this upper limit see partition in module strings 46 representing the electrical effect For this second simulation According to module strings Go back to the Near Shadings definition button Construction Perspective Click the button Partition in module chains on the left Here you can split the field into several equivalent rectangles each representing the area of a complete string nota module If several subfields you should do this for every subfield rectangle This is a rough estimation for a rough computation Perhaps you will not be able to represent the real arrangement of your modules But you can try different configurations perform the simulation and then decide which configuration is the best suited for your particular system When performing the shading animation the partially shaded rectangles will now appear in yellow The new shading factor is the sum of the greytyellow areas by respect to the field area Use in the simulation Inthe same wayas before in the Near shadings please choose According to module strings in the options Use in simulation This will ask for computing the tables and then you can open the iso shading graph for comparing the effect to the Linear one Fraction for Electrical effect this is the way how the yellow parts will be
99. shadows limited by a horizontal line wall shed balcony Reference year year value Reference year The format protocol specifies a reference year i e data are assumed to be regular from January 1st to December 31th not leap year Chapter9 Glossary Glossary 9 In this case the program does notread the date on the file and the Year number must be supplied by the user from 1981 to 2060 Regulator voltage switch Regulator voltage swich Some commercial regulators offer a swichable battery voltage usually 12 24V The right switch position is nota characteristics of the regulator component and will be chosen bythe program according to the battery pack before the simulation process Checks on voltage compatibility as well as input and output maximum allowed currents are performed before the simulation and will produce a warning when not matching Series Resistance PV module PV module series resistance The series resistance Rs is not directly measurable on the PV module It s effect is combined with the I V diode model exponential slope the lower Rs resistance the sharpener I V characteristics toward high voltages Rs is one of the 4 unknown related coupled parameters when adjusting the one diode model Reverse characteristics PV cell Reverse characteristic factor Empirically the behaviour of the cell s characteristics under reverse polarisation is quadratic with the applied voltage This results is fro
100. should include the monthly Global horizontal irradiation Monthly averages of the ambient temperature The file may also include the optional data monthly Diffuse horizontal irradiation monthly average of wind velocity PVsyst includes a database h10 of around 330 sites in the world and you can import meteo datal 113 from many sources Meteo values are displayed and easily defined on the screen The units for capture and display are left to the choice of the user It is to be noted that for the verification of rather uncertain data the clearness index i8 amp Kt is also displayable which is the irradiation actually received on earth normalised to extraterrestrial irradiation in monthly values The monthly average of Kt should usually lie between about Kt 0 25 and Kt 0 75 at any place Limits for data acquisition are defined in Preferences Hidden parameters Monthly meteo values can be used as a basis for the generation of synthetic hourly datalis The specification of sites will be used in the management of hourly meteo files project pre design the localisation of system design projects the display of solar parameters and many other tools Horizon It is to be noted that in PVSYST the basic irradiation values are usually defined for a free horizon Taking the shading of the horizonI38 into account is worked out during the simulation by cancelling the beam component when the sun is hidden below the horizon
101. sizing tool for stand alone systems in order to evaluate the load from a user s point of view In presizing the effective use of the defined values during the simulation process is equivalent either to a constant load or to seasonally or monthly constant values In detailed simulation a superimposed daily profile may be defined Load values read on ASCII file is the most flexible load definition you can edit your own desired load profile either in hourly or in daily values in a spreadsheet editor or any ASCII file and easily import it 55 in PVSYST NB You can save your Load profile as a model for reusing it in another project Chapter 4 Project design 54 55 Project design 4 Load profile ASCII file definition See also User s needs l 54 The most flexible way for defining a custom load profile is to input it as an ASCII file The ASCII input source file can be edited in a spreadsheet program like MS EXCEL or a text editor It should hold one load value per ASCII line Each record line may contain several fields separated by semi colon comma TAB or blank characters and terminates by CR LF or both With MS EXCEL sucha file is easily obtained by saving a usual sheet in CSV format Comma Separated Values You can define either Hourly file which has to contain 8760 hourly values W or kW from January 1st Oh to December 31th 23h or eventually 8784 values if the meteo file used in simulat
102. step define the system components choose the battery model in the database gt the program determines the number of units in series and parallel choose a PV module model gt the program determines the number of modules in series and parallel according to the battery voltage PVSYST cannot support mixing module types in a single system Fourth step Pass to the System configuration parameters Next button the program asks for defining the regulatorhe This may be chosen in the database with constraints specific to each commercial model operating voltage thresholds input and output currents etc But for the first simulations of a project it is recommended to use the Generic Default regulator which ensures a standard behaviour of the system regardless of regulator constraints In this case the regulator parameters are adjusted by default values corresponding to the actual system at the simulation time for example charging discharging thresholds according to the battery pack configuration This way they don t produce compatibility warnings as the existing models do It is possible to use a power conditioning unit MPPT or DC DC converter In PVsyst these devices Chapter 4 Project design Project design 4 are part of the Regulator component definition There are also Generic default devices for both MPPT and DC DC operation In these Generic default components the parameters for efficiency and fixed voltag
103. systems such high concentration systems suffer of two main loss sources the negligible diffuse acceptance diffuse is of the order of 30 even in most sunny regions 40 to 50 in the middle Europe climates and the full loss when reaching the tracking limits of the heliostats These appear of course on the PVsyst Loss diagram On the other hand in the system definition the heat loss factor Kc should be set according to the effective sensor temperature reached under nominal irradiance and which should be specified by the manufacturer some equivalent of the NOCT data Defining a concentrating system A concentrating system is defined when involving a concentrating PV module CPV Defining a CPV module in PVsyst is done in the PV module definitions part Size and Technology Only high concentrating CPV devices with a concentrating factor of the order of 500x are possible in PVsyst These are usually equipped with very high efficiency concentrating cells tripple junction GalnP2 GaAs Ge The optical characteristics and real electrical behaviour of the cell cannot be modelled in detail Therefore as an approximation the full CPV module is treated as it was a flat PV module with a sensitive area equivalent to the optical aperture area The thermal behaviour with heat sinks for evacuating the heat of the cell is supposed to behave in the same way as the flat plate modules i e according to the usual thermal balance 85 equation with a
104. the Arrayloss diagram is not exactly the specified value at this is referenced to the STC when in the diagram value itis by respect to the previous energy Chapter 4 Project design Project design 4 Mismatch loss Losses due to mismatch are related to the fact that the real modules in the array do not rigorously present the same I M characteristics Remember thatin a string the worst module drives the string s current The button Detailed computation helps the understanding of this phenomenon and gives indications on the loss parameter to be set for the simulation according to your hypothesis on your effective module set This parameter acts as a constant loss during the simulation It is lower for thin film modules It could be about null when sorting the modules according to their real performance flash test results provided by the manufacturer NB There is probably a correlation between these 2 last parameters The Module qualityloss is rather related to the average of the module s distribution when the mismatch refers to its width Soiling loss To our experience the soiling effect is about negligible in middle climate residential situations It may become significant is some industrial environments for example near railway lines or in desert climates The monthly definition allows for taking periodical cleaning or rains into account This parameter may also be used for describing a snow effect for example put 50 in w
105. the distribution of values lower than a given value The necessary definitions are the same as those for histograms Please also give a name which will be the plot title in outputs You can use the button at the right to produce an automatic plot name Models The user has the opportunity of saving definition of each plotin a library to reuse itin other projects Please note that the definitions of histograms will have to be updated according to the size of each system Nevertheless the default graphs histograms are automatically updated Simulation and comparison When all parameters are acceptable LED s all green the program gives access to the hourly simulation Simulation dates are based on the Measured data file dates and can be restricted to a limited period Besides the Online graphs and Output files decribed for the usual simulation 88 you should also define the Comparison 7A requirements i e which simulation variable has to be associated to each measured data and under which constraints Then the simulation process beyond accumulating graphs as for pure simulation will also accumulate couples of comparable data in hourly or daily values After completion the simulation comparison allows to open the Results 9A dialog Simulation results for a particular variant can be stored with all involved parameters in a file named as the project s file with the extension CMi i 0 9 A Z Results The simul
106. the plane tilt and azimuth These graphs also indicate your actual choice bya violet dot on the curves showing at once where you are positioned by respect to the optimum The optimisation of the orientation depends on the planned use for the PV energy For grid connected systems the energy is usually sold ata constant price all over the year The relevant optimum is then to maximize the yearly energy For stand alone systems the relevant solar yield for sizing the system is usually the winter months For pumping systems there is no general rule depending on the final use of the water pumped household all over the year or irrigation some specific seasons probably summer Therefore this tool gives the opportunity of choosing the optimizing period Year Winter or Summer this option is fixed according to the system type in the presizing part NB This tool makes use of the Monthly Meteo calculations 184 which perform quick transpositions from the Monthly Meteo values The whole calculation for the curves is performed for several situations in both directions from the point you have chosen tilts at fixed azimuth and azimuths at fixed tilt Chapter 4 Project design Project design 4 Concentrating systems Systems involving concentrating devices are not treated in whole generality in PVsyst Some specific features have been implemented from version 4 2 for evaluating especially high concentrating systems But their acc
107. the PVsyst software In Tools choose the Import Meteo Data button Select a Meteonorm data file directory Meteonorm Output and follow the instructions You just have to define the country and the region If you select a monthly file this will create a Site SIT file in the database If you select an hourly file this will create both an hourly meteo file MET and a Site file SIT Restrictions With Meteonorm V 5 0 and 5 1 the format of the monthly output file is erroneous The MON Dat files don t include the site name nor the geographic coordinates With these versions you should use the import in hourly values which works quite well With Meteonorm V 4 0 the same problem arises when you ask the construction of hourly values Please save the Monthly values before constructing the hourly ones With Meteonorm V 6 0 the hourly files generated for PVsyst were erroneous at beginning If your Meteonorm was installed before September 2007 you should import and install the Patch version 6 0 1 4 or upper from www meteonorm com for importing hourly data properly Importing PVGIS data PVGIS Photovoltaiv Geographical Information System is a research demonstration and policy support instrument for solar energy resource part of the SOLAREC action at the JRC Renewable Energies unit of the European Communities Ispra You will find a complete description of this project at http re jrc ec europa eu pvgis inf
108. the University of Geneva Version 4 35 March 2009 by respect to Version 4 34 Feb 2009 1 Import of Meteo data Bug in some new files of Meteonorm V6 0 containing leap years Bug in some TMY3 files date recognition 2 CdTe PV modules according to our detailed measurements opportunity of defining Recombination Losses 3 Shading factor calculation especially diffuse bug when the plane azimuth is very unusual north in Nordern hemisphere Version 4 34 February 2009 by respect to Version 4 33 Sept 2008 1 Database PV modules from manufacturers especially many amorphous and new inverters 2 Tool for analysing shading of one cell in an array Improvements shows now shaded I V charact and Pmpp Chapter1 Overview 6 Overview 1 loss 3 Meteo data import US TMY3 Importimplemented 1020 stations available Satellight Bug temperatures when importing 5 years ata time PVGIS Bug all months accounted as 31 days overestimate 1 6 PVGIS Now uses PVGIS site new interface much more convivial Meteonorm Monthly files still discovered a new format variant Temperatures Possibility of importing NASA data always available 4 Tracking tilted axis error when axis azimuth not south 5 Measured and Meteo data little bugs extended available date formats Version 4 33 September 2008 by respect to Version 4 31 July 2008 1 Database PV modules update from Photon Magazine 2008 and other manufacturer s data over 3100
109. the by pass diode recovery into account For this you have to choose an intermediate fraction of electrical effect which will depend on your system geometry But we don t have well established value Chapter 4 Project design 26 27 Project design 4 to propose atthe moment 60 to 80 Higher for regular shadings like shed mutual shadings NB The near shading loss doesn t cumulate with the far shadings when the sun is behind the horizon the beam componentis null and therefore there is no near shading contribution Final layout of your system There is in principle no relation in the program between the definition of the system and the definition of your 3D scene Except that at the end of the process the program will check the compatibility of these different parts Namely it will require that the plane orientations are identical and that you have defined a sufficient sensitive area in the 3D scene for installing the PV modules defined in your system But PVsyst doesn t check the real physical geometrical compatibility In a second step you should check the arrangement of your modules and eventually modify the system definition number of modules in series and parallel in order to build a realistic installation PVsyst doesn t offer specific tool for this try and error process in the present state Array losses Finally there are several parameters which are fixed by PVsyst as reasonable default values for your early simul
110. the irradiation in the collector plane is available the program calculates Chapter 5 Geographical and Meteorological data 126 127 Geographical and Meteorological data 5 the corresponding horizontal global and diffuse inverse of the transposition Nevertheless due to edge effects these data will only be valid within the original collector plane If the wind velocity is not available in the source file it will have to be provided manually in monthly values Usually the values are consecutive but if values are missing on the source file for example night values the date should be explicitly mentioned on each line of data Given that the internal file must hold complete days the data for any missing hour will be completed with zero irradiation values and with stable temperatures after the last available reading Gaps of more than one day may be acceptable with the option of writing the date for each reading on the internal file This will cause a gap of one or several full days in the internal file but the use of this possibility is not advisable as the normalisations of the display of simulated values in daily units have not been tested in great detail for these special cases It is also possible to automatically chain data monthly or daily files provided that their name include exploitable identification code ASCII Conversion procedure See also Conversion of hourly data ASCII filesh2 Please follow each step of the co
111. the model basically applies to a single cell which is multiplied according to the module wiring structure Model determination According to a method proposed by Beckman and al the known parameters measured under given reference conditions usually STCI194 allow to construct a system of 4 equations 0 0 Voc and lmpp V mpp ie MUV oc mV C The values of the I V characteristics in 3 distinct operating points lse A fourth equation is provided by the temperature behaviour of the voltage Voc which can be measured relatively easily with the four unknowns Rs lo ref Gamma and muVco This is illustrated by the I V curve shown on the screen it has to pass through the 3 reference points mentioned above The fourth equation should determine which curve is to be chosen between the two displayed limits and therefore give the values for the 4 bound unknowns But in practice the resolution of this system often leads to a set of not physical or even very erroneous values for these parameters Alternative method So that we preferred to offer the user a more visual method allowing him to choose a parametrisation which corresponds better to the supposed physical reality The programme traces the I V characteristics corresponding to the 3 first equations that is passing through the 3 experimental points for different values of Rs comprised between 0 and the maximum R max value compatible with these 3 points Then by
112. the month so that we can apply all mentioned corrections transposition shadings etc using the solar geometry of this middle month day Accuracy This procedure avoids constructing synthetic hourly values and gives instantaneous evaluations with very acceptable accuracy By respect to an hourly computation monthly calculations for Geneva show that the transposition on tilted plane induces a yearly MBE of the order of South plane tilt 0 90 lt 1 3 SE or SW planes tilt 45 lt 1 1 tilt90 lt 4 1 Eor W planes tilt 45 lt 2 7 tilt90 lt 11 If only the global monthly values are known the uncertainty on the monthly diffuse estimation correlation model about 5 mayinduce 1 to 4 error more Transposition model Transposition is the calculation of the incident irradiance on a tilted plane from the horizontal irradiance data PVSYST offers two transposition models Chapter 8 Physical models used 184 185 Physical models used 8 Hay s model a classic and robust model which gives good results even when the knowledge of the diffuse irradiation is not perfect Perez model Perez Ineichen et al is a more sophisticated model requiring good well measured horizontal data Transposition is separately calculated for each irradiance component The beam component involves a purely geometrical transformation cosine effect which does nt involve any physical assumption The two models differ
113. the other hand module shading calculations consider a rectangle as shaded as soon as one pointis shaded When confused with its support surface the baseline of the PV plane is calculated as shaded and invalidates the lower rectangles Near shadings Limitations See also Near shadings general organisation 3 and PV Planes MA There are several orientations situations in PVsyst for which the 3D shading calculations are either approximate or impossible Chapter 4 Project design 44 45 Project design 4 As the shading calculation table cannot be doubled in the present state of the program the configurations with several orientations cannot be calculated accurately This concerns The Seasonal Tilt Adjustment the shading factor is established relatively to the plane orientation The table cannot be valid for the summer and winter situations at the same time Therefore near shadings are forbidden The Heterogeneous double orientation in this situation two independent incident irradiance calculations for both plane orientations are made during each step of the simulation This would normally involve two different shading factors one for each irradiance component which is not supported yet However the program allows calculation approximated if the orientation difference between both planes is not too different the difference limit is fixed at 25 adjustable in the Hidden Parameters 173 In this case it applies the s
114. the project file The description had already defined previously Give a synthetic identifier for the file name without special characters like accents All the files referred to this project will have this name You can define for example Marseille_ Tutorial Save the project Creating your first variant for this project In the Project s dialog button Back Calculation In this window a red button means parameters to be defined or not acceptable An orange button means acceptable but not ideal parameters Agreen lighted button means Parameters defined correct Agreen out button that this topic is not defined for this version The Simulation will be enabled only when no button is red Click Orientation button choose Fixed tilted plane Tilt 25 Azimuth 20 toward east NB When defining the Orientation you have a tool Show optimization for situating your choice by respect to optimum regarding the transposition factor The optimum is different for grid connected systems optimization on the whole year or stand alone pumping systems optimization on the more critical period Click System button definition of the PV system Will open the system definition dialog In the Presizing Help group define Available Area 125 m Choose a PV module The list will show A modules or your Favorites or other categories according to Chapter 4 Project design 24 25 Project design 4 availability
115. the time being the model only allows for the definition of lead acid batteries Ni Cd batteries have quite a different behaviour which has not yet been implemented Basic parameters The most important battery specifications present in any manufacturer data sheet Number of elements or cells Nominal voltage should be 2V for lead acid batteries Nominal capacity as usually specified for a discharge rate in 10 hours noted C10 and for a reference temperature of 20 C Capacity behaviour according to discharge rate and temperature will be defined in the next sheet Internal resistance is considered to be constant in approximation Current efficiency or coulombic efficiency is the discharge charge cumulated currents ratio in Ah For a working range below the overload i e without dissociation of the electrolyte gassing phenomenon appearing at approximately 85 to 90 of full charge itis generally approximately 97 for lead acid batteries When the state of charge increases the dissociation progressively appears and is manifested on the one hand as an excess of voltage in relation to the normal charge curve and on the other hand by a production of gaseous oxygen and hydrogen which consumes a part of the charge current by electrolysis thus disturbing the determination of efficiency The real efficiency therefore depends on the working conditions and on the regulation It will be quantified during simulation and the cu
116. these file in the following directory on Window 7 or Vista c Programdata PVsyst5 Admin on Windows XP and older c Documents and Settings All Users Application Data PVsyst Admin where some subdirectory names i e Users and User may be translated into your language in the File explorer Log files are intended for debugging only In case of persistent error please enable the generation of Log files default option in the Preferences and send them to the author on request You can retrieve the Log files for example when asked by the debugging center in the main menu Files Export Log Files Copy the data structure This will copy the whole Data structure from the PVsyts4 Data location into the chosen location The target location should be in a zone where you have writing rights typically in your My Documents area If the target structure already exists only newer files are copied The target structure in renamed PVsyst_Data for easier identification in your machine This new location associated with your own user Windows session will be referenced in the little file DataPath ini which is located in the c Documents and Settings All Users Application Data PVsyst directory Importing Dispatching data files This tool is meant for importing individual PVsyst data files and dispatching them into their subdirectories For the transfer of whole projects please choose Import Projects Please c
117. this stage GloblIAM GlobShd GlobEff Diffeffl 94 This leads to the so called Effective incident energy i e the irradiation effectively reaching the PV cell surface Other secondary variables essentially ratios of the above energy quantities are available for displays gt Bm GI Diff Gl DifS GI Alb GI Ftransp FIAMBm FIAMGI FShdBm FShdGI FIAMShd 94 Array MPP virtual energy Then the simulation calculates the array temperature energy balance between absorbed and heatloss energy the MPP operating point of the array i e the maximum available energy that is the virtual energy as if the system was perfectly running available at the array s terminals Thus the MPP energy EArrMPP does already include the array losses i e thermal losses wiring losses module quality mismatch and IAM losses gt defined variables at this stage Tarrray DTArr DTArrGl EArrMPP 94 For double orientation fields the whole meteo calculation is repeated for the second field orientation output meteo variables are accumulated as averages between the two orientations weighted by the field area ratio Then both array characteristics are electrically combined in order to search the real maximum power point System energy The next simulation stages are system dependent Grid connected system 8 Stand alone system 90 Pumping system fot DC grid system 90 NB All energies are calculated here as averag
118. to the maximum power point The derivative muVco dV dT These equations are based on the following parameters manufacturer s or measured data ISCref Short circuit current at reference conditions V Open circuit voltage at reference conditions co ref IMP ef VMProf Current Voltage at any point close to the MPP Mugg temperature coefficient of the short circuit current MUyjog temperature coefficient of the open circuit voltage Unfortunately the resolution of this system sometimes leads to a solution whose values lon loRef Gamma Rg do not have a coherent physical meaning Rg negative Gamma out of its physical validity domain between 1 and 2 Model parameters in PVsyst This is the reason why we preferred in the programme PVsyst to use only the first 3 equations and to propose to give the user with the help of a graphical representation of various solutions the explicit choice of the resistance Rs 148 which will completely fix the solution The last equation gives an explicit value for muVco So if he knows the value of muVco often specified by the manufacturer the user may chose the Rg value suitable for obtaining this required value if possible But for the automatic generation of the model used for the whole database we found more reliable to set the Gamma value at a reasonable level i e Gamma 1 35 for Si crystalline which determines the Rg and all other values NB Model pa
119. treated in the simulation A100 value will withdraw the total electrical production of these areas in the simulation This is the upper limit of the shading effect Perform a simulation with this value For the simulation presented to you end customer you can fix a different value for better approaching the reality But sorry in the present time we don t have means for a good estimation of this factor perhaps around 60 80 accounting for the by pass diodes partial recovery 7 Horizon far and near shading cumulation During one step of the simulation the program will first evaluate the beam component according to the horizon line ON OFF full or zero and then apply the near shadings factor on the beam component Therefore when the sun is below the horizon line there will be no near shading loss as the beam is null In other words potential near shadings for sun positions already concerned by horizon will not produce any additional losses Near Shadings treatment In order to apply shading effects we have to treat each of the three components beam sky diffuse and albedo in the appropriate manner The effect on the beam component is of ON OFF kind for a point on the field the sun is or is not visible For far shadings defined by the horizon the whole field is subject to this binary function at a given time In the case of near shading a shading factor representing the fraction of the field illuminated has to be establis
120. which require practically a detailed measurement for each battery model used We have tried to develop a two level phenomenological model 154 whose basic behaviour is simple and may be reproduced using the fundamental data furnished by all constructors but to which specific disturbances are added these being generally described by some manufacturers or battery specialists For these secondary behaviours when unknown the user can do with the default values specific to each type of technology and proposed by the software Therefore the PV module dialog includes several definition sheets Basic data 53 the identificators and the fundamental properties of a specific battery type Detailed Model parameters 154 which gather the secondary behaviours given by default Commercial datalt35 Graphs a tool visualising the usual charge discharge curves of the Battery Model electrical behaviour The Battery database 15is unfortunately limited to a very few manufacturers on the European market Batteries Basic data Battery identifiers Model and Manufacturer will appear in the batteries choice lists Data source usually refers to the main parameter measurement source most often Manufacturer may be an independent institute or your own measurements File name should have the extension BTR Technology specifies vented or sealed without maintenance batteries and tubular plates vehicle starting technologies For
121. with the left button Attribution of modules to system strings The Electrical tab allows to define the electrical properties of your PV modules layout either for defining a cabling schema and for future shading calculations First you should define the number of by pass protection diodes should normally be part of the database but often not defined or not reliable please carefully check this information on the datasheets And you should define whether the sub series of cells protected by one diode are cabled in length or in width in the module useful for detailed shading calculations Now the program shows all the strings defined in your system in all electrical sub fields and gives a representation of all modules in each string These strings are numbered for the whole system whatever the electrical sub field You should attribute each positioned module to a given string For this please choose one string in the electrical representation and you can distribute the modules corresponding to this string on the positioned modules by the left button of the mouse Use the right button for removing an attribution The not attributed modules in the electrical part remain white There is an option for showing the attributed string number on each module This figure may be used on site as a wiring schema Electrical shading effects This detailed layout allows now to define an additional option for the near shadings calculations R
122. you may also redefine an active rectangle for receiving modules You can define as much sub field areas as desired These mechanical sub fields areas defined geographically on your building are not related and should not be confused with the electrical sub fields ofthe PV system definitions corresponding to a set of module strings connected to one or several inverters For sheds arrangements you will define one sub field for each shed or tracker if you have a tracking system For several disconnected roof elements one for each element Chapter 4 Project design 86 87 Project design 4 Module arrangement After defining your available area you can push the Set Modules button which will distribute the PV modules on this area For this operation you have several choices Modules positioned vertically or horizontally portrait or landscape Start filling from left border right border or centred idem for vertical Spacing of the modules in Xand Y Then the program will tell you the number of modules which may be installed on this area In the General PV Array information box you have also the total number of modules to be positioned according to the system definition and the number of modules left to be defined Now you can modify your inactivating rectangles and the modules will rearrange accordingly If you have too much modules you can delete some of them with the right button of the mouse or restore them
123. you will Save as this component under another name This way you will obtain a copy of the regulator suitable for your actual system For all your future systems the specific default values may be adjusted in the Hidden Parameters 173 part NB With converters the user may want to perform the simulation according to different converter efficiencies With DC DC converter the user may also perform the simulation with several Input voltage values Therefore the Max efficiency and Euro efficiency parameters as well as the Fixed input voltage ofthe default regulator will be editable and stored along with the Simulation version parameters Regulator for Pumping parameters Regulator for Pumping parameters See also general considerations about Control device for pumping systems hea The Regulator dialog includes several pages which are only available when pertinent General Tab Reminds the main characteristics of any Pumping System Control Device namely for system control and pump s operating safety The parameter mentioned here are not all useful for simulation but they will characterize the capabilities of each commercial device Main switch and Tank Full level sensor are in principle presentin any control device Pump inlet level sensor is required in deep well systems Electric safety limitations Abs maximum Power Voltage Current will be set according to the pump s in the Default regulators Ifa Power
124. 000 W m TRef Reference temperature for the Isc Voc Impp Vmpp specifications Usually STC 25 C Isc Short circuit current at GRef TRef conditions Voc Open circuit voltage at GRef TRef conditions Impp Max power point current at GRef TRef conditions Vmpp Max power point voltage at GRef TRef conditions mulsc Temperature coefficient on Isc NCell serie Number of cells in series necessary for the determination of the model for one cell NCells parall Number of cells in parallel not really used by the model Cell Area Area of one cell will give sensitive area of the module and allow the definition of a cell efficiency Not necessary Module Length Total length of the module Necessary for the calculation of the module efficiency Module Width Total width of the module Necessary for the calculation of the module efficiency Apparent length Tile modules or BIPV if defined will be used for the efficiency instead of total length Apparent width Tile modules or BIPV if defined will be used for the efficiency instead of total width Max voltage Max voltage attained by the array in worst conditions Voc low temp i e insulation voltage Absorptivity Light absorptivity for the temperature evaluation through the thermal balance Let as default Nb of bypass diodes Not used by the simulation definition not required BRev Special parameter for reverse behaviour not used in the simulation Let as default Parameters of the
125. 1 4 a SI H tandem Gamma 2 8 a SI H tripple Gamma 4 2 measured CdTe Gamma 1 5 unknown CIS Gamma 1 5 measured AsGa Gamma 1 3 unknown As these values are not well established they can be modified by the User in the Hidden Parameter facility Grid inverters Grid inverters parameter are defined through a 5 sheet dialog Main Parameters 49 the identificators and the fundamental properties of a specific inverter type Secundary Parameters 5A the identificators and the fundamental properties ofa specific inverter type Efficiency curve 15 defines the detailed operating efficiency behaviour Sizes physical sizes and weight as well as comments about technology Commercial datalt35 The grid inverter database 154 includes about 30 inverters ranging from 0 8 to 100 kW Grid inverters main parameters This sheet includes the general data which are usually available in the manufacturer data sheets as well as in some Inverter products databases our main source is the Inverter surveys published every year by Photon Magazine Inverter identifiers Model and Manufacturer will appear in the inverter choice lists Data source For most devices the PHOTON magazine yearly survey But we have also many information coming directly from the Manufacturer File name should have the extension OND Input side DC PV array Minimum and Maximum MPP voltages is the voltage window in which the inverter
126. 2 Bug shed shadings new feature according to modules 3 Load definition lowered low limit to less that 0 05W 4 Auto Updates should be operational from next version Version 5 11 April 16th 2010 by respect to Version 5 1 March 25th 2010 1 Bug when importing some meteo data PVGIS and Helioclim 2 Animation video file avi compatible with Windows media Player Version 5 1 March 19th 2010 by respect to Version 5 06 January 26th 2010 1 Automatic auto update for new versions doesn t work well until V5 14 2 Tool for the analysis of electrical effect of cell shading Extended to several cells in one or several sub module groups protected by one by pass diode Generic unlimited shed shadings electrical effect of shadings on the first cell row and bottom string Mismatch histogram for the statistical study of loss distribution System design reference temperatures now part of each project 2 axis tracking shadings compatible with concentration option Help tutorials for project design and meteo data F10 key for directly switching english lt gt local language in most dialogs Helioclim data updated tool according to the new web site data format 9 Defined bi polar inverters in the system design and simulation 10 Inverter bug when efficiency not well defined 11 Heterogeneous fields still bugs in area calculations and mixed fields 12 Video recording of the shading scene now works 13 Stand alone systems
127. 7 Regulation Direct coupling mismatch may be improved by performing a PV array reconfiguration if we consider two identical groups of PV modules at low irradiance all groups are connected in parallel providing the high currents necessary to the pump starting From a given irradiance level the groups are connected in series doubling the voltage and reducing the current of the PV array This requires an electronic switch of rather simple technology cf Salameh 1990 PV array System array reconfiguration Irrad 7 n er ae oe Controller mons 17V 7P limitations U Array I 2 EE EEE a Tank Full Relays 1 NA command aa al Total Head Level diff Friction losses Current i 1 i i i PY array i i Pump H i i i i i i 1 i i 1 i i l PV array low irrad Voltage This strategy is not advised when several pumps are used the Cascading operation 76 is probably more suited in this case But be careful the determination of the irradiance threshold for commuting the arrays is of great importance for the final performances see the Results 7A analysis for details Regulation Fixed DC input converter See also Pumping Configuration 7A previous 7A and nextl7 Regulation Use of a DC DC converter Power Conditioning Unit shows a much favourable figure than direct coupling This cheap electronic device absorbs the power of the PV array at a fixed voltage a
128. 95 Voltage optimisation 168 W Windows Rights 174 Wiring loss 84 Index 210
129. Albedo Albedo attenuation factor Altitude corrections Autonomy and battery sizing stand alone Battery current efficiency Battery maximum charge threshold Clearness_Index Climatic Distance Dates read on the file Diffuse attenuation factor Domestic user s needs Contents 189 189 190 190 190 190 190 190 191 191 191 191 192 192 192 192 193 193 193 193 193 193 194 194 194 194 194 194 195 Double orientation field European Efficiency External transformer losses Generic Year 1990 Grid current in tri phased configuration Incidence_Angle Inverter power overcharging Irradiance loss Longitudinal_Incidence_Angle LOL Loss of load probability stand alone LOL Loss of load probability Pumping LOL Loss of load probability Metal resistivity Module quality losses NOCT definition Ohmic Loss Ratio PV field Plane azimuth Plane orientation Plane tilt Performance Ratio PR Losses Profile Angle Reference year year value Regulator voltage switch Series Resistance PV module Reverse characteristics PV cell Summer Time Daylight Savings STC Transverse Incidence Angle Wind Velocity Synthetic generation Contents Chapter 10 195 Validations 195 Validations of old versions of the program Chapter 11 203 References 1 Overview 1 This overview shows the general organization of the software and of the help syste
130. Center provides monthly global radiation data for 1195 ground sites from a 30 year 1964 1993 data set Unfortunately this database does not include temperature values which should be obtained by another mean for example a near similar site from the internal database or Meteonorm 11 Retscreenh2 or PVGISI118 values The WRDC database is maintained for the World Meteorological Organization WMO by the Russian Federal Service for Hydrometeorology and Environmental Monitoring in St Petersburg The basic data are available as daily irradiation values or eventually hourly in a special unpractical format not readily readable in PVsyst http wrdc mgo nrel gov Chapter 5 Geographical and Meteorological data 122 123 Geographical and Meteorological data 5 You can find a list of available sites with their geographical coordinates on the NREL web site http wrdc mgo nrel gowhtml sites html But several of these sites hold only partial data Sometimes only a few months or even no irradiance at all The NASA and NREL provide an interface for getting either daily values for given real months not useful here or monthly averages over the whole available measurements of the concerned site Importing WRDC Data You can access the WRDC data using this NASA site and easily import them in PVsyst Go to the NASA site _http eosweb larc nasa qov sse Click Ground Sites and then Monthly Plots You will be prompted
131. EPmpAv Available useful energy at pump when running EOutConv EPmpthr For all of the above configurations hydraulic constraints These manage the Hydraulic commands of the pump When the pump is OFF the losses listed above remain and the lost energy is part of the EPmpAvaill 7A ELowLev Pump stopped due to low level aspiration deep well drawdown safety ETkFull Pump stopped when tank is full EPmpOp Pump real operating energy EPmpAvail ELowLev ETkFull Battery Buffer Configuration The Battery buffered configuration 7A has a quite different operating mode as the pump is connected to the battery voltage which is quasi constant and independent of the PV array production The PV battery load simulation process is similar to the Stand alone strategy 90 with the pump as load With this configuration we have chosen to account for the hydraulic losses due to Low level drawdown limit and Tank Full upstream the battery operating losses 73 as we consider them as electrical losses between the Available PV energy at fixed nominal voltage and the Unused energy when the battery is full Indeed there is no loss when the pump is stopped but the battery is not full the available PV energy is simply stored into the battery The necessary variables involved in the simulation are the following EArrMpp Virtual available energy at the maximum power point MPPLoss Loss by respect to the MPP running EArrMpp EArray at Vnom ELowLev
132. F Pump OFF when tank is full Pump OFF when aspiration level is below the pump inlet preventing dry running Eventually motor temperature protection Protection against powers currents or voltages which overcome the maxima specified for the pump s The sizing constraints 66 are very dependent on the system layout Pumps parallel and series connexions Pumps in parallel and in serie Either on the electric side or on the hydraulic side you are advised to connect all the pumps in parallel At the moment PVsyst accepts electrical connexions in serie only for centrifugal pumps with DC motor Other configurations don t make sense The reasons are On the electric side connecting two positive displacement pumps in series will prevent good starting conditions after one pump has started overcoming its peak starting current the current will suddenly drop to the operating value therefore the total current will be limited so that the second pump may never reach its own thresholds current On the hydraulic side itis probably not a good practice to connect two pumps in cascade for obtaining a higher head in the same flow as non linearities in the pump behaviour or electric feeding differences may lead to very unbalanced heads This is especially true for positive displacement pumps Itis far better to choose a pump model which undertakes the nominal foreseen head Regulation Direct Coupling See also Pumping Configuration 73
133. Horizon profile You have the opportunity of importing horizon profile 39 files from some other tools or Software Saving Horizon profile A horizon profile can be saved for reusing it in another project or meteo calculation It is stored in the Shadings subdirectory with an extension HOR NB A file with PVsyst format is not an ASCII file and cannot be exported to other software Treatment during the simulation process The effect on the beam component is of the ON OFF kind at a given instant the sun is or is not visible on the field As meteo is computed in hourly time steps the program determines the exact time when the sun crosses the horizon line and weights the beam hourly value before performing the transposition The effect on the diffuse component is not so clear Up to version 3 03 the diffuse fraction as well as the Chapter 4 Project design 38 39 Project design 4 albedo was not affected by horizon in PVSYST From version 3 1 one admits that radiation from the back side of the obstacles is null and therefore the diffuse attenuation is calculated as an integral of an isotropic radiation over the portion of sphere seen by the plane above the horizon line This is independent of the sun position and therefore constant over the year Albedo contribution is more difficult to estimate For far horizons some radiation may be reflected by the ground ahead of the collector plane We consider the albedo to be linearly de
134. Improvement of the Meteo hourly files management site and comment now editable exportable Implementation of Tracking with vertical axis also useable with positioning of modules on a dish Module temperature calculation revision new parameters absorption etc NOOR WD PV model for amorphous parameter determination according to a specified muPmpp value Adjusment of all triple junction module parameters in the database 8 Bug Tracking azimuth sign error in south hemisphere the tracking was reversed 9 Bug Shadings polygonal fields rewritten the whole modules calculation Version 4 21 September 2007 by respect to Version 4 2 No new developments only corrections of bugs The main ones were 1 Tracking two axis returns to Azim 0 when sun over 90 2 Near shadings verification of interpenetration field objects some editing errors or improvements Chapter1 Overview Overview 1 3 New PV modules didn t appear in the list 4 Simulation sometimes division by 0 with sheds 5 Project situation dialog improved copy of site lt gt meteo 6 Graphs copy of the curve values to clipboard for exporting Version 4 2 July 2007 by respect to Version 4 1 1 Improvement of the navigability in the 3D construction tool copy paste of an object from one variant or project to another one Automatic verification of the Field interpenetration or tangency with another object which may prevent good shading calcula
135. Itis obtained by dividing the irradiance W m or eV m sec by the photon flux density number of photons m2 sec Chapter 6 Tools and databases 142 143 Tools and databases 6 From detailed spectral measurements over one year performed at Loughborough the CREST has deduced a parametrization of this quantity according to The relative air mass which in its simpler form is expressed as AM 1 cos z with z zenithal angle The atmosphere transmission according to the weather usually expressed with the clearness index Kt ratio between the horizontal global and the irradiance outside the atmosphere But as the clearness indexis not independent of the air mass depends on the sun height CREST has chosen to use a clearness index normalised to clear sky conditions Ktcs But while CREST determines the clear sky conditions by adjusting an exponential on the higher global values observed as function of air mass in PVsyst we can use the Clear Sky Model This parametrization looks like the following APE parametrization at Loughborough UK m 1 700 1 750 o 1 650 1 700 B 1 600 1 650 B 1 550 1 600 1 500 1 550 D 1 450 1 500 STC AM 1 5 gt APE 1 6 eV 0 8 5 KTc 16 Air Mass The standard spectrum AM 1 5 corresponds to APE 1 6 eV In the English climate the annual distribution of APE is a bell shaped curve centered on 1 65 eV and with a half height width of about 0 08 eV
136. MainBeg CSV Official list of the countries MeteoDB CSV Basic database of the geographic sites and their monthly meteo data PVModuleDB CSV Basic database of the PV modules InverterDB CSV Basic database of the grid inverters ReadMe TXT Last minute information about the package Admin Data Admin directory PVs yst5 INI Initialisation file containing among other things current directories personalised variables your user s code etc If you encounter any initialisation problem do not hesitate to destroy this file as it will be automatically recreated by the programme with default values do not forget to note your activation code number before Params_5_xxDAT Miscellaneous hidden physical parameters This file is originally stored in the DataRO read only directory at installation Itis saved here in case of custom modifications Currency DAT Defined currencies and exchange rates You can update them in any dialog dealing with economical data yywymmdd_hhmm LOG Log files for debugging created when they are activated in the Preferences dialog To be sentto the author in case of problem The program keeps the last five Log files produced and some older ones when an error occurred Data Sites Data Sites directory Namesite SIT Parameters of geographical sites latitude longitude altitude time zone with their general climatological data in monthly values global diffuse irradiation temperature wind v
137. Maximum electrical power Maximum current Maximum Head implies maximum current and toward the low values Power threshold for starting operating i e not null flowrate which is a function of the Head Boundary operating limits Max Power Max Current Head 41m R Pee E E aai Te E E t g s44 t Max 8 i Voltage g 24 at Threshold Limit FlowR 0 0 r r T 0 10 20 60 70 80 40 Voltage V Boundary limits of the operating domain and I V measurements for pump Watermax BU CIEMAT measurements The equation 0 implies that only 3 of the 4 variables are independent Therefore the model will provide relations allowing to calculate any one of the above variables as functions of two others The basic relations are Ip f Up HT the fundamental relationship which will be used for determining the operating point when directly coupled to a PV array FR f Pp HT completing the preceding relation for determining the corresponding flowrate Pp f FR HT will be used for example for sizing the PV array power or for determining the efficiency The other relations may be obtained by numerically inverting these 3 fundamental ones As acomplement the model also provides functions for determining the Power Voltage or Current threshold i e the boundary where the flowrate drops to zero as function of the Head The Phenomenological Model The problem is n
138. NOCT conditions Us U 1m s gt NOCT 20 C Alpha 800 W m 1 Effic Now in this definition of the NOCT the operating state of the module at open circuit or at MPP is not clear The definition probably concerns open circuit modules i e modules exposed at sun but not reallyin use in which case the Effic value will be 0 But if this definition is suited for working conditions the electrical energy is drawn from the module and this thermal balance is affected by about the efficiency value of the order of 10 In doubt of this definition PVsyst proposes here both relationships to the choice of the user Ohmic Loss Ratio PV field Ohmic Loss Ratio The Ohmic Loss ratio is referred here to the PV array at standard conditions 1000 W m 25 C Itis the ratio of the wiring ohmic loss Pwir Rwir Isc compared to the nominal power Pnom array Rarray Isc Where Rarray Vmp Imp at STC Rwir global wiring resistance of the full system This is computed for a given sub array an inverter MPPT input as the resistance ofall strings wires in parallel in series with the cables from the intermediate connexion boxon the roof to the inverter input The global wiring Chapter9 Glossary 192 193 Glossary 9 resistance Rwir is obtained by putting all the sub array wiring resistances in parallel Use in the simulation The Global wiring resistance value finally used during the simulation may be defined he
139. PPT Conv 26V DC Conv 28V DC Conv 30V DC Conv Direct with Cascade Cascade Booster Direct coupling Array Reconfig Battery 50 Ah Battery Needs 4 m3 day 50 Ah 500 W m2 680 W m2__680 W m2 400 W m2__ 680 W m2 System efficiency Pump efficiency Loss under pump starting Loss under prod threshold gt Loss under thresh 15 4 D Pumped water 1800 E Missing water 1600 O Excess energy 1400 1200 1000 800 600 400 Water m3 or Energy kWh 200 ce Q amp g vt S NS e y K S L A We can observe that all direct coupling configurations show lower performances than systems with power converters The direct coupling yields half the needs only Although itis very dependent on the PV array sizing the performances of such a configuration are always deceiving and strongly depend on details of the system sizing Introducing a booster device improves the situation this overcomes the starting over current set at 1A for this pump in the lack of manufacturer s information we have fixed this value arbitrarily this corres ponds to half the normal threshold current for this head Chapter 4 Project design 80 81 Project design 4 Cascading of the two pumps can be an efficient improvement but in practice needs 2 wells or a very wide one for passing output pipes near the higher pump But be careful the s
140. PV fields in blue First create your objects Menu Create among the available parametrised object s library i e Five kinds of PV planes 42 rectangular polygonal in sheds sunshields and tracking Elementary objects 41 a variety of 2D an 3D predefined shapes Building Composed object 42 an assembly of elementary shapes Buildings can be saved as models for reuse in other shading scenes They can t include PV fields which should be added independently in the global scene Chapter 4 Project design 40 Project design 4 The upper tool bar blue icons provides essentially means for defining the observer s point of view 53 perspective or orthogonal top front and side views and the Zoom The left tool bar gives access to the following actions on the system and it s components Displace the scene on the screen you can do that at any time by clicking out of an object Undo allows to retrieve up to ten lastoperations Ctl U Select an object Each object can be selected by clicking on it Aselected object becomes purple Copy creates a copy of the selected object CtIl C this copy is kept permanently and may be passed to another scene Delete suppresses the selected object Ctl V or Del Modify opens the edition dialog for modifying the selected object in its own referential Double clicking an object also opens its edition modification dialog Position allows to modify the position and
141. The device includes all securities normally mounted in a junction box on the roof fuses non return diodes overvoltage protections The number of String inputs should of course correspond to the effective number of strings Multi MPPT Some inverters now involve several MPPT inputs which allow to connect PV arrays of different sizes module types or orientations This is now taken into account in the simulation In the present state PVsystassumes thatall these inputs are equivalent i e have identical input parameters Master Slave some inverters may operate in the Master Slave mode one of them ensuring the MPPT research and transmitting this information to the other one s This allows to turn ON the required number of devices improving the efficiency at lower powers In this configuration the full array should be connected to all devices at a time in parallel For the Master slave operation you should define the Power threshold from which the second device will be turned ON Internal Master Slave many big inverters are now announced as master slave devices These are assemblies of standard units of a defined power which operate internally in Master slave mode This operation mode results in a very flat efficiency curve of the whole device These should not be treated as Master Slave in the simulation process as this behaviour is already taken into account in the efficiency Other specifications give additional information about
142. V system where the charging current is practically imposed by the solar generator In particular its behaviour in voltage not critical in the intermediary zones should be realistic enough at the end of charge and discharge to make the regulator operate correctly Further it will be important to be able to estimate the ageing and the possible maintenance imposed bythe conditions of use We have therefore opted for a two stage complexity definition A basic very simple model describes the voltage with respect to the state of charge SOC the internal resistance and the temperature It is to be noted that the SOC is rarely chosen as a basic variable by experimentalists for the batteries modelling as itis not directly accessible for measurement Butin the framework of our utilisation in system simulation itis relatively well determined by the charge discharge balance providing that we model the losses from electrolytic dissociation which we will discuss later on Itis to be noted that this model is valid for lead acid batteries It will certainly be necessary to strongly adapt it for Ni Cd batteries which is much less frequently used in solar systems This has not yet been implemented in this version Model description open circuit as function of SOC The basic linear model takes the simple form Chapter 6 Tools and databases 154 155 Tools and databases 6 U batt Vocbase Alpha SOC Beta Tyatt Tref Ri Iatt with U ba
143. Wh kWp day Le Normalized Array Losses Yr Ya Ls Normalized System Losses Ya Yf Pr Performance ratio Yf Yr Simulation variables Stand alone system The following variables are calculated during the simulation process 88 and available as results Meteo and irradiation variables 94 see previous page PV array behaviour EArrMPP Array virtual energy at MPP after wiring module quality and mismatch losses Virtual calculation independent of the system running and voltage operation EArUfix Array virtual energy at fixed voltage Voltage as calculated by the balance loop real battery voltage or Battery reference voltage when PV array disconnected EUnused Unused energy full battery loss EArUFixwhen Charging OFF MPPLoss Loss byrespect to the MPP operation when charging ON Earray Effective energy atthe output ofthe array when charging ON lArray Array Current accumulated in Ah UArray Array Voltage average when Charging ON ArrayON State Duration of the PV production of the array If converter present converter losses CL Oper Converter loss during operation efficiency curve CL Pmin Converter Loss due to power threshold CL Pmax Converter Loss due to power overcharging CL Vmin Converter Loss due to low voltage MPP window CL Vmax Converter Loss due to upper voltage MPP window CnvLoss Global converter losses OutConv Energy at converter output Battery operation storage losses and ageing
144. Yf Economic evaluation After simulation an economic evaluation of the system may be performed on the basis of the defined parameters and the simulation results The special economic tool is accessible in the Results dialog Costs can be defined globally by pieces by installed Wc or by m You can work with any currency and pass from one to another by a selection in the listbox The button Rates allows to adjust their relative parity Choosing one of them as a reference you can modify the exchange rates or add new currencies The first data group determines the investment The number and type of PV involved components PV modules inverters batteries etc are automatically updated from the simulation parameters Prices can be defined for each component When clicking the corresponding open button you may define your own prices for the components used either for one piece or discount price for several pieces These prices may be either saved in your component library or just kept for the current session without modifying the component database After defining your component prices you can get the calculated price in the economic evaluation sheet check the default case or modify it explicitely For the module supports the price by piece is related to one PV module Miscellaneous allows you to define up to 5 additional labels of your own which will appear on the printed output for example Transport or Engineeri
145. You can sort them by manufacturers and then choose for example a module of Photowatt say the PW1000 110W Choose an inverter The commentin the Design the array will propose a suited power for the inverter s In this project we will choose 3 inverters of 4 2 kW for example Diehl Platinum 4800 TL NB the button Show sizing will open a window where all the sizing constraints are apparent Here we see that the maximum voltage of the PV module here 600V is a strong limit for this system far below the Inverter s VmaxAbs 880 V or even Vmppmin 710V Now the warning panel doesn t show any warning in orange not optimal in red would prevent the simulation Only by defining the size of the system and the components PVsyst has proposed an acceptable design for your PV system You can click OK Executing the simulation You can now click the Simulation button which is now activated as there are no red buttons Give a significant description of this variant for example First simulation Press the Simulation button and at the end OK Click button Results and then Report Results This shows the report of your first simulation which has now 3 pages First page all the parameters for this simulation Second page a reminder of the parameters the main results graphics of normalised values 96 and table of monthly values Third page an arrow loss diagram POA showing an energetic balance and all
146. a and an inactive frame for mutual shadings There are four kinds of tracking planes two axis tilted axis horizontal east west and sun shields NB Some special orientation configurations may induce limitations 4a on the 3D shading calculations The specific definition dialogs include 2D view in the PV plane with graduated axis as well as usual 3D perspective and orthogonal views In its own referential the PV plane is defined with its tilt but always facing the OY coordinate Plane azimuth will be defined only when positioning the plane in the global scene Please remember that the total sensitive area should roughly correspond to the total PV modules area as defined in the System part Defining a meaningful commentis not obligatory it will help identifying the object in complex scenes Very important for proper operation the sensitive areas should not be tangent or penetrate other shading objects When positioning the PV fields in the global scene please be careful for always leaving some centimeters between the planes and the other objects Near shadings and Sheds In PVSYST detailed simulation the mutual shading of sheds or sun shields can be computed in two different ways Bydefining them in the Orientation parameters option You have here to define general parameters of sheds width tilt pitch etc valid for the whole PV system and the simplified computation is assumed to be linear without electrical ce
147. a great influence on the pump nominal power namely if the threshold losses are important as itis the case with Direct Coupling simple systems PV array sizing Again as a thumb rule we can choose the nominal PV STC power as about 20 30 over the pump nominal power Oversizing the PV array will result in unused energy by clear weather Undersizing it will operate the pump at lower powers where its efficiency may drop or the thresholds dramatically affect the yield by cloudy or morning evening conditions When using direct coupling configurations the array voltage is also essential Detailed optimizations can only be given bya set of detailed simulations using real devices Tank sizing The tank size is simply determined by the required autonomy using the daily consumption defined by the user and assuming no water production Other secondary characteristics of the pumping system should be determined in a second step wire diameters between PV array and pump pipe sizing etc These are involved in the Detailed Simulation Process Moreover the sizing may be subjected to criteria which may take on different weights depending on the use Reliability of the supply and the consequences of no delivery periods may be overcome by a back up generator Investment and maintenance costs which should take into consideration the cost of the PV generator pump s regulation and maintenance of the system With battery buffered systems a
148. actors The table is a calculation of the shading factor shaded fraction of the sensitive area 1 no shadings 0 full shaded for all positions on the vault of heaven seen by your PV plane It allows the calculation of the shading factor for the diffuse and albedo 4A which are integrals of this shading factor over the concerned spheric portion At each hour the simulation process will interpolate in this table according to the sun position for evaluating the present shading factor on beam component Chapter 4 Project design Project design 4 This also lets the construction of the iso shadings graph 48 which gives a synthetic view of the time in days and seasons where the shadings are problematic The line 1 for example gives all the sun s positions or time in the year for which the shading loss is 1 i e the limit of shadings Now clicking OK will integrate this shading effect in the next simulation In the final loss diagram on the report you will have a specific loss for the Near shadings Electrical effect partition in module strings Now when a cell is shaded the current in the whole string is affected in principle the current of the string is the current in the weakest cell There is no possible accurate calculation for this complex phenomenon in PVsyst We will just assume that when a string is hit bya shade the whole string is considered inactive concerning the beam component This is an upper limit on the
149. acy of the parametrisation of this inverter efficiency Inverter Efficiency Measurements 120 Inverter SOLARMAX 20 donn es fabricant Error on efficiency MBE 10 57 and RMSE 11 04 Error on EOut Inv MBE 181 7 and RMSE 63 34 W 100 a o POut Inv PArray efficiency b D An 20 u 5000 10000 15000 20000 Input Array power VV Fig 5a Inverter response with standard available inverter specification Marzili Inverter Efficiency Measurements Inverter SOLARMAX 20 adjuste for Marzili Error on efficiency MBE 1 03 and RMSE 5 35 Error on EOut Inv MBE 1 87 and RMSE 30 90 W POut Inv PArray efficiency 0 5000 10000 15000 20000 Input Array power VV Fig 5b Inverter response after manual adjustment Marzili Chapter 10 Validations 202 203 Validations 10 Conclusion With the exception of amorphous collectors we can assess that the PVSYST software is capable of simulating a large number of different grid connected systems with excellent accuracy By independently testing each of the algorithms we have tried to identify the uncertainties related to measurement and parameter s determination and those inherent to the modelling Finally it can be stated that the accuracy of the global results of the simulation is of the order of 2 to 3 MBE However the specificity of the PVSYST programme will rather be the detailed and comparative study of special disturbing effects
150. ad 4im ea Pe Pea a go Head 32m pete Eg see a Head 22m f aaae TETES E 354 eHead 12m ogy te Sfertatare clivyy ere ne E E iaie Suan ahhh m aiee gome a T aaea sa EAE aha o as o 25 BSR ie a a s saagaa anda Birgi a Sve 2 S08 E R 3 W204 e eee ss 2 EAE a SIS SE ee EE a AD eana as Fd ee ee ee ee ee eee ee EEE eee ee 10 s EE O ees ME et Be dee Boe ee Bk Sons ee ele Sen Boo es e Si E A a eee bgp I EDATE a ee ee paa geie ai a oi peers r 0 10 20 30 40 50 60 70 Pump Voltage If we avail of 2 voltage curves the efficiency figure is a linear interpolation which improves the model s accuracy Given Pp and FR as f Head for fixed Voltage This is equivalent to the preceding scheme as for each data point the current may be easily determined from power using the fixed voltage parameter of the curve Regulators for stand alone systems The regulator is at the heart of the working of a stand alone system It must ensure the protection of the batteries from overload from the solar generator and from deep discharge by cutting off supply to the users It can also control the starting of a back up generator Even though sophisticated regulation modes can be used in some photovoltaic systems proportional regulators Chapter 6 Tools and databases 164 165 Tools and databases 6 partial cuts in fields for example the type of regulator currently available in PVSYST will only act on an On Off b
151. aily irradiation from 1975 onwards for 50km x 50km aeras computed from spatial interpolation of time series measured in meteorological networks they are provided by the European Commission UE Nasa SSE this resource provides time series of daily irradiation from the 1st of July 1983 to the 31st December 2003 for cells of 1 degree by 1 degree Nasa SSE HelioClim 1 get the best of the NASA SSE and HelioClim Databases of Solar Radiation over the world This service provides time series of daily irradiation from the 1st of July 1983 to the 31st of December 2003 It automatically selects the database offering the best quality for the selected site These data don t provide temperatures which have to be obtained by other means Importing SoDa Helioclim hourly and monthly Data Please open www soda is com select Visitors complete list select Solar data for free or Solar data for pay if you are entitled identical procedures select Solar radiation data for free or for registered users select in the horizontal plane Only 2005 for free Either Monthly values Month HC3 Or Hourly values Hour HC3 NB Monthly averages from 1985 HC1 are no more available They are replaced by daily values in conjunction with Nasa SSE data Reading of these data will be updated in a next version of PVsyst define the site by search map or coodinates if available enter the site altitude select beginning and end date if severa
152. ained with the hourly simulation performed through the Project Design option including realistic available components and detailed system perturbations Especially the financial aspects are based on coarse hypothesis which can widely vary from country to country These hypothetic financial parameters can be adjusted by the user by choosing Edit costs in the economic results sheet Grid connected system preliminary design After defining the Location 17 the System button displays a first screen where you should first define the plane orientation try dragging little red dots NB a little tool helps for the choice of the optimal orientation 33 or the amount of losses resulting of you choice when not optimal Then you have to choose if you want to size your system on the basis of Active area of the collector field Nominal power of the system Annual energy yield Pressing Next gives a second screen for defining system properties especially from the architect point of view Module type standard give also the module power translucide custom with spaced cells you should define the filling ratio or not yet defined Technology will determine the default efficiency that is the needed area for a given power Mounting disposition indicative not used in calculations Ventilation property will slightly influence the efficiency due to module operating temperature Now you can open the Results which giv
153. al axis Stroke limits should be defined here Phi plane tilt from lower limit minimum 90 vertical north to upper limit maximum 90 vertical south This configuration is indeed not suited for PV systems Tracking horizontal axis N S this is the usual configuration of horizontal axis tracking systems You should use the Tilted axis option with axis tilt 0 Tracking vertical axis the collector is kept at a fixed tilt but rotating according to the sun azimuth This configuration may be used with dish arrangements when a big rotating support holds several rows of modules this particular case is made possible as the rotating axis of one row may displaced by respect to the collector Tracking sun shields which may yield solutions to the difficult optimisation between sun protection and PV production For full efficiency this should involve a Backtracking 45 control strategy Double orientation allows to define two collector planes with different orientations You should define the fraction of the field allocated to each orientation Warning the PV modules of a same string should all have the same orientation The electrical behaviour of modules connected in series and having different orientations is very complex and not functionally optimal see the specific related tool and is not supported in the simulation process Unlimited sheds 3 To be used when the sheds are very long by respect to their width If the
154. al ratio Incident Albedo Global ratio Incident energy on collector plane corrected for optical losses GlobHrz GlobShd indicative GloblIAM indicative GlobEff simultaneously DiffEff simultaneously surface Secondary optical factors FTransp GlobInc GlobHor FHrzBm BeamHrz BeamInc FHrzGl GlobHrz GlobInc FShdBm BeamShd BeamInc FShdGl GlobShd GlobInc FIAMBm BeamlAM BeamInc FIAMGI GIlobIAM GlobInc FIAMShd on global GIobEff GlobInc PV array virtual productions for loss evaluations EArrRef Array Reference Energy for PR evaluation Global on collectors corrected for horizon far shadings Global on collectors corrected for near shadings only Global on collectors corrected for incidence IAM only Effective global corrected for IAM and shadings Effective diffuse corrected for IAM and shadings Effective irradiation effectively reaching the PV cell Transposition factor Horizon shading factor on beam Horizon shading factor on global Near shading factor on beam Near shadings factor on global IAM factor on beam component IAM factor on global component Combined IAM and shading factors Virtual energy produced at the manufacturer specification Pnom Equivalent to the Yr normalised value Chapter 4 Project design Project design 4 EArrNom Array Nominal energy at STC efficiency starting point for loss diagram Virtual energy produced at TRef STC 25 C acc
155. ally a power which may be produced for a short time until the inverter s temperature becomes too high As the device temperature is not managed in PVsyst would involve number of unknown parameters it cannot be taken into account in the simulation Nominal AC current is often specified in datasheets Its value is usually the current under Nominal power and Nominal grid voltage see Grid currentho for tri phased which you can obtain by clicking the associated Checkbox Not used in the simulation Maximum AC current is also an absolute rating specified by the manufacturer not used in the simulation of PVsyst Efficiency This panel indicates the maximum efficiency as determined by the efficiency curvel15 Italso computes from this curve the European efficiency which is an average efficiency over yearly operating conditions in central Europe Efficiency defined for 3 voltages After recent tests and data publications about the efficiency as a function of the input voltage there is now the opportunity of defining 3 different efficiency curves The program will perform a parabolic interpolation between them atthe simulation time Chapter 6 Tools and databases 150 151 Tools and databases 6 Grid inverters secundary parameters These are not required parameters defined for some models only String inverter some manufacturers propose now inverters which may directly receive the string terminals without intermediary circuitry
156. am computes the used fuel cost For pumping systems there is also a provision for pump replacement their lifetime being usually of the order of a few years And of course for the batteries when used in the system The total annual cost is the sum of the annuities and the running costs Divided by the effectively produced and used energy it gives an evaluation of the energy cost price of the used kWh This is of course depending on the above hypothesis especially the loan duration and rate as well as the effective system production For grid connected systems the long term profitabilityho may be estimated according to different consumption or feed in tariffs conditions Financial Balance button Long term financial balance In the Economic Evaluation partho2 the investment and annual costs including loan refund are evaluated according to the PV system financing Now for a grid connected system the produced electricity may be either consumed by the owner or more likely sold to the grid utility In both cases the produced electricity has a financial value to be compared to the annual costs in order to evaluate the system profitability This part performs an annual balance between costs and revenues according to several possible sale dispositions Simple feed in tariff A now common procedure especially in several European countries is the purchase by the grid utility of the total energy produced The feed in tariff is s
157. ame shading factor calculated for plane 1 see below to both planes The sheds with sloped bases sheds perpendicular to a 2 sided roof are a particular case of the double orientation situation Here the 3D shading calculation is of particular importance due to the mutual shadowing of the sheds Butin this situation the global orientation differences will not be very marked so that we fall in the approximated case mentioned above NB For 2 different plane orientations the shading factor is globally correctly calculated when the sun is shining on both planes but itis not quite correct to apply it identically on both irradiance components Moreover in the present algorithm the shading factor calculation is of course not performed when the sun is behind the plane and for this limitation the plane 1 is taken as reference This will be improved for a next version For tracking planes the plane situation is well determined for any sun orientation so that the beam Shading Factor may be computed without ambiguity at each time But the diffuse shading factor which results of a yearly average related to a given plane orientation is not yet correct From V4 1 PVsyst computes diffuse shading factor for 5 typical orientations or 4x3 with 2 axis tracking and uses the appropriate value at each time step Near shadings shadows drawing When the global scene is completed you can have a look on the produced shadows for any given sun position
158. ame this file by removing the masque characters as PVsyst doesn t accpt file names with 2 points Importing Horizon from the Horiz ON software The Camera Master tool is a specialized support for your Photo Camera which allows to take several photographies with an horizontal reference every 20 in azimuth The software HoriZON gathers these photos as a single panorama on which you can draw the horizon line by mouse This produces a file directly readable in PVsyst NB when established using a georeferred grid like Carnaval or Meteonorm the exact location should be carefully defined This may be determined using GoogleEarth or a GPS Please remind that a degree in latitude is 111 km a minute is 1850 m and a second is 31m Near shadings 3D construction If you have near shading masks you should construct your PV installation and the neighbours as a 3D scene see the dedicated tutorial 49 The previous instruments including SunEye cannot help for this construction which should be realized using architect s planes or equivalent including heights indications You will performe the simulation with linear shadings irradiance deficit lower estimation of the shading effect and then according to module strings upper bound of the electrical effect higher estimation of the shading losses Finally for the definitive report to be transmitted to your customer you can choose an intermediate value for the electrical effect taking
159. ance like quantity But note that the energy loss behaves as the square of the current or the power so that at half power the ohmic loss is divided bya factor of four The effective loss during a given period will be given as a simulation result It is usually of the order of one half to 60 of the above specified relative loss when operation at MPP The program offers a special tool 84 intended to optimise the wire diameters at each stage of the array This dialog also asks for the voltage drop across the series protection diode The corresponding energy loss will Chapter 4 Project design 84 85 Project design 4 also appear in the simulation results Array Thermal losses Thermal Model The parameters of the Thermal behaviour of the field are defined in the Array Losses dialog available from the system parameter definition see also Array Losses definition 82 The thermal behaviour of the field which strongly influences the electrical performances is determined by an energy balance between ambient temperature and cell s heating up due to incident irradiance U Tcell Tamb Alpha G__ 1 Effic where Alpha is the absorption coefficient of solar irradiation and Effic is the PV efficiency related to the module area i e the removed energy from the module The usual value of the Absorption coefficient Alpha is 0 9 Itis eventually modifiable in the PV module definition dialog When possible the PV efficiency
160. and a different one for others In this case the number of MPPT input should be used in place of the Chapter 4 Project design 60 61 Project design 4 number of inverters NB Some new inverters namely the Tripower series of SMA have 2 MPPT inputs with very different powers In practice this is very useful as you can define an array without much constraints about the module number on the main input and one string with the remaining of your modules to be installed whatever their number on the secondary input PVsyst is indeed not foreseen for treating such assymmetric MPPT inputs Nevertheles you can overcome the problem by modifying the number of MPPT inputs in the inverter definition an save this as a new inverter Please set here your total number of strings After that you can define one subfield with the N 1 virtual MPPT inputs and a second subfield with one string and the remainder of the modules In the reality of your final wiring the N 1 MPPT inputs will of course be one only MPPT input SolarEdge Architecture The SolarEdge distributed architecture is based on a unique system design approach characterized by a distributed DC DC power optimizer for each PV module or group of PV modules These optimizers with a current driven output are connected in series as strings which are then connected in parallel to the input of a special proprietary inverter operating at a fixed input voltage Each power optimizer
161. and there still remain some bugs and you can also do bad manipulations you are advised to periodically save your shading scene using File Save scene as a shd file Please note your definitive scene used in the simulation will be stored along with your MyProject VCi file It doesn t necessitate a SHD file Display in report This scene will appear on the final report If you want to have a specific view of the scene in the report you can request it by File Save scene view Keep this view for the report Use in the simulation Your shading scene seems now to be ready for the simulation Choose File Close You return in the near shadings dialog Choose Linear shadings in the box Use in simulation Here the program checks the compatibility of your 3D scene with the other definitions of your system The plane orientation should match the one defined in the Orientation part If not you have a button for eventually correct the Orientation parameters according to the 3D construction The sensitive area should be sufficient for positioning the PV modules defined in your system definitions This is a rough test which checks only the area not according to the real sizes and geometrical positioning of your modules The maximum area value for warnings is much higher to account for installations with spaced modules When everything is correct the program asks for computing the Table 48 of the shading f
162. antaneous need could be lower than the produced energy at some instants so that there will be some unused energy Parameter definitions are of course different according to system types Grid connected systems 57 Stand alone systems Tea Pumping systems 65 DC grid connected systems 6a Plane orientation PVSYST supports simulations with many plane orientation modes Fixed tilted plane You have just to define the Plane tiltt99 and azimuth hA Seasonal tilt adjustment the plane tilt may be adjusted with two values for winter and summer chosen months Tracking two axes the limit mechanical angles of the tracking device in tilt and azimuth should be defined and are taken into account during the simulation Tracking two axis with frame the collectors are fixed and rotating within a frame itself rotating Two configurations are available a frame with North South axis and collectors with tracking tilt or a frame with East West axis and collectors tracking according to the sun azimuth Tracking tilted axis the axis s tilt and azimuth should be defined the axis azimuth will usually be around O i e near the south in northern hemisphere The rotation angle is called Phi value 0 when plane azimuth axis azimuth with the same sign conventions as for plane azimuth 1193 Limits on the Phi stroke are required Tracking horizontal axis E W the orientation axis is defined as the normal to the horizont
163. app Consumption 120 Wh day When using standard appliances with an AC distribution add about 10 to account for the inverter efficiency Pay great attention to standby consumption of a lot of modern appliances 5W ribbon loss will consume the production of a 50 Wp PV module Domestic use hourly distribution Defines an hourly profile over the day in order to better match the battery behaviour and therefore better calculate its wear and tear Checking the Auto evening use box will automatically restrict the lighting and TV uses to the evening hours i e from 19h to 23h NB In the framework of the Domestic use it is only possible to define one hourly profile valid over the whole year If you need more refined profile according to seasons please use the Daily Load definition instead NB Hourly distribution cannot be specified in the Preliminary Design pre sizing process User s needs probability profile definition See also Users needs 54 When entering this probability profile definition tool please first choose the scale or bin step i e the classes width matching your desired power range During utilisation in simulation the real hourly load power will correspond to the midpoint of a given bin randomly chosen according to the specified probabilities At the first entry in this dialog the probability values follow a default distribution You can drag each probability on the graph or define a given value
164. are formed Near shadings Back Tracking Strategy See also Near shadings Tracking planes MA Heliostat array layout should be carefully optimised regarding the mutual shadings Constraints are much more critical than for the sheds disposition as significant yield may be waited even when the sun is very low on the horizon The mutual shading problem is accentuated by the electrical behaviour of the strings under partial shadings Identical shadings appear on each heliostat and may block many strings ata time The backtracking strategy is now proposed by several manufacturers of tracking arrays when the mutual Chapter 4 Project design Project design 4 shadings begin the tracking angle does no more follow the sun but it goes back in order that no shading occurs In this situation viewed from the sun the trackers remain tangent to each other Of course the incidence angle increases simultaneously Therefore in the 3D shading scene the shading factor remains 1 as far as the trackers do not reach their stroke limits The position of the trackers evolves until coming parallel to the whole array when the incidence becomes near 90 The shading factor falls to O sharply when the sun passes behind the plane of the array It should be noted that the Backtracking doesn t increase the total irradiance received It only improves the electrical loss effects of the shadings The total irradiance reaching the modules is the same as if there were
165. are visualised on the Loss diagram Direct coupling configuration With Direct coupling 7A configurations including improved solutions with booster pump cascading or Array reconfiguration the set of main variables is defined as EArrMpp MPPLoss EArray lArray UArray 1_PmpON 2_PmpON A_PmpON EPStart EPmpThr EPmpOvr EPmpAv Virtual available energy at the maximum power point Loss by respect to the MPP running EArrMpp EArray Effective energy at the output of the array according to the real Voltage operating point This contribution is also accounted for when the pump is stopped due to full tank conditions assuming normal voltage of the pump as if it were running Corresponding current instantaneous A or cumulated Ah Corresponding voltage instantaneous or averaged V Cascading or array reconfiguration configurations Operation duration with one pump low voltage array Operation duration with two pumps high voltage Operation duration with all pumps Energy loss under the starting current threshold EArray when pump not started only for positive displacement pumps without booster Energyloss under pump producing threshold EArray when FlowR 0 for centrifugal pumps which should attain a given speed before reaching the useful head Pump overload energy EArray in excess of the pump s maximum power Available useful energy at pump when running EArray EPStart EP mpThr EPmpOvr before taking th
166. arly efficiency If desired in a second step you can define a user s load profile 65 modify the PV array specific loss 8 parameters thermal wiring resistance module quality mismatch IAM with the Detailed Loss button Chapter 4 Project design 64 65 Project design 4 DC grid load profile For reasons of security and ohmic losses in the overhead lines the public transport networks are usually divided into little islands of relatively modest dimensions of the size of a suburb The power needs are therefore highly variable while a starting tramway can absorb 1 to 2 MW within a few seconds during the rest of the time only a small number of vehicles or often no vehicle have to be supplied The only load which is to be satisfied will then be the ribbon consumption of the vehicle s heating systems and other services specific to the network Due to the fact that the PV installation is unable to store energy these very special characteristics require a preliminary and in depth study of the on site power demand and its spread in time power distribution analysis with a few second sampling PVSYST is able to treat this case through the distributions 54 load profile We can assume that when averaging over a long period an hourly probability profile should be statistically equivalent to few seconds peaks with the same probability distribution With significant PV installations the PV array power sizing should ke
167. asis Its decisions are based on the modelled battery voltage Each action is characterised by two thresholds starting and stopping which can be given either in specific values by element or for the whole battery Regulator parameters Besides identification as in other components model manufacturer etc the regulator parameters include Technology and Data display specification These are only indicative parameters except that MPPT or DC DC converters are specified by the Technology choice Charging thresholds for which default values proposed by the program are slightly dependent on the battery technology Discharging thresholds are the regulator settings controlling the load disconnecting ensuring the battery deep discharge safety Temperature compensation linear is available with some regulators especially recommended for use in warm countries Some regulators have an internal sensor they measure their own temperature other have external sensor to measure the battery temperature Maximum Input and Output currents are one of the most important real device characteristics Before simulation the program will check the consistency of the regulator choice with the system characteristics Associated battery pack mostregulators are suited for one or sometimes two switchable battery voltage The simulation process needs knowing this switch position and updates it at simulation time As thresholds are slightly d
168. asured and simulated data Favourites You can choose your favourite components for showing only limited lists in all choices Your existing favourites are shown in green in the complete lists You can define your favorites in the main database lists of the Tools part Simple way right click the concerned element for selecting or deselecting it For lists of components Click the button Set Favorites Select the desired components in the general list using the Control Key for enabling Multi selection PHOTON database You can directly import components from the PHOTON database In the database management part Tools PV modules or Inverters please press the button Import from PHOTON This will store the Web address of the concerned Photon database that you just Paste in your web browser After choosing your component please select the whole text of the page including Supplier on the top and Paste it Ctrl C Chapter 6 Tools and databases 132 133 Tools and databases 6 Then return to PVsyst and simply press Import PHOTON in the component s definitions You may obtain a warning if some parameters are not understood or compatible by PVsyst Please note Many components are not fully defined in the PHOTON database Some missing parameters often Vco Iscd Vmpp and Impp will prevent PVsyst for the import of this component This is a problem of the PHOTON database PVsyst cannot of course gues
169. asured by carrying out a complete discharge Supposing that we can precisely define the states of full charge and the end of charge But it depends on several factors of which the mostimportant are age discharge rate and temperature In the lack of reliable data the software does not explicitly take the age into account We will suppose that the user will modulate his basic nominal capacity according to its own criteria for the simulation over one year But we cannot neglect the effect of the discharge rate The nominal capacity is usually defined in the manufacturer s data for a discharge in 10 hours thatis a current of one tenth of the capacity In fact these conditions are not realistic in a solar system where the current is usually weaker and the real capacity can increase up to 150 cf curves The model takes it into account by decreasing the SOC at each discharging step byan instantaneous amount weighted by the nominal capacity corresponding to this current value But in order to preserve a correct balance we also have to apply the same capacity correction to the recharging process for this purpose we will memorise an average capacity on consecutive discharge steps in order to apply it to the next charging period This procedure is not rigorous and can sometimes lead to efficiencies higher than 100 but on an average it should to be correct over a long period Finally capacity is reduced with battery temperature this is one of
170. ated for an hourly behaviour neither for local phenomena such as sheet of morning fog which cannot be realistically taken into account On the other hand we do not apply this correction on diffuse irradiation as the increase in irradiation with altitude mainly affects the beam component Autonomy and battery sizing stand alone Autonomy and battery sizing In the Presizing process the proposed battery pack capacity is determined according to the required autonomy of the system given in days The autonomy is defined as the time during which the load can be met with the battery alone without any solar inputs starting of course from a full charged battery state With non constant loads seasonal or monthly definition weekly use this is accounted as the worst case over the year The calculation takes the minimum SOC disconnecting threshold and the battery energy efficiency into account Italso has to apply a capacity correction as this mode of use usually occurs at a rather slow discharge rate therefore corresponding about to the C100 capacity definition i e with discharge in about 100 hours when the nominal capacity of the batteries in the PVsyst database is defined as the C10 value The C100 C10 ratio is usually of the order of 120 to 130 These 3 sizing parameters are adjustable in the Hidden parameter NB When defining a very large autonomy the global system optimisation process will choose the minimum PV size which j
171. ation results are summarised in a printable Report which holds an exhaustive table of all parameters used during the simulation as well as a short description of the main results But many other results may be visualised and printed The simulation involves several dozens of variables A which are all stored in monthly values in the Simulation variant file These monthly results are available as Pre defined tables several tables grouped by parameter themes are immediately available Custom table you can build your own monthly table by choosing eight among any of the calculated variables Chapter 4 Project design 92 93 Project design 4 Custom monthly graphs you can choose up to 4 variables to be simultaneously displayed Be sure to choose comparable variable types energy irradiation etc as the graph holds only one common axis Moreover hourly values are stored for some pre choosed variables These give rise to hourly and daily plots even with simultaneous variables with a comfortable navigation all over the year This constitutes a powerful tool for observing and understanding the instantaneous system behaviour Specialgraphs 9A should be defined before the simulation in order to be accumulated on line during the simulation process About ten such on line graphs of general use are present by default with any new simulation They include a detailed energy loss diagram 934 Monthly or Daily normalised yield ind
172. ations but that you should modify according to the specificities of your system These are available in the System definition dialog button Detailed losses Thermal Losses The thermal behaviour of the array is computed at each simulation step bya thermal balancel85 This establishes the instantaneous operating temperature to be used by the PV modules modelling The thermal balance involves the Heat loss factor U Uc Uv WindSpeed W m K In practice we advise not to use the wind dependency as the wind speed is usually not well defined in the meteo data and the Uvis not well known Therefore we put Uv 0 and include an average wind effect in the constant term According to our own measurements on several systems PVsyst proposes Uc 29 Wim K for complete free air circulation around the collectors nude collectors Uc 15 W m K for integration back insulated as only one surface participates to the convection radiation cooling We don t have well established values for intermediate situations with back air circulation Our measurementon quasi horizontal modules on a steel roof 8 cm spacing and not jointive collectors gave 18 W m K NB up to the version 5 1 the default value was 29 W m free standing From this version the default is set to 20 W m as more and more installations are integrated The thermal loss effect is visible on the arrayloss diagram Wiring Losses The wiring ohmic resistance induces lo
173. ay be understood as a power regulating device Therefore the regulating device should act according to an irradiance level sensor in conjunction of course with the discharge protection of the battery with a threshold carefully chosen in such a way thatit starts a little before the pump s threshold The detailed simulations should help for determining this threshold in each given situation in order to optimize both the water yield and the battery wearing conditions Please have a look on the Results 7A which indicate that the Battery Buffered performances approach the ones with power converters Pumping Results Examples We would like to give here an example for comparing the performances of the different possible configurations of the system Chapter 4 Project design 4 Project design This corresponds to the project given as Demo for pumping systems We have imagined a Deep Well system at Dakar Senegal 15 latitude with a static level depth of 32m anda tank feeding altitude of 6m The water needs are set at4 m3 day all the year The system includes a set of 2 pumps of 100 W each positive displacement with DC motor supplied by 4 PV modules of 60Wp i e 240Wp notideal system of course one only bigger pump would be better in this case but this configuration allows to apply all the system configurations We simulated this system will all configuration options available in PVsyst This gives the following results M
174. ay the data should be perfectly centered If not time discrepancies may be due to the site Time zone definition summer or winter time you should correct it within the site definitions 110 before executing the ASCII conversion the Record Label 134 definition in the format protocol 12 the Legal Solar time specification in the format protocoll127 Check that the Legal time definition is constant during the year PVSYST doesn taccept Summer hour shift in your data If so you have to change the date labels in your source data ASCII file in order to keep the same definition all over the year the longitude definition amisrunning of the clock of your recording equipment In this case PVSYST can t help the time labels should be corrected directly in the ASCII source file before conversion Meteo tables and graphs See also generalities about meteo data M The meteo tables and Graphs tool displays the characteristics and contents of the meteorological hourly files The geographical characteristics are stored in an object identical to the geographical sitel10 definition which may be edited and modified Other characteristics are related to the data source dates recorded parameter etc The meteo file written in a binary format cannot be read using a text editor This tool offers a powerful mean of visualising and analysing meteorological data in graphical or tabular form The tool displays as well The basic
175. berlin H R Rothlisberger Vergleichsmessungen an Photovoltaik Wechselrichtern Schlussbericht des BEW Projectes EF REN 89 045 OFEN BEW 3003 Bern 1993 J M Servant J C Aguillon Essais d onduleurs PV raccord s au r seau EdF GENEC Cadarache 1993 Batteries C M Shepherd Design of Primary and Secondary Cells and An equation Discribing Battery Discharge Journal of the Electrochemical Society vol 112 7 July 1965 pp 657 664 J B Copetti F Chenlo and E Lorenzo Comparison between Charge and Discharge Battery Models and Real DataforPV Applications 11th European Photovoltaic Solar Energy Conference Montreux Oct 1992 pp1131 1134 J B Copetti F Chenlo Internal Resistance Characterization of Lead Acid Batteries for PV Rates 11th European Photovoltaic Solar Energy Conference Montreux Oct 1992 pp1116 1119 Wats un PV User s Manual and Program Documentation Watsun Simulation Laboratory University of Waterloo Waterloo Ontario N2L 3G1 1992 Bopp Gabler Sauer Jossen Hohe Mittermeier Bachler Sprau Willer Wollny A Systematic Effort de Define Evaluation and Performance Parameters and Criteria for Lead acid Batteries in PV Systems 13th European Photovoltaic Solar Energy Conference Nice Oct 1995 Pumping Chapter 11 References References 1 1 L Navarte E Lorenzo E Caama o PV pumping analytical design and Characteristics of Boreholes Solar Energy 68 no 1 pp 49 56 2000 J A Roger T
176. big differences between the regions of the array near the air inlet and at the outlet PVsyst doesn t take this inhomogeneity of the array temperature into account On the other hand the use of the wind dependence is very difficult On one hand the knowing of the wind velocity is extremely seldom Some programs construct synthetic hourly values from monthly data but on which basis and with which models On the other hand the meteo wind velocity taken at 10 meter height is not representative of the velocity at the array level there may be a factor of 1 5 between them In this respect the Uv value is obviously not the same for these two definitions of the wind velocity Default and proposed values Up to version 3 4 the default values proposed by the program were Uc 20 W m k Uv 6 W m k m s values which had been measured on several installations 195 for modules mounted in sheds without back coverage with free air circulation all around These values matched very well the measurements average deviation of the order of 0 5 to 1 C but were defined using Wind data recorded just over the array in built environment Such velocities are quite lower than the usual wind data available in the meteo files recorded ata 10m level or more over the obstacles Therefore with these parameters PVsyst calculated a very high dissipative coefficient and cool array temperature leading to strongly underestimated heatlosses According to their own
177. bject Here choose Parallelepiped and define the sizes Width 10m Length 35m Height 5m Click OK this will place the parallelepiped in the building object s referential In the menu choose again Elementary object New object Here choose Parallelepiped and define the sizes of the second wing of the farm Width 10m Length 25m Height 5m Click OK this will place the parallelepiped in the building object s referential positioned atthe origin Positioning in the 3D scene You have now to position 44 this second wing in the scene Please observe that for selecting an object you have to click on its borders remember the objects don t know their interior The selected object becomes carmin Click the Top View button the five buttons top left are for the positioning of the observer Perhaps you want to diminish the scale Zoom backward button Perhaps you want to recenter your scene click on the scene but not on an object and drag the scene s plane Be sure that the positioning tool is activated button with 4 crosses on the left This opens the Object Chapter 4 Project design Project design 4 positioning dialog Now you can click and drag the red point for displacing the selected object with the mouse and the violet point for orientating it Position and orientate the object roughly at its place as second wing perpendicular to the first parallelepiped The mous
178. ble the corresponding sheet s for input of the data Pump data current thresholds With Positive displacement pumps and in absence of an integrated power converter the motor will require an over current before starting rotating This panel asks for defining these over currents for Head Min Head Max and an intermediate HeadMed at half distance between them The final function at any Head in the model will result of a linear interpolation Also the threshold voltage should be defined This is the voltage at which the pump i e Flow production will stop It usually corresponds to the elbow of the measured Current Voltage curve This elbow is not always well defined not given in the data sheets The model chooses it below the lowest specified running point The f U behaviour between the last significant point and the origin U 0 I 0 is approximated bya quadratic curve for completude of the model but its exact values don t have a great importance during the simulation process Pump integrated power converter Necessity to include the converter in the pump definition When the manufacturer imposes a power conditioning unit device to be used with his pump he usually specifies the converter electrical input and not the pump s input requirements as operating conditions Therefore in these cases the component black boxincludes the converter motor pump set and the PVsyst s pump model should act with the converter as input variables
179. bugs in regulator definitions and system verifications 14 Array voltage was not registred in the simulation 15 Export project tool error warning corrected 00 00 AO ON a GO Version 5 06 January 26th 2010 by respect to Version 5 05 December 18th 2009 1 PV model Saturation current lo limit down to 0 1 pA equation problems atlow temperatures 2 Helioclim data the provider of these data has modified the site s format gt readapted the program for a compatible easy importation Shading calculations sometimes freezed Improve reliability of shading calculations Near shadings elementary objects autorized tilt lt 0 System dialog did not keep the defined parameters when re entering the dialog Inverter database terminated the update according to Photon Magazine 2009 Vista and Windows 7 compatibility Parenthesis were not allowed in the directory program files i86 proposed by Windows Version 5 05 December 18th 2009 by respect to Version 5 04 November 24th 2009 1 Stand alone systems bugs in the Regulator dialog and the simulation process PN On Oi o O 2 Grid system sizing tool still another deep revision for more conviviality bugs with master slave definitions sometimes divisions by 0 possibility of Strongly Oversized inverters by modifying Hidden parameters Chapter 1 Overview Overview 1 3 Inverter for 3 voltages still some little improvements Version 5 04 November 24th 2009 by respect t
180. can define a data channel for each one Daily Profile Generation Daily profile generation As imported data are in daily values the program has to split them into hourly values It may do this in two ways either by constructing a smooth distribution proportional to the Clear Day model thatis a clear day with reduced amplitude according to the required daily sum or by generating a random distribution according to the Markov matrices in the same way as when generating synthetic data The second method is more realistic but global simulation results are not very different Elimination codes Doubtful data may be eliminated from the simulation comparison process and accumulations either in comparison plots or in the tables A Flag code indicates how the elimination was done Eliminations in the original measured data table 0000 0001 Hourly elimination 0000 0010 Daily elimination Eliminations in meas simul comparison plots 0000 0100 Mouse elimination in hourly plot 0000 1000 Mouse elimination in daily plot 0001 0000 Limits on measured values 0010 0000 Limits on simulated values 0100 0000 Limits on differences meas simul data 1000 0000 Limits on ratios meas simul Data Yellow lines in tables indicate missing data in the original file Time label of measurements Time shift In the PVsyst convention the time label always refers to the beginning of the record That is the time label 12 00 refe
181. ch has used data from the METEOSAT Geostationary Satellite and provides free of charge detailed Irradiance and also Illuminance useful for natural lighting studies time series in half hourly values for 5 complete years 1996 Chapter 5 Geographical and Meteorological data 120 121 Geographical and Meteorological data 5 to 2000 and for any pixel of about 5x7 km in Europe These data have been carefully prepared involving complex treatment of multiple Satellite photographies in several wavelengths They exhibit an impressive accuracy of around 20 RMSE without significant bias far enough for the simulation needs in PVsyst It has been established that in hourly values as soon as a considered site is more than 20 km apart from a terrestrial meteo station the satellite data are of better quality than the measured terrestrial ones i e the RMSD Root Mean Square Differences are lower while the MBD mean bias differences averages remain very close to zero The following graph shows comparison difference RMSD between terrestrial measurements of several stations of the ISM network Swiss Meteo Institute showing the effect of the distance between a site and the use of the data This also gives a comparison with the Satellight confidence level lying around 20 which has become even better with the latest developments of the models Relative RMSD for hourly values 50 j jen eee eeeeeeneee e
182. circuit current in such a way that each series comprises modules with close characteristics one can see a quite different behaviour In this case the diodes are no longer involved and the curve again becomes perfectly smooth Each string behaves according to the average of its modules but connecting them in parallel results ina characteristic very close to the average This confirms that sorting the modules before mounting them in series can significantly improve the performances of an array especially when working at fixed voltage PV module array with a shaded cell This tool visualises the behaviour of voltages and currents at the terminals of a shaded or bad cell placed ina module or a group of modules It evaluates the energy dissipation of this cell for various operating points and its resultant temperature by making reasonable hypotheses for the thermal loss factor It has to be noted that these behaviours are studied in a marginal situation representing the most unfavourable case where onlyone single cell is disturbed The user can adjust the irradiance the module temperature in normal operation i e without dissipation and the shading fraction of the considered cell You can visualise three different cases for a single module or arrays Module without protection diode the graph shows the degraded performance curve of the whole module grey to be compared to the normal operation dashed line But it also shows the danger
183. complete elaboration of a project gt _3D near shadings construction 4 Tips for beginners Help you can get contextual Help from almost anywhere in the software by typing F1 or very specific information are often available with little question mark buttons Red dots every time you have red dots on graphical views you can drag them with the mouse to modify the involved parameter examples horizon line plane orientation near shading orthogonal drawings Exporting tables all result tables can be exported to other software by choosing Export in the menu either as text file ASCII CSV format orby Copy as text into the clipboard to be pasted for example in a spreadsheet software orby Copyas image into the clipboard For some scrolling tables solar parameter meteo you can choose the time period to be exported Exporting graphs all result graphs can be exported to other software by choosing Export in the menu either as image file BMP color format or by Copy in the clipboard which can be Pasted within any other software MS Word etc Current window image as in all Windows applications pressing Alt PrintScreen copies the current window into the clipboard Printing tables graphs or other components 18 allow for a double line comment in front of each print form are usually intelligent printings which hold complementary useful parameters offer a preview facility often ask f
184. control device is the heart of the pumping system operation The PVsyst component definition named Regulator for Pumping for convenience includes several functions which may be devoted to separate physical devices in the real system Itdefines the global operating configuration 73 of the system and manages its specific parameters Itensures the operating and safety limitations namely the Power Voltage Current absolute limits as well as the swiching OFF when the tank is full or the input level goes below the aspiration inlet avoiding dry running Itmayinclude a power converter MPPT or fixed V DC DC DC or AC output according to the pump device When several pumps there is usually one power converter for each pump butin some cases there could be one only converter Chapter 6 Tools and databases Tools and databases 6 NB When the PVsyst pump device is defined along with its own power converter the simulation will of course use the parameter of the pump power conditioning unit See Regulator for Pumping parameters fe for a complete description of the component parameter Default Regulator When starting the study of a pumping system the operating strategy choice is of course fundamental but details of the control are not relevant Therefore as for the stand alone systems PVsyst provides a Default Regulator for each configuration strategy The secondary parameters of such regulators are fixed at optimal values acco
185. creasing according to the horizon height up to zero for horizon gt 20 On the other hand if the horizon obstacle is rather near albedo should be considered as null Therefore the user has the opportunity of determining which fraction of calculated albedo he wants to take into account according to the distance of horizon obstacle The reality is certainly very complex and requires more experimental investigations to assess these hypotheses on diffuse and albedo contributions Nevertheless please note that these contributions and their errors are rather low for low plane tilts since the horizon irradiation has a low cosine factor They become more significant for very tilted or vertical planes Horizon in Meteo data In the PVSYST sites database Meteonorm source basic irradiation values are usually defined for a free horizon Nevertheless in the DRY swiss data of very mountainous sites as probably in other DRY or user s own meteo measurements the horizon effect of the measuring site is usually already accounted for in the data since it is the result of a measurement Therefore it is not always clear if a horizon correction is to be applied or not depending on the field horizon by respect to the measuring station horizon Importing Horizon profiles The horizon profile may be defined manually bya set of Azimuth Height points in degrees These may be from on site measurements using land surveyors instruments like compass and clisi
186. d He mayalso require an autonomy storage duration as the production is always dependent on the sun Forareasonable sizing itis sometimes necessary to define a time fraction during which the owner will accept that the needs are not met by the system Loss of load probability According to these requirements and for a given site meteo PVsyst should allow to optimize the pumping system and assess the results of a given configuration As for the other systems it proposes two complementary approach The Presizing tooll 2M gives a quick but rough evaluation of the pump and PV array sizes on the basis of very few parameters The Project Design 22 _ Design part performs detailed simulation of the system with many possible PV pumps coupling strategies This provides namely a detailed analysis of the losses useful for identifying the weaknesses of the design and optimizing the system Pumping Borehole Modelling See also Deep well system 6 for definition of the variables HD and HS If we consider the borehole as an impervious tube when pumping the water level will drop as the flowrate Q m3 h divided by the hole section area Aw m7 On the other hand the re filling of the well from the surrounding porous medium is a diffusive process One can admitas a reasonable hypothesis that the refilling flowrate is proportional to the stress i e the drawdown dynamic head Under these hypotheses the real level in the well or HD evoluti
187. d define the inverter fraction to be used for this string When several inverters are used this will be the fraction for one inverter times the number of inverters This will allow the use of the complement of each inverter within another subfield with the suited fraction for example 70 in one subfield and 30 in another one The total number of inverters defined in the whole system appears in the Global system summary table at the top right of the dialog When inverter inputs are connected to strings of different lengths the program is not able to check the full compatibility of your system You should check by yourself that the defined fractions are compatible with the foreseen strings Simulation With distributed SolarEdge architecture there are no mismatch losses the near shadings should be defined as Linear i e without string partition Linear shading is a good approximation for the shadings in SolarEdge architecture As opposed to the option according to module strings that is used for the upper bound of electrical losses with regular inverters The most exact way for SolarEdge simulation would be to define a string partition with rectangles corresponding to the number of PV modules in series at the input of one Power Box These very little rectangles will reduce drastically the usual electrical shading losses observed with full strings except in very regular cases like shed arrangement where each module of the lower
188. d in the database as they can vary from country to country They are only meant to serve as a memo for the engineer Nevertheless you have the opportunity of defining the price of the components you are using and to store the date when it was fixed These component prices may be fed directly in the economic evaluation 104 of the project design part When using the economic evaluation tool you can link the component price defined in your database using the default checkbox You also have a shortcut for defining or modifying the component price directly in the database During this process the currency in the database may be different of the actual working currency of the economic evaluation tool Phovoltaic modules Parameters summary We give here an exhaustive list of all parameters involved in the PV module definition and their use Main parameters to be defined for any module Nom Power rated power specified by the manufacturer at STCh9 Should be close to Imp Vmp Tolerance Lower tolerance specified for the Nominal power If 0 please put 0 1 as the program interprets 0 as value not available Only used in PVsyst for establishing the default value of the Module quality loss factor fixed at half the lower tolerance Technology Gives choice for the main technologies of PV modules available on the market Acts on the model GRef Reference irradiance for the Isc Voc Impp Vmpp specifications Usually STC 1
189. d way Inverter modelisation analyser h5A this graphical tool allows to superimpose the theoretical efficiency profile of a library s inverter onto real measured data and then to interactively modify its profile in such a way as to make it match the measured data Within the limit of the accuracy of the electrical measurements recorded on the field itself DC input and AC output this gives a direct measurement and parametrisation of the inverter s performances in real conditions You can then save the modified inverter for using it during the simulation process Predefinition of comparisons As in the case of hourly or daily on line graphs the parameters to be compared should be defined before the execution of the simulation So that during the simulation the output file can store the couples of asked values measured and simulated For each comparison set please choose the parameter to be compared from the measured parameter s list the time interval and types of values to be accumulated hourly daily or monthly you can impose some conditions for the accumulation several conditions can simultaneously be specified Horizontal or Incident global irradiation gt 20W m in order to be limited to day time values Cuts of one two or three hours after sunrise and before sunset Selection of hours mid day Eliminations of marked data break downs explicitly eliminated 17 in the comparison graphs or the tables
190. data of the file Global and Diffuse horizontal irradiance ambient temperature and wind velocity Derived values like beam component clearness index Kt 188 or global irradiance on a tilted plane All these data are available in hourly daily or monthly values Graphs can be obtained as time evolution selected periods values distribution histograms or sorted values cumulated histograms To be noted a clear day model curve may be superimposed on the daily curves allowing for checking the data timing qualityho Tables display hourly daily or monthly values in a scrolling mode Printings or data export using clipboard as well as ASCII file can be easily performed for any time period allowing the use these data in other software Hourly meteorological files As meteo hourly basis the programme uses binary files with a special format for PVSYST and characterised by the extension MET The meteo file includes a complete geographical site 110 object followed by hourly values of the meteo parameter that is horizontal global and diffuse irradiations ambient temperature and if available wind velocity The data are recorded for whole days OH 23H Step labels are referred to the beginning of the interval i e the 12 h label corresponds to the 12 13 h interval Acomplete file for one year occupies about 70 kOctets 53 kOctets Chapter 5 Geographical and Meteorological data Geographical and Meteorological data 5 wi
191. definitions organisation is exactly the same Procedure After choosing Project Design and the system type in the main window the procedure is the following First define the Project 28 through the Project Varian button You can also retrieve an existing project through the File menu For each variant define the plane orientation 30 Define the System 2 properties The program verifies the consistency of all parameters and produces Warnings as Orange acceptable for simulation or Red preventing simulation LED s When available all parameters properly defined that is only Green or Orange LED s press the Simulation fes button When the simulation is completed you will enter the Results 92 dialog In a second step you can define if necessary a Horizon profile 38 far shadings Near shadings 37 that is partial shadings of near objects which require a rather complex CAO 3D construction of the PV field environment Measured data analysis general philosophy The objective of this section is to closely compare on site measured data with simulated values either in hourly or in daily values Ithas a two sided function On the one hand ithas helped us for the validation the software by comparing its results with carefully measured data in 7 installations On the other hand it constitutes a powerful tool for the analysis of the operation of PV systems in use allowing for the detection and
192. determination The state of charge remains to be determined Fundamentally it corresponds to the charging and discharging balance currents with respect to the nominal capacity of the battery But a number of corrections are to be made First the electrochemical conversion an SO ion 2 electrons of current is not perfect the balance called coulombic efficiency is of the order of 0 97 for the batteries usually used in solar installations This efficiency can be specified by the user but remains constant in all the conditions of use It should not be mixed up with the global current efficiency including losses from gassing current which depends on the operating conditions and appears as a simulation result The coulombic efficiency is applied to the charging current We then have the loss due to self discharge current which strongly depends on temperature type and age of the battery The temperature behaviour of the self discharge current does not depend very much on the type of battery itis close to an exponential and doubles every 10 C In the programme it is specified by a predefined profile which increases steeply for uses above 20 C Butits basic value at 20 C is asked in the module of the secondary parameters Chapter 6 Tools and databases Tools and databases 6 Capacity corrections Further it must be noted that the nominal capacity of the battery is not a well determined parameter either In practice itis me
193. disturbances in the PV system itself These non significant values should be eliminated from the calculation of the comparison estimators from the monthly accumulations or even eliminated from graphs PVSYST offers several means aiming to mark data for elimination General criteria can be applied to hourly or daily comparison graphs limits on the measured value on the simulated value on their difference or their ratio Whenever possible the graph explicitly traces the limits of the criterion On comparison graphs isolated aberrant points can be individually eliminated by a simple click of the left button of the mouse or contrarily restored bya right click Onmeasured data tables 17 single hourly or daily data can be eliminated with the mouse The eliminations performed on a comparison graph are carried over to all the other graphs of the calculated version The eliminations of values in an hourly graph will therefore cause the elimination of the whole corresponding dayon a daily graph The eliminations performed on graphs can be saved on the file of the calculated variant CMi to be automatically displayed again in a later session Further the indications of eliminations of a calculated version can also be carried over to the original file of measured data DAM file This allows during another simulation to reuse these break down indicators as Chapter 6 Tools and databases Tools and databases 6 conditions f
194. e Gen ve is the Electricity and Gas Utility of Geneva Details of this project may be found in the Final Report of this project unfortunately only available in French at the moment The studyis based on detailed outdoor I V measurements of 6 PV modules every 10 minutes over a period of 3 months This yields a data sample covering all environmental conditions with irradiances ranging from 40 to 1000 W m and temperatures between 0 and 70 C Methodology We followed a phenomenological approach by closely comparing the measured set of data with the model results We used 3 indicators easily identified on each IV measured characteristics the Pmax MPP power Voc and Isc values All our modeling attempts start from the standard one diode model 130 The model main parameters are determined from one chosen I V characteristics among the measured data Knowing one complete I V characteristics the model parameters Iph loref Gamma Rs Rsh mayall be determined accurately With this set of parameters we can now draw the error distributions for our 3 indicators We assess that the precision of the model is mainly represented by the RMSE named sigma of these error distributions i e the model response dispersion over all operating conditions Around the optimum the MBE Mean Bias Error values noted mu are rather related to the basic input parameter uncertainties Vco Isc Vmp Imp at the reference conditions Gref and Tref i e the posit
195. e PVsyst database includes only Stations with well measured irradiations For the main central European countries all available Stations of Meteonorm are referenced in the database of PVsyst Therefore choosing another site in these regions will lead to interpolation Meteonorm provides its data in several ways In Monthly Values as ASCII files named xxxxMON DAT which may be directly read by PVsyst for creating geographic site 13 SIT file in Hourly Values as ASCII files named xxxxHOUR DAT The hourly data are built by a stochastic model quite similar to the Synthetic Hourly Generation hsa performed in PVsyst The Meteonorm process also produces stochastic hourly wind values when PVsyst only puts the monthly average wind speed These data may also be directly imported in PVsyst Moreover Meteonorm proposes other prestations like irradiance computation on tilted planes but these are not useful in PVsyst which uses its own models Importing data from Meteonorm The importing process in PVSYST is quite automatised In the Meteonorm software Choose a location and generate a file will be stored in the MeteoTest Meteonorm Output directory Monthly values just save it as a file default format which will be named xxxxMON dat Hourly values choose the special PVSYST output format before saving the file main menu option Format Output Format and choose PVSYST This will create a file named xxxxHOUR dat In
196. e PVsyst5 exe Help PVsyst5 chn Contains the Help file Images bmp Some images used by the software DataRO h7 csv dat Texts hidden parameter Original databases of Meteo sites monthly data PV modules and Grid inverters Admin 177 Some basic files including PVsyst ini and Log files for debugging Data All databases and writable user data includes the following 10 sub directories Sites 179 Geographical site and monthly meteo definitions Meteo 173 Hourly meteo and other related files ASCII meteo source files may be located anywhere in your computer Datameas 74_ In a similar way as for meteorological files this directory stores internal files concerning measured data ComposPV 78 All PV components of the database each in a specific subdirectory Projects 178 All the project elements files of parameters and results for your projects including Preliminary and Project design Shadings 179 All shading definitions Horizon definitions and shading scenes Objects Models h7 Miscellaneous templates and user defined models Userdata Will contain the user export files for other softwares Namely the file Components xls which can store some database elements geoghraphical sites PV modules or Inverter data in tabular form to be used with Microsoft EXCEL Other Some special files Usually the user will not have to manage or directly memorize the names of the files each file in PVSYST C
197. e Pump stopping due to hydraulic constraints into account MPPT converter configuration EArray Effective energy at the output of the array normally EArrMpp may be slightly different with step down converterh6 voltage limitations Chapter 4 Project design Project design 4 lArray Corresponding current at MPP instantaneous A or cumulated Ah UArray Corresponding voltage at MPP instantaneous or averaged V CL_Oper Converter efficiency loss during operation CL_PMax Converter overload loss acc to the specified strategy limitation or cut EOutConv Energy at the output of the converter EPmpThr Energy loss under pump producing threshold EOutConv when FlowR 0 EPmpAv Available useful energy at pump when running EOutConv EPmpthr NB The converter Voltage or Power threshold losses are included in EPmpThr These losses are accounted even when the Pump is stopped for Hydraulic reasons FA Fixed Voltage DC converter configuration EArrMpp Virtual available energy atthe maximum power point MPPLoss Loss by respect to the MPP running EArrMpp EArray EArray Effective energy at the output of the array at the fixed converter voltage lArray Corresponding current CL_Oper Converter efficiency loss during operation CL_PMax Converter overload loss acc to the specified strategy limitation or cut EOutConv Energy at the output of the converter EPmpThr Energy loss under pump producing threshold EOutConv when FlowR 0
198. e author assumes no responsibility w ith regard to the performance or use of these products All understandings agreements or warranties if any take place directly betw een the vendors and the prospective users Every effort has been made to ensure that the information in this manual is accurate The author is not responsible for printing or clerical errors The product described in this manual incorporates copyright protection technology that is protected by method claims of certain U S patents and other intellectual property rights This user manual w as created with Help amp Manual Index A Albedo 47 184 187 Array behaviour 31 36 37 140 168 Arraylosses 82 83 84 85 93 190 192 Autonomy 188 B BackTracking 45 Back up generator 157 Batteries 153 154 Battery capacitysiang 188 Building objects 42 44 C Commercial 135 168 Compatibility and Troubles 14 Components 133 149 153 157 164 Concentrating 35 Concentration 34 43 Converter 165 166 CopyData 180 D Datacuts 171 Databases 131 147 148 152 156 172 Meteo Database 110 DC DC Converter 166 DC grid line resistance 65 DC grid system 64 90 Deep Well Pumping System 68 69 Design Reference Year 111 117 Detailed simulation 22 24 Diffuse 47 104 109 184 186 189 Directories 174 180 181 E Economic evaluation 22 102 103 Exporting data 2 91 183 Exporting Projects 181 Index F Farshadings 37 38 39 Files 174 180 181 Fi
199. e diode and cannot give rise to excess powers in the diode since the voltage stays very low Model for Thin film and other new technologies Commercially technologies available on the market are now mainly a Si H amorphous including tandem and triple junction CiS and CdTe modules There is no consensus up to now in the PV community about the general modeling of these new modules Several experimental works have observed significantly different behaviours of amorphous by respect to standard Crystalline cells Mertens amp al propose taking recombinations in the i layer into account resulting ina modification of the equivalent circuit and a related modified One diode analytical expression Gottschalg et al 1998 Holley et al 2000 and Mertens et al 2000 report experimental analysis of model parameter dependencies as function of temperature and spectral irradiance contents in amorphous simple and double junctions Betts amp al have studied the spectral contents if the irradiance according to weather in central UK Loughborough and propose a correlation for correcting the response of amorphous modules Modelling in PVsyst Research project at CUEPE In order to clarify these observations and to establish an approached model useable in PVsyst including the necessary proposal of default parameters we have performed an experimental research at the University of Geneva with the financial support of the SIG NER fund SIG Services Industriels d
200. e doesn t allow to get accurate values But after rough positioning the dialog will give you the order of magnitude so you can finely adjust the exact values according to the architect s plans In this case you will put X 10 00m Y 10 00m and don t forget Azimuth 90 0 NB Please avoid the interpenetration of objects This often makes problems for a correct calculation of the shades Now you have to add the roof Main menu Elementary Object New object and choose Two sided roof Gables Define the sizes Base width 11m Top length 30 5 m for eaves Roof tilt 25 and Gable 1 angle 45 Click OK This will put the roof in the building s scene You can position it with mouse and values as before X 5 Y 5 and Z 5 building heigth For the second wing you could do the same You can also reuse this existing roof Edit Copy and Edit Paste You will obtain a second instance of the selected object Position this object by mouse and values be careful with the new azimuth exactly 90 Now the 45 cut gable is not correct For modifying the selected object you can either choose Elementary Object Modify or more easy double click the object on its border Change 45 to 45 and click OK Now your building is finished you can include it in the main 3D scene by the menu File Close and Integrate Adding the PV plane PV planes cannot be integrated in building objects
201. e each variant for further comparisons Definition of the Project The projectis the central object file with PRJ extension for which you will construct different variants of your system files with the same name and extensions VCO VC1 etc for calculation version In the main page of PVsyst choose Project Design Grid connected In the next window choose Project and then button New project Define the Project s name This will appear in the Project s list choices and on the final report The other definitions in this dialog are only for memory they are not used elsewhere in the software You can put for example Tutorial at Marseille Click the button Site an Meteo Choose a site in the sites database contains geographic location and monthly meteo data We will chose Marseille NB If you want to define your own site which is notin the database itis preferable to define it first in the database using Tools Geographical Location This automatically produces a synthetic hourly data file named Marseille_Syn MET NB Atthis stage you can choose another meteo file in the MET available data if desired Click the A b edo button Usually you will never modify the albedo factor The value of 0 2 is a standard adopted by everybody Nevertheless if you are for example in mountain weather with some snow you can define one or two months with 0 8 Click OK You will be prompted to save
202. e eee distance km 0 50 100 150 200 250 Importing Satellight data in PVsyst PVsyst offers an automatised link for importing Satellight data First Get a standard Satellight Data file NomSite tsv from the www satellight com site following the recommended procedure f 2 In PVsyst open Tools Import Meteo Data and follow the instructions displayed in red i e Choose your source file NomSite tsv The site and country names are automatically set if they have been defined in the Satellight file Define the region which will be Europe in normal cases If the source file includes data of several years usually 5 years choose the year NB PVsyst meteo data cannot cover more than one year By default the year will be part of the PVsyst file name NomSite_Year met so that you may create data for the same site and each year All Years you can also import all years present in your source file at a time usually 1996 2000 The program will create the five yearly files and a Site file with the monthly averages This may be used for creating a synthetic hourly file representing the average of the 5 years Please remember that averaging hourly values doesn t make sense only monthly values are sufficiently aggregated to be averaged over several years But in this case you loose the advantage of hourly measurements In the present state the temperatures required for PVsyst simula
203. e input value DC DC may be modified inside the device These values will be reported in the simulation variant parameter NB if you want to modify some disabled values in the Generic components you can save as this component into a different file and modify it as you like Alternatively you can permanently adjust the default values using the Hidden parameter 7 tool expert users only If desired you can also define a back up generator i5 to obtain a stand alone hybrid system You can now play with these parameters and retrieve the automatic proposed values by clicking on the associated checkbox at any time Warnings will be displayed if there are some incompatibilities between the chosen parameters Red warnings are not acceptable simulation cannot be performed and orange warnings are indicative These colours will be thrown back on the System LED s button Fifth step If desired in a further step of the project you can modify the PV array specific loss 82 parameters thermal wiring resistance module quality mismatch IAM with the Detailed Loss button With a new simulation the PV array losses are pre defined at standard reasonable values These standard default values may be adjusted by expert users in the Hidden parameter h7 section Regulator Operating modes When using a power conditioning converter this device is defined in the Regulator parameters part When choosing a commercial regulato
204. e on your data When choosing good days the model curve should be centered on your hourly data If not either the Time Label is not well chosen or the recording data clock was out of order Meteo variables meteo files This tab asks for available parameters on the data file irradiations temperature wind For each chosen parameter you should specify the field order in the record the label will appear on the corresponding field on the sample file display the multiplying factor to be used in order to obtain the PVSYST internal units i e MJ m For example specify 0 0036 if your irradiation data are recorded in W m With the fixed width fields option you can displace the separator columns with the mouse When using Global on tilted plane you should specify the plane orientation Measured variables measured data files For a given system type the program proposes the parameters likely to be measured each of them being of course part of the simulation parameters As above you should choose the available parameters their field order and multilying factor Gathering fields measured data files only In many data acquisition systems you can have several measurements corresponding to a single global simulation variable For example when dealing with several PV fields the measurements are often recorded for each field But as PVSYST will treat this as one only system the currents and energies should be added and the voltages pe
205. e overall system power and geographic extension due to distribution ohmic losses the two basic user parameters are gt The desired system autonomy in days which determines the battery capacity gt The required LOL giving the required PV array nominal power After sizing the PV system with this tool it s real performances should be verified by performing a detailed hourly simulation option Project design using real components and taking all system perturbations into account Stand alone system preliminary design See also Sizing of a stand alone PV system 20 general considerations After defining the Location 17 the System button displays a first screen where you are asked to define the plane orientation NB the button Show optimization opens a little tool which shows the winter yield according to the plane orientation For stand alone systems the plane orientation should usually be optimized according to the worst conditions i e for winter irradiance Pressing Nexf gives a second screen for defining the user s needs 189 from a domestic use point of view You have to specify every foreseen appliance their consumption 561 and use conditions Now you can open the Results which asks for the required autonomy 183 in absence of sun which determines the battery pack capacity the required Loss of Load probability l19h PLOL the planned system voltage 20 These parameters lead to the determinatio
206. e power during one hour They are expressed in kWh h or MJ h that is in a power equivalent unit Therefore with hourly steps Power and Energy hold the same numerical values Although most calculations are indeed related on power quantities we will express them as energies for simplification Simulation process grid system Once the Incident Global Effective irradiation and the MPP running conditions are determined the grid system has to take the inverter behaviour into account that is f EArrMPP doesn t reach the inverter input threshold the arrayis considered as open circuit I 0 and U Voc Ifthe inverter output power exceeds it s nominal power it behaves according to the definitions of the inverter characteristics thatis Limitation the inverter searches on the array IM curve the running point corresponding to it s output nominal power by decreasing the operating current Chapter 4 Project design Project design 4 Cut the inverter input is cut off the arrayis considered as open circuit the power is null Cut until morning once the cut off has occured the inverter doesn t run until the next morning When the MPP voltage reaches the minimum or maximum voltage of the inverters MPP window the array voltage stays at this value on the I V curve Otherwise in normal operation the inverter drives the array at the MPP it s input energy is EArrMPP and output energyis calculated according to it s efficiency curve F
207. e short circuit current Isc analogous to a non homogenous irradiance distribution the open circuit voltage Voc which can also reflect temperature differences The programme calculates each characteristic according to the standard model and then adds up point by point the voltages of the elements in series and the currents from series in parallel The user can visually follow these operations He then obtains the overall resultant characteristic of the field and the program traces the mean characteristic corresponding to elements all of which are identical and two envelope characteristics which can be chosen as 2 RMS values or as extreme random values encountered in the sample The program evaluates the Power loss atmaximum power point and at a fixed operating voltage with respect to the nominal case NB The parameter dispersion being random two successive executions of the same process will never give the same result You can choose the 3 following modes Group of Cells corresponds to the behaviour of the chosen PV module according to its cell s dispersion Usually in a module all cells form one only chain sometimes two or more therefore only the current dispersion is relevant For such a module one can see that the resulting characteristics is strongly influenced by the cell with the worst current resulting in the flattening of the current plateau just below the maximum power point In such a figure a bad cell may work in it
208. e visit our website and install the new update manually Languages Basically and historically PVsyst was written in English Some parts of the software are translated in other European languages French German Spanish Italian but we could not translate the totality of the dialogs up to now Virtually all options related to the design of grid connected systems are now translated as well as all simulation reports documents which can be directly presented to the final customers Dialogs related to Stand alone and Pumping systems are not translated And the Help system has not been translated The choice of the language is available in the main menu or directly in the Print dialog choice only valid for the concerned output NB If some user has competencies for proposing a translation in his own language please contact the author The job consists of filling a list of about 4000 words or pieces of text in an EXCEL like sheet see Texts CSV in the DataRO directory and carefully checking the effect on the printed outputs Nevertheless the present version is limited to languages which only involve a standard ANSI character Chapter 6 Tools and databases 172 173 Technical aspects T set Special characters problems PVsyst uses a standard ANSI character set for showing texts This is quite standard for usual characters But for some special characters the conversion table provided by Windows depends on the internati
209. ead to cheaper converters without MPPT algorithm implementation It also allows to use standard converters with standard not solar pumps Finally the Battery Buffered system gives equivalent results as power converters At the condition that the Pump starting threshold by respect to irradiance is set sufficiently low Otherwise the pump is not running sufficiently often and the battery becomes often over charged But of course it involves the use ofa little battery pack which have to be replaced periodically Water needs increase We tried to increase the water needs to 5 m3 day the limit for not missing water with the MPPT The results are given below They are quit similar and confirm that the converter technological options are rather equivalent But the results of Cascading and Array Reconfiguration are a little worse by respect to converters Chapter 4 Project design Project design 4 Pumping system performances acc to configurations E Pumped water Missing water O Excess energy Array losses in PVSYST See also Array losses in PV systems 8 general considerations In PVSYST Array loss parameters are initially set to reasonable default values so that modifications only need to be performed during a second step of the system study PVSYST treats in detail the following loss types in a PV array Thermal losses 85 Ohmic wiring losses 84 Module quality losses 194 M
210. eal electrical shading effect This will be developed in a future version NB The Layout definition will be saved with your project At the moment it doesn t have any implication on the simulation will be used in the future for shadings It is not part of the final report you should print it here in the dedicated tool Module Layout subfields A sub field area is a geometrical surface element for receiving the PV modules This should not be confused with the sub fields Sub arrays that you have defined in the System definitions which concerns the electrical arrangements in strings homogeneous for a set of inverter inputs You can construct here sub field areas of any shape for receiving the modules of your system You can define as much sub field areas as necessary by the button Add independently of your electrical sub arrays For example is sheds arrangements you will define a sub field area for each shed For complex systems you are advised to give significant names can be typed in the ComboBox to each sub field These names will namely appear in the wiring schema output of this tool assigning each module to an electrical string Chapter 4 Project design Project design 4 Module Layout secondary rectangles Each sub field area is a rectangle based area in which you can include secondary rectangles of any size for defining areas forbidden for modules button Add These secondary rectangles may be p
211. ectory Data Sites Please open Geographic sites You can choose the country or region of interest and a given station The definitions of a geographic site are gathered on two pages r FZ Geographical site parameters k E So Monthly meteo Locatiorr Site name Gen ve Country Switzerland v Region Europe ov Decimal Deg min Latitude 4612 46 7 Noth South hemisph Longitude 6 08 KEG 5 East West of Greenwich Altitude 9 37 M above sea level a arie Time zone 1 E Corresponding to an average difference Legal Time Solar Time Oh 361 egal Time Solar Time m a B Pint Ty New Site Export table Export line Import x Cancel JS OK 1 The Geographic coordinates page defines The name ofthe site country and region The Latitude Longitude Altitude which uniquely define the x y z coordinates of a given point of the earth and the time zone Ex for central Europe the Winter time corresponds to GMT 1 while the summer time is GMT 2 Chapter 5 Geographical and Meteorological data Geographical and Meteorological data 5 You can obtain accurate Latitude Longitude coordinates from your GPS or GoogleEarth In this dialog you can also see the sun paths corresponding to your site import export the site data by copy paste for example in a spreadsheet like EXCEL print a complete form with the data of this site r SSS a Geogra
212. ectric and Gaz Utility This project included detailed long term measurements of 6 PV modules in real conditions It also gave a quantified validation of the standard model for crystalline and CIS modules 2 Extended component database Over 1 200 PV modules and 400 inverters are now referenced with dates for identification of market availability or obsolete components With such big lists a mechanism for quick access time and background process update had to be implemented 3 Near shading 3D tool View of the shading scene in realistic colors settable by the user for each object instead of iron wires representation improves the understanding of complex scenes and gives a much more attractive image of the project for the final customers Animation over a whole chosen day also clarifies the shading impact of a given situation 4 Implementation of tracking planes in the 3D shading tool Especially suited for the optimisation of heliostat arrays layout 5 Review and improvement of the Simulation Process Clarification of the losses at any stage of the system extension to battery systems with DC DC converters rewriting of the heterogeneous field treatment etc 6 Detailed loss diagram Gives a deep insight on the quality of the PV system design by quantifying all loss effects on one only graph Losses on each subsystem may be either grouped or expanded in detailed contributions 7 Restructuration of the internal representatio
213. ed Kingdom Meteorological Office MET 0 1 Eastern Road Bracknell Berkshire RG12 2SZ UK USA hittp rredc nrel gowsolar old_data nsrdb tmy2 1035 TMY data which can be directly imported 114 in PVSYST Meteorological data averaging Meteorological data averaging Meteorological data are often available for several individual years and aggregating them for obtaining an average situation is not straightforward Only Monthly meteo values may be averaged as the seasonal distribution is not very different from one year to another one Hourly or Daily values cannot be averaged It would not make any sense to construct an average year by aggregating each day of different years mixing sunny and cloudy days This would resultis a time series with only mean days without clear nor bad days which has no physical meaning The right way for obtaining average conditions for hourly data is the construction of DRYI17 which should obey statistical constraints and is a matter of specialists Therefore for obtaining the average behaviour of a complete PV system from several real years you have two solutions either you accumulate your meteo hourly or daily data in monthly sums average the monthly values and generate a new synthetic hourly file or you perform several one year simulations with your different real meteo hourly files and then average the results of the simulation Meteorological data sources Besides the Meteo Database i10
214. ed to the project your project s location and another geographical site is defined within the hourly meteo file These sites are not necessary identical When different the climatic distance will be mentioned this should not exceed some dozens of km Standard procedure Choose a geographical site in the database Ifa corresponding meteo file same site name is available in the Meteo database this will be automatically selected Otherwise a synthetic hourly file will be automatically created according to the monthly data of your site Standard procedure with customised site name Choose the nearest available geographical site in the database Modify the site name which will appear on the final reports for the customer by opening the site This will of course keep the meteo monthly values of the original site You can also modify not too much say lt 1 2 the coordinates Latitude Longitude These values will be taken as basis for constructing the eventual synthetic meteo file and in the solar geometry namely transpositions within the project Ifa corresponding meteo file same site name is available in the Meteo database this will be automatically selected Otherwise a synthetic hourly file will be automatically created according to the monthly data of your site Starting from a meteo data file Choose the desired Meteo file in the database Copy Meteo Site gt Project Site You maychange the site
215. ed within the pump definition the converter parameters of the pump are transferred into the Regulator device just before the simulation overwriting the own regulator s definitions Efficiency As for other converters or inverters in PVsyst the efficiency curve may be either manually defined or automatically constructed using the Maximum efficiency and Euro efficiency specified values When the converter is specified within the pump definition only the specification of Max and Euro efficiency is available in the Pump definition dialog Battery Management When using a battery this panel defines the charge discharge regulator parameters in the same wayas in regulators 164 for stand alone systems Commercial Data Identical to the other components 13 Provides an unlimited editing place for a detailed description of the device Converter in the pump s definition Converter in the pump s definition When the pump s parameter are specified along with a Power Conditioning Unit its characteristics will be automatically transferred into this Control device just before the simulation Therefore in a real Regulator for Pumping device you should decide whether the PCU is included in the pump s definition or not This definition cannot be present at both places That is controllers with a PCU definition cannot drive pumps with a converter Control device for pumping systems Control device for pumping systems In PVsyst the
216. egree latitude globally and longitudinal resolution ranging from one degree in the tropics and subtropics to 120 degrees at the poles This in tum is regridded to a one degree equal angle grid 360 longitudes by 180 latitudes The regridding method is by replication wherein any grid region that is larger than 1x1 degree is subdivided into 1x1 degree regions each with the same value as the original Getting NASA SSE data of a particular site Identify the geographical coordinates of your PV system you can easily do this using GoogleEarth Choose Tools Import Meteo Data NASA SSE fill in the geographical parameters and press the button Import The full available Irradiance Temperature data of the NASA project are included in the PVsyst package and are readily imported Alternatively you can also find the data directly on the NASA site Go to the NASA site http eosweb larc nasa gov sse Click Data Retrieval Meteorology and Solar Energy Enter Latitude and Longitude of yoursystem or choose on the map NB in the data the conventions are the same as in PVsyst positive longitudes from Greenwich toward east Choose Parameters for sizing Insolation average Min and Max Meteorology Air temperature at 10m Eventually Wind speed at 50m NB we do not recommend to use these wind data for estimating Module temperatures 85 in the simulation Then you can print these data and you should enter them manually
217. elocity NB The sit files include monthly meteo data and allow to perform some quick but approximate meteo calculations They may also be the source for generating synthetic hourly data met files necessary for the detailed simulation Chapter 7 Technical aspects Technical aspects T Data Meteo NB From version 5 0 the original database for sites is stored in the file MeteoDB CSV in the directory DataRO This directory will holde the files that you create or modify by yourself Data Meteo directory Meteo MET TypeFmt MEF FTransp TFT Data DataMeas Internal file of hourly meteorological data associated with a measurement site and containing Global Diffuse and if necessary ambient temperature and wind speed in binary format A year s complete file occupies about 70 kOctets Specification of the format of ASCII source files for hourly or sub hourly meteorological data import They contain all the necessary indications for the recognition and the transformation of data when reading various ASCII formats The main constraintis that the data of one time step hourly or sub hourly figure on one ASCII line ending with CR and or LF Tables of transposition factors calculated for all orientations used in the orientation optimisation tool Data Datameas directory TypeFmt DAF DataMes DAM Data ComposPV Specification of the format of source files for hourly ASCII measured data Same
218. em by using GoogleEarth don t use the near environment definition The near obstacles which produce partial shades on the PV field should be defined in the Near shadings 3D tool in PVsyst compute the horizon line and then define your simplified horizon by following the line with the mouse The exported values will only be the green points which you have defined here press the button export the simplified line The choice of the Azimuth scale doesn t matter as PVsyst will recognize any chosen option export save as a text file Carnaval will add masque txt to any text you type here Therefore the final name will hold a points before masque which is not accepted in PVsyst You should rename the file in order to eliminate the forbidden characters i e the point before use in PVsyst Now your file is ready for direct import in PVsyst Meteonorm produces Horizon profiles which you can also import in PVsyst The filename of these profiles Chapter 4 Project design Project design 4 holds the exact coordinates of the site evaluated Horiz ON software this is to be used in conjunction with a specialized support for your Photo Camera which allows to take several photographies with an horizontal reference every 20 in azimuth and gather them as a single panorama on which you can draw the horizon line by mouse cf www energieburo ch web produkte horizon This produces a file with extension HOR which is direct
219. ems the interpretation of the Available energy at pump is not well defined so that we preferred the second alternative Friction Loss Factors Friction Loss Factor Some examples of the Friction Loss Factor values for piping circuits may be added for several singularities 45 elbow standard 0 35 90 elbow standard 0 75 90 elbow long radius 0 45 Tee along run branch inactive 0 4 Tee used as elbow 1 5 Gate valve open 0 17 Gate valve open 0 9 Gate valve 2 open 45 Gate valve 4 open 24 Diaphragm valve open 2 3 Diaphragm valve open 2 6 Diaphragm valve 2 open 4 3 Diaphragm valve open 21 Butterfly valve 5 0 24 Butterfly valve 20 1 54 Butterfly valve 40 10 8 Butterfly valve 60 118 Non return valve disk 10 Non return valve ball 70 Water meter disk 7 0 Water meter piston 15 Water meter Turbine 6 0 Pumping system configuration Several system layouts and coupling strategies are possible Direct coupling 74 between the PV array and the pump s without power converter unit This is of course only possible with DC motor pumps Although often used owing to its simplicity this layout requires a very careful electrical optimization and cannot yield a good efficiency in any operating conditions It may be improved by several special regulation modes Booster device 75 electronic device for overcoming high starting current due to friction losses Cascading 761 when using se
220. eorological data comparisons ISM hourly data in the database Importing data from Meteonorm Importing PVGIS data How to import US TMY2 TMY3 data Importing Canadian EPW data Importing Satellight data Getting Satellight data from Web Importing WRDC Data Getting NASA SSE data of a particular site Importing SoDa Helioclim Data Importing Retscreen Data Conversion of hourly data ASCII files ASCII Conversion procedure Conversion protocol Time label of measurements Time shift Tools and databases Favourites PHOTON database Phovoltaic modules Phovoltaic modules Basic data Characteristics of a PV Module model description Photovoltaics modules database PV Modules Serie Resistance determination Grid inverters Grid inverters main parameters Grid inverters secundary parameters Grid inverters efficiency curve Contents Chapter 7 152 152 153 153 154 154 156 157 157 157 158 159 159 160 160 160 164 165 166 166 166 167 167 168 168 169 169 170 170 171 171 171 172 172 172 173 Grid inverters adjusting the efficiency curve Grid inverter database Batteries Batteries Basic data Batteries Detailed model parameters Batteries Model description Battery Database Back up generator Pump definition Pump technologies Pump data general page Pump data performance curves Pump data detailed parameter Pump data current thresholds Pump integrated power co
221. ep the over energy PV energy which cannot be used by the load at a reasonable level This could be a serious limiting condition to the system size when the ribbon consumption is low DC grid line resistance The PV to user line resistance is taken downstream the array output up to the end user vehicle It should not be confused with the PV array ohmic resistance which is distributed along the PV array connexions see shema With undefined load profile i e illimited load the array output voltage is assumed to be the given Main power supply parameter In this case the voltage at the user level is the nominal voltage minus the line ohmic loss the supply to user line resistance is meaningless as well as the overvoltage protection When a load profile is defined the Main power supply is the conventional supply nominal voltage The program determines the user voltage after the Supply to user line resistance voltage drop and the PV output voltage user voltage increased with the PV to user voltage drop The PV current is then calculated according to the array I V characteristics The load current is the difference between the PV current and the user s need current If the PV array cannot deliver it s current due to low load it s voltage will increase according to the array I V characteristics and could reach the overvoltage limit All these currents and voltages are interdependent and have to be calculated from current balances ina lo
222. ependent on the battery technology we also have to define it here Back up generator management is rarely available with little PV systems When controlling the running ofa back up generator some logic in the hierarchy of the thresholds should obviously be respected for example it would be stupid to define the generator s starting threshold as lower as the threshold of deep discharge security The programme refuses erroneous configurations and produces an error message To decide on the adjustment of the working thresholds it could be useful to have a look on the voltage curve of the battery according to the state of charge One of the advantages of detailed simulation of PVSYST is thatit allows an in depth study of the behaviour and the life of the batteries as a function of the thresholds chosen for regulation MPPT or DC DC converter Some PV systems are using a Power Converter 164 for a better match of the PV array characteristics to the user voltage usually battery voltage In PVsyst simulations the parameters defining this optional power conversion unit are part of the regulator device Generic Default regulator When using commercially available regulators the program checks if itis suited to the system properties But in the early stage of the system study the exact regulator strategy doesn t matter That is the reason why we introduced a general purpose generic default regulator 16 which automatically matches the system c
223. equired monthly sum This could be used for annual variations analysis but in PVsyst we usually renormalize the data for obtaining the original monthly sums Use monthly diffuse in the same way the diffuse partis evaluated using the Liu Jordan hourly correlation At the end of each month the diffuse values are renormalized in order to match the specified monthly diffuse NB This was not the case in the version 4 In middle Europe the Liu Jordan correlation tends to over estimate the diffuse Now when the monthly diffuse is specified usually lower this increases the beam component and therefore the transposition results The temperature model was established on Swiss meteo data with a detailed analysis of climate type dependence But the differences between all these options are very low slight coupling differences between irradiance and amplitude or inertial shifts Visualization of the hourly values MET files In PVsyst the hourly values files MET are binary files which cannot be edited in a text editor For visualizing their contents you have to use the button Meteo Tables and Graphs in the Tools group After choosing your meteo file you have the opportunity of visualizing them as Graphs and Tables Both may be in Hourly Daily or monthly values Graphs of hourly values In the Graph tab please choose Hourly Global and Diffuse default when entering and click the button Chapter 5 Geographical and Me
224. er components mounting financial costs taxes and so on Modules and inverter costs are dependent on the quantities Mounting and maintenance costs follow an exponential rule referred to a 5 kWp system with an exponential coefficient of 0 8 Cost Pnom 5 kWp 0 8 Basecost for 5kWp These hypothetic default financial parameters can be adjusted by the user by choosing Edit costs in the economic results sheet Please be aware that at this pre design stage costs are based on very coarse hypothesis They can widely vary from country to country from time to time or from user to user what costs are included here customer or retailer costs which interventions on the building designer fees taxes etc The economic evaluation 104 at the detailed simulation stage will offer a flexible and more precise tool for evaluating real costs according to the specific user s criteria This partis aiming to perform a thorough PV system design and performance analysis using detailed hourly simulations These are organised in the framework of a Project which essentially holds the geographical situation and meteorological hourly data Optimisations and parameter analysis can be performed through different simulation runs called variants Procedure NB You have a step by step tutorial 24 for elaborating your first project After choosing Project Design and the system type in the main window the procedure is the following First def
225. er outputis turned off until the evening some old inverter models Irradiance loss Irradiance loss In PVsyst the evaluation of the Losses of a PV array as for the definition of the normalised performance ratio takes as starting point the energy which would be produced if the system worked always at STC conditions 1000 W m 25 C AM1 5 The loss due to operating temperature instead of 25 C is well known and referenced by everybody It is strange that nobody tells anything about the loss due to the irradiance level which is of the same kind Please have a look on the graphs of the behaviour of a crystalline PV module in the PV module dialog choose Graphs Efficiency vs Irradiance you will see that the efficiency decreases for lower irradiances this leads to the Irradiance loss by respect to 1000 W m7 Therefore this Irradiance loss is a consequence of the one diode model for PV modules Chapter9 Glossary 190 191 Glossary 9 One of the advantages of some amorphous modules is that this loss is lower Unisolar has even published efficiencies which constant or increased efficiency towards 150 W m see the results from the modelling according to our own measurements of SHR 17 in the database This is which explains along with the temperature coefficient why amorphous systems show a better productivity kWh kWp than crystalline ones in middle Europe climates Longitudinal_Incidence_Angle Longitudinal Incide
226. ermined the model will also need the specification of the efficiency for each given Flowrate Head operating point For an operating point the electrical power is easily deduced from the Efficiency using the Hydraulic Powerl 7A calculated as the product of the Head and Flowrate Therefore this case is equivalent to the model from Head and Power as f FlowRate 163 Pump model from Head and P as f FR fixed U or speed Pump model from Head and P as FR fixed U or speed Standard centrifugal pumps designed for grid applications are usually specified by one Head vs Flowrate curve for nominal grid conditions fixed voltage 50 or 60 Hz To be fully determined the model will also need the specification of the electrical power or efficiency for each given Flowrate Head operating point This is not always provided by the manufacturers as the power consumption is not a key parameter when using grid powered pumps Pumps without this minimum specifications cannot be used in PVsyst Using this only information at nominal speed centrifugal pump behaviour at other speeds may be very well described by the so called Similarity laws model see Abella 2003 Suehrcke 1997_ 1997 These relations state that for two operating points at different speeds along an iso efficiency line one has FLI FLO 1 00 P1 PO w1 a0 H1 HO 1 00 Using in addition a cubic spline interpolation on the given Head FlowRate curve solving these equations all
227. ernal needs of the device and doesn t produce power From this threshold the device is supposed to produce an AC power proportionally to Pin PThresh This production is penalized by an ohmic loss of the internal components transformer and transistors which increases quadratically with power like R I When translated into efficiency this gives a maximum efficiency usually around 50 60 of the nominal power PVsyst model for automatic profile In PVsyst the contribution of the Resistive loss is fixed according to a normalized resistance factor proportionnally to the difference between the given Max and Euro efficiency Then supposing the Max Efficiency point at 60 of the nominal power the effective threshold Pin_eff is adjusted in order to obtain the specified Euro efficiency The normalized resistance factor commands the losses at high powers above the 60 point by respect to the losses due to Pin_threshold We choose a usual value of 3 0 arbitrary units as default The accuracy of this model is probably largely sufficient for representing most inverters The less difference between Max and Euro efficiency the less possible discrepancies of the model Grid inverters adjusting the efficiency curve If you avail of hourly measured data and in these data of the the Inverter Output energy as well as the Array Energy parameters measured with good accuracy this tool allows to compare the Inverter efficiencyli5h def
228. es a detailed contextual help by typing F1 anywhere in the program Compatibility and Troubles This software is now available in several languages English French German ltalian Spanish Portuguese Additional languages could be included by filling the files Texts csv But the languages using other Character sets than the standard ANSI may cause great difficulties PVSYST V5 0 runs under any Win 95 98 Windows NT or 2000 Windows XP Vista 32 bits and Windows 7 Most of the data files from PVSYST versions 3 xx and 4 xx projects components meteo can be read with this new version 5 0 But the inverse is not true upward compatibility Importing Meteo Data Link for direct import from the Meteonorm A software versions 4 5 or 6 Link for direct import from many popular meteo data sources 112 from the web including NASA for the whole world US TMY3 PVGIS Helioclim Satellight Retscreen etc Almost any custom Hourly Meteo or Measured Data ASCII file can be imported whenever it holds one data record on one ASCII line Most detailed data hourly or daily data produced by the software can be Output to CSV customised ASCII files compatible with any spreadsheet program Many Data Inputs or Output are possible through the clipboard graphs or tables as bitmaps tables as CS V text images allowing direct export to spreadsheet programs like Microsoft EXCEL Many input files in ASCII format are accepted i e
229. es the Nominal Power Area or Annual energy yields as well as some result graphs table and economic evaluation 221 to switch from one to the other please use speed buttons left You can now play with the parameters and immediately see the results You can print a report or store graphs and tables in the clipboard to export it to another software You can also save your project and load another one for immediate comparisons Computation The evaluation of the available irradiance on the collector plane uses the Monthly Meteoli84 tool algorithms and the system energy output computations are done using constant efficiency and correction coefficients according to the chosen system parameters The accuracy is of the order of 10 20 worst case for fa ade installations if necessary the coefficients used for this tool may be modified in the Hidden parameters 173 Chapter 3 Preliminary design 18 19 Preliminary design 3 Stand alone system presizing Pre sizing is a rough estimation of the PV system energy yield and user s needs satisfaction based on a few very general parameters Itis aimed to determine the size of the optimal PV array power and battery pack capacity required to match the user s needs The input solar energy is computed in monthly values taking plane orientation and horizon into account and requires only the monthly data provided bythe Sites database Besides the Battery voltage which is related to th
230. esult for example PV module quality loss or mismatch or soiling The real meteo values when running are rarely known or sometimes not recorded with sufficient care and operating parameters measurements are also subject to errors The real performances of the components used especially the PV modules is rarely checked in detail at the installation time For getting reliable conclusions the measurement conditions and the validation process should be clearly defined Namely comparisons between measurements and simulation should be performed in hourly values We present here validations performed with old versions of PVsyst 1996 on 7 Swiss installations The yearly power was predicted with an annual accuracy of the order of 5 except with an installation involving amorphous modules which were not well modelled in this early version Recently we analysed very roughly several plants in Geneva over 2 3 running years usually designed with PVsyst using the straightforward simulation i e with all default loss values and renormalising the results to the real monthly irradiation the yearly results were within 5 We also analysed the data of a 10 kWc system of amorphous modules and closely compared them to the simulation The conclusion is that the calculation procedures are relatively reliable within 1 2 MBE accuracy over one year PVsyst tries to use the best models or the most suited for simulating each part of the
231. et by a long term contract usually 20 years at a level determined at the system commissioning time and fixed for the whole contract period Therefore the first and simplest option in PVsyst is to define a single feed in tariff over a given contract period It is also possible to define a connexion annual tax as well as a progressive decrease of the system production and also of the feeding tariff itself if necessary Finally the residual feed in tariff at the end of the contract period should be defined As usually the contract period will correspond to the loan refund period the annual balance after this period even with lower tariff will dramatically increase until the end of life of the system Modulated feed in tariffs In other cases for example in the USA the tariff is dependent on the hour of the day or even on the season PVsyst allows to define Night and Day and even Peak tariff levels for specified hours of the day These tariffs may be different in summer and winter with specified months In this case the final tariffs after the preferential contract period are all decreased by a same factor Net metering The Net Metering concept is defined here with a consumption tariff when the owner is able to use the produced energy for himself economy on the electricity bill and another tariff for selling the overproduction to the utility Chapter 4 Project design Project design 4 This calculation requires of cour
232. eteo and irradiation variables 94 see previous page PV array and inverter behaviour Earray Effective energy at the array output taking inverter behaviour into account larray Array current taking inverter behaviour into account Uarray Array voltage taking inverter behaviour into account InvLoss Global inverter loss IL Oper Inverter Loss during operation efficiency curve IL Pmin Inverter Loss due to power threshold IL Pmax Inverter Loss due to power overcharging IL Vmin Inverter Loss due to low voltage MPP window IL Vmax Inverter Loss due to upper voltage MPP window Syst ON System operating duration Energy output and use EOutinv Available Energy at Inverter Output E Load Energyneed ofthe user ifload is defined E User Energysupplied to the user ifload is defined Chapter 4 Project design 96 97 Project design 4 E Grid Energy re injected into the grid SolFrac Solar fraction EUser Eload Efficiencies EffArrR Array Efficiency EArray rough area EffArrC Array Efficiency EArray cells area 0 when cells area not defined EffSyR System efficiency EOutlinv rough area EffSyC System efficiency EOutlnv cells area EffInvB Inverter efficiency Threshold loss included EffInvR Inverter efficiency When operating Normalised performance index 94 Yr Reference Incident Energy in collector plane GlobInc kWh m day Ya Normalized Array Production EArray kWh kWp day Yf Normalized System Production EOutinv k
233. eved by developing decision making tools e g RETScreen Software and by training people to better analyse the technical and financial viability of possible projects RETScreen International is managed under the leadership and ongoing financial support of Natural Resources Canada s NRCan CANMET Energy Technology Centre Varennes CETC Varennes For Renewable Energy Studies the RetScreen software includes a climatic database including average measurements for 4 700 ground stations compiled from over 20 different sources and covering the period 1961 1990 These data are presented as a unique coherent database and present numerous parameters including Irradiation air temperature and wind velocities Several sources are for one only country CERES for Canada SAMSON for USA The main source elsewhere in the world are WMO OMM WRDCh2 when more than 5 years The irradiance are completed by the NASA i23 Data data when ground measurements are not available or reliable Importing Retscreen Data You should first download and install the RetScreen 4 software from http www retscreen net Open the software Retscreen 4 will open in msEXCEL In the main menu choose Retscreen Climatic database Choose your country and site There is no direct mechanism for getting the Retscreen data You have to copy and paste each item independently site name country latitude longitude be careful with sign altitude Then you select the i
234. evel See the reverse cell characteristics model had The relevant coefficient brev defined along with the other parameters of the PV module in the Components part can vary strongly from one cell to the other and is highly dependent on temperature But this behaviour is not critical in the qualitative evaluations of the PV array behaviour tools If itis not precisely known we can usually use the default value proposed by the programme PV module without by pass diode the solid line represents the whole module characteristics that is all cells in series With identical cells the total dissipated power is equally distributed on every cell The blue dotted line shows an arbitrary operating reverse current identical current in all cells in series If one cell has a lower photocurrent due to its quality or shading or a better BRev flatter curve then its voltage will follow its own reverse curve and at the imposed common current it can produce a much higher power than for the other cells therefore giving a rise of temperature see the Hot spot phenomenon in the tool for one shaded cell 37 PV module with by pass diode shows the resulting module characteristics when the module is protected with one or more by pass diode mounted in reverse bias In this case the whole module reverse voltage is limited to the forward voltage of the diode about 0 7V for one diode 1 4V for 2 diodes etc The excess currentis drawn by th
235. f the losses in PVsyst The array losses start from the rough evaluation of the nominal energy using the global effective irradiance and the array MPP nominal efficiency at STC Then it gives the detail of the PV model behaviour according to the environmental variables In stand alone systems the diagram gives a detail of the battery use that is which part of the energy effectively transits by the battery Minimizing the battery use is of some importance for the lifetime number of charge discharge cycles NB Each loss is defined as percentage of the previous energy quantity Therefore the percent values are of course not additive when grouping the losses the overall percentage is not the sum of the detailed values NB The accounting of the individual losses is far from being trivial problem The simulation process and some variable definitions had to be deeply reformulated for obtaining a coherent figure And some contributions are impossible to evaluate rigorously For example in stand alone systems the ohmic losses are evaluated using the usual relation Ploss R I But in reality the array resistance modifies the PV operating point and the whole circuit equilibrium so that a more accurate calculation would probably be simulating the complete system with and without this resistance and evaluate the differences But even with this method some loss contributions will be transferred to other ones By the way even if some individual los
236. for registration with your e mail address and a password free Here you have 2 possibilities Either you choose geographic coordinates and the nearest site will be selected Or you select a country and then a site in the country Select the Monthly Averages item other ones are daily values The required data will appear along with the geographic coordinates Select the data from the Country name to the bottom of the table and copy Ctl C into the clipboard Come back to PVsyst Tools Import Meteo Data WRDC press Import and follow the instructions in red As they are not included in the WRDC data you will be prompted to define the monthly temperatures from another source Getting NASA SSE data of a particular site NASA SSE Surface Meteorology and Solar Energy programme are monthly data average of 1983 1993 satellite measurements provided for any cell in a grid of 1 x1 over the world 111km x 111km cos Lat See http eosweb larc nasa gov sse for further information Also available from this database but direct import not implemented in PVsyst irradiances or temperatures in daily values for any period in the 1983 1993 range In contrast to ground measurements the SSE data set is a continuous and consistent 10 year global climatology of insolation and meteorology data It is derived from several databases including Goddard E arth Observing Systems GEOS 1 the International Satellite Cloud Climatology P
237. forms physical unit conversions to match the PVSYST internal standard format MJ MJ m C m s Dates may be sequencial read or not on the file or can have holes Possibility of automatically chaining daily or monthly files with coded filenames Date format separator Data separator for date format The standard separator is the field separator you defined in the general characteristics The character may be one or several non numeric characters The values between parenthesis are optional If months MM or year YY are not present in the data put their field number to zero Sequencial dates The format protocol specifies sequencial dates i e data are assumed to be contiguous without any holes In this case the program does not read the date on the file and the beginning date must be supplied by the user Data Multiplicator Multiplying factor This is the multiplying factor to be applied to your data in order to obtain the PVSYST internal units i e MJ m2 and MJ Examples Irradiances given in W m2 gt Multiplicator 0 0036 Irradiances given in kW m2 gt Multiplicator 3 6 Powers given in Wh gt Multiplicator 0 0036 Powers given in kWh gt Multiplicator 3 6 Energies given in Wh gt Multiplicator 0 0036 Energies given in kWh gt Multiplicator 3 6 Variable definitions Variables definitions Please choose the available variables in the data and define thei
238. ften hidden For visualizing hidden files or directories in the File Explorer you should modify the parameters of this tool For this Choose option Organize left under the menu Choose Options of Directories and Search Display Advanced parameters and in the box Hidden files and directories check Show the hidden files directories and disks NB Since version 5 2 the working data directory has been displaced in the c ProgramData PVsyst directory avoiding this problem This is the new location where you should look for your files Chapter 7 Technical aspects Technical aspects T Seing hidden files and directories in Windows Explorer Often some files or directories are not visible in the Windows file explorer For visualizing all existing files you should modify the parameters of the Windows file explorer Under Windows 7 and Vista click Organize top left of the menu choose Options of the files and research Under Windows XP this tool is in the menu Tools Directories options on the right In this windows tool please choose Display Advanced parameters and in the box Hidden files and directories check Show the hidden files directories and disks Log Files The Log file records the main actions of the program and some error messages It is stored in the Admin directory PVsyst keeps the 5 more recent log files and some special ones when errors occurred Windows will write
239. g obstacles buildings trees which can be adapted from template shapes Assembly is done in a global perspective or plane view Once this scene has been well established you can visualise shadows 45 produced for any sun position or time of the year You can also run an animation of the shadow evolution over a given day During simulation the calculation of the shading factor for each hour would spend too much computing time Therefore the programme establishes a table of shading factors 4 as function of the sun s height and azimuth During simulation the hourly shading factor can be calculated very fast by interpolation An informative tool is the iso shading curves 48 which are superimposed on a sun s paths height aamuth diagram allowing to estimate ata glance the shading effects according to the season and time of day The shading factor is applied to the beam component The program has also to calculates the shading factor for the diffuse component 47 as well as for the albedo which is independent of the sun position and therefore constant over the year Simulation results include shading loss calculations for Beam Diffuse and Global irradiation components Itis to be noted that the real effect of partial shading on the electrical production of the PV field is non linear and depends on the interconnections between the modules The program gives the possibility of partitioning the field into rectangles each of which supposed to represen
240. ge Current characteristics Such data are suited only when the pump is coupled to the PV system through a power converter If needed the basic function Ip Up Head requires additional informations These could be provided either bya setof Ipp points for at least two head values on which we can adjust curves or by several parameters Nominal voltage and Current at a given reference Head AV AI at fixed Head i e dynamic resistance and AI AH at fixed voltage When specifying such parameters instead of curves we assume linear behaviours which will of course penalise the accuracy of the Ip Up characteristics Pump model from Ip and FlowR as f Head Pump model from Ip and FlowR as f Head with fixed voltage This is the common data usually specified for positive displacement pumps Complete characterisation of the model requires such data sets for several operating voltages Itis unfortunately a common practice to specify such a data set for only one nominal voltage This is of course not suitable for computing direct coupled configurations The extension to other voltages requires a strong hypothesis which is in this first status of the model that the Pump Efficiency is constant when varying the voltage The figure shows an example of measured efficiency profile We can observe that within the reasonable operating range 30 64V the variations are of the order of 15 Efficiency vs Voltage 50 4546 eHe
241. ge Tank 7 and Hydraulic circuit 7 parameters Alittle graphical tool shows the total head and its contributions as a function of pump flowrate Pumping system lake or river to storage See also Pumping Systems Generalities ler Pumping systems from a lake or river are similar to deep well systems but with some technical simplifications The pump may be placed near the source no more than 4 5 m above the water surface less at high altitudes for avoiding cavitation problems The pump is not necessarily of Submersible type therefore much cheaper On the other hand it s maintenance is more easy Remember that the Pressure or Head 72 is mainly related to the difference between the input and output levels The pump has to provide a total head resulting of several contributions In PVsyst we take reference to the ground level we have cf fig HT HG HS HF where HG head due to the height of the outlet pipe above the ground assuming that outlet pressure is negligible HS static head due to the depth of the water level by respect to the ground HF friction losses in the piping circuit which depend on the flowrate Feeding level Ev Ground pump close to men l pumping level Pumping level Immersed pump recommended For this system in the Pumping Hydraulic definitions dialog you will be asked to specify The lake or river level depth by respect to the ground This may be also be give
242. gible causes can lead to highly significant losses This graphical tools should lead the engineer to carefully study the wiring of the PV fields in such a way that the foreseen shadings simultaneously affect the smallest number of series possible For example in shed mountings he should place the module series longitudinally in order that the mutual shadings on the lower part of the back shed be limited to just one branch of cells or modules Shadings general organisation We distinguish between two fundamentally different types of shadings Far shadings are the horizon 3e effects Far shading acts on the PV field in a global way at a given instant the sun is oris not visible on the field Near shadings are partial shadings which affect only a part of the field The shaded part changes during the day and over the seasons We call shading factor the ratio of the illuminated part to the total area of the field or inversely shading loss is its complement The treatment of near shadings is the most complex part of the PVSYST software For beginners you have a tutorial 4A which explains the main procedures on an example General procedure Near shading calculations necessitate the reconstitution of the exact geometry of the PV field and its environment Chapter 4 Project design Project design 4 in the 3D space You have first to build the global scene 40 of the PV system by assembling parametrised elements PV fields shadin
243. guration Pumping Results Examples Array losses in PVSYST Array losses general considerations Array incidence loss IAM Array mismatch loss Wiring loss optimisation Array ohmic wiring loss Array Thermal losses Module Layout Module Layout subfields Module Layout secondary rectangles Simulation Simulation process irradiance and PV array Simulation process grid system Simulation process stand alone system Simulation process DC grid system Simulation process pumping system Export ASCII file On line graph definition Simulation and comparison Results Loss diagram Normalised performance index Simulation variables meteo and irradiations Simulation variables Grid system Simulation variables Stand alone system Simulation variables pumping systems Simulation variables DC grid systems Economic evaluation Long term financial balance Geographical and Meteorological data Meteorological data Tutorial Importing monthly meteo values Checking the imported meteo data time Contents Chapter 6 109 109 110 110 111 112 112 114 117 117 118 119 120 120 122 122 123 124 126 126 127 127 130 131 132 132 133 133 136 147 148 149 149 151 151 Meteo tables and graphs Hourly meteorological files Geographical locations monthly meteo data Meteo database in PVsyst DRY or TMY hourly data Meteorological data averaging Meteorological data sources Met
244. h It allows inclusion of a number of elbows as well as eventual other Friction Loss factors 7A for diverse hydraulic singularities valves etc The overall friction head loss appears on the little graphical tool below the green line as a function of the flowrate It should be kept negligible at nominal flowrates of the system by choosing the appropriate pipe diameter Pump motor technology Pump motor technology The motor technology is not crucial in PVsyst This specification will be mentioned in some result outputs Brushless DC motors seem to have the higher efficiencies The only relevant information used by the program is whether the motor is AC or DC Hydraulic Power and Energy Hydraulic Power and Energy The mechanical power of a Hydraulic flow is basically the product of the fluid flowrate by the head at which itis transferred When using usual units in PVsyst P hydr W or P hydr kW FlowR m h Head Bar 1000 36 FlowR m h Head Bar 1 36 In the same way the energyis related to the total water volume transferred E hydr kWh Flow m Head Bar 1 36 or E hydr MJ Flow m Head Bar 1 10 Head and Pressure units Head and Pressure units In solar pumping systems Head is usually expressed in units of Level difference meter or feet The pressure at the basis results of the water column weight Physically passing to pressure units involves multiplying the height by the water
245. hapter 7 Technical aspects Technical aspects T includes an explicit header description which will appear in all the choice lists in the program in addition to the file name You are advised to carefully define these descriptions when available in a unique manner by a significant comment about the set of parameters concerned When the parameters of a component an element of a project etc are modified the program will remind the user to save the modifications carried out either in the same file button Save or in a new file Save as for creating a new component Export Import of data files The data structurel174 in PVsyst is well structured and this structure should of course be carefully respected for proper operation Several tools help managing import export of external data In the main menu Files Copy the whole data structure fs allows to displace your working Data structure anywhere on your system This is useful especially for users who don t have the writing rights in the directory of the main program program files in old versions of PVsyst Since the version 5 2 the data are located in an area which should always made writable If you want to localize you data in a personal place for example periodically saved If you want to share your data structure with other users network working In this case make your network data path as a virtual disk When choosing an external data location PVs
246. haracteristics This allows for performing the first simulations of a system without defining a specific regulation device Converter step down technology Converter step down technology As a result of an electronic design constraint most of the DC DC or MPPT converters operate on step down principle This means that without transfo they cannot deliver a voltage greater than the input voltage Therefore in a pumping system the PV array MPP voltage should rise over the voltage required by the pump at the desired flowrate at any time Otherwise even when the available power is sufficient the pump operating voltage will adjust until reaching the corresponding I V point on the PV array characteristics reducing the effective useful power This step down limitation can be taken into account by the simulation only when the voltage behavior of the pump is well defined With pumps specified only by power curves itis neglected NB This means that when using standard pumps designed for 230VAC grid operation the PV array should deliver at least 325V to the inverter for obtaining undistorted sinus at the pump unless special step up inverter or inverter with transfo is used Chapter 6 Tools and databases Tools and databases 6 MPPT or DC DC converter In PVsyst the MPPT or DC DC converter device if present is considered as part of the Regulator 164 lts operation and parameters are quite similar to the Inverter ones in fact t
247. he inverter is a MPPT AC converter i e DC DC converter Nominal Fixed Input voltage MPPT converter Minimum and maximum MPP tracking voltages Both Absolute maximum input voltage Power threshold Efficiency profile according to power Maximum and eventually European efficiency Behaviour type at power overload or outside the voltage window As for inverter the simulation process accumulates detailed specific energy losses during operating inefficiency under threshold power overload outside voltage requirements etc Generic default regulator When using commercially available regulators 1164 the program checks if itis suited to the system properties But in the early stage of the system study the exact regulator strategy doesn t matter That is the reason why we introduced a general purpose generic default regulator When editing this regulator most of the characteristics are preset at default values and cannot be changed These values thresholds maximum currents etc are automatically preset by the program according to the associated system configuration in order that they are suitable for a correct simulation Therefore the first simulations may be performed with default regulation without defining a specific device NB If you really have to change these default values For one specific system please uncheck the Universal Regulator option this allows for modifying the parameters then
248. he loss diagram should in principle match this Battery Global Energy Loss calculated above i e EBattLss EBattEff EBSelf EBGass But during the simulation all these contributions are determined from the Currents balance of the system PV array Battery Load multiplied by the Battery Voltage which is varying with currents charge discharge state state of charge temperature etc The resulting energies are therefore defined with some uncertainties On the other hand as explained above the ESOCBal is also not well determined Therefore the overall energy balance on the battery cannot be quite rigorous WeCycle Wearing due to cycling WeState Wearing state cycling and age MGass Dissociated Electrolyte Mass per cell System operating conditions EBkUp Back up Generator Energy UBatt BkUp BkUp Back up Generator Current accumulated in Ah BkUp ON Back up Generator running duration FuelBU Fuel consumption of Back up Generator Energy use E Avail Produced available Solar Energy Effectively used energy ELoad Energyneed of the user Load Defined as Input data EUser Energy supplied to the user Including back up energy E Miss Missing energy Eload Euser SolFrac Solar fraction EUser ELoad TLOL Duration of Loss of Loadli9h Duration user not supplied Pr LOLProbability of Loss of Load Efficiencies EffArrRArray Efficiency EArray rough area EffArrC Array Efficiency EArray cells area 0 when cells area not defi
249. he opportunity of choosing Color B amp W or leave PVSYST choose itself according to the actually connected printer Main physical models used in PVSYST calculations Meteorology Irradiation computations 18A PV system Components PV modules 133 Inverters 149Batteries 153Reqgulators 164 Pumps 157 PV system design Grid system presizing 18 Stand alone system pre sizingl 14 Pumping system pre sizing 6 Simulation process 8 Others Pumping deep welll63 Chapter 7 Technical aspects Physical models used 8 Incident irradiation models Irradiation on the PV field We call effective incident irradiation Hoge the luminous energy actually falling on the PV cells Itis obtained according to the following steps Ifonly monthly meteorological data available Generation of hourly synthetic 184 meteo data horizontal global irradiance and temperature If diffuse irradiance measured data not available diffuse irradiance model 180 If horizon 38 far shadings calculation of the beam effective component in this version of the program the diffuse is considered as not affected by horizon At this stage we have the Horizontal global diffuse and beam components at disposal with the relation Gh Dh Bh Computation of the so called incident energy by a Transposition model 184 i e calculation of the irradiance on the PV tilted plane At this stage the plane irradiance is composed of global
250. he relative loss when connected in parallel One can see that when the array voltages are comparable the power loss is usually low even for very different currents different orientations along the day or different parallel strings In this case the performances of each array are simply added together But for different voltages the resultant characteristic shows two distinct maxima with a serious loss of power This could also induce the MPP tracking device into error as it may choose the secondary maximum When the arrays are expected to operate under different voltages heterogeneous arrays but also by partial shading effects itis also veryimportant to connect blocking diodes in each string The dotted line shows the resulting behaviour if these diodes are omitted the production of the higher array may flow into the lower one inducing a feeding power into the overvoltage region Sheds mutual shadings PVSYST offers a special tool for viewing and optimising the shed mounting and also sun shields This is implemented in several places in the software In Tools Tables and Graphs of Solar parameters you can define the geometry optimise it with the mouse and view the mutual shading effects of your choice on an Height azimuth diagram In Tools Monthly Meteo Computations you can moreover have a quick meteo calculation for your site and immediately estimate the irradiation losses over the year During the definition
251. he standard one diode model although it is not well suited for these technologies There is no consensus up to now in the PV community on how to model these devices The task of finding a general model is by far above our possibilities lt would require a big research project at the international level Nevertheless we carefully measured a single device in great detail a SI H tripple junction and tried to find improvements of the standard one diode model We found and implemented two adjustments which can improve significantly the performances of the model the Shunt resistance of the device is drastically increasing exponentially when the irradiation diminishes the temperature behaviour which is fixed as a result in the standard model can now be adjusted at any desired value often given by manufacturer For our test device this diminished the modelling error over a 4 month continuous measuring period from about 11 to a very few 1 to 3 But this doesn t take spectral effects into account see the Help for further details Be aware that these are available tools but we cannot assess parameter values for any modules or any technologies 2 Orientation optimising tools There is now an on line tool showing the collecting performance as a function of tilt and orientation when choosing them Also for shed disposition a new graph shows the annual yield curves taking shadings into account for optimising the tilt shed s
252. heat loss factor U as parameter Now there is no general rule for the determination of this this thermal factor which depends on the heat sink properties Therefore this should be specified by the module manufacturer The CPV module is only able to use the beam component A concentrating factor of 500x means an ideal acceptance angle of 2 5 at most less than 1 in the reality so that the diffuse contribution is completely negligible This is the reason why the industry of CPV modules has fixed the STC irradiance value at 850 W m instead of 1000 W m for usual modules but still with a cell temperature of 25 C When specifying a CPV module in PVsyst you have the opportunity of defining specific corrections namely for the spectral behaviour This correction is named the CPV Utilization Factor For applying this correction you can define in the PV module model parameters a double linear behaviour according to The Beam normal value DNI The air mass the CPV module will always operate in clear day conditions The ambient temperature not for spectral response but for accounting of optic s mechanical deformations Again these corrections are determined from long term measurement in real conditions and should be given by the manufacturers Chapter 4 Project design Project design 4 PV array electrical behaviour This option presents a set of graphic tools intended for a better understanding of the electric phenomena
253. hed for each sun s position height azimuth table 48 The sky diffuse component is also affected by the near shading obstacles For simplification we assume that the diffuse sky irradiation is isotropic At a given time the shading effect on the diffuse irradiation can be thought as the integral of the shading factor over the visible part of the vault of heaven that is the spherical dihedron between the collector plane and the horizontal plane This is independent of the sun s position and therefore constant over the year Chapter 4 Project design 52 53 Project design 4 The albedo is only visible from the collectors if no close obstacle is present till the level of the ground This is why we have to integrate the shading factor at zero height on the portion of the sphere under the horizon included between the horizontal plane and the plane of the collectors It is however to be remembered that for non vertical planes the energetic contribution of the albedo is weak in the global incident energy and that errors in its estimation will therefore only have secondary repercussions This is also independent of the sun s position and constant over the year Diffuse Shadings factor according to module strings Spatial distribution of shadings on diffuse irradiation are smooth enough so that we can suppose that they don t affect the electrical behaviour of the field Therefore we will use the same diffuse and albedo shading factors com
254. heory of the direct coupling between DC Motors and PV solar Arrays Solar Energy 23 pp 193 198 1979 Ziyad Salameh A K Mulpur F Dagher Two stage Electrical Array Reconfiguration controller for PV powered Water Pump Solar Energy 44 no 1 pp 51 56 1990 H Suehrcke J Appelbaum B Reshef Modelling a Permanent Magnete DC Motor Centrifugal Pump Assemblyin a PV system Solar Energy 59 nos 1 3 1997 M Alonso Abella E Lorenzo F Chenlo PV Water Pumping Systems based on Standard Frequency Converters Progress in Photovoltaic Research and Applications 2003 11 1 13 M Alonso Abella F Chenlo J Blanco D Manso Use of Standard Frequency Converters in PV pumping systems 2nd World Conf and Exhibition on PVSEC Vienna 1998 M Alonso Abella CIEMAT Detailed measurements of several pumps 2004 Private communication 2004 Andr Mermoud Pump behaviour modelling for use in a general PV simulation software 19th European PVSEC Paris France June 7 11 2004 Andr Mermoud Pumping System Sizing and Modelling Tool 19th European PVSEC Paris France June 7 11 2004 Chapter 11 References 206 University of Geneva 1994 2010 All rights reserved Product and company names mentioned in this manual may be trademarks or registered trademarks of their respective companies Mention of third party products is for informational purposes only and constitutes neither an endorsement nor a recommendation Th
255. his option offers the same disposition possibilities for pitch and misalign as above for two axis planes Horizontal axis east west this old option corresponds to a disposition analogous to parabolic linear concentrators in distributed thermal plants with trackers one behind the other like in fixed sheds Itis not really suited for PV systems as the horizontal tracking takes advantage of the seasonal variations but is not very efficient over the diurnal sun course As above the Pitch Misalign and Transversal Slope parameters allow almost any configuration Sun shields are taking a great importance with the architectural integration But with fixed sun shields it is very difficult to find a good compromise between an efficient sun protection and an acceptable PV yield The shadings from one sun shield to the lower one when the sun is high i e during the best summer hours is difficult to overcome especially when the fa ade is not exactly south This could be partially solved by using tracking sheds with a backtrackingNear_Shadings_BackTracking strategy The construction dialog offers a tool for testing all possible rotations in order to check the mechanical compatibility of your array layout using the orthogonal plane or side view The Shading animation over one day provides a powerful tool for optimising your tracking layout by trial and error Heliostat array layout should be carefully optimised regarding the mutual shadings Constrai
256. hoose the Source directory using the Browse button The source may be one subdirectory or a root with several subdirectories all PVsyst files in any of these subdirectories will be shown The Targetis of course the PVsyst data structure Colours underline the status of the concerned files If some file already exists in the PVsyst data it also appears in the right panel with specific colour Green the file is new doesn t exist in the PVsyst database Blue the corresponding file in the PVsyst data is from original database identified bya file date equal to 12 00 but the file to be imported is newer should be copied Red the file in the PVsyst data is from original database and the corresponding file to be imported is an older one in principle should not be copied Orange the file in the PVsyst data is not from the original database ithas been modified by the user for example defined component s prices In the latter case One of the main reasons of importing updated database files is when the availability of the component has Chapter 7 Technical aspects 180 181 Technical aspects T changed i e is no more available on the market Therefore PVsyst gives the opportunity of performing an intelligent copy which consists of maintaining your modifications and just updating the market availability dates in the component You have choice between this intelligent copy recommended for database update or a nor
257. hourly files represent weather conditions that result in approximately average heating and cooling loads in buildings Because they represent typical rather than extreme conditions they are not suited for designing systems to meet the worst case conditions occurring at a location They are especially suited for the EnergyPlus program The CWEC EPW data are derived from the Canadian Energy and Engineering Data Sets CWEEDS of hourly weather information for Canada from the 1953 1995 period of record How to import Canadian EPW data Canadian EPW data can be directly and very easily imported into PVSYST First download the desired file from the web site referenced above After choosing the desired EPW file you can simply download it by choosing File Save As it in your web browser Then come back to PVsyst option 7oo ls Import Meteo Data Canadian EPW and follow the instructions on the screen i e simply Choose the file and press Import NB If the file downloaded by this mean is not suited for PVsyst gives errors this may be due to a transformation of the format by your browser In this case you should download the ZIP file and extract the epw file The import of EPW data will create a Geographic site sit file and an Hourly Meteo data file met file with Global Diffuse Temperature and Wind speed values Importing Satellight data Satellight results from a European Project Team cf www satellight com whi
258. i e sunrise are on the right of the graph as the sun progression Therefore gives realistic image of the horizon drawing Measured data Importing widely debugged Possibility for ASCII lines of more than 255 characters Data import is now possible with input Daily Values Measured data with orignal irradiation measurements in the collector plane Graphics and comparison tool are debugged and improved Version 3 0 December 1999 by respect to Version 2 21 The PVsyst software has been entirely rewritten using the Borland DELPHI 3 platform instead of the old Borland Pascal 7 gaining in user graphical interface quality and reliability as well as in compatibility with most recent versions of the Windows operating system The user s interface has been redesigned and navigation in the software was strongly improved with the collaboration of the LESO EPFL team Introduction of a Green line for guiding the user in the project development Preliminary design Implementation of this quite new sizing feature for grid connected and stand alone systems Project design The Project organization has been simplified Parameter definition and results are summarised in one only Simulation Version file Several valuable tools were added including the sizing expert for building the system parameter Chapter1 Overview Overview 1 Several new Tools which help understanding more deeply many PV system behaviours Help system which provid
259. icators indexl 94 performance ratio input output diagram incident energy and array output distribution etc Economic evaluation After the simulation you can perform a detailed economic evaluation 104 of your project taking the parameters for example nb of modules inverters and results into account Printing You can choose to print the following forms General simulation parameters which summaries all the parameters involved in a variant Detailed simulation parameters such as Horizon drawingtpoints table Near shadings detailed user s needs etc Apre defined form with the main parameters and main results of this simulation The detailed loss diagram Anyspecific result graph or table displayed on the screen along with the main parameters The economic evaluation sheet The Result dialog offers the opportunity of recalling other variants of the project in order to perform quick comparisons Loss diagram The loss diagram provides a quick and insight look on the quality of a PV system design by identifying the main sources of losses Little buttons enable to group the losses into general topics meteo and optical PV array system energy use or to expand any topic to detailed losses The loss diagram is available for the whole year or for each month in order to evaluate seasonal effects of particular losses Please refer to Array losses general considerations 82 for a general explanation o
260. ifically in the model thatis the algorithms of the basic functions mentioned above will be different for each kind Given p and FlowRateas f Head for fixed Voltage leh usually for Positive Displacement Pumps Given Powerand FlowRateas f Head for fixed Voltage 164 equivalent set as U is defined for each point Given FlowRate as f Power for fixed Heads 164 usual for solar centrifugal pumps but doesn t include Current Voltage specification therefore only suited for configurations with converter Given Head and Poweras f FR fixed voltage or speed 163 is the usual way of defining standard centrigugal pumps for grid operation This definition leads to the Similarity Laws model Given Head and Efficiencyas f FR fixed voltage or speed 163 is equivalent to the preceding the power being easily deduced for each operating point Pump model General requirements Pump model general requirements The pump model 168 should match the following characteristics Input Output variables The model should describe the dynamic evolution of the output variable usually the flowrate as a function of the pertinent input variables which are basically the head and voltage input for any conditions within the admitted operating values Indeed when a given voltage is applied to the pump this will run at an operating point characterised bya flowrate yield as well as bya current drawn from the source Therefore currentis also a functi
261. illed water checks and addition Unfortunately or fortunately the problem is not all that simple as some sealed batteries said to be without maintenance contain a catalyst which allows the recombination of H3 and O gases to again give water Model use in simulations Thus PVSYST avails of a model which is certainly not perfect but whose results seem to fulfil the exigencies of the simulation of a PV system In particular it will help explore the effects of regulation s threshold adjustments either on the performances of the PV system or on the ageing conditions of the battery This model requires a minimum number of parameters to quickly become operational It can be more finely adjusted if the user can avail of supplementary data about his own battery The whole set of parameters appears on the standard sheet printed by PVSYST The model gives rise to charge discharge curves which can immediately be compared to those of the manufacturers in order to verify the conformity of the model Battery Database The database is constituted of some battery models available on the Swiss or European market for different types and different technologies Notice that though often used in small solar installations in holidays houses the car batteries often called starting batteries are not best suited to a solar installation running conditions Built to stay charged most of the time and to produce a big starting current they are not able t
262. ily or hourly values and even transferred to other software The Loss Diagram is particularly useful for identifying the Chapter1 Overview Overview 1 weaknesses of the system design An engineer report may be printed for each simulation run including all parameters used for the simulation and the main results A detailed economic evaluation ho can be performed using real component prices any additional costs and investment conditions Measured data analysis 169 when a PV system is running and carefully monitored this part located in the Tools part permits the import of measured data in almost any ASCII format to display tables and graphs of the actual performances and to perform close comparisons with the simulated variables This gives a mean of analysing the real running parameters of the system and identify even very little misrunnings In addition Tools 13 include the databases management for Meteo data and PV components as well as some specific tools useful when dealing with solar energy systems import of meteo data from several sources tables and graphs of meteo data or solar geometry parameters irradiation under a clear day model PV array behaviour under partial shadings or module mismatch optimizing tools for orientation or voltage etc Tutorials There are presently 3 available tutorials about the following topics gt Meteo data managementl1o4 import from external sources gt Project design2
263. ily values Total 345 points Daily average 10 6541 kVWVhi day Meas Model Error aver 0 0812 rms 0 243 kVWVhiday Meas Model Error aver 0 75 rms 2 24 Measured values kyVh day ia 5 10 15 20 25 Simulated values kWVh day Fig 3a Simulation Measurement Comparison for the output of the PV field LESO sheds installation daily values LESO Sheds Field Energy Output Hourly Values Total 3570 points Hourly average 1048 927 VV Meas Model Error aver 7 847 rms 54 55 W 3000 Meas Model Error aver 0 75 rms 5 2 2000 Measured values W 500 D 500 1000 1500 2000 2500 3000 3500 Simulated values W Fig 3b Simulation Measurement Comparison for the output of the PV field LESO sheds installation hourly values Amorphous tandem technology The LESO USSC installation equipped with a H SI tandem amorphous collectors has shown one ofthe limits of the collector s model used Table 1 shows that the global results of the field are clearly underestimated by the Chapter 10 Validations 200 201 Validations 10 simulation Fig 4 shows that the values with strong beam are very well reproduced MBE 0 5 while the points of pure diffuse irradiation are clearly under evaluated This is attributed to the fact that this type of collector is more sensitive to diffuse irradiation which cannot be reproduced by our model which does not take the spectral distribution of the incident irradia
264. increase of about 1 5 to 2 by respect to the operation near the optimal voltage In practice this implies that benefits of a MPP converter may be cancelled by the inefficiency of this device when the operating voltage is well adapted The Efficiencyis rather flatwhen modifying the user s voltage but drops more sharply toward high voltages Chapter 6 Tools and databases 168 169 Tools and databases 6 The diode and ohmic resistance voltage drops maybe a significant contribution affecting the user s voltage match In middle latitude climates the usual 36 cells modules match well the battery charging voltage about 14V fora 12 V battery In very hot climates especially with long wiring circuits this could require modules with more cells Special 33 cells modules are only suited for very simple installations without protection diode not recommended Comparisons between measured and simulated values The Comparisons between measured and simulated values is a verysimilar process as the Simulation process RA The main difference is that the original Meteo file of the project is replaced by the measured data file 1168 which is attached to each variant so that the Project can treat several measured data files for example for different periods Therefore the measured data file should contain the meteorological data necessary to carry out the detailed hourly simulations Regarding other aspects the Project and parameter
265. ine cells as well as CIS the Rsh value is high and its exact value has rather little effect on the general module behaviour low shunt current loss But with amorphous or other thin film technologies it becomes significant and should be ideally be specified by the manufacturer in the future For a very accurate modelling of all modules and especially for amorphous the Rsh should be corrected according to the Irradiance 1148 Reverse characteristic of a cell Reverse Characteristics of a cell i e current behaviour when a reverse voltage is applied on it is involved in all situations where the currents are not well balanced in a module array This is the case namely in mismatch situations of cells in a module or modules in an array partial shadings or heterogeneous arrays with different orientations i e different irradiances Severe consequences of the Reverse Bias in arrays can result in so called hot spot phenomena These are the overheating of unbalanced bad or shaded cells which can lead to their destruction Bypass diodes mounted in the PV modules are intended to protect them against these dangers PVsyst offers a specific tool 140 for visualising and understanding these special array behaviours But they are not implied in the simulation process of PVsyst which doesn t calculate the electrical array behaviour in detail at each hour Therefore the reverse bias model exact determination is not crucial in PVsyst as itis on
266. ine the Project 28 through the Projec Variant button You can also retrieve an existing project through the File menu For one Project including basically Geographic Location and Meteo with eventual Albedo data you can construct different system variants as much as needed For each variant define the plane orientation 30 Define the System 2 properties The program verifies the consistency of all parameters and produces Warnings as Orange acceptable for simulation or Red preventing simulation LED s When available all parameters properly defined that is only Green or Orange LED s press the Simulation 88 button Red buttons or warnings indicate bad definitions which prevent the simulation When the simulation is completed you will enter the Results 921 dialog and consult the main results on the Report document After simulation each variant may be saved for further comparisons please use Save as for not overwriting your previous variants You are advised to define a significant description for each variant in order to easily retrieve them in the list and to obtain a suited title in your final report For a given project you are advised to first construct a rough variant keeping all parameters to their proposed default values In a second step you can define the required refinements Inthe System definition panel you can modify the Detailed losses 82 temperature parameters wi
267. ined for your device with the experimental data Moreover you can adjust your Inverter Device Specifications in two ways either you can perform an automatic best fit on the data or you can drag the reference points with the mouse in order to visually obtain the desired characteristics You are advised to save the inverter data with another name for your specific measured project and you will then be able to use it when performing the comparison simulations Grid inverter database The library includes about thirty inverters available on the Swiss and European market in the range of 0 8 to 100 kW Most of them have been measured by independent institutes ISB Ingenieurschule Burgdorf Be Switzerland or GENEC Groupement Energ tique de Cadarache France Chapter 6 Tools and databases 152 153 Tools and databases 6 The greatest inverters are often modular or made to measure Itis not possible to propose current models and we don t avail of measurements independent of the manufacturers But these data will be easily introduced in the PVSYST s library with the help of the technical data from the manufacturers There are several Inverter databases recently available But these usually don t give an explicit efficiency curve behaviour which is a necessary data for the PVSYST simulation process Batteries We have given up to use the classical models for example Shepherd s model where a number of parameters are involved
268. ing Data CEC JRC Ispra Issue 4 1 june 1993 Meteo and Irradiance models R Perez P Ineichen R Seals J Michalsky R Stewart Modeling Daylight Availability and Irradiance Component from Direct and Global Irradiance Solar Energy 44 no 5 pp 271 289 1990 R R Perez P Ineichen E L Maxwell R D Seals A Zelenka Dynamic Global to Direct Irradiance Conversion Models ASHRAE Transactions Vol 98 Part 1 3578 1992 P Bremer S Kunz R Voltz METEONORM Vol 1 Th orie Vol 2 Donn es Vol 3 Proc dures de calcul Vol 4 Sources de donn es Office F d ral de l Energie Berne 1986 Chapter 10 Validations References 1 1 Jan Remun4d Esther Salvisberg Stefan Kunz METEONORMS95 Energie solaire et M t orologie Manuel du concepteur Notions de base et logiciel METEONORM V2 0 Meteotest and Office F d ral de l Energie Bern 1995 METEONORM Version 3 0 1997 METEONORM Version 4 0 METEONORM Version 5 0 2004 METEONORM Version 6 0 June 2007 Distribution Nova Energie Gmbh Scachenallee 29 CH 5000 Aarau Switzerland www Meteotest ch www Meteonorm com David Bloom Sara Dagher Stuart Frye Qiumin Hu Marianne Baldwin Brett Gouviea John Duffy Bill Berg William Beckman and Ronald Stewart International Solar Irradiation Database Version 1 0 Info diskette University of Massachusetts Lowell Photovoltaic program USA R J Aguiar M Collares Pereira and J P Conde Simple P
269. inter month with 15 days coverage IAM loss The incidence loss reflexions due to the fresnel s laws is sufficiently well defined by parametrization proposes by the Ashrae US standards office You will in principle never modify this parameter NB Assuming an isotropic diffuse the IAM factor on the diffuse part is computed by an integral over all spaces directions which include important low incidence contributions Project definition When creating a project you have to define The project name which will identify the project in the file list in your data library The PVsystem customer address facultative not used elsewhere in the software The geographical location 115 The hourly meteo file 109 in internal PVSYST format MET files NB These are defined in the Project Situation and Meteo 29 dialog The relations between Geographical site and meteo file may be of different kinds Finally the Next button leads to the definition of the albedol18 characteristics of the project site The project parameters are stored in a file with the extension PRJ All variants will have the same with extensions VCO VC1 etc Site and Meteo data in the Project The project is located at a geographical Site M Sites are described in SIT files with geographical coordinates and meteo in Monthly values The detailed simulation process requires the following meteorological hourly data Horizontal Global Irradia
270. involved when connecting several modules together in arrays Electrical connections of non identical modules are not trivial They lead to complex I V characteristics shapes and current flows which are far from being intuitive They often involve the reverse characteristics 140 of the cells in the module which has to be modelled In PVsyst this reverse cell model is only involved in the frame of these phenomenological and didactic tools moreover in the practise modules are protected again severe cell reverse bias through bypass diodes Therefore the exactness of this model is not crucial The four graphical tools are Reverse characteristics 140 of cells or modules Array or Cells Mismatch 36 effects and calculation Array or Module with one shaded cell A hot spots effect of bypass diodes Heterogeneous arrays 31 connected in parallel Arrays with characteristic s mismatch This tool allows for the phenomenological study of the resultant I V characteristic of a module or PV array composed of non identical cells or modules The program simulates the connection of any number of elements in series and in parallel by affecting to the I V model parameters of each element a random dispersion The user can choose between a normal gaussian distribution or a square distribution between 2 limits The elements can be cells assembled in a module or modules protected with by pass diodes The parameters that can be modulated are th
271. ion In the shed disposition the diffuse effect is particularly important as the heavens vault view is limited in front by the previous shed affecting rather high incidence angles and to the rear side by the plane itself Due to its permanent effect this is often the main part of the losses This situation is even much more sensitive with sun shields General features and optimisation of sheds With shed disposition we should be aware that The area occupation is strongly depending on the collector tilt For acceptable shadings the Limit shading profile angle 193 should be kept below about 18 to 20 With 30 collector tilt this implies that you can only install a collector area limited to 45 of the total available area The mutual shading effect is also strongly dependent on the shed orientation when not south the morning or evening performances are much more affected The software offers two complementary tools for well understanding these situations The beam shading graph which shows the periods which are affected by the shadings One can notice that with south orientation the effects are rather limited to summer morning and evening But as soon as you change the azimuth the shading losses increase rapidly and arise especially in regions where the incidence angles are high The yearly yield graph shows the relative gain by respect of the horizontal layout as a function of the module tilt This factor is based
272. ion is a leap year Daily file with 365 or 366 daily values Wh day or kWh day from January 1st to December 31th The file can have any number of head lines for titles To import the file in PVSYST choose the ASCII source file its contents will appear for interpretation define the separator define the number of head lines will be coloured in yellow define the order of the Load field column define the time step and units Then clicking Read file will import the values inthe PVSYST user s needs part of the simulation variant parameters which can be visualised or saved as a model file Domestic User s needs See also User s needs 54 This is a simple tool aiming to facilitate the domestic load estimation from a practical end user point of view This tool also clearly identifies the consumption of each appliances and perhaps will help optimising the customer needs options for example bring attention on stand by or washing machines real cost in PV systems The user has to define the number of appliances their unit power and daily use The table shows the resulting daily consumption The Week end use option may be applied to each season or month independently and acts by putting the load to zero during some days of the week The last line defines the Standby consumption which applies over 24hours by definition When using Week end option you may choose leaving these appliances co
273. ion of the reference I V characteristics inside the distribution Standard model validation on Mono Crystallie module Chapter 6 Tools and databases Tools and databases 6 One of our measured modules was a Siemens M55 monocrystalline We used it mainly as a calibration of our method and experimental set up and especially as a reference for the study of the spectral effects As a by product this yields a validation of the standard model for this technology Surprisingly the pure standard model did not reproduce well our measurements The model strongly underestimates the PMax data at low irradiances giving a MBE of 6 and a RMSE of 3 9 This could be very well corrected by applying an exponential correction for the Rshunt as for the amorphous modules with an appropriate Rsho value the MBE on Pmax reduced to 1 1 and the RMSE to 2 3 This correction also strongly improves the Voc behaviour the RMSE passing from 6 0 to 1 0 We should emphasize that our test module is very old 15 years and presents significant corrosion around the collector grid We cannot say to what extent this Rsh behaviour could be related to these module deficiencies Nevertheless we strongly feel that the Rshunt exponential correction is a general feature which should be applied to any PV module for proper modeling But the required parameter Rsho and even the basic Rshunt value at reference conditions cannot be determined from manufacturer data sheets Sta
274. ir parameters are detailed on the final report but the simulation results concern the whole installation 3 Inverter their definition includes many parameters which were not operational in the simulations up to now Multi MPPT devices you can define a specific sub field for each input Possibility of Master Slave operation the Inverter s cascading is taken into account in the simulation process For some models power limitation when running under a specified input voltage is now taken into account Efficiency profile for 3 different input voltages 4 Heterogeneous orientations systems with 2 different orientations may now involve different sub fields in each orientation and or a subfield for which the strings of a given inverter are distributed on both orientations with mix of the I V curve for correct calculation of the MPP 5 Database management the big lists of components stored as individual files which took very much time to be loaded in the previous version and sometimes caused bugs are now replaced by centralized databases CSV files This results in an immediate access and facilitates the updates of the DB of the software Only the files you are creating or modifying by yourself will still be stored as individual files as before This Chapter1 Overview Overview 1 concerns The PV modules which should approach 5 000 modules in the DB of 2009 The inverters The geographic site database 5of which the lis shows now the
275. is able to search for the MPP When sizing the array voltage number of modules in series this should be taken at operating conditions around 50 C or 60 C Absolute Maximum PV voltage is the absolute allowable maximum under any operating conditions When sizing the array it should be compared to 1000 W m conditions at the lower temperature higher voltage possible This is fixed at 10 C for middle Europe This temperature condition may be adjusted in the Hidden parameters for other regions Minimum voltage for PNom Some inverters cannot deliver the full nominal voltage when the input voltage is too low but still over the minimum MPP voltage This corresponds in fact to an input current limitation PVsyst takes this limit into account during the simulation by displacing the operating point along the IM curve in order to respect this current limit Nominal MPP voltage is sometimes specified by the manufacturer In this case this may be an indication for the optimal number of modules in series Not explicitly used in the sizing tool in the present time Power threshold is the minimum input power needed to operate It is admitted to be the own inverter power operating consumption Sometimes referred to as Starting production at in the datasheets If not known Chapter 6 Tools and databases Tools and databases 6 you can take it at around 1 of the nominal power This means that your inverter will begin to produce AC electricit
276. is calculated according to the operating conditions of the module Otherwise itis taken as 10 The thermal behaviour is characterised bya thermal loss factor designed here by U value formerly called K value which can be split into a constant component Us and a factor proportional to the wind velocity Uv U Uc Uv v U in W m k v wind velocity in m s These factors depend on the mounting mode of the modules sheds roofing facade etc For free circulation this coefficient refers to both faces i e twice the area of the module Ifthe back of the modules is more or less thermally insulated this should be lowered theoretically up to half the value i e the back side doesn t participate anymore to thermal convection and radiation transfer Determination of the parameters The determination of the parameters Uc and Uv is indeed a big question We have some reliable measured data for free mounted arrays but there is a severe lack of information when the modules are integrated What value should be chosen according to the air duct sizes under the modules and the length of the air path One can observe that the heat capacity of the air is very low Even with large air vents the flowing air under the modules may quickly attain the equilibrium with the modules temperature at the end of the duct leading to no heat exchange at all Therefore for the top of the array the U value may be the fully insulated U value you can have
277. is is the potential currentin excess by respect to the instantaneous load current In Normalised performance index 94 all these array losses are accounted for in the Collection Losses Lc that is the difference between Yr the ideal array yield at STC 194 and Ya the effective yield as measured at the output of the array Nevertheless unlike Ispra recommendations in PVSYST the unused energyis specifically designed as Lu Unused loss see Normalised performance indexl 94 for details Array incidence loss IAM The incidence effect the designated term is IAM for Incidence Angle Modifier corresponds to the weakening of the irradiation really reaching the the PV cells s surface with respect to irradiation under normal incidence In principle this loss obeys Fresnel s Laws concerning transmission and reflections on the protective layer the glass and on the cell s surface In practice itis often approached using a parametrisation called ASHRAE as ithas become a standard in this American norm depending on one only parameter bo FAM 1 bo 1 cosi 1 with i incidence angle on the plane For single glazed thermal solar modules the usually accepted value for bo is of the order of 0 1 Butin a PV Chapter 4 Project design Project design 4 module the lower interface in contact with the cell presents a high refraction index and our specific measurements on real crystalline modules actually indicate a value of bo 0 05
278. ismatch losses 84 Incidence angle IAM losses 83 Press the Losses Graph button for visualizing the effect of these losses on the PV array I V characteristics in given running conditions In the simulation results the effect of each loss will be available in hourly daily or monthly values They may be visualized on the Loss diagram 9A Array losses general considerations Generally speaking array losses can be defined as all events which penalise the available array output energy by respect to the PV module nominal power as stated by the manufacturer for STC conditions M This is the philosphy stated by the JRC Ispra European Centre recommendations through the Normalised performance indexl 94 Several of these loss sources are not directly measurable Starting with incident irradiation in the collector plane after taking irradiation shading effects into account one can imagine that an ideal PV array should yield one kW kWp under an irradiance Ginc of 1 kW Thatis assuming a linear response according to Ginc the ideal array will produce one kWh energy under one kWh Chapter 4 Project design 82 83 Project design 4 irradiance for each installed kWp as defined at STC This ideal yield is diminished by the following losses Incidence angle modifier IAM 83 is an optical effect reflexion loss corresponding to the weakening of the irradiation really reaching the the PV cells surface with respect to irradiation unde
279. issue 1 Pump Model Development of a general and original pump model suitable for use in PV applications Chapter1 Overview Overview 1 This should be suitable for any type of Pump or Motor useable in PVsystems This should describe the operating of the pump over a large Electrical and Hydraulic domain encountered in PV conditions Its parameter should be available from usual pump manufacturer s datasheets For a given pump the model may be specified using several kinds of original data Its accuracy over the whole domain has been checked for some pumps using measured data The defining dialog shows graphics of the behaviour of the model as functions of all relevant variables The pumps database is still limited to about 20 30 models only one manufacturer has answered our request for datasheets 2 Controller Converter device for pumping Model for a new controller for pumping systems including the System Configuration controls and Power converter Adefault controller is proposed for each system configuration with parameters automatically adjusted according to the system for optimal operation 3 Pumping systems Three system types are proposed Deep well Pumping from lake pond or river and Pressurisation system For each type several system configurations are possible Direct coupling with eventual improvements like booster pump cascading or array reconfiguration with Power converter MPPT or Fixed V or battery b
280. ite is represented as a line Chapter 5 Geographical and Meteorological data 106 107 Geographical and Meteorological data 5 The year 1990 In PVsyst we have adopted the convention to label all data which don t correspond to really measured data ata given time as 1990 This is the case namely of all Synthetic hourly data see later or TMY DRY datafiles You will observe that recent data are really scarce in the public published data This can be explained by the fact that analysing and assessing real measured data sets for sizing purpose is a very complex job and the results of these research groups are only available later on Generation of synthetic hourly values MET files Now the simulation process operates on hourly values Therefore if we don t avail of really measured hourly data we have to construct a set of hourly meteo data from these monthly values The hourly data will be stored in MET files and stored in the Data Meteo directory For the irradiance the synthetic generation 188 of hourly values from monthly averages is performed by using stochastic models due to the Collares Pereira team in the 1980 s This model generates a sequence of days and then a sequence of hours in the day using Markov transition matrices These matrices have been established in order to produce an hourly sequence with distributions and statistical properties analogous to real hourly meteo data measured on more than 30 sites all arou
281. ither on the irradiance distribution i e location orientation meteo and on the periods at which the water needs are the more important Moreover the pump characteristic is strongly dependent on the head displacing the curve parallel to itself Therefore the sizing will also be dependent on the conditions of use impeding using simple thumb rules valid for any system at any place Regulation Direct Coupling with Booster See also Pumping Configuration 73 previous 74 and next 76 Regulation This is an improvement of the Direct coupling 7 configuration often necessary with DC displacement pumps Chapter 4 Project design Project design 4 SS SiS aa Tank Full PV array i System Direct coupling Controller Booster I Array gt ween memo So 1 Level sensors Total Head Level diff Friction losses Current Yoltage Most displacement pumps require a significant peak of current at low voltage when starting in order to overcome the internal friction forces We see on the PV characteristics diagram that the array currentis notable to provide the peak unless by waiting very high insolation increasing the irradiance threshold Help is usually provided by an electronic device named Booster which stores the PV energyin a big capacity and gives it back as a peak of current This strategyis useable with a single pump system When several pumps are involved in the system the Ca
282. itis ready for a shading analysis Push Shadow animation over one day button And in this tool Play Record animation The shadows will be shown for the whole selected day After execution you have a scrollbar for reviewing one or the other situation For each time step the date hour sun position and shading factor are mentioned on the bottom of the 3D window You can try this for different dates in the year If there is some shade that you don t understand well you can click the button View from the sun direction on the top group This way you will have a direct view of the shades and their cause Colours You can now personalize the view of your scene by defining colours Click the 9th button from left Realistic view The colour of each element may be defined in its definition dialog For example for the building Double click the building this will open the building construction Double click the roof this will open the definition dialog Here you can define the colour of the roof and the colour of the gables independently Please note the colours are defined at bright sun choose them rather light If you define your own colours store them as personalized colour in order that you can reuse them for other similar objects Recording the scene If you do some bad manipulation you have an Undo opportunity 2nd button left As the 3D tool is not fully safe in PVsyst sorry this is not easy to program
283. ity given the load profile and the probability that the user will not be satisfied Loss of Load 9MLOL probability or equivalently the desired solar fraction For Pumping systems given water requirements and a depth for pumping and specifying some general technical options this tool evaluates the pump power and PV array size needed As for stand alone systems this siang may be performed according to a specified probability that the water needs are not met over the year Project Design 22 itaims to perform a thorough system design using detailed hourly simulations Within the framework of a project the user can perform different system simulation runs and compare them He has to define the plane orientation with the possibility of tracking planes or shed mounting and to choose the specific system components He is assisted in designing the PV array number of PV modules in series and parallel given a chosen inverter model battery pack or pump In a second step the user can specify more detailed parameters and analyse fine effects like thermal behaviour wiring module quality mismatch and incidence angle losses horizon far shading or partial shadings of near objects on the array an soon For pumping systems several system designs may be tested and compared to each other with a detailed analysis of the behaviours and efficiencies Results include several dozens of simulation variables which may be displayed in monthly da
284. ity that the user s needs cannot be supplied i e the time fraction when the tank is empty It may be understood as the complement of the Solar fraction although itis described in terms of time rather than energy or water volume During the sizing process specifying the required LOL allows for determining the required pump nominal power and the corresponding PV array size The LOL is calculated using a simplified and fast yearly simulation the program splits the monthly meteo values into a realistic random sequence of 365 days according to Collares Pereira model Then it performs a day by day balance of the tank state in order to accumulate a realistic LOL yearly value This process is repeated with different pump and PV array sizes in order to find the exact devices matching the required LOL LOL Loss of load probability LOL Loss of load probability This value is the probability that the user s needs cannot be supplied i e the time fraction when the battery is disconnected due to the Low charge regulator security It may be understood as the complement of the Solar fraction although itis described in terms of time rather than energy Chapter9 Glossary Glossary 9 Metal resistivity Metal resistivity The resistivity of wiring metals is strongly dependent on the temperature which can widely vary due to dissipating currents For pure metal one has Copper Rho 1 68E 8 1 0 0068 Temp C Oh
285. king power threshold The efficiency elbow at low powers is for a great part due to the mathematical transformation of this threshold Inverter manufacturers try to improve the efficiency at low powers giving rise to a hardly visible improvement on the beginning of the straight line when represented as Input Output graph Defining the efficiency curve The efficiency curve is rarely explicitly given by the manufacturers For some inverters the database gives the efficiency curve measured by independent institutes The programme offers the possibility of entering a profile characterised with at most eight points in any one of these 3 modes Pout f Pln or Efficiency as a function of Pout or Pin Points may be entered by edition or mouse displacement The particular behaviour which appears at nominal power i e curve stop or sudden dropping discontinuity is characteristic of the chosen overload power behaviour Interpretation of the efficiency curve In most of the specifications the manufacturers or databases give the so called European Efficiency which is intended to provide an average efficiency over yearly operating conditions From these two values specified by the user Maximum efficiency and European efficiency PVsyst constructs a default profile with the following hypothesis Up to the power threshold often named Starting operating at in datasheets the input power corresponds to internal consumption for the int
286. ky model or also by a plot comparing morning and afternoon Kt values When the import of the data implies a solar model using the solar geometry for example the model for diffuse or much more important the retro transposition when measuring the GlobInc POA value the time shift should already be defined for the importing process i e in the Format definition Therefore when importing an unknown data set especially with diffuse calculation or POA First import without precautions The program will guide you to the graphs for the assertion of the correct time shift Evaluate the effective time shift of your data If more than 30 min you should modify the begin end interval choice or the timezone of your reference site Apply the observed timeshift in the format protocol and re import the data NB In PVsyst the time defined around sunrise and sunset for solar geometry is the middle of the interval when the sun is over the horizon This third part of PVSYST gives access to the following topics Meteo Database 119 Geographic sites 113 geographic parameters of about 200 sites in the world including monthly meteo data horizontal global and temperature Synthetic hourly data_generation 184 to generate meteo hourly synthetic data from any above monthly data Importing Meteo data from external Databases 112 allows the use of meteo data from the most popular databases Import ASCII meteo files h2 allows to
287. l VAT is charged for Swiss users only No additional taxes nor shipping costs are required for all other countries at least from the exporter point of view Transferring the software code to another machinel 7 7 NB The Activation Code is constructed using the Local number provided by each installation of the software on a given workstation If you have to reinstall your Windows environment the Local number will change and your code will no longer be valid Therefore before reinstalling Windows you should transfer the codel 1A to another workstation in order to keep your activation code valid After reinstalling Windows and PVsyst on the original workstation you will be able to retransfer back your code from the other workstation NB In special cases people who need to dedicate the code to a given machine whatever the Windows installation for example in classrooms machines where windows has to be reinstalled frequently you can get another type of License code based on the Hard Drive number Nevertheless this code cannot be transferred to another machine Network Installation on a network server is not recommended Nevertheless it is authorized only if each user computer has a valid activation code Please note that this software has not been fully tested for this mode of operation But you can share your data area in network with other users For this please open Files Directories and here you can copy your working space
288. l years are selected only the first year is taken into account by PVsyst when available let Tilt angle 0 Azimuth angle 0 Albedo 0 2 PVsyst only imports Meteo data on horizontal plane if available select the time step hour month is not very useful if available select the time reference UT Universal Time output in Text File or screen select Textfile CSV like select output format SoDaCSV press Execute the SoDa service Click with eft button and you will obtain CSV like data directly on your screen select all the data if hourly values up to 31 12 copy the selected data into the clipboard Ctrl C return to PVsyst and click Import for Pasting these data and then follow the instructions the city name and country are not part of the results and should be filled manually you will be prompted for defining monthly temperatures that you may take from a nearby location in the database or other sources Chapter 5 Geographical and Meteorological data Geographical and Meteorological data 5 with hourly values please carefully check the consistency of the data with the Clear sky model on the hourly plots Importing Retscreen Data The RETScreen International Clean Energy Decision Support Centre www retscreen net seeks to build the capacity of planners decision makers and industry to implement renewable energy and energy efficiency projects This objective is achi
289. l16d Technical features of the motor pump aggregate are not needed in detail In PVsyst many Pump are associated with a power converter which have to be included in the pump device definition In these cases the input electrical variables are those of the converter All parameters related to a given Pump as well as graphs ofits behaviour are available in the Pump definition dialog which is composed of several definition sheets General datal158 which holds the pump identificators and main electrical and hydraulic characteristics Detailed parameters 159 specifies some additional electrical parameters and the choice of a model according to the available operating data set Data curves 159 tab s hold the definition of the operating data according to the model choice Current Thresholds 160 tab asks for the definition of the starting current thresholds in a graphic assisted way Size and Technology allow for writing a technical description of the pump features as a text without limitations Commercial datal135 Graphs and Running Conditions offers a set of curves for visualizing the model behaviour as well as a little tool intended to compute the pump operating state for any desired input or output variable Pump technologies Pump technologies There are two classes of pump technologies Centrifugal Pumps The water is moved with a rapid rotating impeller The pump should rotate ata sufficient speed for
290. ll other functions seem to be perfectly compatible 12 Introduction of many Logs in the program in order to facilitate the debugging of user s problems Version 4 1 January 2007 by respect to Version 4 0 1 MultiLanguage The Simulation output reports are now available in French German Spanish Italian useful for presenting the PV system characteristics to customers Please contact the author if you wish to implement yourself a translation into your own language you should have a good knowledge of the technical terms used in the PV technology 2 Windows user s rights compatibility The DATAstructure has been modified for compatibility with the user s rights protections in Windows Auser without writing rights can now copy the whole DATA structure for use in his own writable area Data may be shared or not between different users of the machine 3 Files and projects transfers Archiving or importing projects as well as database updating tools have been improved 4 Bugs in special shading parts Several youth bugs in newly developed features often on special requests of users have been fixed Especially in the Shading part concerning tracking mechanism as well as sheds with a tilted baseline or double orientation Version 4 0 June 2006 by respect to Version 3 41 The main new feature in this PVsyst 4 0 version is the study of Pumping systems which involves complex developments which may be not quite safe in this first
291. lls effects and for unlimited length that is neglecting edge effects on both extremities of the sheds Byexplicitely defining a PV plane as sheds in the Near shading scene In this case the computation accounts for shed edges and a module partition can be defined Please note that these two options should not be used at the same time as the shadings will be accounted for two times Definition by the Orientation parameter shed option This option is most suited when you have a field of numerous and little sheds for example one module wide sheds sufficiently long as you can neglect the edge effects Nevertheless if you have to combine such an array with other surrounding shading obstacles in a near shading scene you should define the basic arrayin the near shading scene as an horizontal plane covering the sheds base extent i e the whole area used for installing the sheds on which the surrounding shadings will apply This way the mutual shadings will be taken into account by the plane orientation shed algorithms while the surrounding shadings will apply on the basis plane This is of course an approximation but the only way when the sheds are so numerous that the near shading complexity and calculation times become prohibitive Shed definition in the Near Shading scene The Near shading shed construction should only be used when the number of sheds is less than say fifty sheds The computing time and complexity
292. lso the initial cost of the batteries as well as that of their maintenance and replacement Durability Quality of the pumps and regulators ease of maintenance and replacement special wearing conditions like sands or impurities in the water etc Pumping Systems Generalities Solar Pumping System sizing and optimization is a rather complex task Hydraulic and Electric requirements are strongly coupled with highly non linear interdependence which prevent an easy understanding of the behavior and performances of the complete system Most pump manufacturers do indeed propose their own standard system configurations or graphical tools for evaluating the production of their pump during a normalized day But these don t give any information about the yield in real conditions over the whole year according to fluctuating needs or depth and in a given climate PVsyst deals with three types of pumping systems Pumping from a deep welll 69 to a tank storage boreholes usually have some limitations drawdown level depending on the flow pumped static level variable over the seasons Pumping from a lake or river 70 here also the level may be seasonal Pumping into a pressurized tank 70 for water distribution The general problematics is the following the customer usually specifies Chapter 4 Project design Project design 4 lts water needs in volume over the year The head level difference at which it should be pumpe
293. ltage Clearness_Index Clearness Index Kt The Clearness Index Kt is defined as the ratio of the horizontal global irradiance to the irradiance available out of the atmosphere i e the extraterrestrial irradiance multiplied by the sinus of the sun height The extraterrestrial irradiance is the Solar constant 1367 W m corrected by a yearly Chapter9 Glossary 188 189 Glossary 9 sinus function of amplitude 3 3 accounting for earth orbit ellipticity Climatic Distance Climatic Distance According to the Meteonorm definition the Climatic distance between two sites is the quadratic sum of their horizontal distance and the altitude difference weighted by a factor of 100 DistanceClim Dist Hor 100 Diff Altit 4 Following Meteonorm Standard it can be admitted that a meteorological site is representative of a given place if their climatic distance does nt exceed about 20 km Dates read on the file Dates Read on the File The format protocol specifies dates read on the file but the Year is not read In this case the year must be must be supplied by the user Diffuse attenuation factor Diffuse attenuation factor The sky diffuse component is affected by the near shading obstacles as well as the incidence angular modifier IAM In order to take it into account we suppose as simplification that the diffuse sky irradiation is isotropic Ashading factor on this diffuse irradiation independent of the sun s position
294. ly calculated from the steady state conditions t Aw HDref Qref For example in the case of a borehole of diameter 0 15 m in Rotunda this is about 4 minutes Therefore this Chapter 4 Project design 68 69 Project design 4 dynamic model describes the short term behavior of the well Medium term annual variations are likely due to modifications of the phreatic water level along the seasons They may be introduced in PVsyst by specifying a monthly profile of the static head HS Long term exhausting effects caused by an excessive water drain involve complex and not sustainable phenomena which are not modelled here in PVsyst Finally the simulation as well as the real system regulation should take the maximum head Hmax i e the inlet level of the pump into account for stopping the pump avoiding dry running Pumping deep well system See also Pumping Systems Generalities Ea Many solar pumping systems are of the Deep Well type i e made of a submersible pump placed in the bottom of a borehole The borehole is usually sunk by specific machines with a diameter of about 12 to 20 cm Special submersible pumps are designed for being inserted in such boreholes They should of course lie below the water level and are connected to the surface by a pipe for the water and the feeding control electrical wires The water is pumped into a storage tank according to sun availability Remember that the Pressure or Head 72 is mainly
295. ly readable in PVsyst NB when established using a georeferred grid like Carnaval or Meteonorm the exact location should be carefully defined This may be determined using GoogleEarth or a GPS Please remind that a degree in latitude is 111 km a minute is 1850 m and a second is 31m Your own profile asa file to be recognised as a valid horizon profile you can also provide any text file with the following characteristics ASCII file with comma semicolon TAB or space separator Firstline maybe a comment One line per defined point Each point defined as an Azimuth and a Height value expressed in degrees Should hold the extension HOR and be placed in the directory Data Shadings of the PVsyst data structure For example a horizon file edited in EXCEL with first column as Azimuth and second column as Height and saved as CSV file will be valid after renaming itas HOR Near Shadings main dialog See also Near shadings general organisation 3A This dialog gives the general commands when using near shadings You have first to build the global scene 40by clicking Construction Perspective button You may also load an existing shading model from the library if available The shading scene you build here is part of the present variant attached to the current project Nevertheless you can save it in the library for other uses in another variant of this project or another project The description commentis especially i
296. ly used in the phenomenological array behaviour tools Empirically the behaviour of the cell s characteristic under reverse polarisation is quadratic with the applied voltage This result comes from our own measurements and is confirmed in Roger and al ley lbh Brey Vt Rl a for V lt Ran This expression could be valid till the avalanche zone Zener situated around V 30V Butin reality under irradiation high photocurrent Iph the dissipation which varies with the cube ofthe reverse voltage reaches a destructive limit well before this elbow For example the cells constituting the Arco M55 modules dissipate about 18 W at a reverse voltage of 18V and 25W at 20V corresponding to a rise in temperature of the order of 100 C This is even more dangerous as the temperature s rise sharply increases the parameter Droy and therefore the reverse current leading to an unstable situation PV Module reverse behaviour This tool presents the operating of a PV module when itis polarised towards negative voltages as itcan happen in the framework of an array or a module when the cells are different or if the irradiation is not homogeneous The tool show three typical situations Chapter 6 Tools and databases 140 141 Tools and databases 6 One single PV cell we see that under bright irradiance reverse bias of the cell rapidly involves high powers to be dissipated as the current is already at least at the cell Photocurrent l
297. m When beginning with the PVsyst software you are advised to have a look on the Tips for beginners This Help System is currently under deep reorganization Please apologize for any inconsistency and navigation problems General description of the PVsyst Software PVSYST V5 0 is a PC software package for the study sizing and data analysis of complete PVsystems It deals with grid connected stand alone pumping and DC grid public transport PV systems and includes extensive meteo and PVsystems components databases as well as general solar energy tools This software is geared to the needs of architects engineers researchers Itis also very helpful for educational training PVSYST V5 4 offers 3 levels of PV system study roughly corresponding to the different stages in the development of real project Preliminary design 17 this is the pre sizing step of a project In this mode the system yield evaluations are performed very quickly in monthly values using only a very few general system characteristics or parameters without specifying actual system components A rough estimation of the system costis also available For grid connected systems and especially for building integration this level will be architect oriented requiring information on available area PV technology colours transparency etc power required or desired investment For stand alone systems this tool allows to size the required PV power and battery capac
298. m m Default value Temp 50 C gt 22 mOhm mm m Aluminium Rho 2 7 E 8 1 0 0043 Temp C Ohm m Default value Temp 50 C gt 33 mOhm mm 7 m Module quality losses Module quality loss Itis well known that most of PV modules series don t match the manufacturer nominal specifications Up to now this was one of the greater uncertainties in the PVsystem performance evaluation Now with guaranteed power assertions and increasing availability of independent expertises the situation seems going toward some clarification Module series are sold with a given tolerance and actual powers usually lie under the nominal specified power but stay in the tolerance PVSYST allows for accounting for this discrepancy by defining a loss factor which is an energyloss at MPP constant during the simulation process For fixed voltage operation battery DC grid the loss factor is supposed to be the same NOCT definition NOCT Definition Some practicians and most of PV module s catalogues usually specify the NOCT coefficient Nominal Operating Collector Temperature which is the temperature attained by the PV modules with free air circulation all around under standard conditions defined as Gincid 800 W m T mb 20 C gt Wind velocity 1 m s Open Circuit The NOCT factor is related to our loss factor U by the thermal balance U Tcell Tamb Alpha Gine 1 Effic where U Uc Uv WindVel which gives with the
299. m our own measurements and confirmed in ref 15 lev IL Brev V Rs I for V lt Rs l This expression could be valid till the avalanche zone Zener but in reality the dissipation in the cell which varies as the cube of the reverse voltage reaches a destructive limit well before this elbow Summer Time Daylight Savings The internal PVsyst meteo data in Legal Time don t take the Summer Time hour shift also called Daylight Savings Time into account the hour is related to the original Time Zone usually Winter Time all over the year When importing meteo data the source data could include such a shift which has to be corrected The shifting dates are never fixed but obey to rules which may be different in some regions of the world In the present state PVsyst only knows the rules applied in Europe the passage to summer time arises on the last Sunday of March and to Winter time on last Sunday of October For other conventions or modifying the European standard the user will be invited to define these dates at each conversion as they will depend on the year NB Please carefully check the results on daily plots after conversion i e the shift of the hourly data by respect to the Clear Sky model STC STC Standard Test Conditions The Standard Test Conditions are normalised operating conditions when testing the PV modules They are defined as 1000 W m Irradiation 25 C Module temperature
300. mal copy which will overwrite your modifications Taking care of these status you can choose the files which you effectively want to transfer Or ask for copying all the eligible files according to the above criteria After transfer the source files become grey or disappear if moved and the copied files are blue Invalidating files Abad file can disturb the normal running of the program and produce unrecoverable errors Invalidating it puts a as first file name s character You will always be able to rename it when necessary Exporting projects This tool gathers all files involved in a simulation project for export to an archiving place or sending to another PVsyst user The source is of course the local data structure It shows the Simulation projects in green and the Presizing projects in maroon You choose the desired projects to be exported You have to choose the target directory anywhere in a writable area on your machine which could be named PVs yst_ExtData by default If not existing a data structure analogous to the structure of PVsyst i e 3 subdirectories Projects Meteo and Components will be created When clicking on the transfer button the concerned files are dispatched to their corresponding subdirectories The copied structure is reversible and could be re imported as such by another installation of PVsyst of same or posterior version It may also be zipped for sending to another PVsyst user
301. may be represented by an equivalent resistance and the loss will be computed as R I during the simulation Generic Year 1990 Generic Year 1990 By convention in PVsyst all data which are not relied to real meteorological measurements of a given year are considered as a generic year labelled as 1990 This is the case for most of the monthly data in the database which proceed from averages over several years This also holds for synthetic hourly data or Design Reference Years DRY Grid current in tri phased configuration In tri phased configuration when well balanced the AC current in each phase conductor is obtained by dividing the total Power by the Voltage SQR 3 voltage between phases Power Voltage Current SQR 3 Incidence_Angle The incidence angle is defined as the angle of the sun s rays by respect to the normal to the collector plane Incidence angle is zero for normal incidence and 90 for rays parallel to the plane The sun s height on the plane is the complement to 90 of the incident angle Inverter power overcharging Inverter overcharging Behaviour at power overcharging i e when the output power overcomes the nominal output power AC power Limitation the PV field s running point moves along the I V curve in order to limit the output power at the nominal value Cut the inverter outputis turned off until input power at MPP matches the output nominal power Cut until evening the invert
302. me back to PVsyst choose Tools Import Meteo Data PVGIS and follow the instructions in red How to import US TMY2 TMY3 data Data files of Typical Meteorological Year TMY 1 are available on the web for 1020 stations in the USA at the address _http rredc nrel gowsolar old_data nsrdb 1991 2005 tmy3 They can also be obtained as a single zip file or on a CD ROM These data sets are derived from the National Solar Radiation Database NSRDB and produced by the National Renewable Energy Laboratory s NREL A complete User s manual is available on the web site Formerly available as TMY2 239 stations 1961 1990 data since 2008 this database has been extended to TMY3 1020 stations 1991 2005 data These new TMY3 are base on more recent and accurate data TMY h1f are data sets of hourly values of solar radiation and meteorological elements They are Chapter 5 Geographical and Meteorological data Geographical and Meteorological data 5 juxtapositions of months or periods of real data chosen in the multi year data set in such a way that they represent a typical 1 year period Their intended use is for computer simulations of solar energy conversion systems and building systems to facilitate performance comparisons of different system types configurations and locations in the United States and its territories Because they represent typical rather than extreme conditions they are not suited for designing systems to meet the worst
303. measured data files of any kind For example if the conversion encounters an extra comment or unreadable line it will ask the operator for skipping it s processing It also performs global checks limits consistency on each value After conversion you are advised to check your file with the Graphs and Tables tool either for meteo or for measured data files and carefully check the time _shiftl130 of your data Conversion protocol See also Conversion of hourly data ASCII filesh2 The conversion protocol window holds several tabs and includes a sample view of your source file where you can follow step by step the effects of your choices General Tab Defines the general file organisation Separator time step of your data lines to be skipped Chapter 5 Geographical and Meteorological data Geographical and Meteorological data 5 When choosing the proper separator the display sample file will be organised in field columns Date format Please choose among Reference year your source data are well organised in a yearly sequence from January 1st not leap year In this case the program does not need reading the dates nor writing them on the file This is suitable for clean TMY or DRY files Sequencial dates not read on the file your source file is still a clean sequence of records but not necessarily starting from January 1st and of any duration one year maxi Therefore the program can only memorise the beginning and
304. meter They can also be imported from several sources Solmetric SunEye instrument This is a computerized instrument using a fisheye type camera for the recording of the environmental masks www solmetric com www soleg de It provides an horizon height for each degree of Azimuth i e 360 points The software produces several files one of them being a specific file for PVsyst named SkyOx_PVsyst hor Don t use this file it was designed for the old PVsyst version 4 x and is restricted to 120 to 120 You should choose the file ObstructionElevation csv file instead The new Version 5 0 has been updated for importing this file in a clean way by taking the highest height among 3 azimuth points therefore reducing the data to 120 points from 180 to 180 This resolution is far sufficient for the hourly computations of PVsyst Carnaval is a free open source software which may be downloaded from incub energie free fr Itis based on a geo referred grid for calculating the horizon line at any place between longitudes 6 W to 10 E and latitudes 41 to 52 N therefore largely covering France East of Spain etc Ituses satellite data from the spatial US programme SRTM Shuttle Radar Topography Mission giving a grid of altitudes with a 3 resolution about 92 x65 m When using Carnaval V 0 7 you should choose the Lat Long WGS84 coordinate system GPS compatible you can identify the exact coordinates of your syst
305. minor modifications date of availability price have been modified Export Log Files gathers the LOG files produced by your PVsyst runnings when they are requested be the debugging center Chapter 7 Technical aspects 176 177 Technical aspects T Directories contents Since version 5 20 PVsyst places by default its Data folder in a zone writable by anybody Under Vista and Windows 7 c ProgramData PVsyst Data Under XP and olders c Documents and Settings All Users Application Data PVsyst Data and the Log and PVsyst5 lni files in the parallel folder Under Vista and Windows 7 c ProgramData PVsyst Admin Under XP and olders c Documents and Settings All Users Application Data PVsyst Admin These folders should be writable by the user of PVsyst from his Windows session If not they have to be made writable by the administrator of your machine in an administrator session NB If you don t see these structures in your machine you have to allow Windows for the display of Hidden files had DataRO This directory DataRO pour Read Only is in the program s structure c Program files PVsyst5 DataRO It contains Texts _5_xx CSV List of all the texts used in PVsyst for multi language uses Params_5_xxDAT Miscellaneous hidden physical parameters Values can be edited and modified through the Preferences Edit hidden parameters option in the main menu Countries_
306. mperature conditions 20 C should not be above the inverter s voltage range for MPPT The maximum array voltage in open circuit Voc at 10 C in Europe should not exceed the absolute maximum voltage at the input of the inverter The maximum array voltage in open circuit Voc at 10 C in Europe should not exceed the allowed system voltage specified for the PV module NB The Voltage values calculated by PVsyst for Amorphous modules are the stabilized ones after degradation The initial values may be up to 15 higher during the first months This should be taken into account when sizing the system especially concerning the absolute maximum voltages for the inverter input or the module insulation The inverter power sizing is a delicate and debated problem PVsyst proposes a methodology 59 based on the predicted overload losses This usually leads to Pnom ratios far below those recommended by inverter s providers but we think that they are closer to an economical optimum All these conditions are explicitly displayed on a system sizing graph button Show sizing You can now play with these parameters taking your own constraints into account You can retrieve the automatic proposed values by clicking on the associated checkbox Warning messages will be displayed if there is some incompatibilities between the chosen parameters Red warnings are not acceptable simulation cannot be performed and orange warnings are indicative These col
307. ms a very simplified simulation which runs over one year in daily values The evaluation of the available irradiance on the collector plane uses the Monthly Meteo 18 tool algorithms which calculate irradiation s monthly averages on the basis of instantaneous data for one day per month This is not sufficient to manage the water storage balance evolution from day to day and the effective use of solar incident energy Therefore the program generates a random sequence of 365 days according to the algorithms of Collares Pereira renormalised to the monthly sums for calculating the daily balance from day to day and the PLOL This simulation is repeated with different array and pump size arrangements until matching the input requirements namely the desired PLOL The program is able to propose The pump s size power The PV array nominal power Arough estimation of the investment cost and the cost of water pumped If necessary the pre defined parameters used array system matching and pump efficiency etc are user modifiable through the menu option Preferences Edit Hidden Parameter l173 Of course this early layout proposition should be asserted by a detailed simulation using real commercially available components and taking all system features into accountin an hourly modeling Chapter 3 Preliminary design Preliminary design 3 Preliminary design economic evaluation Costs are given as specific costs for modules oth
308. mulation over one year During the elaboration of the shading table the points sun s positions situated behind the plane of the PV field appear in blue Chapter 4 Project design 48 49 Project design 4 Near Shadings tutorial The near shadings are one of the most difficult parts of PVsyst Therefore we present here a full exercise for explaining the main steps and tips advices for an easier use of this tool First please remind that there is no possibilities of importing 3D shading scenes from other software like Autocad or GoogleSketch The basic data structure in PVsyst is completely different and it would be quasi impossible to reconstruct it automatically from the data of these software We will create a Farm as constructed in the Geneve Demo project This is built from the following architect plan 35m Silo El vation Roof tilt 25 AN Above all walls Eaves of 0 5m H 5m Defining the 3D scene Open the button Near Shadings and then Construction Perspective You obtain the main 3D window where you will construct your scene Constructing the building The building 42 will be an assemblage of elementary objects 41 gathered afterwards as one only objectin the main 3D scene In the menu choose Object New Building Composed object This will open a secondary 3D window which is the referential of the building object In the menu choose Elementary object New o
309. multaneous improvement of the Pmax response For example on our SHR 17 tripple junction the RMSE on Vco drops from 3 3 to 0 7 and the MBE from 4 to 0 2 with this correction Simultaneously the RMSE on Pmaxis improved from 5 8 to 4 1 It should be noted that this new term doesn t modify significantly the procedure used for getting the model Chapter 6 Tools and databases Tools and databases 6 parameters Simply the photocurrent value is now affected by a voltage dependent correction in the equations Nevertheless the resolution of the model gives a quite different gamma value compatible with it physical limits Back to Standard One diode modelI138 Back toAmorphous and Thin films modules 14A Thin film modules Fit on input values of Rshunt This little tool allows for adjusting the exponential parameters according to some known Rshunt values at different irradiances The Rshunt value can be obtained on the basis of measured I U characteristics of the module Rshunt is the inverse of the slope around V 0 i e the short circuit point at Isc If you avail of such data or measurements at different irradiances you can put them on the plot You can use the right button of the mouse for creating a new point and then slide it to obtain the desired value For deleting a point simply click on it with the right button The Fit button will then give the adjusted exponential parameter See also Rshunt exponential correction vs I
310. n be driven by diverse AC or DC motor technologies The model will also apply to other standard pumps not specifically designed for solar applications with AC induction motors driven by frequency converters inverters Ideally the parameters necessary for achieving the modelling should be available from the manufacturer data sheets in order that any user of the program can inputits own pump model characteristics In practice manufacturers usually give performances for only a limited set of actual operating conditions Details about the motor or pump technology and related fundamental parameter are usually not available Therefore the model will apply to the motor pump group as a whole without reference to intermediate values like torque or speed which are highly technology dependent and rely to unavailable specific technical parameters Chapter 6 Tools and databases 162 163 Tools and databases 6 Model basis The model 160 will be a phenomenological one based on the specification of some Operating points FlowR Head Current Voltage Power from which the operating properties will be interpolated or extended for any conditions Pump model from Head and Effic as f FR fixed U or speed Pump model from Head and Effic as RFR fixed U or speed Standard centrifugal pumps designed for grid applications are usually specified by one Head vs Flowrate curve for nominal grid conditions fixed voltage 50 or 60 Hz To be fully det
311. n height and the azimuth is adjusted for no shadings Other geometries could be imagined but would require additional parameters Tilted axis the Phi angle around the axis is adjusted for no shadings conditions This doesn t allow for misaligned arrays Sun shields When the sun is high in the heavens the sun shields become highly tilted It is also the case for east west orientations when the sun is low on the horizon The compatibility with comfort conditions has to be studied Near shadings effect of thin objects If the shading objectis sufficiently thin its shade will not cover a full cell Even if itis rather far and produces a broad semi shading due to the sun s diameter the irradiance loss should be considered as the integral of the shading figure and will be the same as the effect of a well delimited thin shading of the same wire This is the case of electrical wires above the array handrails etc In these cases the current in the cell will be reduced by a factor of the order of the wire diameter by respect to the cell s size This is the value which should be attributed to the Thin object electrical effect ratio parameter Then during the simulation the Module loss caused by this thin object will be reduced by the Thin object ratio The reduction is directly taken into accountin the loss factor according to modules Near shadings partition in module strings The real effect of partial shadings on the electrical pr
312. n in seasonal or monthly values in the Water Needs next dialog The Pump depth maybe atmost5 m over the source depth You will also define the Storage Tank 7 and Hydraulic circuit 7A parameters Alittle graphical tool shows the total head and its contributions as a function of flowrate Pumping pressurization system See also Pumping Systems Generalities le This system assumes pumping from a generic water source other storage lake or river into a tank which ensures a water static pressure allowing for distribution to customers This is an alternative of high tanks like water towers The pressurization is obtained by the compression of the air in the closed impervious tank volume when water level increases The pump s problematics is the same as for lake river except that it s maximum head capabilities are usually higher The pump may be placed near the source no more than 4 5 m above the water surface less at high altitudes for avoiding cavitation problems Chapter 4 Project design 70 71 Project design 4 The pump is not necessarily of Submersible type therefore much cheaper On the other hand being in open space it s maintenance is more easy Remember that the Pressure or Head 72 is related to the difference between the input and output levels to which the pressurization should be added The pump has to provide a total head resulting of the following contributions In PVsyst we take reference to the
313. n irradiance and temperature and should not introduce mistakes on the predictive average values of the PVSYST results Diffuse irradiance is not measured in the ANETZ grid it is calculated according to the Perez Ineichen model Importing data from Meteonorm The Meteonorm software version 3 0 1997 version 4 0 2000 version 5 0 2003 Version 6 0 June 2007 6 1 2009 provides basically monthly meteorological data for any location on the earth These are based on more than 7700 well established meteo station data from which about 1 500 named stations avail of Irradiance measurements Data are monthly values averaged over the period 1961 1990 when available A second period 1981 2000 for irradiations 1995 2005 for temperatures may be chosen in the new version 6 0 Data for any location on the earth specified by its geographic coordinates may be obtained by interpolation between measuring stations taking altitude and region typology into account For regions with poor terrestrial measurements covering help of satellites data may be used In this software Stations design the meteorological stations which avail of irradiance measurements WMO OMM are the meteorological stations recording many parameters but which don t avail of irradiance data Chapter 5 Geographical and Meteorological data Geographical and Meteorological data 5 Towns are a set of some main big cities for which the data are interpolated Th
314. n of the array nominal power i e the installed STCI194 power according to the manufacturer specifications and the battery pack capacity The first result graphs shows the potentially available solar energy along with the user s needs The second one gives the average state of charge of the battery low values could lead to a quicker deterioration of the batteries and PLOL monthly distribution The table holds all monthly values including then needed back up energy Finally the rough economic evaluation 22 gives an idea of the investment and energy price You can now play with the parameters and immediately see the results You can printa report or store graphs and tables in the clipboard to export it to another software You can also save your project and load another one for immediate comparisons Computation The evaluation of the available irradiance on the collector plane uses the Monthly Meteo 184 tool algorithms which calculate irradiation s monthly averages on the basis of instantaneous data for one day per month This is not sufficient to manage the storage balance evolution from day to day and the effective use of solar incident energy Therefore the program generates a random sequence of 365 days according to the algorithms of Collares Pereira renormalised to the monthly sums and calculates the daily battery balance for three intervals in a day morning day and evening The accuracy is of the order of 10 20 worst ca
315. n of the electrical production of the field and its specification is not critical Our model resulting from a simple thermal balance gives remarkable results By using the default value suggested by the programme k 29W m7 k for all the collectors without back covering and by adapting this value for the integrated installations we obtain in all cases errors lower than 1 C with hourly dispersions of 2 to 4 C atthe most Chapter 10 Validations 198 199 Validations 10 Module temperature Total 3576 points 17 eliminated Hourly average 22 4611 C Meas Model Error aver 0 2863 rms 1 5629 C Meas Model Error aver 1 27 rms 6 96 Measured values C 10 0 10 20 30 40 50 60 Simulated values C Fig 2 Comparison of the measured temperature with respect to the model Marzili Installation Array output calculation The electrical output measured at the collector array terminals DC energy is calculated by the simulation on the basis of the incident irradiation given the shading and non normal incidence corrections the temperature of the modules and the collector model operating at MPP keeping in mind the ohmic losses of the wiring and the module s mismatch The excellent results obtained especially in LESO sheds the SIG or at the EIV show that these models work perfectly at least for silicium crystalline modules Chapter 10 Validations Validations 10 Leso field 3 E Out Field da
316. n of the physical variables These two lastimprovements were made possible thanks to a very deep revision of the internal data structure in Chapter1 Overview 10 11 Overview 1 order to obtain more flexibility when using the simulation variables This reorganization is transparent for the user but allows now many enhancements of the simulation process namely easy adding of new variables when necessary including them dynamicallyin the simulation process according to specific system configurations for example defining regulator losses when used in a battery system or inversely discarding other ones when they are not relevant The old fixed variable set did not allow a coherent description of the system losses Therefore simulation has to be performed again for getting the Loss Diagram on the old result files Caution In spite of intensive tests these deep modifications may have produced some bugs which have not been detected by the author We thank the users for carefully reporting any misrunning or strange behaviour of the software to the author 8 Measured data simulation comparison Improvement and debugging of the Measured Data Importing Tool and the comparison between measured and simulated values Improvement of the break down data eliminations 9 Daily and Hourly Plots of the load profiles Version 3 3 February 2004 by respect to Version 3 21 1 Output results presentation and hourly plots When displaying simulatio
317. n results the standard printable result forms are now directly accessible while they were only available through the preview option in the print dialog up to now During simulation process the program can store a sample of chosen variables in hourly values This allows for displaying graphics in hourly or daily values with several variables on the same plot Thanks to a very fast and easy navigation over the whole year this offers a powerful tool for visualizing the instantaneous behaviour of the system all over the year This helps for example identifying unexpected behaviours of the system in some specific operating conditions for example SOC and regulation states in stand alone simulations 2 Stand alone systems implementation of MPPT and DC DC converters Up to now the stand alone systems were only defined with a simple usual configuration i e PV array directly connected to the load and battery through the regulator Itis now possible to include a MPPT or DC DC converter between the PV array and the battery load This converter is part of the regulator definition 3 New tool for optimising Fixed Input Operating voltage Shows the average power or efficiency of the PV array over a period year summer winter as a function of a fixed user s voltage Shows ohmic and diode voltage drop effects 4 Hourly profile for domestic use load definition In order to better estimate the battery behaviour and wear Automatic placeme
318. n the model This is the case when the pump model is given bya set of Flowrate f Power curves completed by additional I f U curves on the pump input For Positive Displacement pumps the converter replaces the booster as the starting over current is usually required at very low voltage so that the starting power is not prohibitive Description of the pump model Description of the pump model See also the General Requirements 164 governing the elaboration of this model Variables Let us define the following variables Up Ip Voltage and current applied the pump Pp Up Ip Input power of the pump Chapter 6 Tools and databases 160 161 Tools and databases 6 Uc Ic Pe Voltage Current and Power applied to the input of the power converter if any FR Flowrate produced bythe pump HT Total Head sum ofthe Static Head related to the difference between input and output water levels and Dynamic Head due to friction losses in the pipes and system Dynamic head is dependent on the flowrate and will be computed by the system simulation process Model Structure The pump characteristics may be considered as a set of operating points represented as a surface in the 4 variable space i e corresponding to the equation Up Ip HT FR 0 This function will be defined on an operating domain which is bounded by some limits usually specified by the manufacturer Maximum voltage applied to the motor pump
319. named Power Box can manage 1 to 4 PV modules and performs the MPP tracking at the module level The output current is fixed by the inverter and the output voltage is adjusted accordingly in order to deliver the maximum available power from each module In the simulation model the efficiency loss of the PowerBox will be included in the inefficiencies of the global inverter The Power Boxes in a string operate completely independently one from the other so that at a given time the module productions may be different without any affect on the system shadings mismatch different orientations etc The main relevant parameters of a PowerBox are Input parameters VmppMin VmppMax and VabsMax which determine the possible number of PV modules to be connected at the input in the same way as for any MPPT inverter input PPBmax the maximum power admissible on the device May be the Nominal power of the PV modules or better for optimal sizing the maximum attainable Power of these modules in this system under real conditions VPBoutMax the maximum output voltage of the PowerBox for example 60V VPBoutMin the minimum output voltage of the PowerBox for example 5V PBoutMax the maximum output current of the PowerBox The main parameters used for the sizing of the inverter are PmaxAC The nominal output power to the grid PMaxDC the corresponding power at the DC input i e PmaxAC efficiency at PMax VinvNom fixed
320. nancial balance 103 G Generator 157 Generic default regulator 166 Genset 157 Geographic site 104 110 112 114 Grid current 190 Grid inverters 60 149 151 152 190 Grid voltage standards 63 Grid connected system 18 57 59 60 89 H Head Units 72 Hidden Parameter 173 Historical evolution of the software 3 Horizon 38 39 Hydraulic energy 72 IAM 82 83 Importing data 126 127 169 180 Importing Meteo 117 118 119 120 122 123 124 126 Importing Projects 181 Incidence Angle Modifier 82 83 Internationalization 172 173 Inverters 60 149 151 152 190 Irradiance loss 190 L Languages 172 License 14 16 17 Load 54 55 56 57 Load profile 65 Losses 82 84 85 93 190 208 209 Index Measured data 92 169 170 171 Measured data analysis 1 Measurementtool 47 Meteo 104 Meteo Data 109 110 112 114 126 131 184 186 111 112 114 117 118 119 120 122 123 124 126 190 Meteo Database 111 112 114 117 Meteonorm 117 Mismatch 82 84 Models 52 184 186 Module quali 68 133 136 149 153 154 164 183 tyloss 192 Module strings 46 MPPT Conve N rter 166 Nearshadings 31 32 33 37 40 41 42 43 44 45 46 47 48 49 52 NOCT 85 O Ohmic loss 82 84 One diode model 136 Orientation Orientation o P 30 193 ptimisation 33 Partial shadings 37 40 41 42 43 44 45 46 47 48 49 52 Plane orientation 30 193 Power Converter 166 Preliminar
321. nce Horizontal Diffuse Irradiance optional may be constructed bya model Ambiant Temperature Wind velocity optional for module temperature calculation These data are stored in meteo files 109 written with the internal PVSYST format MET files When creating a project you will usually first choose a Site in the database By default if no matching meteo file same name as the project site is available in the library a Synthetic Hourly Datal1s8 file will be automatically generated from the monthly meteo data defined for the Project site Chapter 4 Project design 28 29 Project design 4 But you can also choose an existing meteo hourly file in the library for example 22 Design Reference Years for Switzerland in the PVSYST library You can also obtain Hourly Meteo files in several ways all available in the Tools part of the software Importan synthetic hourly meteo file from the Meteonorm 1 software For the US import a US TMY2 114 file Typical Meteorological Year available from the web free For the whole Europe import measured data from the Satellightli20 project free Convert any custom meteo ASCII file h28 your own measurements or Design Reference Year of other sources etc using the PVSYST special converting tool Project Site and Meteo When creating a project 28 the Geographical Site and Meteo may be defined in several ways Please remember that a geographic site is attach
322. nce Angle Beta Letus call Profile Plane the plane passing through an horizontal line perpendicular to a given azimuth and the sun We call Longitudinal incidence angle the angle formed by the projection on the profile plane of the normal to the collector plane or the azimuth line with respects to the sun s direction LOL Loss of load probability stand alone LOL Loss of load probability This value is the probability that the user s needs cannot be supplied i e the time fraction when the battery is disconnected due to the Low charge regulator security It may be understood as the complement of the Solar fraction although itis described in terms of time rather than energy During the sizing process the LOL requirement allows for determining the PV array size needed for a given battery capacity The LOL is calculated using a simplified and fast yearly simulation the program splits the monthly meteo values into a realistic random sequence of 365 days according to Collares Pereira model each day being divided into 3 periods morning day with solar gains and evening Then it performs a day by day balance and reports the daily system state in order to accumulate a realistic LOL yearly value This process is repeated with different PV array sizes in order to find the exact PV size matching the required LOL LOL Loss of load probability Pumping LOL Loss of load probability This value is the probabil
323. nd behaves as a current generator for feeding the DC motor of the pump Chapter 4 Project design Project design 4 PV array System Fixed DC converter Tank Full Controller Converter Total Head Level diff PY array Friction losses Aspir level At the input side the voltage may be chosen close to the maximum power point and stays quite near for any irradiance On most commercial DC DC devices the input voltage may be adjusted by hardware PVsyst includes a specific tool optimisation 168 for determining the optimal DC voltage setting Performances are only related to the array and meteo they don t depend on the pump configuration Array average effic by respect to MPP operation 120 Average MPP operation 67 V ion 100 Yearly array Yield at fixed operating voltage A cs 2 sara i Sine i EEEE EEEE E By respect to MPP operat ee ee ee 0 40 45 50 55 60 65 70 75 80 Fixed operating voltage At the output side the power is supposed to be transmitted to the motor at the optimal current voltage point corresponding to the available power For AC pumps a PCU DC or MPPT converter suited for a given pump is usually proposed by the pump s manufacturer Itis supposed to fit the inputs requirements voltage and frequency for proper operation Efficiency Nowadays the converter efficiency is usually of the order of 95 in the high powers region This efficiency dr
324. nd if the section is defined the corresponding length will appear as well as the voltage drop at STC Securities with weak grids Please note that the sizing of the cables up to the injection point may be very important when the grid is weak country regions Indeed when injecting power into the grid the grid voltage will increase due to line impedance Then your inverter is equipped with a safety device which will cut the production when overcoming a given maximum voltage Therefore you are advised to minimize the voltage drop at leastin the parts where you have the opportunity of doing this Albedo The albedo coefficient is the fraction of global incident irradiation reflected by the ground in front of a tilted plane This effect takes place during the transposition computation of the horizontal irradiation onto a tilted plane The albedo seen by the plane is of course null for an horizontal plane and increases with tilt In the project definition the albedo values can be adjusted each month in order to take any possible snow cover into consideration The value usually admitted in the urban localities is of the order of 0 14 to 0 22 and can go up till 0 8 for a snow cover Ideally the best value is obtained by a direct measurement on the site But in practice except for vertical planes this value does not take on any great importance as the albedo component is relatively weak in the incident global irradiation this contribution can
325. nd sets a broad panel of the different available technologies as well as delimits their implementation boundaries 7 Heat transfer factor for thermal losses of PV array Some users has pointed out that the proposed parameter accounting for wind velocities was not correct and lead to underestimated thermal losses There is a new detailed discussion on this subject in the Help and the program now advices to use wind contribution only when the wind velocity is quite well determined now default value is Kv 0 W m K m s 8 Inverters Several parameter usually specified in the datasheet have been added to the inverter definitions But none of them is used in the present simulation Refinements of the inverter modelling are planned for a next version These new data have been added in the whole database when available Almost 300 new inverters were introduced many also suited for US market The database includes now more than 650 inverters The 50 60 Hz frequency has become a choice criteria in the lists 9 PV modules The choice listshows a nominal MPP voltage of each module for making the system design easier Chapter 1 Overview Overview 1 The database includes now more than 1 600 PV modules The PV module definition dialog was improved and some bugs fixed Specifying the Voltage or Power Temperature coefficient is now possible also for amorphous modules 10 Remarks in PV components An unlimited text editor is now available for giving
326. nd the world For the temperatures we don t avail of a model predicting the temperature evolution by respect to the daily irradiation as the temperatures are mostly governed by atmospheric circulations Therefore the sequence of daily temperatures is mostly random with constraints on the transition from one day to another one of course Nevertheless within a day the temperature profile is well correlated to the irradiance this results in a sinusoidal like shape with an amplitude proportional to the daily irradiation and a delay of around 3 hours the warmest hours are at around 3h solar time This involves that the average temperatures waited by the program are indeed the 24h average measurements over the month usual meteo data Diurnal temperatures are not suited as the job is done by the model Please note that this generation is a fully random process two successive generations performed from the same monthly data will result in completely different years When performing simulations of grid connected systems this may produce variations of 0 5 to 1 in the yearly result For obtaining the synthetic hourly data from your monthly definitions Press the second button Synthetic Hourly Data Choose the desired site holding monthly meteo data Press the Execute Generation button There are some options that you will in principle never modify Monthly Renormalization the sum of the generated hourly data doesn t match the r
327. ndard model applied to the CIS module With an analogous correction on Rshunt our CIS module Shell ST40 behaves quasi perfectly according to the standard model The error distributions are far better than with our mono crystalline module With an optimal Rsho parameter we observe on PMax MBE 0 0 and RSME 2 1 and on Voc MBE 0 0 and RSME 0 5 Measurements on a Si H triple junction Our 4 other modules were amorphous 2 identical tiles Unisolar SHR 17 with triple junction a Solarex MST43 MV not yet produced and a RWE Asiopak 30SG both with tandem cells One of the SHR 17 had already been tested during the whole summer in 2001 when the second one had never been exposed to the sun The parameter and performances of these two modules were quasi identical and very surprisingly we didn t observe any initial degradation on the new module Our first observation was that for any I V characteristics itis always possible to find a set of the standard model parameter Iph loref Gamma Rs Rsh which exactly matches the I V curve The RSME between the 30 measured current points and the model is always lower than 0 3 0 4 ofthe ISC i e 0 5 mAat40 W m 4 mA at 800 W m This means that the electrical diode behaviour of the amorphous junctions is quite similar to the crystalline modules The problem is now to determine these parameter dependencies according to irradiation and temperature For correcting the standard model
328. nditions These parameters therefore include Gref and Tref the reference irradiation and module temperature conditions during measurements Ise and Voc module short circuit current and open circuit voltage at these given conditions Impp and Vmpp any operating point in the region of the maximum power point at these given conditions ulsc current temperature coefficient This has only weak influence on the module behaviour When not known it can be taken as about 0 05 C Internal model result tool After defining these basic parameters the program still needs the definition of additional parameters i e Shunt and Series resistance as well as the number of cells in series to establish the One diode model 138 parameters This special tool displays the module operating parameters calculated by the PVSYST model for any given irradiation or temperature conditions See also the PV module parameter summary 134 for a complete description of all parameters Phovoltaic modules Sizes and Technology Important parameters Module size should be defined properly as it determines the module area and efficiency The number of cellsin series is also important for the model calculation A very erroneous definition will give rise to a warning and prevent establishing the model The number of cells in parallel has no influence on the model When defined the cell area allows the calculation of the cell efficiency But this data
329. ne irrad MBE simul 5 6 1 0 0 7 0 7 3 1 14 13 6 meas 8 7 10 0 2 2 5 0 3 4 10 8 8 9 RMSE daily 11 0 15 5 5 2 9 8 6 5 17 7 13 4 values RMSE hourly values System AC output MBE simul meas RMSE monthly values RMSE daily values RMSE hourly values Table 1 Summary of the 7 tested installations comparisons between simulation and measurements A positive MBE indicates that the simulation overestimates the measured values Chapter 10 Validations 196 197 Validations 10 Incident irradiation models The first delicate stage is the treatment of the incident irradiation in the collector plane it involves models for the estimation of the diffuse irradiation from the global irradiation and for transposition These models have been otherwise studied Perez et al but proved to be the weakest link in the comparison process with differences reaching more than ten percent for some of the data used For the SIG installation at Geneva the only site where measurements of the horizontal diffuse irradiation is available the deviation does not exceed 2 to 3 But other sites show differences going up to more than 10 It should be emphasised that these results are highly dependent on the quality of the instruments used for the irradiance measurements especially the calibration and sometimes the positioning We supposed that the standard deviation in hourly values is a good indicati
330. ned EffSysR System efficiency E User rough area EffSysC System efficiencyE User cells area 0 when cells area not defined EffBatl Battery current charge discharge efficiency EffBatE Battery energy charge discharge efficiency Normalised performance index 94 Chapter 4 Project design 98 99 Project design 4 Yr Reference Incident Energyin collector plane GlobInc kWh m day Yu Normalized Potential PV Production battery never full kWh kWp day Ya Normalized Array Production EArray kWh kWp day Yf Normalized System Production EAvail kWh kWp day Pr Performance ratio Yf Yr Lu Normalized Unused energy Yr Yu Le Normalized Array Losses Yu Ya Ls Normalized System Losses Ya Yf Lur Unused full battery Loss Inc Energy Ratio Lu Yr Ler Array Loss Incident Energy Ratio Lc Yr Lsr System Loss Incident Energy Ratio Ls Yr Simulation variables pumping systems The following variables are calculated during the simulation process 9 of the pumping system and are available as results The Irradiance and PV Array variable 94 topic describes all the preceding simulation variables which lead to the last quantity really independent of the system running conditions the Array virtual energy at MPP The set of variables involved in the pumping system simulation as well as their signification and order is dependent on the System Configuration 7A The energies in blue at different levels of the system
331. nexl75 Regulation Direct coupling between the PV array and the pump is only possible with DC motor pumps The simplified electrical layout is the following Chapter 4 Project design 74 75 Project design 4 E tortura eet WOM tee te yee Tank Full PV array System Direct coupling aa Controller I Array Total Head Level diff Friction losses Current PY array pump oso Voltage The following figure shows a typical pump behavior superimposed on the I V array characteristic An equivalent figure with your real components is available in the System definition dialog in PVsyst when you are choosing your Pumps and PVmodules PV array and Pump Characteristics 1000 W m 55 C 12 800 Wim 50 C 600 Wim 45 C 400 W m 40 C 200 Wim 35 C Current A Pump characteristics Head 20m DC DC converter 0 10 20 30 40 50 60 70 80 90 Voltage V Such a configuration implies in a very careful optimization At any time the operating pointis the intersection of the two characteristics PV production and pump consumption If the pump curve is too high array current undersized the pumping threshold will be high penalizing the low irradiances low season bad days and morning evening If itis too low the full potential power of the arrayis not used during bright hours The optimal sizing is therefore depending e
332. ng fees An eventual underworth corresponding to the substitution of an allowance for example facade element replaced by PV modules comes in deduction from the rough investment The net investment for the owner is derived from the gross investment by substracting eventual subsidies and adding a tax percentage VAT Choosing a loan duration and interest rate the program computes the annual financial cost supposing a loan pay back as constant annuities The loan duration Chapter 4 Project design 102 103 Project design 4 should correspond to the expected lifetime of the system This procedure is justified by the fact that as a contrary to a usual energetic installation when purchasing a solar equipment the customer buys at a time the value of the whole energy consumed during the exploitation The running costs depend on the system type Fora grid connected system usually very reliable they are limited to an annual inspection eventually some cleaning of the collectors and the insurance fees Some Inverter suppliers provide a long term payable warranty including replacement which are assimilable to an insurance Fora stand alone system one should add a provision for the maintenance and periodical replacement of the batteries This last contribution is calculated by the program as a function of the expected lifetime of the battery pack calculated by the simulation Moreover when using an auxiliary generator the progr
333. nge to a suited dialog for the SolarEdge architecture and predefine the number of required inverters for your system size You have first to choose the Power Box to be used in your system in the PV module group Then in the Array design part please define the Power Box input configuration i e the number of PV modules connected to each Power Box according to number of available inputs Then you define the inverter input The number of Power Boxes in Series The limits described above are shown on the right of the edit box The nominal power corresponding to a whole string is shown as well as the part of the inverter capacity in percent This very important information indicates how many identical strings you can connect on one inverter For example if more that 50 only one string of that length can be connected to each inverter The number of Strings in Parallel When one only string is allowed per inverter this will be limited to the number of inverters Below 50 capacity this will be 2 times this number or more You are of course advised to use the Show Sizing tool for visually checking the sizing of this sub field Systems with different strings When you have strings with different lengths you should define different sub arrays one for each length to be defined In this case within a subfield only a part of the inverter will be used for each string Therefore you should define Uses fractional Input option an
334. nnected or not during the non utilization days When defining seasonally or monthly values you have a facility for copying an already defined profile to one or several other seasons months For this please click on Copy choose the source profile and select the target seasons Daily distribution When used in pre sizing process the daily load profile is assumed to stay constant over the day That is from the computation point of view the Domestic User Load is equivalent to a yearly seasonal or monthly constant profile except if week end use is defined When used in the project design part detailed simulation it is possible to customise an hourly profile 5e valid for the whole year for example enhancing the evening use of lighting TV etc This can affect the battery use results and wear owing to charge discharge distribution Details of the defined appliance profiles can be saved on a file for reusing in other projects or printed either in the load dialog or along with the simulation results Chapter 4 Project design Project design Consumption of some appliances Power Consumption Fluorescent lamp 7 18W Television acc to screen size 40 120 W Video recorder 20 25 W Personal computer 120 W Fridge deep freeze consumption 0 4 1 2 kWh day Micro wave oven 1 kW Washing machine dishes clothes 2 2 kW Consumption 1 2 1 8 kWh washing DHW solar system pump regulation 30 W Stand by 5 W
335. note that with MS Word you are advised touse Paste special and then uncheck the option Dissociate from text as image frames are very difficult to manage in this software Memory resolution options But be aware that such an image of an entire page takes up quite a lot of memory Thatis why the Options provide the opportunity of choosing the resolution Please note that 200 DPI will give good outputs when printing but consumes about 3 2 MB of memory 100 DPI will give coarse outputs but occupies only 790 kB for each page 150 DPI give almostas good results as 200 DPI but for 1 8 MB After pasting in MS Word this image is compressed and the resulting MS Word DOC file will be about 60 to 70 kB per PVsyst page image at 200 DPI Color options The image may be stored either in Colors or in Black and White Of course most of the external software acceptimages in color But the different colors in graphs will not be reproduced on Black and White printers nor will the colors be distinguished Therefore when printing PVSYST looks for the actual printer capabilities and modifies the graphs accordingly with color printers it keeps the colors displayed on the screen With B amp W printers it will adapt the graph lines using variable line widths and dotted lines or the bars fillings with grey levels Thatis the reason why the final graph destination has to be precised at the time when PVSYST builds the image The options give t
336. nput parameters accordingly This offers a powerful way to exactly determine the real system parameters as well as temporarily misrunnings 5 Elimination of break down events 174 most of time measured data hold undesired records break down of the system or the measurement equipment easily identifiable on the graphs These can be selectively eliminated in order to obtain clean statistical indicators mean bias and standard deviation corresponding to normal running of the system Checking the measured data files To check generated files in detail you can use scrolling tables of monthly daily hourly values as well as a set of control graphs for each parameter time evolutions histograms etc Time interval definition check The synchronisation of your data with the solar time is of great importance for solar geometry calculations especially for the transposition model Time definition checkingho is performed through the same tool as for Meteo files System data and running checks On the other hand some specific graphs usual when analysing measured data are also available which allow to use PVSYST as a complete tool for the presentation of data These are input output diagrams which shows the system production as a function of the input irradiation immediately gives indications about the misrunning days Normalised performance 94 monthly and daily graphs summarising the system running performances in a normalise
337. nt of lighting and TV uses to evening hours 5 Improved irradiance clear sky models for very high altitudes up to stratospheric For very special uses of the software 6 Meteonorm input adaptation The outputs format of the Meteonorm monthly files has been changed with the new version 5 and we had to match the reading format accordingly This is not yet quite fixed namely the new Meteonorm files don t include the Station name nor the geographical coordinates which have to be input manually 6 Databasse update Added about 500 new PV modules from the PHOTON magazine tables of February 2003 and February 2004 Added about 40 Inverters from PHOTON magazine march 2003 Created a listof the main component manufacturers This list is now selective according to Manufacturers Retailers and Component type Version 3 21 November 2002 by respect to Version 3 2 Chapter1 Overview Overview 1 Shading factor calculations with partition in Modules chains Some computation errors had been introduced with v3 2 fixed Horizon definition with more than 20 points now possible Minimization iconisation of the Program window now works Corrections for compliance with Windows XP environment Version 3 2 July 2002 by respect to Version 3 11 1 Thin film modelling The main novelty is the special tools for the treatment ofThin film technology modules 14H a SI H with tandem or tripple junctions CIS CdTe Up to now the program used t
338. nt will be mainly affected by the worst cell Partial shading electrical effects limiting each string current to the more shaded cell are of course depending on the sun position They are not explicitely calculated in PVsyst but can only be roughly evaluated using the Near shadings according to modules 46 MPP loss i e the difference between the effective operation conditions and the maximum available power point For MPP use grid inverters this loss is neglected in PVSYST For fixed operating voltage it can be quantified from the output simulation results see EArrMPP EArrUFix MPPLoss 97 Ohmic wiring losses 84 as thermal effects essentially result in a voltage drop of the I V array characteristics The real effectis different whether the array operates at MPP or fixed voltage At MPP operation PVSYST applies the wiring loss before computing the MPP At fixed voltage the effective losses are strongly dependent on the array overvoltage by respect to the operating voltage Regulation loss is the energy potentially available from the PV array but which cannot be used by the system In MPP applications this could be the array potential PV production outside the inverter input voltage limits or during power overloads This is usually accounted in Inverter losses thatis in system losses In stand alone systems it corresponds to the excess energy which cannot be used when the battery is full In DC grid installation th
339. ntended to specify your shading constructions in your model library Once this scene has been well established i e the scene is complete PV field area and orientation are compatible with the rest of the system the Table button allows you to calculate the shading factor table faa This process also calculates the diffuse attenuation factor 4A constant over the year After that you will be able to see the Iso shading diagram 4 and run the simulation If you have defined a partition in module strings 4 during your 3D construction two tables will be calculated simultaneously one with the conventional linear shading factor and one with the shading factor according to the module strings Please note that although these factors for beam component are different the diffuse attenuation factor is unique related to the linear factor because diffuse irradiation is supposed to be rather uniformly distributed on the field area Finally the Use in simulation group allows you to run the same variant under different shading conditions without shadings linear or according to modules without modifying your shading construction Near shadings global scene building See also Near shadings general organisation 37 The global scene gathers all the objects according to their relative position in a referential 53 based on the cardinal points In Construction mode the shading obstacles are represented in black and the sensitive area of the
340. nts are much more critical than for the sheds disposition as significant yield may be waited even when the sun is very low on the horizon The Backtracking 45 control strategy helps improving the electrical behaviour of tracking arrays Near shadings object positioning Each object PV plane elementary object or building is builtin it s own referential which has to be positioned in the global scene Please choose the Position speed button or use menu this will show the positioning dialog Positioning operations are greatly facilitated when using orthogonal views in order to drag the object in the scene red dots Plane view also allows to rotate the object violet dot Final fine tuning may be achieved by parameter edition From a mathematical point of view parameters are defined such thatthe objectis first displaced in the main referential then itis rotated by the given aamuth angle and finally tilted around the new OX rotated axis This process is the same for positioning an elementary object in a building object Important notice When positioning PV planes among other objects please always leave a little space between the plane and the support surface Indeed shading calculations involve complex calculations ofintersections and reunions between 2D projections of these objects Confused points and also points confused with a surface often cause problems to these routines and may sometimes lead to topological errors On
341. nversion dialog Give a significant name to the internal file to be created This will identify the file in the meteo or measured data list boxes Please carefully choose this title since you won t be able to change it after conversion Choose the geographical site If not available in the database you can take a near site and change it s parameters site name coordinates etc This site will stay internal in your meteo file so that these modifications will not be thrown out to your site database unless you explicitely save it as file Choose your ASCII source file which can reside anywhere on your disk Choose the target internal PVSYST file which will be in the Meteo directory meteo MET files or in the Datameas directory measured data DAM files Choose or define the Format Protocole 2 interpreter In some cases depending on the Format protocole the program will still ask for the beginning date or the year When ready press the Start Conversion button During execution a control executing window displays the contents of the source file s line currently being processed as well as the actually converted meteo values which will be transcribed on the internal destination file You have the opportunity of examining the process step by step in order to ensure that the values are correct The ASCII interpretation has been made as reliable as possible regarding to all unexpected events which may arise on
342. nverter Description of the pump model Regulators for stand alone systems Converter step down technology MPPT or DC DC converter Generic default regulator Regulator for Pumping parameters Converter in the pump s definition Control device for pumping systems Seller list Array Coupling Voltage optimisation Comparisons between measured and simulated values Measured data analysis general philosophy Checking the measured data files Predefinition of comparisons Transformations of data files Data elimination in Tables Cuts of erroneous data Technical aspects Updating Software and Databases Languages Special characters problems Contents Chapter 8 Chapter 9 173 173 174 174 176 177 179 180 180 180 182 182 183 183 184 184 184 185 186 186 187 187 187 187 188 188 188 188 188 189 189 189 189 Hidden Parameter Default values and costs Uninstall File organisation Export Im port of data files Directories contents File delocalization with Vista and Windows 7 Seing hidden files and directories in Windows Explorer Log Files Copy the data structure Printing Print_Head Copying Printer pages to Clipboard Physical models used Incident irradiation models Meteo Monthly calculations Transposition model The Hay transposition model Diffuse Irradiance model Synthetic data generation Glossary AC ohmic loss from inverter to injection point
343. o Version 3 01 3 02 and 3 03 Database updates will be periodically available on the WEB site www pvsyst com A special tool allows to dispatch the files into the PVSYST data structure Printed outputs Printed results forms may also be exported as image for pasting in other software like MS Word Allows to fully insert PVSYST results in documents useful for example for sending them by e mail Im port of Meteo data Import from Meteonorm software now quite debugged except for bugs of the Meteonorm software itself with monthly data the program tells you how to come over Direct import of US TMY files 240 US sites available free from WEB User s needs definitions Graphs and printings are now available Anew feature allows for importing Load Profiles in hourly or daily values from ASCII files e g for example from EXCEL Horizon definition Diffuse and Albedo factors are newly introduced Horizon treatment in simulation strategy has been changed itis now equivalent to the near shadings treatment i e included in the shading loss calculation Near Shading tool Further debugged Undo facility up to 10 levels Very useful new tools for distances and angle measurements on the scene Simulation Losses New parameter accounting for the real quality of PV modules South hemisphere compatibility Fully debugged with new azimuth definition negative toward east clockwise Sunpath diagrams are now from right to left negative azimuts
344. o Version 5 03 November 10th 2009 Hidden parameters were not modifiable bug Regulator definition had intempestive warnings preventing using it Heterogeneous fields compatibility and warnings Orientation lt gt Shadings Tracking frames with N S frame the tilt limits were not active Inverter database partial update about 30 from Photon Magazine 2009 Version 5 03 November 2009 10th by respect to Version 5 02 October 2009 26th 1 Corrections in the Grid system sizing tool MPPT inverters not yet perfect 2 Some background colors make things unreadable in Vista and Windows 7 Version 5 02 October 2009 26th by respect to Version 5 01 October 2009 12th 1 System definition freezed when defining multi MWc systems No more limit to the system size 2 Improved the system sizing tool 3 Corrected further bugs in the report sometimes over printing at head of the page 4 Improved the ordering tool sometimes e mails were not well sent and we did not receive your order Version 5 01 October 2009 12th by respect to Version 5 0 October 2009 6th 1 We just discover a important bug in some cases synthetic generation without specified Diffuse monthly values the Diffuse is very low leading namely to over estimated transposed values GlobInc Please reinstall this new version and open the projects elaborated under V 5 0 If this occurs the program will give a warning re calculate the meteo file and you should
345. o be cycled have an important self discharge and their lifetime is limited to about 4 5 years Their use is economically justified in low used installations holiday houses or caravans Chapter 6 Tools and databases 156 157 Tools and databases 6 For industrial or professional uses the special solar batteries with grids or tubular open or sealed without maintenance are more expensive at buying time But due to their lifetime the real stored energy costis often lower In the warm countries where the overcharging and evaporation risks are important the open batteries will be preferred to the sealed maintenance free models thus the user can always complete the electrolyte by distilled water Back up generator In PVSYST the back up generator is only considered as an alternator rectifier element ensuring the recharging of batteries when the solar energy is insufficient to satisfy the user s needs Itis supposed to work only at nominal power Its parameters are no more than the definition of the nominal power supplied as well as a specific fuel consumption in volume per hour to evaluate the back up consumption Provision is made for defining commercial available devices sizes weight etc butno one is proposed in the database Pump definition General frame The pump device is considered as a black box with Current and Voltage inputs on the electric side and Head and Flowrate values at the hydraulic side cf Pump model
346. o fag htm data The Gls database covers two regions in different ways European subcontinent Geographical data digital elevation model 1 km x 1 km for horizon evaluation administrative boundaries CORINE and Global land cover cities etc Chapter 5 Geographical and Meteorological data 118 119 Geographical and Meteorological data 5 Spatially Continuous Climatic data monthly global irradiation from 566 ground meteorological stations 1981 1990 averages from the ESRA project diffuse global ratio air temperature Linke atmospheric turbidity useful for a future improvement of the clear day model Other computed values not directly useful for PVsyst optimal inclination angle for PV collectors yearly irradiations on different inclined planes PV yield etc Mediterranean basin Africa and South West Asia Geographical data elevation model 1 km x 1 km or 2 km x 2 km administrative boundaries Global land cover cities etc Spatially Continuous Climatic data monthly global irradiation from Helioclim 1f241 database Ecole des Mines de Paris Armines based on METEOSAT images 1985 2004 with resolution of about 30x30 km Air temperature Linke turbidity Several data sources of different kinds have been used to develop this database which are listed on http re jrc ec europa eu pvgis info fag htm data You will also find here an estimation of the global accuracy of the results Owing to their continuous s
347. o normal size is onlyin the menu The Hand button allows to displace the scene on the screen During the shadow drawing you have the possibility of viewing the scene from the sun direction User s needs load The programme offers great flexibility to define the needs of the user or the load of the system You can choose among the following options Unlimited load which only concerns installations connected to a sufficiently strong grid to absorb all the power produced This is the default option with grid systems But this option obviously makes no sense with a stand alone installation where production and especially battery behaviour are closely related to electricity use Fixed constant load offers the simplest way to define user s needs You just have to define it as constant power or yearly energy Monthly values gives the possibility of defining monthly averages which will be used by the simulation as constant over each month no daily modulation Values are defined using a special graphic tool 57 Daily profiles in hourly values can be user defined using a graphic tool s7 as Constant over the year the same profile all along the year Seasonal modulation four specific daily profiles for each season defined as June August September November December February March May Monthly normalisations one only daily profile the amplitude of which being modulated according to given monthly sum values Weekly modulation
348. oduction of the PV field is non linear and depends on the interconnections between the modules In the PV array the current of each cell string is limited by the current of the worst cell in the series Thatis when one only cell is shaded the entire string is strongly affected which has also dramatic effects on the IV characteristics of the whole array This may be understood using the specific tool Electrical behaviour of PV arrays in the Tools section Even with by pass protection diodes this string does not participate more than marginally in the production of the PV array This phenomenon is too complex to be treated in great detail with real string distribution of modules in space Chapter 4 Project design 46 47 Project design 4 during the simulation process Nevertheless the program provides a simplified method giving the possibility of partitioning the field into rectangles each of which supposed to representa string of modules in series Then it calculates a Shading factor according to strings stating that as soon as a string is hit bya shadow the entire string rectangle is considered as electrically unproductive Although not perfect this second approach should give an upper limit for the real shading loss evaluation In practice one often observe that except for regular arrangements like sheds this upper limitis not so far from the lower limit thatis the linear loss Since version 5 0 you have the oppo
349. of the shading factor calculation grows with the square of the number of elements When you define sheds in the 3D scene you have to choose a fixed tilted plane not sheds in the Orientation parameters with the real values of tilt and azimuth of one shed Near shadings Tracking planes The basic definitions of tracking planes are very similar to the sheds _definitions 4 several identical trackers with a sensitive area and an inactive frame for mutual shadings Chapter 4 Project design Project design 4 There are four kinds of tracking planes in which the disposition may be differentas the sheds This is the reason why when creating a new tracking array your first action should be to define the Tracking Parameters This dialog is analogous to the one of the Orientation general parameters it will define the kind of tracking the mechanical stroke limits of your trackers and eventual parameters for backtracking or concentration The four tracking kinds are Two axis by default the alignment is defined along the east west direction with a given pitch between trackers But you may also define a misalign value for a diagonal disposition or even a set of trackers one behind the other by setting the pitch 0 Tilted axis this corresponds to most of the one axis tracking PV arrays for which the trackers are usually aligned along the east west direction This option should also be used with horizontal north south axis T
350. olarEdge architecture special option for decentralized architecture with Powerboxes 4 Fixed bugs in Inverter definition Projects Latitudes over polar circle etc Version 5 14 June 30th 2010 by respect to Version 5 13 June 25th 2010 1 Onsome machines for unidentified reasons firewall proxy the AutoUpdate function induces crash at the opening of the software Version 5 13 June 25th 2010 by respect to Version 5 12 May 25th 2010 Autoupdate freezing at opening on some Windows installations web access AC loss now possible after inverter or after external transfo AC loss bug when identifying mono tri situation Heat loss default values bug not always possible to change value Stand alone economic evaluation bug fuel consumption Stand alone Available energy and Time fraction bugs when very bad design Simulation Bug Hourly plots for some variables 07 005 Oe Ol OS cee aL SO Ob ONS Chapter1 Overview Overview 1 Version 5 12 May 25th 2010 by respect to Version 5 11 April 27th 2010 1 PV modules definition shows the apparent Series resistance Rsapp different from Rsmodel Efficiency plots vs irradiance display low light values Improved parameter definition in the help 2 Still bugs for the automatic update freezed the program in some cases Version 5 11 April 27th 2010 by respect to Version 5 1 April 16th 2010 1 Thermal U value default definitions for some typical situations
351. old PV sensitive planes When necessary these have to be created and positioned in the global scene independently of the building object Near shadings PV planes See also Near shadings general organisation 3A PVSYST offers 5 kinds of PV fields which are created in their own referential and then positioned 4A in the general scene The PV planes can be defined either by parameters or by dragging the red points in the PV plane view 2D button Rectangular planes you can define as many non overlapping rectangles as you want in the same plane each with its own height length and position Polygonal PV plane you can draw any polygonal shape in the plane To add a point click nsert and then click on the desired segment Planes in sheds several identical planes Each plane includes the sensitive area as well as a frame for the shading on the next plane You have to define the sensitive area sizes the pitch and the tilt and the inactive edge widths You can also specify a lateral misalign between the sheds Use orthogonal views to adjust tilt pitch or misalign by dragging Transversal slope Itis now possible to define a slope between sheds for example disposition on a hill Baseline slope Special case of tilted baseline if the sheds have to be placed perpendicularly on a tilted surface for example a 2 sided inclined roof the baseline of the sheds may be tilted In this case you will define the PV plane tilt by
352. om monthly meteo data See also Meteo Databasel118 and Meteorological data sources M Monthly meteo The geographic site M definitions SIT files holds the site and country names the geographical coordinates and should include monthly meteorologigal data at least Horizontal global irradiation and ambient temperature 12 monthly values each They can also hold diffuse irradiation and average wind velocity when available These monthly data are easily introduced or modified manually and there are tools for importing them from several sources Hourly meteo The hourly meteo 10 files MET files include an associated geographical site as defined above They hold Horizontal global and ambient temperature in hourly values Diffuse irradiance and Wind velocity are optional When not available in the original data the diffuse irradiance is calculated during the building of the internal file When another irradiance beam horizontal or normal beam is available in the original data this is of course used Otherwise the program uses a model Liu and Jordan correlation for diffuse estimation in hourly values the wind velocity only used for the calculation of the PV modules temperature 85 during operation and therefore of weak importance in PVSYST processes is taken as a default value or from the associated site monthly data if specified Due to the poor reliability of primary data the use of wind velocity is not recommended
353. ominal power or the available area as starting point The software indicates the required ranges for the number of modules in series and in parallel Anew powerful window shows all the constraints when sizing a field i e The voltages of the operating array by respect to the inverter s specifications Histogram of the waited power production of the array compared to the inverter s nominal power Estimation of the overload losses and visualization of their effect on the histogram This tool allows to determine precisely the ratio between array and inverter Pnom and evaluates the associated losses 14 The default losses management has been improved especially the Module quality loss which is determined from the PV module s tolerance and the mismatch on Pmpp which is dependent on the module technology 15 Losses between inverters and grid injection have been implemented These may be either ohmic wiring losses and or transformer losses when the transformer is external Version 4 37 June 2009 by respect to Version 4 36 April 2009 1 Changed the program for the installation The old one was no more compatible with the new ServicePack 3 of Windows Version 4 36 April 2009 by respect to Version 4 35 March 2009 1 CdTe modules the module definitions of the old database are affected by the new recombination losses gt Recreated files in the database for all CdTe modules including recombination term according to our recent measurements at
354. on will obey the following equation dHD dt 1 7 HD Q t Aw One can easily see that for steady state conditions dHD dt 0 this equation leads to a drawdown height HD linear with the flowrate Indeed compared to a reference case we have for any flowrate HD Q HDref Qref Under this hypothesis the ratio HDref Qref is a characteristics of the well which we will call the specific drawdown expressed in meter m3 h This parameter is mainly related to the geologic properties of the surrounding ground permeability storage capacity and the construction technique of the borehole It may be measured rather easily using a portable engine pump and measuring the water depth and flowrate in stabilized conditions Borehole parameter in PVsyst As a matter of fact a pumping testis often performed for measuring the borehole performance which yields essentially 3 parameters the static level HS a reference flowrate available from the well Qref and the corresponding dynamic level HDref Navarte 2000 reports several results of such tests in Africa of which we give some examples HS HDref Qref HD Q rm m m3 h m m3 h Angola Rotunda 20 25 7 2 3 5 Chamaco 12 20 6 9 2 9 Lupale 20 24 5 4 8 Morocco Abdi 13 22 21 6 1 0 Ourika 17 2 10 8 0 2 ferd 10 50 36 1 4 We can observe from these examples that the Dynamic contribution is not to be neglected The recovery time t corresponding to a 1 e re filling is easi
355. on factors over the viewed part of the vault of heaven The same thing holds for the albedo attenuation factor ar Then the hourly simulation performs the following steps for each hour Incident effective energy calculation Reading one hour data on the Meteo file Horizontal global irradiation temperature eventually diffuse Chapter 4 Project design 88 89 Project design 4 irradiation and wind velocity Ifnot available computes diffuse irradiation with the Liu Jordan correlation model Ifnecessary applies the horizon correction on the beam component gt defined variables at this stage GlobHor DiffHor BeamHor T Amb WindVel 94 performs the transposition global diffuse albedo irradiations in the collector plane using either Hay or Perez model according to user s preference This is done using solar angles at the middle of the time interval calculated from project s site not the site of the meteo file With explicitely given meteo files TMY or own measurements this could give not very reliable results at early morning or evening if the time properties of the meteo file are not properly defined legal or sun time or if latitudes of the two sites is very different gt defined variables at this stage GlobInc BeamInc Diffinc DiffSiInc Albincl 94 applies the shading factor if near shadings defined on the beam component applies the IAM factor on the beam component gt defined variables at
356. on of the Voltage and Head inputs Functions The general model will give all the relationships between these 4 variables i e calculate any variable from the 3 other ones Therefore it will include the determination of the Current Voltage characteristic of the pump which is necessary to the calculation of the operating point when coupling the pump directly to the PV array Without I V information needs a Power converter In many cases the motor is specified for use ata nominal voltage and detailed I V behaviour is not available The Flowrate is then given as a function of Head and input electrical Power These only 3 variables are in principle sufficient for characterizing the operating point when the power input is fed through some power conditioning unit which will provide an adequate unknown voltage and eventually frequency to the pump motor Thatis a power converter is always required when the Current Voltage are not specified Starting current Besides these 4 operating variables most positive displacement pumps also require special starting conditions i e a starting peak current for overcoming the torque due to the friction forces when stopped Applicability to any technology The model should cover any motor pump s technologylt5 available on the market for use in PV systems centrifugal pumps positive displacement pumps including piston membrane or diaphragm progressive cavity rotating displacer etc These pumps ca
357. on of the performances of the model itself and in this respect the installation of Marzili MBE 1 and hourly RMSE lt 7 8 confirms their validity The mediocre results of the LESO can be explained by the considerable distance several hundred meters between the horizontal solarimeter and the measurement in the collector plane Global irrad in collector planr daily values 350 Total 364 points Daily average 131 353 Wim Meas Model Error aver 1 711 rms 7 638 Wim 300 Meas Model Error aver 1 3 rms 5 81 250 200 150 Measured values W m7 100 50 D 50 100 150 200 250 300 350 Simulated values W m7 Fig 1a Measurement Simulation Comparison for Incident Irradiation Marzili installation daily values Chapter 10 Validations Validations 10 Global irrad in collector plane hourly values Total 3576 points 17 eliminated Hourly average 319 85 Wim Meas Model Error aver 3 038 rms 24 936 Wim Meas Model Error aver 0 95 rms 7 8 600 600 400 Measured values V m 200 D 200 400 600 800 1000 1200 Simulated values W m7 Fig 1b Measurement Simulation Comparison for Incident Irradiation Marzili installation hourly values Array temperature model The second model is the estimation of the temperature of the PV field using values of ambient temperature and irradiation This temperature only acts as an auxiliary parameter in the calculatio
358. on pumps where an alternating piston in a cylinder draws up the water from the inlet or pushes it out of the chamber to the outlet using non return valves Membrane pumps actin a similar way except than the piston s imperviousness is replaced bya moving membrane Progressive cavity pumps use a Special vis shaped rotor in a cylinder which imprisons a volume of water in the input chamber and pushes it along the tube to the output Rotating displacement pumps are made of rotor resembling to a paddle wheel rotating in a cylinder with inlet and outlet openings Positive displacement pumps are well suited for high head systems Their efficiency is usually rather constant for different flowrates Surface and deep well Normal surface pumps are made of a motor and a pump aggregate which are not necessarily integrated in a single case giving the opportunity of coupling different motor types with different pump devices The pump should be placed not too far from the water source and ata maximum of about 5 mWater height for avoiding cavitation problems There are no problems of accessibility for maintenance But in many cases the fact of being placed above the water level requires a priming procedure and some precautions for avoiding air entries For deep wells submersible pumps have to be placed at the bottom of the well These should have of course a cylindric shape adapted to the well diameter and the electrical part should be perfectly wa
359. onal settings This is especially the case for Asiatic users Now PVsyst uses only a very restricted set of special characters within the Ansi set These are essentially the square cube or degrees upperscripts which may appear as local characters on some Asiatic machines They may even lead to a crash of the program as these characters are stored in 2 bytes instead of one The management of this ANSI table is quite confuse in the present Windows versions and it seems to be quite impossible to choose a given table for use in a specific software written in DELPHI Therefore in case of problems the user has the opportunity of disabling the use of special characters which will be replaced by standard ones or equivalent expressions Hidden Parameter Many parameter and physical values involved in the physical models and tools of PVsyst have to be predefined These variables are initialised with reasonable values as determined by the author at design time But most of them may of course be subject to discussion and therefore can be adjusted by the user according to his own situation or hypothesis This is achieved through the Preferences Edit Hidden Parameter option in the main menu This will open a list of variables with their effective initial value modifiable by the user Changes should of course be made by expert users only no validity check being performed at this stage of the program Each value is accompanied by a check box
360. ood by cloudy conditions lower Ktc Finally it should be noted that the final spectral correction used in PVsyst has to be renormalized to the UF of the reference conditions when establishing the model STC AM 1 5 spectrum corresponding to APE 1 6 eV This is the reason why the program will ask for the conditions in case of specifications based on outdoor measured data Four our 3 month measurement campaign the Spectral correction calculated from this parametrization looks like the following Utilizing Factor Correction for a Si H 1 20 AAG hee oot ee eee eigenen eS Sake eee Relative UF 0 80 0 200 400 600 800 1000 GlobP Wim Chapter 6 Tools and databases 144 145 Tools and databases 6 where we clearly identify the clear sky conditions and the sensitivity enhancement for cloudy conditions but acting on low power hours NB In the same conditions for crystalline modules the UF varies between about 0 81 and 0 91 indicating a better use of the whole spectrum But applying this correction to the measured data doesn t improve the results of the model Back to Standard One diode modell30 Back toAmorphous and Thin films modules 14 Thin film modules Recombination losses When it fits well the behaviour of Vco in Crystalline and CIS modules the standard model fails to reproduce the amorphous modules voltage in any irradiance and temperature conditions Amorphous junctions differ f
361. op procedure DC grid Overvoltage regulation The output voltage at the PV field terminals is the end user s voltage bus tramway to which is added the line loss corresponding to the PV current through the line resistance PV to user When the user s needs become too weak this voltage will increase following to the PV array I V characteristics and may reach the array Voc value if there is no more load at all It is therefore necessary to introduce a regulation system avoiding the possibility that this voltage goes over the maximum admissible voltage for the network This regulation can operate according to 3 different modes Global cut of the PV system Progressive decrease of the PV power by cutting off some strings of modules Progressive decrease by cutting off some modules in each string which is not a very practical solution Pumping system definition See also the Generalities 67 about pumping systems The complete definition of a pumping system involves several aspects which are split in a pipe of 5 to 6 dialogs which communicate through Prev Next like buttons Chapter 4 Project design Project design 4 First step Choose one of the three available systems Pumping from a deep welll 69 to a tank storage Pumping from a lake or river 70 Pumping into a pressurized tank 70 for water distribution and define the Hydraulic Circuit configuration Storage Tank 7 and Pipes 72 Second step
362. operation an inverter nominal power about 20 25 below the array nominal power is sufficient Moreover an incident irradiation of 1000 W m is rare on usual arrays For example fa ade installations in medium latitudes don t usually receive more than 800 W m Thus the inverter fine sizing requires a preliminary simulation to determine the Array output distribution Finally an economic optimisation can compare the price of the lost energy to the economy realised when under sizing the inverter Such optimisations showed that for medium Europe the inverter optimum size could be a factor of 1 2 to 1 4 below the array nominal power at STC or even a factor of 2 for fa ades Different sub systems multi MPPT inverters You can define up to 8 different and independent sub systems within a same project with different inverters different modules types different numbers of modules in series Provided that for a given sub system i e a given MPPT input the PV array is homogeneous You may also define sub systems for different orientations 31 but only 2 orientations may be defined at a time During the simulation each sub system will be modelled independently but only the energy and losses sums will be available as outputs If you want to study the losses of a specific sub array you should perform a simulation of this sub system alone This feature also allows the use of multi MPPT inverters you can define a subsystem for some MPPT input s
363. ops toward low powers as other similar devices like inverters It is treated as such in PVsyst an efficiency profile is constructed using the maximum and euro average efficiency defined in a similar way as for inverters By the way efficiency drop often arises at powers which are below the hydraulic threshold of the pump therefore it doesn t affect the normal running Of course the DC DC converter also plays the role of a Booster The starting high currentis usually required under very low voltage therefore low power You can have a look on the Results 79 which confirms that the Fixed Voltage DC technology gives performances approaching the MPPT and is not very sensitive to the fixed voltage Chapter 4 Project design 78 79 Project design 4 Step down technology We have to point out here a design constraint most of the DC DC converters operate on step down principle This means that they cannot deliver a voltage greater than the input voltage Therefore the PV array MPP voltage should be over the maximum voltage required by the pump at the maximum desired flowrate This means for example that when using standard pumps designed for 230VAC grid operation the PV array should deliver at least 325V for obtaining undistorted sinus at the pump This step down limitation can be taken into account by the simulation only when the voltage behavior of the pump is well defined With pumps specified only by power curves itis neglected
364. opy it to clipboard 3 On the first computer the computer for which you have the valid license open the menu License in the main window then Transfer to another machine and follow the steps described in the license transfer wizard 4 When requested by the wizard carefully report the Local Number of the second computer and your License Name Then click Next 5 The new activation code for the second computer will appear please note or save it carefully you can also send it by email and report it for use in to second computer 7 Be careful after clicking Close the program will turn in Demo mode on the first computer the present activation code will become invalid and the software will not be able to run anymore with full capabilities To come back you will have to transfer back the activation code from the second computer NB It is not possible to transfer the code If you are not Administrator of your machine Ifthe opportunity of transferring has been disabled previously on this machine anti theft If your user s code is of a special kind based on the Hard Drive number of your machine It is the pre sizing step of a project It is aimed to quickly define the general features of a planned PV system In this mode the system yield evaluations are performed very quickly in monthly values using only a very few general system characteristics without specifying specific system components A rough estima
365. or accumulation of new comparisons This proves to be particularly useful for the elaboration of monthly comparisons graphs where the elimination of break down days is primordial This chapter describes all technical aspects when using the software Updating Software and Databases Software and databases are periodically updated To check for a new update of the software and or the databases choose Web Check for updates in the main menu This will run the Thraex Software s AutoUpdater tool that automatically checks for new updates on our website www pvsyst com The AutoUpdater tool wizard will open as follows a Welcome Info This program can update all your programs that use Thraex Software s AutoUpdater tool For more information go to www thraexsoftware com To use this program you need an internet connection If you know that you have a proxy server or you have any problems connecting to the internet dick the connection button and define your connection settings Normally you can just click Next Click Next to proceed with updates checking if your internet connection needs a proxy configuration click on Connection If a new update is found the AutoUpdater tool will inform you about the version number available and then will automatically download the setup file Click Install at the end to install the update If the AutoUpdater tool fails to automatically install the updates pleas
366. or desired details about outputs Screen resolution PVSYST has been developed and optimised using the standard SVGA 800x600 pixels screen resolution with small fonts Using old VGA 640x400 is not advised it will superimpose all dialog windows hiding the historical tree of window labels indicating where you are presently located in the software With higher screen resolutions you are not advised using large fonts which can produce unexpected display effects as the software was not quite tested for them For changing the screen resolution please open the msWindows tool Display settings You can usually reach it by right clicking the windows main screen and choosing Properties Chapter1 Overview 2 Overview 1 Historical evolution of the software Of course any newly discovered bug and bugs reported by the users are repaired for each new version Also the contextual Help system is continuously updated either concerning new developments or according to the numerous questions of users Version 5 3 November 30th 2010 by respect to Version 5 21 September 3rd 2010 1 Help system completely new CHM version now fully compatible with Windows 7 APDF version is available on the site 2 New tool for the Meteo data quality check Kt plots clear days check Implemented middle interval shift for optimizing treatment of not centered meteo data 3 Importing meteo data from Global Incident POA measurements bug fixed POA measu
367. or each case the energy loss by respect to the MPP ideal running is independently accumulated as well as the array operating voltage and current Finally if user s load has been defined corresponding to the own consumption of the user self consumed and re injected energies are accounted The main output variables calculated here are InvLoss EArray Eoutinv Euser 96 Simulation process stand alone system Simulation simultaneously manages Array production Battery eventually Back up production and the user consumption At the meeting point battery terminals all voltages are the same and simulation has to perform a current balance For each component the current is a complex function of the voltage PV array search the operating point on the I V array characteristics irradiation and temperature already known paying attention that ohmic module quality and mismatch losses have an action on the actual current for a given voltage Battery voltage characteristics of the battery model depends on state of charge SOC temperature and current Load Given energy states current as function of the voltage Back up generator Given energy states current as function of the voltage so that balance has to be achieved by successive iterations Once the currents are determined SOC and battery voltage are calculated for the end of the time interval Moreover the system behaviour depends on the regulation state They could be
368. or each sensitive field element for example each shed The greatest difficulty with this procedure resides in the calculation of reunions and intersections of polygons in the plane in the general case This operation has proved to be extremely complex to programme using polygons defined by their summits The difficulties mainly appear when the summits or the segments are overlapping or very close as itis the case in most of the object constructions when each summitis a part of several elementary surfaces in the 3D space Topological decisions depend on the proximity of points in space It is therefore necessary to define distance criteria as functions of the resolution of the calculations of the machine or topological criteria etc and the reliability of this procedure is not absolute Thus in some cases the result may be erroneous Often the programme finds it out on its own and again begins the calculation with a slightly different solar position trials with modifications of 1 in height or azimuth If itfails again the shading factor is calculated in a completely different manner the PV field is partitioned in about 2000 points and the shading is calculated for each point Although this method is an approximation it always leads to a reliable result Nevertheless some calculations may sometimes stay erroneous the program doesn t detect the error by itself but in practice this error has usually very little influence on the global si
369. or which the whole charge current is used for electrolyte dissociation Gassing overvoltage profile as a function of the state of charge Phenomenological curve not to be changed Lifetime vs depth of discharge often given by manufacturers for solar batteries The product of the depth of discharge by the number of cycles gives the total stored current during the battery life Static lifetime at 20 C usually given by manufacturers for solar batteries Batteries Model description Model choice justification We have developed a non conventional battery model trying to avoid the pitfalls which arise in a number of existing PV softwares either an extreme simplification which can onlylead to rough evaluations of the system behaviour or adjusted models based on numerous often interrelated parameters whose physical meaning is often not clear to the user and practically necessitate a complete measurement of each battery used We have therefore tried to fulfil the following criteria On the one hand the model should be presented to the user in a very simple manner involving a priori only obvious parameters specific to each battery type of technology voltage or number of elements nominal capacity possible internal resistance and Faradic efficiency whose value is not critical and which can be taken at their default value But on the other hand it should be sufficiently detailed to satisfy the needs of the simulation of the P
370. ording to the PV model This differs from the preceding as it is based on the model parameters instead of PNom PV array losses and MPP running GlincLss PV loss due to irradiance level Difference E Glob Eff T 25 C by respect to calculation at STC efficiency i e decrease of the model efficiency with decreasing irradiance TempLss PV loss due to array temperature Difference E GIlob Eff TMod by respect to model calculated at Tmodule 25 C SpctCor Spectral correction for amorphous Calculated from the_Spectral correction43 model ModQual Quality module loss fixed constant parameter MisLoss Module mismatch loss fixed constant parameter for MPP or fixed V operation depending on system OhmLoss Ohmic wiring loss calculated at each hour with the real array current EArrMPP Array virtual energy at MPP after wiring and mismatch losses Virtual calculation independent of the system running inverter regulator Tarray Average module temperature during operation DTArr Temperature difference between modules and ambient DTArrGl DTArr weighted by effective global irradiation TExXtON Average ambient temperature during system operation Further simulation variables are system dependent Grid connected system Ea Stand alone system TIA PumpingsystemPumping 9M DC grid system MoA Simulation variables Grid system The following variables are calculated during the simulation process 88 and available as results M
371. ositioned on corners or anywhere in the main rectangle representing for example a window a chimney with its shaded environment etc either by mouse or by coordinates These rectangles may also be transformed into a rectangular triangle for example for representing a four sided roof When defining a triangle please choose a comer for the initial shape position After that you can modify it as you like by mouse and coordinates Within an inactive secondary rectangle you may also redefine an included active rectangle for receiving modules After distributing the modules on the area you can still define or modify the inactive rectangles and the module layout should adapt automatically Simulation When all parameters are acceptable LED s all green or orange the program gives access to the hourly simulation Simulation dates are based on the Meteo file dates and can be restricted to a limited period The simulation process s8 involves several dozens of variables which are stored in monthly values in the results file and will be available as monthly tables and graphs Nevertheless the program cannot store all these data in hourly values Data of interest for the user should be defined before the simulation in order to be accumulated during the simulation process PVSYST offers three ways for the output of detailed hourly or daily data Accumulating Hourly values the user may choose a set of variable of interest to be accumula
372. ou have a facility to copy an already defined profile to one or several other seasons For this purpose click on Copy choose the source profile and select the target seasons The same holds for the Weekly modulation mode In the Monthly normalisations mode be aware that the daily sum has to match the pre defined value for the considered month as defined in the preceding dialog So that when changing a single value all other values are automatically modified accordingly In this mode the best suited working unit may be of daily load User s needs monthly values definition See also User s needs 54 When entering this monthly definition tool please first choose the working units At the first entry all values are null You can use the operator facility to modify all values at a time First choose the operator which can be Fix identical values for each month Add a given value to each month Multiply all values by a given value Renormalise all values to obtain a given yearly sum or average Then define the Operator value and click Work out You can also drag each month value on the graph or define a given value by editor NB If you are in daily profile mode the Next button will open the similar Daily values dialog 57 Grid connected system definition The system is defined as the set of components constituting the PV array the inverter up to the connexion to the grid First rule all the st
373. ould be used in order to avoid dirt and mosses accumulations on the bottom side Sun Shields mutual shadings In the Orientation option and for near shadings sun shields are treated in a similar wayas sheds see Shed Mutual Shadings 31 discussion Nevertheless the user should be aware of two phenomena With sun shields the accepted part of the diffuse irradiation is very limited on one hand there is at most only one half because of the rear wall and on the other hand the upper sun shield also cuts an important fraction of the remaining diffuse component In regions with a high diffuse fraction above 45 latitude it is usually more than 50 this gives a very significant loss Please be very careful with orientations not exactly facing the south or north in southern hemisphere You can use the special tool Shading graph to visualise this dramatic effects For simulations if you define near shadings inthe Orientation parameters and you want to define other near shadings please consider the collector plane in the Near shading scene as a vertical plane on the wall Orientation optimisation tool When choosing the fixed plane orientation an information panel indicates the corresponding Transposition Factor the difference loss by respect to the optimum orientation and the available irradiation on this tilted plane Clicking the Show optimization button you can see a graph of the Transposition Factor as a function of
374. ources are not available everywhere Some of them are for given locations other ones perform interpolations or are for discrete grids of variable sizes Climate variability the sources apply for measurements of given years or averaged periods which differ from one source to another one or even for one location to another one depending on historical measurements availability Measurements ground stations or satellite image data interpretations involving sophisticated models Available parameter many sources don t provide temperature measurements or not reliable Chapter 5 Geographical and Meteorological data 114 115 Geographical and Meteorological data 5 Comparison criterion For the comparison we have chosen as reference the annual available irradiation kWh m year This parameter is relevant for PV grid systems as the PV output is quasi linear with the solar energy input For other systems like stand alone the monthly distribution may also be of interest but comparisons would require much more complex statistical methods We don t show temperature results which are of lower importance in PV systems For most comparisons we refer to the Meteonorm data which are the default data in the PVsyst database and therefore likely to be used in any first simulation of a given system Global comparison between all sources The next figure shows a comparison between all available sources for 12 locations in Europe
375. ours will be thrown back on the System LED s button NB All the sizing parameters mentioned above array temperatures Pnom array inverter ratio warning limits may be modified in the Hidden parameters 73 This is especially the case for sizing temperatures in different climates If desired in a second step of the development of your project you can modify the PV array specific loss 82 parameters thermal wiring resistance module quality soiling mismatch IAM with the Detailed Losses button define a user s load 54 profile for determining the owner s own consumption and the injected sold energy to the grid net metering You will usually define a hourly profile in order to take realistic daily production and consumption distributions into account Array voltage sizing according to inverter The number of modules in series has to match the following conditions The minimum array operating voltage i e at max module operating temperature 60 C by default should be above the minimum inverter s operating voltage Vmin of MPPT range The maximum array operating voltage i e at min module operating temperature 20 C by default has to stay below the maximum inverter s operating voltage Vmax of MPPT range The maximum array absolute voltage i e Voc at min temperature 10 C by default has to stay below the absolute maximum inverter s input voltage The maximum array absolute voltage i e Voc at
376. ous reverse bias applied on the shaded cell for example at the V 0 point short circuited module or at the Maximum Power Point operation of the whole array The reverse bias voltage occurs along with a current greater than the nominal photocurrent resulting in a serious power dissipation of the shaded cell resulting in its temperature increase This dangerous situation named Hot Spot can be explained as each cell in the module is producing its rated current at bright sun with its normal voltage all of this power being dissipated in the shaded cell as they are connected in series the current flow is identical in each cell and the sum of voltages shaded non shaded is the module overall voltage i e zero when short circuited Module with protection by pass diode this graph also shows the regulating action of the protection diodes connected in antiparallel to a module or two half modules In this case the reverse voltage at the module s terminals is limited to the diode voltage about 0 7V the excess current being drawn by the diode In this case the power dissipation of the shaded cell is limited to the power production of the other cells inside the protected series If too much cells in series the module s manufacturer will distribute several diodes along the cells string These behaviours help understanding that the effects of partial shadings on an array give rise to highly non linear electrical behaviours and that apparently negli
377. ow to determine this function We would like to avoid references to technology specific parameters thatis to physical models describing the motor or pump Therefore our model is mainly based on the known performances i e the operating points either specified by the manufacturer or measured by other sources If these points are sufficiently well distributed over the operating domain they will completely define the pump behaviour The informatic model has to interpolate between the given points in practice it will perform cubic interpolations between points and linearly extrapolate the data up to the boundaries Therefore this model is just a phenomenological one without any physical contents Physical assumptions will be necessary only if the data setis not sufficiently well distributed for allowing extrapolations within the entire operating domain These very general assumptions will be established according Chapter 6 Tools and databases Tools and databases 6 to general behaviours observed when measuring a great number of pump technologies These could probably be refined during our future works Of course this lack of primary information in the basic data will result in lower accuracies of the model s predictions In practice the manufacturers use to specify the performances of their products by giving different kinds of data sets We identified 5 of them which may be input directly in the PVsyst model Each one has to be treated spec
378. ows to determine any operating point from two given variables Validation The results are impressive The next figure shows a comparison between measured and modelled values for the model established only on 3 operating points at nominal voltage and for a wide range of operating conditions Model FlowRate Pelec Head Measurements 70 4 Head 32m gg 4 Head 22m e Head 12m 40 foo lll eee FlowRate Model l min 0 10 20 30 40 50 60 70 80 FlowRate Measurements l min Model validation on a Solarjack SCS 160 pump CIEMAT Measurements Abella 2004 Asignificant deviation is observed only at lower flowrates powers This is probably due to the converter and Chapter 6 Tools and databases Tools and databases 6 motor efficiency change with power or speed which are not taken into account here Such pumps are most ofthe time driven by AC synchronous motors and may be powered using a cheap standard Frequency Converter FC see Abella 2003 When using a DC motor the Ip Vp characteristics is strongly dependent on the motor technology and seldom known Pump model from FR asf Pp for fixed Heads Pump model from FR as Pp for fixed Heads Grids of FlowRate Power curves for different Heads is the usual way of specifying the solar centrifugal pumps These allow to get a very good determination of the Hydraulic Power behaviour but don t hold any information about the Volta
379. pacing and collecting ground area ratio 3 Components Database tools Export and Import of PV components PV modules Inverters between the PVsyst database and spreadsheets like MS Excel allowing for displaying input and correcting component data in tabular form Improved and securised default values for the input of new PV modules in the database only based on Manufacturer datasheets The Excel sheet shows clear detailed information about required optional and PVsyst calculated parameter Inverters Automatic build of efficiency profile according to Maximal and Euro efficiency data This allows for a much more easy input of inverter data from Manufacturer datasheets Be aware that due to additional parameter PV module and Inverter files written by Version 3 2 are not yet readable with anterior versions butold files can of course be read by version 3 2 Update of the Database which includes now more than 600 PV modules and 200 inverters of the market 4 Miscellaneous Near shadings several little bugs and practical improvements Improved the tools for manipulating and zooming the scene on the screen Implemented the display of shadings calculated by points when standard polygon algorithm fails Included a full example as tutorial for the Measured Data Analysis part which allows for importing measured data in PVsyst and closely comparing them with the simulated values Revision and improvement of the PV array behaviou
380. pecified In this way you can obtain specific lists by clicking only the desired options The PVsyst basic database currently includes some addresses of manufacturers of international interest not exhaustive It cannot of course list retailers in each country Nevertheless you can input your own contacts and mark them as such in order to easily select them Array Coupling Voltage optimisation This tool evaluates the PV array performance as function of a fixed user s operating voltage The MPP operating voltage of a PV array varies along the day and the year according to Irradiance and Module temperature Estimating the performances for a given fixed voltage is depending on The climate will not be identical for tropical and medium latitude The meteo distribution the optimum may be computed for a year or a given season The PV plane orientation The Array composition PV module number of modules in series parallel The protection diode voltage drop The Array wiring resistance at the user level the ohmic voltage drop will lower the nominal array output proportionnaly to the instantaneous current The Relative average power yield or efficiency for different user voltage values is computed using meteo hourly data over a given period Observing the results may lead to the following remarks The Optimal fixed voltage is very near from the average MPP voltage Pure MPP operation gives a rather low yield
381. pen circuit voltage with irradiance which is a straightforward result of the model favours the efficiency at these running conditions The device is mounted on a heat spreader passively cooled which ensures an acceptable operating temperature of the order of 80 C or less Electrical modelling in PVsyst We did not develop a specific model in PVsyst for such a configuration But some manufacturers of concentrating devices 35 use to give performance data for their whole Chapter 4 Project design 34 35 Project design 4 component including concentrators in a way comparable to usual photovoltaic modules That is when a set of concentrators with their PV devices is assembled as a module they give the usual parameters Isc Vco Imp and Vmp referenced to the irradiance on the aperture area Sometimes under 850 W m instead of 1000 W m The I V curve is very sharp with an excellent fill factor Then we do the hypothesis that the standard one diode model applies to this system even though it has no real physical meaning This is motivated by the sharpness of the I V characteristics and by the fact that our model allows to set a customised temperature coefficient as required by the manufacturer Therefore power behaviour according to irradiance and temperature necessary for the simulation process should be close to the reality In this phenomenological model any optical aberrations are neglected NB By respect to standard
382. ph of the sun paths at your location Chapter 4 Project design Project design 4 Horizon line drawing Plane tilt 35 azimuth 20 Sun height Azimuth Defining horizon line by hand The horizon Height Azimuth values may be recorded on site using a compass and a clinometre measuring the height angles or a land surveyor instrument You can move any red point by dragging it with the mouse or define accurately its values in Edit boxes For creating a new point right click anywhere For deleting a point right click on this point You can of course save this horizon as a file fur further use in others projects in PVsyst Importing Horizon from Solmetric SunEye instrument The SunEye records the horizon line using a fisheye camera and provides results as files You should choose the ObstructionElevation csv file Don t use the SkyOx_PVsysthor file which was elaborated by Solmetrics for the old versions 4 xx of PVsyst NB You should correct the data if near objects are represented in the record Importing Horizon from the Carnaval software Carnaval is a georeferred software including altimetric data able to establish an horizon line for any place given byits exact geographical coordinates Latitude and Longitude in France and neighbours You should not use the near objects option in this software for establishing far shadings PVsyst masks Carnaval produces a file named YourProject masque ttt Please ren
383. phical site parameters EN CENE Geographical Coordinates Site Gen ve Switzerland Data source Meteonorm 97 Global Irad Diffuse Temper Wind Vel Lee aol hl p kwh r mth kwhrm mth c m s V Horizontal global irradiation i V Average Ext Temperature January 23 0 19 0 22 3 20 February es 28 0 26 3 50 Pee March 90 0 47 0 6 0 3 50 2 5 aaa Api 1330 B10 35 350 V Horizontal diffuse irradiation May 157 0 76 0 13 1 3 20 M Wind velocity June 170 0 78 0 16 3 3 00 July 183 0 78 0 20 2 3 00 earl eli August 160 0 68 0 13 8 2 90 ein aoe September 117 0 52 0 16 4 2 90 C Md n day October 71 0 37 0 11 7 2 90 C MJ m mth November 32 0 20 0 6 2 3 00 C Wine l December 25 0 16 0 a7 3 20 C Cleatness Index Kt Year 1212 0 580 0 10 6 3 1 2 tk Default from NASA SEE x Cancel lt S OK The Monitly meteo page holds the monthly meteorological data Values for Global irradiance and Temperature are mandatory for use by the simulation Global diffuse and wind velocity are optional They will be evaluated by models when necessary You can choose the units for the edition you will find many kinds of units in other data sources If you define a new site by its geographical coordinates you can always obtain default Global horizontal and Temperature from the Nasa SSE data which are available for any point on the earth bysteps of 1 x1 la
384. possible to specify an eventual back up generator Fifth step open the Controller Regulator Device All system running specificities are defined in the Controller Regulation device This includes namely the boundary operating conditions Tank full dry running Power Voltage Current limits etc In most cases the controller holds parameters specific to the system configuration strategy which should be defined bythe user for example Irradiance thresholds for pumps cascading or array reconfiguration converter input voltages etc Back to Third step After that you should return to Third step for checking the PV array definition Please note that now the PV module listincludes an indication of the MPPT nominal voltage which makes easier the choice of a suitable module fora required operating voltage The PV array sizing is particularly difficult when dealing with Direct coupling 744 configurations in these cases you have to match the Array Voltage with the Pump Characteristics The IMV matching button shows a specific graph which should help for this task For MPPT or DC converters the PV array voltage should usually be chosen as high as acceptable by the converter This way you will have more chances to overcome the Step down 164 voltage limitation Ultimate step after your first simulations You may open the usual Array Losses 8A dialog for modifying special array and wiring parameters perhaps define the wire sizes P
385. puted from the linear shading factor table for evaluating the shadings according to modules Reflexions The reflections on near obstacles usually specular cannot be calculated by PVSYST However though they are spectacular these effects have negligible energetic consequences they are in general involved only for very special hourly periods and in the presence of the beam component moreover their effect on the real output of a sizeable PV field remains negligible when considering that to benefit from it a complete chain of cells in series should be uniformly illuminated by this supplementary supply the production of a chain is indeed limited by the production of the weakest cell In the same way the reflection on the back of a shed on the one hand only intercepts a small efficient part of the beam component and on the other hand only illuminates a non homogenous band in the lower part of the collector Note Notice that the usual acception of the diffuse component on a tilted plane includes the sky diffuse and the albedo Near Shadings 3D construction Global_Referential Referential of the global scene The referential of the global shading scene is based on the cardinal points In the northern hemisphere the X direction corresponds to the WEST Y to the SOUTH Z to the ZENITH As for the usual definition for the PV fields the azimuths are given with respect to the South OY and positively towards the WEST thatis clock
386. qual to the incident energy in the array plane expressed in kWh m day Ya Array Yield is the array daily output energy referred to the nominal power kWh KWp day Yf System Yield is the system daily useful energy referred to the nominal power kWh KWp day Le Collection Loss Yr Ya is the array losses 82 including thermal wiring module quality mismatch and IAM losses shading dirt MPP regulation losses as well as all other inefficiencies Ls System Loss Ya Yf include inverter loss in grid connected systems or battery inefficiencies in stand alone PR Performance Ratio YF YR is the global system efficiency by respect to the nominal installed power For stand alone systems or every system with limited load we also introduce Lu Unused energy the potentially available energy at the array output which can t be used because the system is saturated full battery or limited load in DC grid system This should be determined during the simulation and we have Ya Yr Lu Lc In this case Lcis the collection loss only when the system is able to use the produced energy Important remark about units There is often a unit s confusion with the quantity Yr which may be understood either as the incident energy with units Hours at 1kWh m day or kWh m day or as the ideal array Yield according to Pnom expressed as kWh KWp day This numerical identity results of the STC
387. r graphic tools Included a detailed Help Perez transposition algorithm not the Hay transposition model proposed by default had a little bug which caused a discrepancy of the order of 2 3 on yearly results for vertical planes and of course less for less tilted planes Revision of the tool for defining Currency Rates which had some bugs Chapter1 Overview 12 13 Overview 1 Revision of the general displaying conditions when using screen settings with large fonts Many windows appeared not full developed and had often to be resized Also graphics and tables had sometimes very little fonts Reading of files without Archive attribute which is sometime removed bysome file managers is now possible Version 3 11 by respect to Version 3 1 Meteo generating meteo hourly files in CSV format for export Meteo transposition tables possibility of 180 180 scale Horizon automatic import of files from Meteonorm and HoriZON software PV module Pnom tolerance from manufacturer included as parameter Simulation The user can now define a PV module quality loss by respect to the manufacturer nominal data on which is based the PV module model Therefore the results can be adjusted if necessary for Energy Yield Warranty Installations in Polar regions Possibility of defining meteo and performing pre sizing and simulations for Arctic and Antarctic meteo including months with zero irradiation Version 3 1 by respect t
388. r this choice will automatically be updated according to the chosen regulator capabilities With the Default regulator option you have to choose the desired operating mode here in order that the program can select the suited Generic Default regulator DC grid system definition This is to be applied to some Public Transport networks which operate at DC voltage in the 600 1500V range Upper voltages are difficult to carry out because of the maximum allowable voltage of the common PV modules Such an installation doesn t require power conditioning nevertheless very heaw safety disconnector devices should be foreseen for short circuit protection in both directions Please give the desired nominal power give the operating DC voltage of the grid the maximum allowed voltage on the grid and line resistancel 651 from the array s output up to the end user usually a vehicle The line resistance from the conventional supply to the user should be defined only if a load profile is specified chose the regulation behaviourl 6s when the PV array output voltage overcomes the maximum grid safety voltage choose a PV module model gt the program determines the number of modules in series and in parallel You can now play with these parameters The program cannot determine the exact optimum of the number of module in series Therefore you should find this optimum by performing several simulation runs and compare the maximum system ye
389. r field number and multiplicator You may also gather several measured data channels in one only PVSYST variable for example add several arrays or calculate energy from available voltage and current To do this First choose the target PVSYST variable in the list Then choose Gathering fields tab choose this variable and define the number of channels and the operator This will duplicate the corresponding variables in this list so that you can define a data channel for each one Chapter 5 Geographical and Meteorological data Geographical and Meteorological data 5 Data in Power or Energy Power or Energy If your source file is recorded with a time step less than one hour you have to specify if the data are in Power ex W m2 or in Energy ex kJ m2 Wh m2 With power measurements the interpreter performs an average over the hour With energy measurements it will perform asum Meteo Variable definitions Meteo variables definitions Please choose the available variables in the data and define their field number and multiplicator Gathering Several Measured Variables Gathering several variables Please choose the preceding tab Measured variables and choose among the available PVSYST variables in the listbox Then come back to this tab select this variable and define the number of channels and the operator This will duplicate the corresponding variables in this list of the preceding tab so that you
390. r it as an option it in a further version Synthetic data generation Synthetic data generation provides a mean of constructing meteorological hourly data from only monthly known values This is required since numerous simulation processes have to be computed as instantaneous values or pseudo instantaneous as hourly averages This is the case for example with the transposition model which closely depends on the solar geometry Irradiance generation For global irradiance we dispose of well established random algorithms Aguiar et al which produce hourly distributions presenting statistical properties very close to real data The algorithm first constructs a random sequence of daily values using a Library of Markov Transition Matrices probability matrices constructed from real meteo hourly data of several dozen of stations all over the world Then it applies a time dependent Autoregressive Gaussian Model for Generating the hourly sequences for each day Temperature generation For temperature such a general model doesn t exist We used procedures adjusted only on Swiss meteo data Scartezzini et al for which generalisation to any world climate is not proved In fact the ambient temperature daily sequence shows only weak correlations to global irradiation Of course the temperature should be continuous therefore this sequence is constructed using essentially randomly daily slopes with constraints on the monthly average But
391. r normal incidence irradiance Loss i90 the nominal efficiency is specified for the STC 1000 W m but is decreasing with irradiance according to the PV standard model Thermal behaviour 85 of the PV array The standard test conditions are specified for a cell temperature of 25 C but the modules are usually working at much higher temperatures The thermal loss is calculated following the one diode model 138 For crystalline silicon cells the loss is about 0 4 C at MPP For fixed voltage operating conditions the temperature mainly affects the I M curve voltage and effective losses are strongly dependent on the array overvoltage by respect to the operating voltage The parameters available to the user thermal loss factor involve the cell temperature determination by respect to given external conditions Real module performances 194 of the module by respect to the manufacturer specifications PVSYST uses effective specification parameters to calculate the primary PV array characteristics The user may define a relative loss factor which is related to the average effective module power at STC and acts as a constant penalty during all simulation conditions Mismatch losses 84 of the PV modules which can be evaluated bya special tool butis only taken into account as a constantloss during simulation Dirt on the PV modules which is not taken into account in PVSYST but could behave as mismatch losses i e the string curre
392. rUfix Array virtual energy at fixed voltage Voltage as calculated by the balance loop real load voltage or line reference voltage when PV array disconnected MPPLoss Loss byrespect to the MPP operation EUnused Unused energyloss over the user s demand Earray Effective energy at the output of the array lArray Array Current UArray Array Voltage ArrayON State Duration of the PV production of the array System operating conditions Esupply Energy from Conventional Power Supply Chapter 4 Project design Project design 4 LigLoss PV to User Line Ohmic Losses Energy use E Avail Produced available Solar Energy ELoad Energyneed ofthe user acc to Load definition EUser Energy supplied to the user SolFrac Solar fraction EUser ELoad U User User Voltage Efficiencies EffArrR Array Efficiency EArray rough area EffArrc Array Efficiency EArray cells area 0 when cells area not defined EffSysR System efficiency E User rough area EffSysC System efficiencyE User cells area 0 when cells area not defined Normalised performance index 944 Yr Reference Incident Energy in collector plane GlobInc kWh m2 day Yu Normalized Potential PV Production kWh kWp day Ya Normalized Array Production EArray kWh kWp day Yf Normalized System Production EAvail kWh kWp day Pr Performance ratio Yf Yr Lu Normalized Unused energy Yr Yu Le Normalized Array Losses Yu Ya Ls Normalized System Losses Ya
393. rameters with measured I V characteristics When we avail of one measurement of the complete I V characteristics not the case in PVsyst the model parameters may be determined without ambiguity Rsh is simply fitted on the data around V 0 while Rs is determined by minimizing the errors between the measured and the modelled values one only free parameter Reverse part of the Characteristics Some tools in PVsyst namely in the study of Shading or Mismatch in arrays require the knowing of the reverse characteristics when a negative voltage is applied to the module region V lt 0 This model is not as well determined in PVsyst as the direct characteristics see Reverse characteristics modelling 14d but this description is sufficient for understanding the behaviour figures in the involved tools It is not used in the hourly simulation process Chapter 6 Tools and databases 138 139 Tools and databases 6 Phovoltaic modules Model parameters Besides the basic electrical Isc Voc Impp and Vmpp data the PV module One diode model 13 implemented in PVSYST involves the following additional parameters which usually are not given in data sheets Module shunt resistanceModule_ShuntResistance Rsh Module series resistanceModule_SeriesResistance Rs lo ref inverse saturation current of the diode model Gamma factor diode quality Factor It also implies that you have correctly defined the number of cells in series as
394. raphical and Meteorological data 112 113 Geographical and Meteorological data 5 and also 1981 2000 in version 6 0 All stations i e with irradiance measurements of the main European countries are referenced in the PVsyst database Data for any other site may be obtained by interpolation usually between the 3 nearest stations WRDGC 122 Data World Radiation Data Center provides monthly irradiance for 1195 sites in the world averaged during periods between 1964 and 1993 Many of them are only over a few years These data don t include temperatures which should be obtained from another mean NASA SSEIi23 Data Surface Meteorological and Solar Energy Programme hold satellite monthly data for a grid of 1 x1 111 km covering the whole world for a 10 years period 1983 1993 PVGIS ESRAI118 Data give monthly values interpolated for any geographical location from average of 1981 1990 terrestrial measurements for Europe and satellite 1985 2004 data Meteosat for Africa Helioclim 1 124 are satellite data from Meteosat given for each year 1985 2005 independently for Europe and Africa The public access for tests is restricted to the 1985 1989 data Retscreen i2 is a Canadian software which holds a complete database for any location in the world optimised for using the best available data at each location from about 20 sources the main ones being the WRDC and the NASA irradiance data Temperatures and wind velocities are
395. rding to the system definition this is achieved just before the simulation process But for each configuration some operating values are basic choices of the user which are a main part of the System definition parameters These are for example Irradiance thresholds for Pumps cascading or Array reconfiguration Input Voltage adjustment in DC DC converters etc Real and Commercial Control devices In the reality all functions of the PVsyst Regulator component will not always be gathered in one only commercial device Therefore for your definitive simulations with real components you will probably have to define your own Regulator for Pumping device dedicated to your project This may include the properties of one or several commercial components for example existing control device existing power converter as well as some parameters specific to your project for example Irradiance thresholds NB Aspecific Control device as well as a power converter when needed is often proposed by the pump manufacturers for each of their products But they sometimes hold some switchable options so that we have to define several corresponding components in the PVsyst database Seller list The program proposes the frame for a manufacturer and retailer list which is only meant to serve as a memo to the engineer Each element of this database may be marked as Manufacturer Retailer or Own contact The concerned component type may also be s
396. re as a Ohmic Loss ratio the default value is 1 5 at STC or given explicitely in mOhm The Detailed computation tool is only a help for this calculation When you use it its result is reported in the Global wiring resistance value by checking the Calculated checkbox Of course the ohmic losses behave in a quadratic way with the array current Ploss R I so that the ratio diminishes linearly with the output current Therefore the average wiring losses are much lower during the whole running year Plane azimuth Plane azimuth In northern hemisphere the plane azimuth is defined as the angle between south and collector plane This angle is taken as negative toward east i e goes in the antitrigonometric direction Example south plane azimuth 0 east plane azimuth 90 In southern hemisphere the plane azimuth is defined as the angle between north and collector plane This angle is taken as negative toward east i e goes in the trigonometric direction Plane orientation Plane orientation If you don t have horizontal meteo data measurements you can use the irradiance measured in the collector plane This is the reason why you should define the orientation of the solarimeter here PVSYST will recalculate the Horizontal Global and Diffuse irradiations which are likely to produce this tilted plane irradiation inverse transposition During the data analysis and simulation comparisons you will be able to use either
397. re it will be determined with respect to the values given for reference conditions Gref Tref lbh G Gef I lbh ref Muse Me Terep l where G and Gref effective and reference irradiance W m7 Te and Te et effective and reference cell s temperature K musc temperature coefficient of the photocurrent or short circuit current The diode s reverse saturation current is supposed to vary with the temperature according to the expression o oref 1 T Te Te pep exp 4 Egap Gamma k 1 Te reg where EGap Gap s energy of the material 1 12 eV for cristalline Si 1 03 eV for CIS 1 7 eV for amorphous silicon 1 5 eV for CdTe Chapter 6 Tools and databases Tools and databases 6 Determination of the model parameters Thus for a given temperature and irradiance we have a model based on 5 unknown parameters Rsh Rsh Iph lo ref and Gamma The value of the shunt resistance Rsh representing the inverse of the slope of the plateau I V for low V will be independently treated that is fixed in the equations As it is not possible to deduce it from the manufacturer s datasheet PVsyst has to choose a default valuel144 for processing the Database In order to determine the 4 remaining parameters we can write the 4 equations below for the specified reference conditions Gref and Tc ref V at point V 0 short circuit I V at point O open circuit I V at any other point close
398. re simulate all your calculations for this project Please discard the old inputs of such erroneous projects 2 Help improved for system design and inverter sizing 3 Bugs in the report of the Heterogeneous multi orientation fields 4 Module database completed for all modules references in Photon Magazine 2009 now about 5 300 modules Version 5 0 September 2009 by respect to Version 4 37 June 2009 This is a major modernization of the software Many internal mechanisms have been improved since more than 2 years of development in parallel to version 4 xx updates Therefore there may be bugs which have not been detected during the development Please be so kind as to report them carefully to the authors de GO TO aa 1 Multilanguage the simulation report was already available in several languages but now the software itself is partly available in English French German Italian Spanish and Portuguese This is not yet a full translation only the mostused parts especially regarding grid connected systems were translated up to now This is a very time consuming job more than 200 dialogs and hundreds of information warning pieces to the user and we will continue it progressively On the other hand we don t intend to translate the Help at the moment 2 Multi fields you have now the opportunity of defining several field types for a given project with different PV modules or inverters number of modules in series etc The
399. reaching the head required by the external system The efficiency is mainly related to the flowrate It shows an increasing curve from zero efficiency at zero flowrate until a maximum which usually doesn t depend much on the Head After this maximum the efficiency decrease is more marked for lower heads The flowrate has a quadratic behaviour as a function of the power with a power threshold depending on the Head this corresponds to the minimum speed before reaching the external head Centrifugal pumps are suited for systems with rather low heads and high flowrates For extending the head range many pumps use a multistage technique thatis implementing several impellers in series on the same motor axis each ensuring a part of the required head Positive displacement pumps Chapter 6 Tools and databases Tools and databases 6 In a positive displacement pump the uncompressible water is shut in an impervious moving volume either with valves or with moving pieces with special geometric shape Therefore some water is pumped as soon as the pump is rotating and the flowrate is directly proportional to the pump speed Power threshold is due to electrical losses in the motor before reaching a sufficient force for overcoming the torque In many pumps this starting torque is higher than the running torque the friction losses are higher when the pump is stopped requiring a starting over current There are several technologies Pist
400. red value now in the recorded data Concentrating PV module CPV definition with spectral corrections Concentrating systems complete revision of the simulation process variables Update of the loss diagram also for concentrating systems Inverter definitions some bugs fixed 3 voltage reading bi polar sizing Heterogeneous fields old files V4 37 prevent simulations 0 everywhere IAM calculation on diffuse also with customized IAM function Version 5 21 September 3rd 2010 by respect to Version 5 20 August 3rd 2010 1 Direct link for importing PV modules and Inverters from PHOTON database Shadings define a new object mansard or roof window Favorites choice in the main Database lists easier by right click Directory Names now acceptaccents and some special characters solving problems with Czeck Republic Windows XP installations Meteo data the wind speed is now part of hourly values when defined monthly Inverters still problems with 3 voltage efficiency definition solved Sun shields bug during mutual shading calculations Fixed littles bugs printing of PR soiling table in parameters etc Version 5 20 August 3rd 2010 by respect to Version 5 14 June 30th 2010 1 File organization and localization has been changed Your working Data structure is now in a writable area avoiding delocalization of files written by PVsyst under Vista and Win7 2 Module layout tool for the geometrical arrangement of your system 3 S
401. refore this calculation requires the specification of the number of strings in the transverse dimension of the shed as well as the size of one cell Please note that with thin film modules with long cells of around 10 mm width the cells should be placed in the transverse dimension of the shed so that only a little part of each cell is shaded ata time The three parts of the shed tool geometrical design shading graph and yearly yield graph are meant fora better understanding when optimising 3A a shed layout Please carefully see the limitations when using sheds with near shading scenes 43 Shed optimization Shadings on Beam and Diffuse First of all when optimising sheds one should keep in mind that the shading losses are of two kinds The shadings which we usually visualize are applied on the beam component They apply especially on some periods ofthe day or the year and often when the sun is not very high on the plane surface therefore affecting hours of rather low production there can be an exception with mutual shading of sheds reinforced by the electrical effect of cell partial shadings The shading on the diffuse component which applies permanently with the same value when assuming an isotropic diffuse distribution This shading factor is related to the part of heavens which is seen by the collectors Remember that in central Europe climates the Diffuse fraction is of the order of 50 of the total incident irradiat
402. respect to the mechanical layout on this roof But the real orientation of the shed planes will be different from that of your mechanical supports this value appears in the definition dialog With such an installation on a 2 sided roof it is impossible to obtain a same orientation for the two sets of sheds therefore you should use the Heterogeneous option in the Orientation parameters NB With heterogeneous fields for a given simulation time step the shadings factor is calculated only once and applied identically on both planes Therefore when using near shadings the orientations should not be too different the program seta limit NB When defining sheds in the Near shading scene you should not use the Shed option in the Orientation parameters definition otherwise the simulation will account twice for the mutual shadings See also Near shadings and sheds 43 Sun shields same definitions as for Sheds except that the collectors are aligned on a wall It has to be noted that the fa ade itself induces a significant irradiance loss especially in summer when the sun has a course Chapter 4 Project design 42 43 Project design 4 over the east and west azimuths Fa ade slope Although the fa ade is usually vertical you may define an inclined base from one unit to the next one Tracking planes 43 the basic definitions of tracking planes are very similar to the sheds several identical trackers with a sensitive are
403. rhaps averaged not a very good idea if you have current and voltage measurements for computing the power energy at each step for averaging several module temperature sensors Therefore this tab allows to gather the data of several source channels in one only target internal variable This can be performed using sum product or average operator After defining the number of gathered fields desired for each variable the corresponding label will appear Chapter 5 Geographical and Meteorological data 128 129 Geographical and Meteorological data 5 several times in the field order list for associating different source fields Chaining files One only file the usual case Manual chaining at the end of the file the conversion process asks the operator for the next file to be written on the same internal data file One file per day the file names DOS names restricted to 12 characters should include day and month identifiers in a specified coded format Then the conversion will automatically chain the daily files One file per month as above for monthly files Generalities The format protocole defines all characteristics governing the ASCII source file reading Meteo or Measured data files The ASCIl file is assumed to hold one record line per time step Time steps should be hours or fractions of hours The Protocol defines Skipped lines Separator Variables to be read Variables reading format It per
404. ring resistance module quality mismatch soiling IAM eventually define a Horizon profile 38 far shadings Near shadings 37 that is partial shadings of near objects which require a rather complex CAO 3D construction of the PV field environment The next table shows an outline of the project s organization and simulation process Chapter 3 Preliminary design 22 Project design 4 Hourly meteorological data Monthly meteorological data Hourly meteo measurements Reference Year TMY Satellight Sites database Custom horiz or in coll plane Generation of synthetic hourly values Project Specification of the site geographic coordinates Hourly meteorological data Eventually Meteorological corrections Albedo Altitude etc Simulation variant Many simulation variants may be defined for a given project Incident irradiance in the collector plane Transposition from horizontal values to the collector plane fixed plane tracking 1 or 2 axes seasonal adjusment heterogeneous fields If infinite sheds or sun shields mutual shadings calculation Far shadings Horizon definition The far shadings affect the whole field at a time Near shadings partial shadings on the field Shading of near objects require a detailed 3D description of the system Shading factor for beam component linear or according to modules Shading factor for diffuse spherical integral of the linear shading factor User s load Necessary
405. rings of modules connected to the input of an inverter or a MPPT input should be homogeneous identical modules same number of modules in series same orientation Exceptions may sometimes be acceptable as far as only differences in the current of strings are concerned for example strings of different orientations cf Heterogeneous planes 3 PVsyst now allows the construction of heterogeneous systems with several different subfields 60 up to 8 For a given subfield you have to define your requirements and PVsyst will automatically propose a suited arrangement The basic requirements for a sub field i e the parameters you should input are The desired nominal power or alternatively the available area for installing modules The inverter model chosen in the database A PV module model chosen in the database Chapter 4 Project design Project design 4 Then the program will choose the required number of inverters according to a pre defined Pnom array inverter ratio of 1 25 It will then propose a number of modules in series and a number of strings in order to approach the desired power or available area The acceptable choices for the number of modules in series parallel are mentioned on the dialog They should meet the following requirements The minimum array voltage in worst temperature conditions 60 C should not be under the inverter s voltage range for MPPT The maximum array voltage in worst te
406. ristics behaviour analogous to partial shadings effects This can resultin high losses and eventually hot spot risk See the special tool Electrical behaviour of PV arrays in the Tools Solar tool box part of PVSYST for visualising and understanding these phenomena European Efficiency MPPT or DC DC converters European Efficiency The converter doesn t operate always at its maximum efficiency Therefore PVsyst defines a European Efficiency for converters in the same wayas itis usually defined for inverters Chapter9 Glossary Glossary 9 The European Efficiency is a calculated efficiency averaged over a power distribution corresponding to middle Europa climate yearly operating conditions If we denote by E50 the efficiency at 50 of nominal power itis defined as EuroEfficiency 0 03 xE5 0 06 xE10 0 13 x E20 0 1 x E30 0 48 x E50 0 2 x E100 External transformer losses External transformer losses In some big PVinstallations in the MWp range the transformer is not part of the inverter but an external device directly connected to the MT grid The main losses associated with the transformer are The iron losses mostly due to hysteresis and eddy currents in the core are proportional to the square of the core flux i e to the square of the voltage As we have a constant grid voltage this is considered as a constant loss The ohmic losses either in the primary and in the secondary windings These
407. rly Meteo Database Detailed simulation requires meteorological data Global horizontal and Temperature in hourly values Synthetic hourly dataliad files may be generated from any monthly meteo described above This generation is automatically performed when choosing a site during the Project definition The only hourly data originally included in the PVsyst package are meteorological hourly DRY Design Reference Years of 22 stations in Switzerland These data proceed from 10 years of measurements in the frame of the ANETZ meteorological stations grid of the ISM 1 Swiss Institute for Meteorology Hourly data may be imported 112 from several sources Satellight TMY2 Helioclim DRY or TMY hourly data Design Reference Years DRY or Typical Meteorological Years TMY are meteorological data files constructed on the basis of real measured data series The elaboration of DRY or TMY obeys a sophisticated normalised procedure It usually consists of a juxtaposition of selected months chosen among 10 years or more of real measurements according to several statistical criteria and approaching average values The month s extremities are eventually corrected for harmonious continuations and these data sets should also include realistic extreme behaviours They are constructed so that the whole year reproduces a typical meteorological situation for the design of energetic or architectural systems The 22 ISMA Swiss Institute for Meteorology
408. rocedure for Generating Sequences of Daily Radiation Values Using a Library of Markov Transition Matrices Solar Energy Vol 40 No 3 pp 269 279 1988 R J Aguiar M Collares Pereira TAG a Time dependent Autoregressive Gaussian Model for Generating Synthetic Hourly Radiation Solar Energy Vol 49 No 3 pp 167 174 1992 J L Scartezzini M N Ferguson F Bochud LESO EPFL Lausanne Compression of Multi Year Meteorological Data OFEN 3003 Bern Final Report 1990 B Molineaux P Ineichen Impact of Pinatubo Aerosols on the seasonal trends of Global Direct and Diffuse Irradiance in two Northern Mid Latitude Sites Solar Energy 58 no 1 3 pp 91 101 1996 PV modules behaviour and modelling J A Roger and C Maguin Photovoltaic Solar Panels Simulation Including Dynamical Thermal Effects M Camani D Chianese S Rezzonico Centrale di Prova per componenti PV TISO c o STS CH 6952 Canobbio Rapporto Finale 1990 1993 OFEN BEW Bern M Camani N Cereghetti D Chianese S Rezzonico DB TISO PV modules A Database permanently updated about 830 modules referenced 1998 available from internet on the site below B Booklet no 3 november 1998 extract TISO LEEE Scuola Universitaria professionale 6952 Canobbio Switzerland Tel 41 91 94047 78 Fax 41 91 942 8865 e mail leee dct supsi ch http Awww supsi ch home html Thin film PV modules behaviour and modelling R Gottschalg M Rommel D G Infield
409. rofile explicitely given as file Graph SPL On line graph models which can be used as such to be called before performing simulations Expfile SFl Format models for the creation of export files for the results with a view to using them in other software Data UserData This is a place where you can put your own files regarding PVsyst For example the files generated by the simulation process NB If you don t find the files your have generated here itis possible that Windows has put them in a delocalized place 17 VirtualStore File delocalization with Vista and Windows 7 Valid only for old PVsyst versions before 5 20 With these new versions of Windows when the program attempts to write in the Program files subdirectory or Program files i86 for 32 bits programs in 64 bits OS these new versions of Windows automatically redirect the writing to a virtual location situated at c Users User AppData Local Virtual Store Program Files PVsyst5 Data Therefore all data that you have created by yourself or modified under PVsyst versions before 5 13 will be stored in this directory You will also find here the LOG files or the PVsyst5 ini file This directory should be destroyed when completely uninstalling the program NB in the Windows File Explorer some of these directories are translated into the local language for example in French Utilisateur instead of User NB The AppData subdirectory is o
410. roject ISCCP D 1 from data of the Geostationary and Polar Satellites for Environmental Observation GOES and POES the Chapter 5 Geographical and Meteorological data Geographical and Meteorological data 5 European Geostationary satellite Meteosat and Japanese ones etc Although the SSE data within a particular grid cell are not necessarily representative of a particular microclimate or point within the cell the data are considered to be the average over the entire area of the cell For this reason the SSE data set is not intended to replace quality ground measurement data Its purpose is to fill the gap where ground measurements are missing and to augment areas where ground measurements do exist Accuracy The accuracy of Satellite measurements has been evaluated using numerous ground based measurements Although the reliability of these ground measurements themselves is not always well assessed the NASA estimates that the RMS Error on monthly values is around 13 16 and the Mean Bias Error MBE lies from 2 to 0 7 Further information about the data generation The solar energy data is generated using the Pinker Laszlo shortwave algorithm Cloud data is taken from the International Satellite Cloud Climatology Project DX dataset ISCCP ISCCP DX data is on an equal area grid with an effective 30x30 km pixel size The output data is generated on a nested grid containing 44 016 regions The nested grid has a resolution of one d
411. rom other junctions by the presence of an intrinsic layer p i n junction J Mertens 1 al propose to take the recombination losses in this layer into account by adding a term in the general IMV equation This term is equivalent to adding an element to the equivalent circuit representing a current leak depending on the photocurrent and the voltage _ Photo l Recom current bination User ae 7s el AZ Ren v R OR r lt lon i lrec lpn V Modelling of this phenomenon leads under some hypotheses to the following expression for the recombination current Irec Iph di uteff Vbi V IRs where di Thickness ofthe intrinsic i layer ofthe order of 0 3 um uteff Diffusion length ofthe charge carriers p and n uteff 2 gt unt pptp unan up tp Vbi Intrinsic voltage built in voltage of the junction Its value may be considered as constant and is about 0 9V for an amorphous junction With this new term the general one diode model I V expression becomes l lbh lbh di pteff 1 Vbi V IRs l exp q V I Rs Ns Samma k To 1 VFR Ro In our phenomenological study of 4 amorphous modules we considered the quantity di uteff as one only parameter and we sought the value which optimized the Vco response of the model For all our modules we found that a value di uteff around 1 4 V gives excellent results and corrects quite well the Vco distribution with a si
412. rovide your complete address specially your email address and fill in the order form with the type and the quantity of desired activation codes Choosing Send by Email will send an email to PVsyst administration admin pvsyst com containing your order form and the Local Number specific to the installation of the software on your machine A copy of that email is sent to you at the same time 2 From the website www pvsyst com choose Download Purchase Then log in to your user account with your email address and password or create a new account and complete the web form You will be asked to provide the Local Number specific to the installation of the software on your workstation the Local Number is found by clicking the menu License Status and Activation Payment by Credit Carde Bank Transfere or PayPall 1 is possible Please note that the license code is closely related to the Local number which is created the first time you install the software The Local Number is then closely related to the machine on which PVsyst is installed If you order several activation code s you may specify the number of desired code s on the main order After receipt of your order an activation code will be sent to you by email within a few working days in order to run the software on your machine Payment conditions Payment by Credit Card or PayPal Payment by credit card is possible on our website www pvsyst com via the
413. rradiance 148 Thin Films Rshunt exponential correction vs Irradiance The shunt resistance Rsh corresponding to the inverse of the slope of the I V curve around V 0 is considered as a constant parameter in the standard one diode model But itis easy to observe on amorphous I V curve families that this slope decreases with the irradiance The next figure shows the measured Rsh behaviour over our measured sample SHR 17 Old R shunt function of Irradiance 1000 Ly 3 Measurements 800 amp eee ge ye ee A Parametrization 600 400 R Shunt measured ohm 200 0 200 400 600 800 1000 Irradiance W m This distribution may be approximated by the following exponential expression Rsh Rsh Gref Rsh 0 Rsh Gref exp Rsh exp G Gref We observed a similar behaviour on all our measured data including the Si Crystalline and CIS modules And curiously all data may be rather well approached using a unique value Rshexp 5 5 Therefore this value is set as default value in PVsyst In this expression there are 2 unknown parameter left Rsh Gref i e Rsh in the standard model and Rsh 0 which may be determined on measured data but are not available in the usual manufacturer s data sheets For processing the database PVsyst has to propose default values which are deduced from our own measurements on 6 modules but cannot be of course very reliable The Rsh default
414. rradiance column copy CtI C it into the clipboard and Paste it in PVsyst Idem for the air temperature column You have still to define the origin of the data ground or NASA Conversion of hourly data ASCII files PVSYST offers a very general programmable interpreter for importing ASCII files either meteo or measured data files Conversion procedure h2 The format of the source file may be very varied however it has to fulfil the following minimal criteria Include the values of one time step hourly or sub hourly per ASCII line Each ASCII line ends with the characters CR LF or only LF Sub hourly records are gathered in order to give PVSYST hourly internal records Comment lines at the beginning of the file or of each day or month can be skipped Data are organised in fields with a chosen separator semi colon comma TAB blank etc or fixed widths PVSYST accepts a great variety of date formats and adjusts the source data physical units The available parameters should include the minimal data which allow the calculation of the horizontal global and the ambient temperature Since simulation also requires the horizontal diffuse irradiation this is calculated for example from the normal global and beam data usual measurements in the USA or from the horizontal global and beam data If not available the diffuse irradiation is reconstituted using the Liu and Jordan correlation With measured data if only
415. rrent lost in electrolysis will give an estimation of the quantity of dissociated electrolyte In all of these definitions the voltage specifications may be displayed either by cell or for the whole battery Chapter 6 Tools and databases Tools and databases 6 Sizes Specify the physical sizes and weight of the battery Batteries Detailed model parameters Allows to act on the secondary parameters used by the battery model 154 which you should in principle not pay any attention to except if you have specific data at disposal The default values can be restored at anytime by clicking on the Default checkbox Open circuit voltage These parameters concern the modelling of the open circuit voltage assumed to be linear up to the gassing region and down to the deep discharge beginning These values characteristic of the electrochemical Pb H SO couple are drawn from a manufacturer s catalogue Miscellaneous parameters Self discharge current at 20 C behaves approximately as an exponential with temperature doubling every 10 C The general temperature behaviour is specified as a dimensionless profile Capacity vs discharge current usually increases bya factor 25 to 35 by respect to the rated C10 capacity in solar use Capacity correction vs temperature increases by about 5 to 10 with temperature increases of ten degrees Saturation charge current charging saturation voltage at the reference temperature i e limit f
416. rs to an average or the sum usually in legal time in the interval 12 00 13 00 hourly data run from Oh00 i e 0 1h interval to 23h00 23h 0h interval daily data identify the day ex 01 06 2010 0h00 corresponds to 01 06 2010 from OH 00 to 23H Chapter 5 Geographical and Meteorological data 130 131 Geographical and Meteorological data 5 59 59 monthly data are identified by the first day of the month Now in measured data files each record usually holds a time label Depending on authors or data acquisition systems this time may be referenced either to the interval beginning or the interval end or to the interval middle point Or even at any other shifted time within the hour for example ISM Anetz data are recorded from 0 20 to 1 20 When using these shifted data PVsyst will keep its full hour labels when displaying most of the results The calculations related to the solar geometry diffuse part transposition models shadings etc should be performed using an average time within the effective hourly accumulation period Usually at half the hour for usual well centered data But when the data have been accumulated over different periods the solar geometry should be evaluated at a shifted time by respect to the middle of the hour The tool Check data quality in the Meteo Tables and Graphs part allows an accurate evaluation and setting of the real time shift of your data by comparing the data to the Clear S
417. rtunity of specifying the intensity of the real effect on the electrical production of the partially shaded strings This should allow to presenta final simulation with a better estimate of the shading loss but the value of the electrical effect ratio is not easy to establish even using the tool Electrical behaviour of PV arrays Please also see the effect of thin objects ey like electrical wires handrails etc Procedure In the global scene click on the Partition in module chains speed button You have to define the rectangle number in length and width or their sizes Definitions are accepted even if the rectangle sizes don t match the field sizes If the scene has several fields you have the option of extending this rectangle size definition to all other fields No checks are made by the program on the compatibility with the effective module chains defined in the PV arrays system definition Near shadings measurments In the shading scene there are four measuring tools for real distance or angles determination You define segments by clicking on two points of the scene When clicking on an existing summit of the scene the measuring point will stay attached to it After defining them you may always drag the existing points to other positions Distance measurement Click on two points to define the distance arrow In perspective view the distance is only defined between existing summits of the scene Angle measurement
418. s i 2 is the mathematical result of the spherical integral of a constant irradiance from all directions seen by the plane i e the orange slice between the plane and the horizontal Diffuse Irradiance model When it is not explicitly measured the diffuse irradiation should be estimated from horizontal global by a model We can mention two wide used such models Liu and Jordan s correlation which results from an experimental correlation of the D G ratio by respect to the clearness index _Ktha Perez model Perez Ineichen et al is a more sophisticated model taking hourly data sequence into account In PVSYST the diffuse irradiation uses the robust Liu and Jordan s correlation When applied to our data from the SIG the only simultaneous measurement of global and diffuse irradiations we have at our disposal this correlation gives good results with an MBE of 1 7 and a RMSE of 27 with respect to the value of the diffuse irradiance or 13 referred to global irradiance Note The most sophisticated model of Perez Ineichen has also been tested but does not give significantly better results From the opinion of one of the authors P Ineichen in our laboratory who has also evaluated the Liu Jordan correlation this is especially suited for very well measured data Applying it to synthetic hourly data doesn t make great sense This is the reason why we didn t implement it in the current version Nevertheless we intend to offe
419. s reverse characteristics region thatis with a negative voltage on part of the current plateau Remark You will understand here the difficulty in exactly representing the operating of a real module with the help of usual models describing single cells and that the use of too sophisticated cell models i e two diodes models will notimprove the situation if they do not include this statistical distribution Group of modules simulates a whole array In this case the resulting figure looks quite different with a bumped shape all along the plateau This is due to the by pass protection diodes supposed to be always present in the modules These give usually even better performances than nominal modules below half the nominal current but degrade until the Maximum Power Point One can see that the MPP power is much less affected than at fixed voltage operation below the MPP point Remark in the region of low voltages some modules are operating in the reverse polarisation region The by Chapter 4 Project design 36 37 Project design 4 pass diode blocks the reverse current which normally would flow be consumed through the cells This is the reason why the performances are better Without diodes the characteristics would show a linear plateau analogous to the cells behaviour in a single module near to the worst module characteristics Group of modules with sorted modules If we sort the PV elements to put them in increasing order of short
420. s the missing parameters Phovoltaic modules All parameters related to a given PV module as well as graphs of its behaviour are available in the PV module dialog which includes several definition sheets Basic datal133 which holds the module identificators and main electrical characteristics Model parameters 134 specifies some additional parameters necessary to the PV one diode model h3 and calculates the model unknowns The Model parameters include the following subsheets see Parameter summary 136 Rshunt RSerie define these two basic parameters for the establishment of the model Rshunt Expon describe the experimentally observed exponential behaviour of the Rshunt value Recombination losses special modification of the model for amorphous and CdTe technologies see modified one diode model for thin films hah Spectral correction to be applied to amorphous technologies but not CdTe Temper coeff allows to fix a required value for the muPmpp temperature coefficient Size and Technology 134 with physical and secondary characteristics Commercial data h3 Graphs a tool visualising usual and less usual graphs of the PV modell130 behaviour over a great variety of operating conditions Photovoltaic modules database 147 data source adding new modules Photovoltaic modules database in Tabular form 142 Phovoltaic modules Basic data Module identifiers Model and Manufacturer will appear in the module
421. s the system performances Now you can open the Results which asks for choosing either the tank volume or the autonomy of the system in days These parameters are coupled according to the daily needs of water the Loss of Load probability P LOL i e the time fraction during which the operator will accept that the needs are not met tank empty These parameters lead to the determination of the array nominal power i e the installed STCI194 power according to the manufacturer specifications and the pump nominal power required These are very rough estimations as the pumping system performances are strongly dependent on the pump technology head flowrate as well as the electrical matching between pump and PV array The first result graph shows the potentially available solar energy along with the user s water and energy needs The second one available by the speed buttons on the left gives the average filling state of the tank and the missing water P LOL monthly distribution The table holds all monthly values including an eventual required back up energy Finally the rough economic evaluation 2 gives an idea of the investment and water price You can now play with the parameters and immediately see the results You can printa report or store graphs and tables in the clipboard to export it to another software You can also save your project and load another one for immediate comparisons Computation PVsyst perfor
422. samples WindVel database Helioclim 3 Europe Hourly Meteosat from 02 2004 GlobH ca Direct SoDa Africa gt today no temper 2005 free by copy paste NASA SSE Worldwide Monthly Satellites 1983 1993 GlobH Web Direct 1 x1 cells 111 km averages Temp free Hourly WRDC Worldwide Daily 1195 stations 1964 1993 GlobH Web Direct Monthly each no temper free by copy paste PVGIS ESRA Europe Monthly Europe 566 stations 1981 1990 GlobH Web Direct Africa Interp 1x1 km averages Temp free by copy paste S W Asia Africa Meteosat 1985 2004 Linke turbidity Helioclim 1 database Web Helioclim 1 Europe Monthly Meteosat 1985 2005 GlobH restricted Direct SoDa Africa 50x50 km each year no temper 1985 89 free by copy paste RETScreen Worldwide Monthly Compil 20 sources 1961 1990 GlobH TA Software Direct incl WRDC NASA averages WindVel free by copy paste Meteorological data comparisons PVsyst now gives access to many popular meteorological data sources 11 These show that the available meteorological data are far from being an exact science There are big discrepancies between these databases and it is very difficult to estimate which one is the best suited for a given project or location and what is the probable error We have performed a comparison between these sources for several locations from north to south of Europe Comparisons cannot be made rigorously because of the variety of conditions All s
423. scadel7 configuration is best suited Regulation Direct Coupling with Cascading See also Pumping Configuration 735 previous 75 and nex 7A Regulation If the system is equipped with several pumps the regulation should switch them ON according to the available PV power in order that each pump runs near its optimal efficiency PV array System Pump cascading Inrad dicta aaa Controller meas Tank Full Total Head Level diff Friction lasses Current 2 pumps 1 pump Voltage Aspir level This opportunity improves drastically the performances of the direct coupling 7A configuration lowering the irradiance threshold and improving the operating at high irradiances But be careful the determination of the irradiance threshold for starting the second pump is of great importance Chapter 4 Project design 76 77 Project design 4 for the final performances see the Results 7 analysis for details For pumps with MPPT power conditioning units the cascading cannot be used unless the MPPT algorithms are suited for Master slave operation Indeed the operating point of the characteristics of the PV array cannot of course be driven simultaneously by two independent MPPT devices Such an operation mode is not yet implemented in the present version of PVsyst Regulation Direct Coupling with Array Reconfiguration See also Pumping Configuration 73 previous 75 and next 7
424. se for very tilted installations If necessary the general parameters array overall efficiency battery efficiency battery low charge threshold are user modifiable through the menu option Preferences Edit Hidden Parameter 173 Chapter 3 Preliminary design Preliminary design 3 Stand alone system design When sizing a PV stand alone system the basic constraints are the availability of solar energy during the year and the satisfaction of the user s needs The problem to be solved is the optimisation of the size of the photovoltaic generator and the storage capacity subjected to criteria which may take on different weights depending on the use Reliability of the supply which is very important for example in decentralised telecommunication installations But in a domestic installation this may be overcome with a small back up generator This reliability is measured as the Loss of Load Probability P LOL Investment and maintenance costs which should take into consideration the cost of the PV generator the initial cost of the batteries as well as that of their maintenance and replacement The high price of the kWh used necessitates a highly detailed study of the real user s needs and the use of specific appliances that are highly economical regarding to energy consumption Durability the cost of the batteries is closely related to the quality of the batteries chosen as well as their longevity which is itself dependent
425. se that the user s needs are specified and computed during the simulation and that these data are stored in hourly values These tariffs may also be modulated according to the day hour The consumption tariff is likely to be increased during the next years therefore an annual increase rate can be defined PVsyst calculations Using the effective production given by the simulation PVsyst shows the annual balance as well as the accumulated balance over the foreseen lifetime of the PV system according to all these strategies It also shows details on an annual table But be careful these balances result of differences of large quantities and little perturbations either on the real production or the effective costs may result in dramatic deviations of the final profitability This is namely the case for the annual real irradiance variations by respect to the meteo data used in the simulation Failures of the system all over its lifetime may also significantly affect the effective balance NB In this part when annual evolutions are specified in year these are of the initial value not the preceding one PVSYST clearly distinguishes between two kinds of Meteorological data Monthly meteo data SIT files which are associated with the definition of every geographical site Hourly meteo data MET files which can be DRYM Ain the database imported h1 from known sources or custom ASCII files or synthetic data generated 18 fr
426. ses only the excess virtual energy during very high productions allowing to oversize_the_nominal_array power 60 by respect to the inverter power economic optimisation depending on the system properties Cut when reaching overload some old inverter models were simply cutting the PV production by safety i e the array current was zero and the array voltage attained Voc Cut up to evening same case as above but the inverter was notable to start again as long as the input was notnull Behaviour at Vmin Vmax Limitation as above in modern inverters the operating point stays on the limit voltage when MPP goes outside the window Cut in some old models the inverter production was stopped when encountering such conditions Grid inverters efficiency curve Grid inverters efficiency curve The inverter s efficiency is characterised by a power transfer function during normal operation depending on the instantaneous power Chapter 6 Tools and databases Tools and databases 6 This transfer is usually given in terms of efficiency as function either of the input or of the output power Thatis it is represented bya non linear curve with a threshold input power which may be understood as the inverter s own consumption However it may be more convenient to transform this curve into an input output power characteristic the behaviour then becomes practically linear with a pseudo straight line cutting the abscissa at the wor
427. ses are not quite well determined the Energy values at each main step of the simulation are in principle correctly calculated You can refer to the following pages for a detailed description of the individual variables Chapter 4 Project design Project design 4 Meteo irradiation and PV arrayl 94 Grid connected system 96 Stand alone system PA DC grid system fo Normalised performance index In order to facilitate comparisons between several PV installations JRC European Joint Research Center introduced the following Performance Index These indicators are related to the incident energy in the collector plane and are normalised by the Pnom Array nominal installed power at STCh9A as given by the PV module manufacturer kWp Therefore they are independent of the array size the geographic situation and the field orientation In these definitions the yield energies are expressed as kWh KWp day In other words these quantities are numerically equal to the Equivalent operating time under a constant irradiance of 1 kW m that is they can also be expressed as Hours day when running at 1 kW m or kWh m day see the remark below We define the following quantities Yr Reference system Yield is the ideal array Yield according to Pnom as defined by manufacturer without any loss It can be understood as each incident kWh should ideally produce the Array Nominal Power Pnom during one hour Yr is numerically e
428. sheds are too short as one cannot neglect the edge effects you should define sheds in the Near shadings CAO option instead Unlimited sun shields 33 Same remarks as for sheds The optimization of electrical yield of sun shield Chapter 4 Project design 30 31 Project design 4 systems is very difficult and only suited for south fa ades Limitations The tracking strategy in only computed using the solar geometry so called astronomical algorithms A simulation using a strategy with irradiance optimization on the collectors is much more complex to implement and is not yet available in PVsyst Please note that the near shading calculations cannot be applied to Seasonal Tilt adjustment For double orientation heterogeneous fields the shading factor is computed once for both fields ata time so that it becomes not well applicable induces errors when the difference in orientation is too big For sheds please carefully see the special combination of Orientation option and Near shadings treatement 434 Also be aware that with tracking planes the mutual shadings of several neighbour tracking units can become very important at extreme angles see the shed optimization tool 3T with very tilted collector plane The collector s spacing should usually be very large so that the horizontal space use is rather low Also Backtracking 45 control strategy may help optimizing the electrical yield Heterogeneous Fields Itis com
429. source of data 6 Favorites you can now define a list of your favorite components in the database which drastically simplifies the use of big componentlists 7 Near Shadings the full dialog and tool have been improved You can now Easily read and write a scene ora building directly from the 3D tool Multiple selection allows to define groups of objects that you can replicate or save on a file Define fix the characteristics of the view you would like to appear in the final simulation report Register the shading s animation as a little video 8 Special tracker devices with PV modules rotating on a tracking frame with either N S or E W axis are defined as special shading objects with database of existing devices 9 Shading of thin objects like electrical wires or handrails is now possible by weighting their effect on the Module shading part of the shaded areas 10 Shading on strings you can puta weight on the effect of the shading according to strings in order to better approach the real shading effect on the electrical production not only an upper limit in the simulation 11 lImport Horizon profiles directly from Somletric SunEye Carnaval software Meteonorm 12 Synthetic hourly data generation the diffuse part may be renormalized to specified monthly data when available This was not possible in the previous versions 13 Improvement of the sizing tool for grid systems You have now the opportunity of specifying either the n
430. sses 844 R between the power available from the modules and that at the terminals of the array These losses can be characterised by just one parameter R defined for the global array The program proposes a default global wiring loss fraction of 1 5 by respect to the STC running conditions But you have a specific tool 84 for establishing and optimizing the ohmic losses press Detailed Calculation button This tool asks for the average length of wires for the string loops and between the intermediate junction boxes and the inverter and helps the determination of the wire sections NB remember that the wiring loss behaves as the square of the current Therefore operating at half power 500 W m will lead to only a quarter of the relative loss The effective loss during a given period will be given as a simulation result and shown on the loss diagram It is usually of the order of one half to 60 of the above specified relative loss when operation at MPP This part also includes the definition of eventual losses between the output of the inverter and the injection point energy counter You have just to define the distance and the loss will also appear in the loss diagram Module quality loss The aim of this parameter is to reflect the confidence that you putin the matching of your real module set performance by respect to the manufacturer s specification The default PVsyst value is half the lower tolerance of the modules The resultin
431. standard one diode model Chapter 6 Tools and databases Tools and databases 6 Rshunt Rsh G 0 RshExp Rserie model Shunt resistance at GRef Measured as the inverse of the slope of the I V characteristics around Isc at STC If not specified you can keep the value proposed by PVsyst Intercept at G 0 of the exponential behaviour of Rsh according to irradiance Parameter of the exponential Series resistance involved in the one diode model For crystalline modules you can keep the proposed value Rserie max Maximum possible value of Rserie A higher value would not allow the I V characteristics to pass through the 3 reference points Rserie app Apparent series resistance as measured on the I V curve around Vco at GRef TRef This slope is the sum of the Rserie model and the exponential effects Gamma Quality factor of the diode involved in the one diode model muGamma Thermal linear correction factor on Gamma modification of the standard model for obtaining a specified muPmpp if necessary loRef Diode saturation current involved in the one diode model muVco Thermal behaviour of the Vco Related to Rserie but the manufacturer data is usually not attainable with reasonable other parameters This value is a result of the model and will usually not be compatible with the manufacturer s data muPmpp Normally a result of the model May be forced to a specified value by acting on the muGamma parameter muPmppReq
432. system and taking each behavior into account But the parameter you put in the simulation are the main source of uncertainty mainly the meteo data usually known at 5 10 and also the real behaviour of the PV modules by respect to the specifications For the modules PVsyst uses a PV model experimentally studied by myself with a very good accuracy provided you put the good parameters The meteo annual variability is around 5 but the last few years are sometimes considered exceptional Therefore any production warranty should always be done under condition of renormalizing the real results according to actual meteo data which become more and more available from satellites data but often not free Validations of old versions of the program The seven tested grid connected installations We have carried out detailed validations of the programme using the data from 7 grid connected systems whose detailed characteristics appear on table 1 These systems have been chosen on the one hand for the quality of gathering data and on the other hand as an attempt to representa variety of different situations sizes of 0 5 to 100 kWe fields in sheds or integration roofing facade types of collectors Si mono Si poly or amorphous types of climates plain mountain etc possible near shadings The validations have to be carried out carefully using measured data with an hourly or sub hourly time step over sufficient periods one year
433. t as intelligent forms including all relevant parameters All printer forms include one or two Head lineshs which can be customized including your Company name and one or two Comment lines which can always be specified at the time of output Whenever possible in general table or graph outputs the program produces an intelligent form which includes several parameters or references related to the printed table or graph For example solar geometry tables will include the geographical location parameters as well as plane orientation or shed arrangement when applicable Printer dialog Change Configuration allows the definition of the properties of the printer or to change the printer Head comments define up to two comment lines at the head of the form These can appear bold if desired Options Definition of the head of the form and a few other formatting options these definitions can be made either for the present form only or stored as Preference for any future output Preview performs a preview of the form s to be printed Print sends the output form to the printer Copy to Clipboard allows for copying the whole printed form as an image in the clipboard for immediate paste in another software like MS Word MS Excel Paint or others This allows for storing the whole printer page in documents or sending results for example by e mail Please refer to Options 183 for format details If several pages
434. t xlong Ifdata are given as lines or columns in a spreadsheet you can paste entire columns ata time As for any database element you are advised to always mention the source of your data After defining or modifying a site the program will ask whether you want to keep your modifications and if so it will modify or create a new site in the database i e a new file in the Sites directory PVsyst native database The main PVsyst meteo database including around 300 sites in monthly values is based on the METEONORM 1 database This software defines about 1 500 Stations for which measured irradiances values are available The Meteonorm data are usually 1961 1990 average values the new Meteonorm V6 0 includes also some 1983 1993 averages but usually not very different In Meteonorm data of all other sites are interpolated values between the 2 3 nearest stations For all big European countries all the measured stations available in Meteonorm are in the PVsyst database But for many regions of the world the measured Stations are very scarce and Meteonorm has to use Satellite data for completing this information But besides the original database PVsyst offers tools for easily importing meteo datalt14 from many other sources See later in this tutorial NB The original database is stored in the file MeteoDB CSV located in DataRO which may be opened ina spreadsheet for example in EXCEL In this file each s
435. ta string of modules in series and calculates another shading factor according to module cabling 4 Altough not perfect this second approach should give an upper limit for the real shading loss evaluation Horizon Far shadings We distinguish between two fundamentally different types of shadings The horizon is describing far shadings effects This is the simplest way for defining shadings but it s use should be limited to obstacles distant of say twenty times the PV array size Horizon acts on the PV field in a global way at a given instant the sun is or is not visible on the field Near shadingsl37 are partial shadings which affect only a part of the field The shaded part changes during the day and over the seasons Near shadings management require a 3 D construction of the field and it s envronment and is much more complex to deal with Defining horizon profile is a very simple operation with the PVSYST graphical tool The horizon is a broken line superimposed on the sun path diagram which can hold any number of points To modify it simply drag the red dots with the mouse or define the desired value in the corresponding edit box To add a point click anywhere with the right button To delete a point click on this point with the right button On site horizon measurements height and azimuth of some significant points can be obtained with a theodolite a detailed map a fish eye photography etc Importing a
436. tarting threshold of the second pump is a crucial setting If too low the starting current will stop the running of the first pump while in a very efficient irradiance range Flowrate function of Irradiance Flowrate function of Irradiance Values from 01 01 to 3142 Values from 01 01 to 3142 Average flow Rate when running m3h Average flow Rate when running mh 0 200 400 600 800 1000 1200 Effective Global corr for IAM and shadings Vim 0 200 400 600 800 1000 1200 Effective Global corr for IAM and shadings im The Predefined Graphs Flowrate function of irradiance in the results is a suitable tool for understanding the behaviour and optimising the threshold Here for the 500 W m and 680 W m thresholds The array reconfiguration option shows quite similar performances as pump cascading Although suitable controllers seem to be not available on the market itis very easy to construct without deep investment in sophisticated electronics And it may be used of course with one only pump which avoids the practical disagreements of the pump s cascading As for cascading the threshold determination is very important and should be carefully determined with the same tools Power converters offer of course the best results And as expected MPPT converter is the more efficient But we can observe that DC DC converters with fixed input voltage are almostas efficient and that the fixed voltage value is not critical This could l
437. ted by PVsyst are the stabilized ones after degradation The initial values may be up to 10 15 higher during the first months This should be taken into account when sizing the system especially concerning the absolute maximum voltages for the inverter input or the module insulation Amorphous degradation and array voltage sizing It is well known that the amorphous modules suffer of a significant initial degradation during the two first operating months due to the Staebler Wronski effect This is sometimes specified in the data sheets and the voltage can be about 10 over the stabilized value As the electrical data used for the sizing of the PV array are the stabilized ones dangerous voltages overcoming the absolute admissible voltages may appear just after the commissioning of the system This may be taken into account in the Sizing dialog Now when the commissioning takes place in Summer the reference sizing temperature may be chosen much higher With a usual temperature coefficient muVco of around 0 3 C and a reference temperature gain of 20 C 10 C instead of 10 C usual in middle Europe this will reduce the Voc value by 6 Otherwise if your sizing overcomes the voltage limit you can also suppress one module in each string during the first operating months Inverter Array sizing The inverter power sizing is a delicate and debated problem Most inverter providers recommend or require a PNom array limit or a fixed Pnom
438. ted in hourly values Each variable will occupy about 18 kB on the output VCi file By default the program chooses about ten fundamental variables These will allow for displaying detailed plots of one or several simultaneously variables with a very comfortable navigating tool over the whole year Special graphsl92 the user can pre define four kinds of special graphs time evolution scatterplot histogram and sorted values for any variable in daily or hourly values About ten specific and usual graphs are already defined with each new simulation ASCII export filesl91 the user can choose any among the variables to be written in daily or hourly values on an ASCII file for exporting to another software spreadsheet e g Microsoft Excel The ASCII file is generated during the simulation process After completion the simulation allows for opening the Results 92 dialog Simulation results for a particular variant can be stored with all involved parameters in a file named as the project s file with the extension VCi i 0 9 A Z Simulation process irradiance and PV array The simulation involves about fifty variables 944 which are all accumulated in monthly values When starting the early parameter definition parts in the program have already verified the consistency of all input parameters In a first step the diffuse attenuation factor 18 should be calculated by integrating simultaneously shading and IAM attenuati
439. teo data in the Project Project Site and Meteo System definition Plane orientation Heterogeneous Fields Sheds mutual shadings Contents Shed optimization Sun Shields mutual shadings Orientation optimisation tool Concentrating systems Defining a concentrating system PV array electrical behaviour Arrays with characteristic s mismatch PV module array with a shaded cell Shadings general organisation Horizon Far shadings Near Shadings main dialog Near Shadings tutorial Near Shadings treatment Near Shadings 3D construction User s needs load Load profile ASCII file definition Domestic User s needs User s needs probability profile definition User s needs daily profile definition User s needs monthly values definition Grid connected system definition Array voltage sizing according to inverter Amorphous degradation and array voltage sizing Inverter Array sizing Grid Inverter sizing Different sub systems multi MPPT inverters SolarEdge Architecture Normalised Grid voltages Stand alone system definition Regulator Operating modes DC grid system definition DC grid load profile DC grid line resistance DC grid Overvoltage regulation Pumping system definition Pumping system sizing Contents Chapter 5 67 73 79 88 89 90 90 91 91 92 92 92 93 94 94 96 97 99 101 102 103 104 104 108 109 Pumping Systems Generalities Pumping system confi
440. teorological data Geographical and Meteorological data 5 Graph This will open a graph with the hourly meteo values and you can walk through your entire data using the Scrollbar on the right The plot includes a blue line which represents the Clear day model superimposed on your data Please observe a good day itis very important that the data should be more or less centred on the blue line This will always be the case for the synthetic data or the data imported from known sources using the Import meteo data PVsyst tool But this may be different with personal imported data when using the mport ASCII meteo files tool If the data are not matching the Clear day model i e are shifted toward morning or evening this indicates that the hour stamps of your data don t match the PVsyst standard and all the models using solar geometry will not work properly When walking through the year you will observe that clear conditions correspond to low diffuse component and when the sun becomes hazy the diffuse part increases The difference between the global and the diffuse corresponds to the beam component Graphs of daily values Have a look on the daily values Each point represents the daily irradiance of one day in kWh m2 day along with the Clear day model as an envelope curve This plot gives a first check of the quality of the data Now if some data significantly overcome the clear day model say by more than 3 5 this indicates
441. terference as far as they don t share the same Data structure because some files of new versions may be incompatible with older versions File organisation Installation The PVSYST software can be installed in any directory of your choice defined during the installation This directory the root of PVSYST say PVSYST5 by default contains the main programme and its executing files It is usually placed in the Program Files part of your operating system No other files are put elsewhere in your system by the installation program except under Vista or Windows 7 see below PVsyst doesn t make use of the Windows Registry The various help image and data files are spread out into sub directories also created during installation according to the list defined below Please note the installation as well as the first execution of the program should be performed in a windows session with administrator rights New file organization and data positioning since version 5 2 Up to the version 5 13 the working area Data directory was located by default in your installation location i e under PVsyst5 Data But when you don t have administrator rights in your Windows session Windows forbids writing in the Program Files area With Windows XP this was an absolute conditions and when not administrator of your machine you Chapter 7 Technical aspects 174 175 Technical aspects T had to displace copy your working area
442. terproof all over the life time The technical constraints are more severe and their quality should be much higher as the maintenance is not easy Therefore the price of such pumps is usually much higher than for surface pumps Moreover it is technically very difficult or impossible to put several pumps in the same well Nevertheless there are now very sophisticated well immersed solar pumps on the market some of them even including the power converter and accepting a very large range of input voltages These dramatically facilitate the system design Pump data general page Pump device identifiers Model and Manufacturer are identifiers which will appear in the pump choice lists Data source usually refers to the main parameter source most often Manufacturer may be an independent institute or your own measurements File name should have the extension PMP You can create a new pump device by changing the file name Electric side Definitions related to the input of the pump device considered as a black box Define the motor typel7A especially regarding AC or DC mode Define the power converter 160 type if any Define the Nominal voltage at nominal Head and nominal or maximum powers at the three Head values specified in the hydraulic panel These nominal or maximal powers are not quite clearly defined They will be used during the simulation as nominal values absolute maximum ratings should be defined in the
443. tests under simulator or in natural illumination Photovoltaics modules database in tabular form The user has now the opportunity of exchanging all the parameter Module with an EXCEL file or an ASCII text file in tabular form one line per module The Microsoft EXCEL sheet Components xls has been specially formatted for a good interpretation of the parameters Required Optional Defined by PVsyst etc When editing the PV module the button Export to Table will store the data of the module in the clipboard which you can Paste in EXCEL Inversely if you Copy a valid line in the EXCEL sheet a button Paste from Table will appear in the PV module dialog which allows for importing the data in the PVsyst program and file You can also export a set of chosen modules from the Module List in the Tools section on the software When importing new modules without Rshunt and or Rserie parameters these will be set to default values by the software in order to offer a valid model immediately useable NB The same feature is available for Inverters PV Modules Serie Resistance determination The Serie Resistance is one of the 4 unknown related coupled parameters when adjusting the one diode model The condition of passing through the three points Isc Mpp and Voc will fix the 3 other parameter Iph loref and Gamma as functions of a given Rserie value which can be chosen between 0 and RsMax The plot shows the corresponding
444. that the data are not good Tables of Hourly Daily or Monthly values Perhaps you want also show your data as tables You can choose up to 8 values to be tabulated ata time including the irradiance on a tilted plane transposition model or the normal beam component for concentration As for each data table in PVsyst you have the opportunity of Printing the table this printed form usuallyincludes the main parameters concerning the data and for big tables hourly or daily you can choose the desired period Export Copy as text this will copy the full table in the clipboard so that you can directly Paste it into an external spreadsheet like msExcel Please remember in msEXCEL the imported data will usually be gathered in one only column For expanding the data to the cells you have to use the standard EXCEL options for importing data menu Data Convert and here you should choose Delimited Semicolon separator NB The data will be copied with a decimal point If you are using decimal commas international preferences in Windows you will perhaps have to change all points into commas Export Copy as image to be used for directly put the table as such in a report Export Copy to file will create a CSV file which you can open in any spreadsheet program Importing Meteo data from many popular sources Please choose the mport Meteo Data button Here you have documented and easy to use tools for importing
445. the Swiss sites while the standard deviations RMSE are comparable in all cases It appears therefore that the Perezs model which is more complex and especially more sensitive to a realistic determination of the diffuse irradiation is often not justified in the PVSYST software Therefore by default the PVSYST programme uses the Hay s model However if the user can avail of good measurements of the diffuse irradiance he can choose the most sophisticated model of Perez Ineichen main menu option Preferences Preferences The Hay transposition model The Hay transposition model applies differently to the different components of the irradiance The Beam component results of a pure geometrical transformation BeamInc BeamHor sin Hsoli sin Hsol The Diffuse component is supposed to be mainly constituted of an isotropic distribution and a circum solar contribution proportional to Kb Diffinc DiffHor 1 Kb 1 cos i 2 Kb sin Hsoll sin Hsol The Albedo component is the irradiance reflected by the ground seen by the plane Albinc p GlobHor 1 cos i 2 where i Plane tilt Hsol Sun height on horizontal plane Hsoli Sun height on the plane 90 incidence angle Kb Clearness index of beam BeamHor lo Sin Hsol lo Solar constant depends on the day of year p Albedo coefficientl187 usual value 0 2 Chapter 8 Physical models used Physical models used 8 The expression 1 co
446. the configuration features and securities of the device not used in the simulation These are Isolation Monitoring is a continuous check of the isolation of the PV array by respect to ground DC Swich indicates if the device includes it otherwise it should be foreseen externally on all DC inputs AC Swich indicates ifthe device includes it otherwise it should be foreseen externally AC Disconnect adjust the inverter should cut the AC connexion immediately when the grid voltage goes out of a given AC voltage range in Europe 230 V or 400V 6 and 10 This feature allows to adjust these limits ENS indicates that the cut off security in case of grid defection work on the basis of the grid s impedance measurement This system is mandatory in Germany Finally other parameter related to old technologies may be used for specific tests or analysis Operating mode will always be maximum power point i e the input electronics is continuously searching for the operating point on the array characteristics giving the maximum power I V Although the fixed voltage mode is quite obsolete with modern inverters itis still supported by PVSYST Behaviour at nominal power at AC output can be the following Power limitation during overload too much available energy at MPP any modern inverter will limit the input power at the nominal value by displacing the operating point on the array I V curve This mode gives rise to usually low los
447. the original values ora recalculated plane irradiation At this stage plane orientation may be slightly modified but big changes are not advised as the tilted plane irradiation looses some information by respect to horizontal true measurements Plane tilt Plane tilt The plane tilt is defined as the angle between the plane and the horizontal Performance Ratio PR Losses Performance Ratio This is a quantity defined namely bythe European Communities JRC Ispra which represents the ratio of the effectively produced used energy by respect to the energy which would be produced bya perfect system continuously operating at STC under same irradiance Incident Global in the plane The PR includes the array losses Shadings PV conversion mismatch wiring etc and the system losses inverter efficiency in grid connected or storage battery unused losses in stand alone etc Unlike the Specific energy production indicator expressed in kWh kWp year this is not directly dependent on the meteo input or plane orientation allowing the comparison of the system quality between installations in different locations and orientations Profile Angle Profile Angle Letus call Profile Plane the plane passing through an horizontal line perpendicular to a given azimuth and the sun We call Profile angle related to a given azimuth the angle formed by the profile plane and the horizontal plane This is the characteristic angle describing the
448. the reasons why the effective temperature of the battery should be know during operating and should therefore be specified in the parameters of the PV system The model evaluates the capacity in accordance with a predetermined profile which is not critical and not specific to each battery Ageing and wear and tear One of the advantages of the programme is also to evaluate the wear and tear of the battery depending on the running conditions and therefore the investment to be planned for its replacement Ageing is governed by two phenomena onthe one hand a static longevity characteristic of the battery whether itis used or not This value is often given by the manufacturer at a reference temperature 20 C But it strongly varies with temperature and we will agree with most of the manufacturers that it reduces by half for an elevation of 10 C Andon the other hand a deterioration due to use depending on the depth of the discharge at each cycle is given by manufacturers as a characteristic profile For each discharging step we therefore evaluate a wear and tear increment proportional to the current but weighted by the actual depth of the state of discharge The global wearing out of the time step is considered as the maximum value of these two evaluations Maintenance The modelling of the gassing current also allows for the calculation of the quantity of electrolyte consumed giving an idea of the frequency of maintenance dist
449. the upper tool bar Realistic view after construction you can have a look on your scene in a more realistic way than the iron wire representation used during technical construction You can define your own colors for each elementary object This realistic representation helps understanding some complex constructions and improves of course the presentation to a customer Most of these tools are also available either by Popup menu right button or by keyboard accelerators Near shadings elementary objects See also Near shadings general organisation 3 PVSYST proposes a library of elementary shapes basic or usual in architecture 2D shapes Triangles whatever isosceles or rectangle rectangles trapezium regular polygon pseudo circle sectors 3D shapes Parallelepiped square pyramid triangular hexagonal or octogonal prism portion of cylinder Building elements House 2 sided roof Tree Roof like diedre 2 sided rooftgables 4 sided roof prism chimney The Elementary object dialog allows to build one elementary object at a time in it s own referential The user chooses the shape and sizes either by using available parameters or by dragging significant points in the orthogonal views plane side or front views You can choose a custom colour for each elementary object Remember that the chosen colour will be that at bright sun In the global scene surfaces not facing the sun will appear darker More
450. the water delivered to the users the missing water the excess unused PV energy and the system efficiency during the year or performance ratio And if economical features are defined the global investment yearly costs and cost of the pumped m Export ASCII file Simulation Export file allows for writing chosen daily hourly or monthly values on an ASCII file in order to be used in another software It should be defined before the simulation as the output file is generated during the simulation process Procedure Define the output file name which will be placed by default in the PVSYST DATA UserData directory Choose the fields format separated or fixed fields and the separator The date and hour format including Microsoft EXCEL compatible dates The type of values Hourly Daily or Monthly The parameters to be accumulated Models The user has the opportunity of saving these definitions in a library to reuse it in other projects Note Although your file parameter definitions will be kept over different simulation runs you may choose if you want to effectively produce the file or not By default after producing the first output it will turn on No Output and you will have to explicitely ask for an ASCII output before running the next simulation Tip for monthly values you will have a very fast way of exporting data by using direct export of the monthly result tables either through a file or by Copy
451. thout wind velocity When importing own measurements the meteo file can be restricted to limited periods and even have full days holes In this case the date is included in each record on the file The meteo files may be obtained in several ways 22 DRY Design Reference Years for swiss locations are available in the database ASCII data files 124 official meteorological data like DRY or TMY or measurements carried out directly by the user can be imported in a great variety of formats using a special programmable data interpreter NB In order to facilitate the analysis of existing systems the programme also accepts irradiation measurements carried out in the collector plane Generation of synthetic hourly values from monthly meteo values of global irradiation and temperature The physical bases of this generator follow the directives of Meteonorm 95 using Aguiar Collares Pereira et al and Scartezzini algorithms Directimport from the Meteonorm 117 software or US TMY datal119 free from the web The characteristics and the contents of the hourly meteo files can be visualised and analysed thanks to the meteo tables and graphs 109 tool Geographical locations monthly meteo data A geographical site is defined by it s name country and world region its geographical co ordinates latitude longitude altitude and time zone Monthly meteorological data To be used in the simulation the minimum meteorological data
452. till fundamental as it consumes a part of the charging current and therefore affects the global operating of the system in particular the real efficiency of the battery We suppose that this phenomenon induces an excess voltage with respect to the linear behaviour depending on the SOC The shape of this excess voltage is a predetermined S curve ref 22 The gassing current increases exponentially with the excess voltage and substitutes itself progressively for charge current The Delta coefficient of the exponential has been measured bya German team for various batteries of different ages and is established at about 11 7 v ref 23 The end of charge is another predetermined limiting curve depending on the charging current ref 20 It corresponds to the situation where the whole currentis used for the dissociation and allows to fix the logass parameter l exp Delta dU gass ogass gass Temperature dependence and polarisation To put it more simply the dependence of the voltage on the temperature is assumed to be linear in all operating conditions In the same manner the internal resistance is assumed to be constant any possible dependence on temperature studied in ref 21 is ignored We also neglect the polarisation effects or voltage drift depending on immediately preceding operating conditions they show characteristic times less than one hour and only affect the states of very low current State of charge
453. time which should be specified in the parameters of the site during the accumulation and therefore giving rise to two distinct files during the conversion process Be aware that PVSYST data files cannot run over 12 months Merging data thatis introducing one or several parameter data belonging to another internal data file Example of use introduction of meteorological data simultaneously measured by another acquisition system on a very near site Cut of data according to dates You can eliminate some given period integer number of days from a data file Tip You can also use the data eliminationh7Atools for hiding faulty data in a file without definitively removing them Data elimination in Tables You can mark eliminate break down datali7 in the tables by clicking on the desired line With the leftbutton elimination With the right button to restore data The eliminations performed in daily values will be thrown back to all hourly concerned values You can also perform eliminations directlyon comparisons graphs These eliminations are of the same kind and will appear here if saved with the data file DAM file NB If you modify the data eliminations the program will ask you for saving theses modifications on the data file Cuts of erroneous data During a real data acquisition the measured data often include erroneous measurements which correspond either to deficiencies in the measurement equipment or to break downs or
454. tion are not present in the Satellight data Therefore they have to be defined in monthly values The PVsyst procedure will invite you to define these values which may be imported from any close site from the database Press Import for creating the hourly meteo file met along with a site file sit with monthly values for use in PVsyst The importing procedure will then generate synthetic hourly temperatures according to irradiances using the usual synthesismodel 188 Please carefully check the data quality using the graphs of hourly values Especially check the values of Chapter 5 Geographical and Meteorological data Geographical and Meteorological data 5 some clear days against the clear day model Getting Satellight data from Web The Satellight Meteo data may be obtained free from the web site www satellight com Nevertheless you should register on this site First make sure that your browser accepts cookies unless several features of the site will not operate correctly and you will not be able to choose your site Then you are required to register or give your Identifier and Password Press Login button Then press Site in the main menu and follow the Satellight procedure for choosing your site or location 1 Select the Region on the map 2 Select your site If available you are advised to choose your site in the Database so that its name will appear in the file and be directly set in PVsyst
455. tion into account USSC Field Output Energy beam global gt 0 7 450 Total 792 points Hourly average 296 021 VW 400 Meas Model Error aver 1 38 rms 19 701 VW Meas Model Error aver 0 47 rms 6 66 350 300 250 200 Measured values W 150 100 50 D 50 100 150 200 250 300 350 400 450 Simulated values W Fig 4a Comparisons for the amorphous collectors of the LESO USSC strong beam USSC Field Output Energy beamiglobal lt 0 25 450 Total 1493 points Hourly average 20 38 WV 400 Meas Model Error aver 22 89 rms 10 94 W Meas Model Error aver 112 31 rms 53 67 350 300 250 200 Measured values W 150 100 sol 0 50 100 150 200 250 300 350 400 450 Simulated values VY Fig 4a Comparisons for the amorphous collectors of the LESO USSC purely diffuse irradiation Inverter modelling Chapter 10 Validations Validations 10 Inverter s operation modelling does not give any special problems except the exact determination of the power efficiency profile the programme offers a specific tool to superpose the characteristic of an existing model presentin the componentlibrary on the measured input output data of the inverter The exact profile corresponding to the data can then be adjusted interactively by the user and itcan be assumed that the residual errors of the simulation are notimputable to the calculation model of PVSYST but only to the inaccur
456. tion of the system cost is also available The procedure is straightforward you just go over the three buttons Location System and Results First click on Location button you have to give a description of your pre sizing project in order to identify it after saving The pre sizing projects are simple files which don t allow for several variants Choose a location in the database You can obtain the location details or even create or import a new location from Meteonormlh1 or US TMY datali19 using the open button When necessary you can also define an Horizon 38 profile Click on System button The pre sizing procedure is then specific for each type of system Grid connected system 18 Stand alone system 19 Pumping systemI 21 Chapter 2 Licensing Preliminary design 3 Grid System Presizing Pre sizing is a rough estimation of the PV system energy yield based on a few very general parameters and mainly dedicated to architects during an early evaluation of a site You should not use this tool for the study of a system The meteo input data are computed in monthly values taking plane orientation and horizon into account and applies efficiency coefficients according to a PV technology and other considerations These coefficients may eventually be re adjusted by an expert user for special conditions in the Hidden parametersl173 The expected precision could be around 10 or more More precise results will be obt
457. tions 2 Backtracking strategy with all tracking systems involves tracker width and distance definitions 3 Sun shields definition in the 3D tool also with backtracking which may considerably improve the sun shield s performances 4 High Concentrating systems simulation associated with 2 axis trackers adaptation of the simulation process and loss diagram 5 Long term financial balance tool including several Feed in tariff strategies day night or seasonal variations feed in and self consumption tariffs etc and system ageing 6 Soiling parameter included in the simulation and loss diagram with opportunity of defining monthly variations 7 Direct import of meteo values from NASA SSE database over the whole earth by 1 x1 cells and practical procedure for importing meteo values from WRDC database especially for countries where METEONORM data are scarce 8 Improved the model for amorphous PV modules especially safety of parameter boundaries and behaviour presentation to the user 9 Improved the Project dialog and choice of a site meteo Improved compatibility checks between the project s site and hourly meteo Extraction edition of the site geographic properties within an hourly meteo file which was not possible up to now 10 Database update with PV modules and inverters of 2006 2007 now around 2250 PV modules and 770 inverters 11 Adaptations for Windows VISTA OS especially concerning the visual interface A
458. to purchase activation codes This price is a one time fee per company The set of the PVsyst license rights and the activation code s is considered as a group identified by a Customer ID Activation Code After installation PVsyst runs in evaluation mode with full capabilities during 15 days Afterwards it turns in DEMO mode and you have to request an activation code 16 which will allow you to run the software in unlimited time mode Chapter1 Overview 14 15 Licensing 2 One activation code per workstation is required The activation code is paired with the Local Number resulting of the installation of PVsyst on a given workstation Requesting an activation code 16 Upgrade and Update If you already own a previous version of PVsyst with a lower major version number i e V4 xx or V3 xx an upgrade activation code is required to upgrade to the latest version 5 xx of the software One upgrade activation code per workstation is required Update of the software i e change to a higher minor version number e g V5 21 to V5 3 is free of charge An automatic tool in the software checks for new version available each time you run PVsyst and performs the installation upon user request Price list PVsyst License Rights 800 CHF per company Activation Code s 200 CHF workstation Upgrade Activation Code s 100 CHF workstation V4 xx or V3 xx Discount for Academic and 20 Educational Institutions VAT An additiona
459. to your personal working area see below Now with Vista and Windows 7 when the program is writing in these area Windows delocalizes these filesl178 to a special VirtualStore directory c Users User AppData Local Virtual Store Program Files PVsyst5 Data This is the reason why from version 5 2 PVsyst puts by default the Data subdirectory in a location always writable by anybody Under Vista and Windows 7 c ProgramData PVsyst Data Under Windows XP and older c Documents and Settings All Users Application Data PVsyst Data Customizing the location of your data If you want to put your PVsyst data structure elsewhere in your working area you can copy the whole Data structure using the dedicated tool 188 main menu Files Directories The customized location will take the name PVsyst_Data NB This opportunity of copying the Data structure is also useful if you want to share your projects with other users on a network But please note that PVsyst is not really meant for sharing data and doesn t perform any checks for avoiding user s collisions In this case PVsyst doesn t recognize the network paths beginning by Please make your remote directories as a disk unit File organization and description The Directory tree and file content is organised as follows PVsyst5 or any other root that you may have chosen during installation contains the executable programme fil
460. tor applies to the beam component reaching the PV plane When the incident angle is high even high loss factors will act on very low irradiance component giving rise to reasonable effects on the overall efficiency Near shadings Table of shading factor The shading factor is a complex calculation which spends too much time to be performed during simulation at each time step Therefore the program builds a table in sun s height 10 steps and azimuth 20 steps The simulation can then interpolate in this table Shading factor computation details The geometric configuration of the shadow falling on the field and the determination of the shading factor are carried out in a purely geometric and analytical manner For a given solar position the programme first carries out a transformation of the co ordinates of the whole system so as to point the OZ axis in the direction of the sun Next for each sensitive element of the PV field sheds rectangles polygons it projects each elementary surface of the system on the plane of the field being considered The intersection of the field element with the positive projections i e in front of the plane of each element is then calculated The reunion of these elementary shadows forms a polygon representing the global shading on the field element under consideration The shading loss factor is the ratio of the area of the shadow polygon to that of the sensitive element This process is repeated f
461. tructure the main results and parameters of this project are often presented as coloured maps at regional or continental level Importing PVGIS data Please open the web site http re jrc ec europa eu pvgis In the frame Interactive access to solar resource and photovoltaic potential click on the Europe or Africa icon You will obtain a GoogleMap like tool for choosing your site Typing a town name will put it at a suitable scale for navigating and easily find your exact location On the right dialog select Monthly Radiation tab and check the following variables to be imported Horizontal Irradiation Dif Global radiation optional Daily Average Temperature not available for Africa will be imported from other sources PVsyst does not make use the Average Daytime Temperature as the synthetic generation model for the daily profile includes the Day Night effect and waits for a 24h average as input Then you choose Web Page output option and click Calculate Select the whole text from PVGIS to the end of the table and Copy Ctrl C it into the clipboard NB If the data window doesn t appear after Calculate it is usually because your web navigator is blocking the advertising windows In MS Internet Explorer you can manage this in the Options of the main menu NB Up to the version 4 33 import of PVGIS data was performed using the old interface of the PVGIS site This new interface is much more convivial Co
462. tt voltage for a battery element U anaes intercept of the open circuit voltage linear part at SOC 0 SOC state of charge varies from 0 to 1 Alpha slope of the open circuit line depends on the chemical couple Pb SO T att temperature of the battery Tef reference temperature usually 20 C Beta temperature coefficient 5 to 6 m V C R internal resistance assumed to be constant Ipatt battery current charge gt 0 discharge lt 0 This model is then completed bya series of disturbances whose values are predefined in the programme modulated especially by the chosen technology but which can of course be adjusted by the user if he has more specific data for his own battery at disposal Over charging and deep discharge The first two disturbances to be taken into account are the behaviours at the end of the charging and the discharging processes which mainly affect voltage and therefore regulation When the battery approaches complete discharge the voltage falls progressively whatever be the current We have fixed a fall of a quadratic shape starting from a SOC of 30 which gives realistic results for most of the batteries But this exact shape is of little importance for the behaviour of the system as a whole At the end of charge the problem is more delicate because of the apparition of the electrolyte dissociation gassing This phenomenon is rarely treated explicitly in the usual models but itis s
463. ufacturers are also used Manufacturer s specifications as well as these source databases contain the main necessary parameters for the introduction of new modules in the PVSYST library Nevertheless for definitive simulations the user is advised to carefully verify the library data with the latest manufacturer s specifications some technical data may be modified especially care must be taken about geometrical dimensions We drop out any responsibility about the integrity and the exactness of the data and performances included in the library On the other hand the data from manufacturers or TISO are not always complete Some parameters necessary to the model are often missing and should be fixed at realistic values These are especially The series and shunt resistances never available in the catalogues these values are sometimes given along with detailed measurements on modules The shunt resistance may be estimated by a measurement of the slope of the I V characteristics in the short circuit region or the module resistance in darkness The program default valuel40 gives a value near to the measurements performed on several modules in our laboratory This value has only little influence on crystalline silicon modules but becomes significant with thin film modules By default the series resistance is then fixed in order to get a reasonable Gamma factorh4 These choices may appear as arbitrary but correspond to very close beha
464. uffered Water needs and Head characteristics may be defined in yearly seasonally or monthly values 4 Presizing tool for Pumping systems As for stand alone systems a Pre Sizing tool has been developed which proposes a PV power and Pump power sizing according to the location and meteo user s needs and LOL requirements This simplified model takes the pump technology and system configuration into account It also proposes a very rough estimation of the costs 5 Detailed Simulation The design of the pumping system rather complex with such a number of pumps and system technological aspects is assisted by numerous sizing propositions and helps advices graphs blocking of uncompatibilities etc when choosing the system layout and configuration The hourly simulation accounts in detail for all features defined for the system and is specific for each configuration listed above direct coupling with converter or battery As for the other systems a detailed engineer report explains all parameters and results of the simulation All the losses and mismatches along the system are quantified and visualised on the Loss Diagram specific for each configuration 6 Help for pumping systems The development of this Pumping tool has brought a deep understanding of the PV pumping systems problematic and the operating efficiency limitations inherent to the numerous possible solutions This Help describes in detail the implemented models a
465. umping system sizing When sizing a PV pumping system the basic constraints are the availability of solar energy during the year and the satisfaction of the user s water needs The problem to be solved is the optimisation of the size of the photovoltaic generator and the pumps taking the head and the electric PV Pump matching into account as well as the chosen System configuration 73 Chapter 4 Project design 66 67 Project design 4 We give an idea of the procedure for a first rough estimation We start with the pump sizing We first determine the Hydraulic Energyl 7 needs over one day assuming that Flow and Head are rather constant over the year otherwise the day by day rough simulation provided in the presizing tool 21lis unavoidable As a thumb rule we can assume that on rather good days the pump will run at its equivalent full operation during about 6 hours i e provide a flowrate m h of about the daily water yield m 6 h Assuming now a pump efficiency usually about 50 for positive displacement or 35 40 for centrifugal pumps we can deduce the Pump Electrical nominal power suited for these clear day conditions We should of course increase this value accounting for the possible bad weather conditions over the year Here the day by day simulation is necessary if we want to determine accurately the nominal power required to geta predefined LOL 9h At this stage we should emphasize that the system layout has
466. uracy is not quite established The general study of concentration systems involves a detailed description of the irradiance distribution which cannot be available using the present treatment of the Meteo nor the limited information included in the meteo database site database Namely high concentrating performances require a good knowledge of the beam component Then accurate models for achieving this evaluation would involve parameter like turbidity water and aerosol contents of the atmosphere which are not defined in our database As an example the eruption of the Mt Pinatubo in 1991 had little effects on the global irradiance less than 2 but induced a very high loss of beam component the pure direct was scattered by aerosols resulting in a strong halo around the sun up to 30 during almost 2 years This had dramatic consequences on the productivity of the high concentration thermal plants all around the earth Molineaux 1996 In PVsyst the simulation of concentrating systems has to deal with 2 aspects Acceptance of the Diffuse component The higher the concentration the lower the acceptance angle which implies a limited acceptance of the diffuse component The maximum achievable Concentration Ratio CR is related to the acceptance half angle 0 as CRmax 1axis 1 sin 6 CRmax 2axis 1 sin 6 Kreith and Kreidler 1978 p 248 In the present state PVsyst is only able to treat 2 axis high concentration systems
467. ust meets the required LOL This may lead to a very low average State of Charge value over large periods of the year which is quite damaging for the battery In these cases the actual PV array sizing should be slightly increased by respect to the PVsyst proposal in the definitive Project study Battery current efficiency Battery current efficiency This parameter is the Electrochemical conversion current efficiency without gassing The global coulombic efficiency including gassing losses depends on use conditions and will be a result of the simulation The energy efficiency including voltage losses between Charging and Discharging processes will be a result of the simulation too Battery maximum charge threshold Battery maximum charge voltage threshold The end of charge voltage threshold is slightly dependent on the battery technology For vented lead acid batteries it should be 2 23 V element while for sealed batteries with recombination catalysator it can be raised to 2 25 Vielement manufacturer recommendation According to manufacturer data sheets the end of discharge threshold may depend on the discharge current due to internal resistance voltage drop Nevertheless this applies in back up use with high currents discharges in one hour or less With solar use currents are usually far less and this effect can be neglected PVSYST as usual solar regulators doesn t take it into account and proposes a fixed threshold vo
468. valuel140 at reference conditions has already been chosen when establishing the model For amorphous modules PVsyst proposes a Rsh 0 value of 12 times Rsh For Si crystalline and others we observed optimum values around 4 Rsh but this cannot be asserted for any module Therefore PVsyst doesn t propose any exponential correction as default this remains an optional Chapter 6 Tools and databases 146 147 Tools and databases 6 refinement In the future these values should ideally be provided by the module manufacturers in their data sheets NB When two or several Rsh values are available PVsyst offers a tool for adjusting the corresponding Rsh ref and Rsh 0 parameters 1148 Back to Standard One diode model 138 Back to Amorphous and Thin films modules 147 Photovoltaics modules database The PVSYST database contains references to more than 6000 PV modules available on the European market These earlier data came from a compilation of manufacturer s specifications gathered by the TISO Centrale di prova per componenti PV Ticino Switzerland Some modules were really measured in real conditions and on a long period by this institution Now the database is periodically updated using data published by the German Journal PHOTON Magazine This PVSYST database has been limited to modules of power greater than about 35 Wp for Si crystalline modules best suited for grid connected systems Some new models submitted by the man
469. veral pumps Array reconfiguration 77 half array serie parallel switching not common but rather simple technique involving simple controlling device with relays Systems with Power conditioning units A matching the voltage current PV characteristics to the specific electrical needs of the pumps DC motor behaviour mainly current driven using modern electronic switching Chapter 4 Project design Project design 4 techniques On the solar side these can be either Maximum Power Point Tracking MPPT or with fixed voltage DC input Such a device is of course necessary with AC motor pumps inverter Battery buffered 7A systems where a batteryis used to regulate the pump running in time The PV Battery behaves like a standard stand alone system and the pump is always running in optimal conditions at the nominal battery voltage Astrategy of switching the pump ON OFF according to the irradiance level may be used to minimize the battery solicitation Nevertheless the simulations show that a high charge discharge rate is unavoidable in this configuration leading to rapid wearing of the battery pack and a high rate of replacement You can have a look on the simulation Results 79 for comparing the performances of these operating strategies Controller By the way even the simplest configurations direct coupling require the presence of a control device which should atleast assume the following functions Manual Power ON OF
470. viours of the model especially when restricting at MPP operation The cells area is involved in the efficiency estimation of the active area If it is quite unknown it may be put to O without danger then the corresponding efficiency will be null It may be important to define it with modules of special layout like tiles or spaced sells for which the module area is not significant The reverse characteristicli40 parameter is only used in the visualisation tools of array s behaviour with shaded or mismatched cells Their influence is mostly qualitative and depends strongly on the temperature We don t avail of reliable indications except our own measurements on some modules Therefore the database puts this measured value as default for any module The number of protection diodes is usually not a basic characteristics of the module type sometimes it has to be specified during the order Data given in the database are not reliable The temperature coefficient of the open circuit voltage muVoc is normally determined by the program one diode model during the choice of the series resistance Nevertheless it s variation s domain is restricted and it is often hard to match the given value with an appropriate choice of Rs Nevertheless PVsyst gives the opportunity of adjusting the muVco value to a given value but this is not recommended In version 3 4 some additional modifications 44 have been added to the Standard On diode Model in order
471. wise antitrignometric direction In the southern hemisphere the X direction points to the EAST and Y to the NORTH The azimuths are given with respect to the North OY and positively towards WEST thatis anticlockwise trignometric direction To facilitate the system construction the user can build it s whole scene in a referential related to his system for example parallel to his building and then rotate the entire scene by the desired orientation angle Observer Observer s point of view The upper tool bar blue icons as well as the Observer menu provide means for defining the observer s point of view Perspective by default gives a standard view height 20 and azimuth 30 with the observer at 200 meters The observer s view angles may be changed in several ways scrollbars on the image top arrows keys on the keyboard or by the menu The observer distance can only be changed through the menu Observer Detailed position This could be necessary if you have a very big scene Axonometry this representation is equivalent to a perspective from infinite distance Axonometry preserves parallel lines Plane front and side views are defined according to the referential axis These are the only views which allow displacements or other operations in dragging mode red or violet points Chapter 4 Project design Project design 4 on the objects Forward and Backward Zooms are available by buttons and menu but back t
472. y design 1 17 18 19 Presizing 17 18 19 Printing 2 Project 22 182 183 24 28 29 Project design 1 20 22 24 29 57 61 63 64 65 86 88 89 90 91 92 Projects transfer 181 Pump Pump model 157 Pump model Pump 157 160 162 163 164 158 159 160 Index Pumping System Configurations 66 73 74 75 76 77 79 166 167 Pumping Systems 21 65 66 67 68 69 70 71 72 73 79 91 99 166 167 PV array behaviour 31 36 37 131 140 168 PVcomponents 133 149 153 157 164 PVmodel 136 139 140 141 143 145 146 PVmodules 133 134 135 136 139 140 141 143 145 146 148 PVplane 30 R References 203 Registration 14 16 17 Regulation loss 82 Regulators for stand alone systems 164 189 Results 88 89 91 92 102 103 Reverse characteristics 140 S Satellight 120 122 Screen 2 Shadings 31 32 33 37 38 39 40 41 42 43 44 45 46 47 48 49 52 Sheds 31 32 33 43 Simulation 61 88 89 90 91 92 Simulation variables 93 94 96 97 99 101 Solar geometry 131 SolarEdge 61 Special characters 173 Stand alone system 19 20 63 90 System design 1 20 29 57 59 60 63 64 65 System sizing 20 29 57 59 60 63 64 65 7 Temperature behaviour 82 85 Thermal loss 82 85 192 Thin film PVmodel 141 143 145 146 Tools 1 33 36 131 184 Tracking 43 45 U Uninstall 174 Updates 172 Updating database 180 Index User s needs 54 55 56 57 V Validations 1
473. y from an irradiance threshold of 10 W m The following parameters are often given by manufacturers and sometime with a contractual constraint But they don t have a real physical meaning as they depend namely on the plane orientation please see the sizing tool They normally don t present any danger for the inverter at running time as by overload this device adjusts the power drawn from the PV array by displacing the operating point along the I V curve Nominal PV power is a usually specified parameter for inverters It may be understood as the recommended nominal STC power of the PV array Maximum PV power is sometimes specified by the manufacturers It may be understood as the absolute maximal STC power of the PV array If this is a contractual condition you have to check the Required checkbox so that the sizing tool will warn you in red in case of excess Maximum PV current is the absolute maximal current admissible at the input of the inverter usually the ISC current of the PV array at STC If this is a contractual condition you have to check the Required checkbox so that the sizing tool will warn you in red in case of excess Output side AC Although fundamental features of the inverter the AC output parameters are not involved in the simulation results nor the system performance evaluation which is only given in terms of Output Power Exception the Voltage Current characteristics at the AC side influence the eventual
474. y shading object Portion of cylinder According to the plan define Radius 3m Aperture angle 360 Nb of segments 16 Height 12m Click OK In the main scene be sure that the Positioning tool is activated click Top view and position the silo with the mouse if you don t know the order of magnitude or signs and then with values X 18m Y 45 m You can also puta tree in the courtyard Object New Elementary shading object Tree For determining the sizes and shape of the tree you can use Front view and here play with the red points for adjusting the shape of your tree And then you position it as you like in the courtyard please remember a tree doesn t have definitive sizes Positioning by respect to the cardinal points Chapter 4 Project design 50 51 Project design 4 For convenience you construct the scene in the referential of the architect After that the button Rotate whole scene will perform the final orientation of the global scene Select the reference object for the orientation normally the PV plane In the Rotate Whole Scene dialog define the new azimuth here 20 west This will orientate your whole scene But each time you will have to re position an object in the scene it will be easier to come back in the original system s referential i e to a plane orientation of 0 or 90 Shading test and animation Now your 3D scene holds obstacles and sensitive area
475. yst automatically remembers this in the little file DataPath ini which is located in the Documents and Settings All Users Application Data PVsyst directory Export whole Projectslieil allows gathering all files involved in a projectl18 for exporting to an archiving place or sending to another user of PVsyst These files are dispatched into an external directory usually named PVsyst_ExtData as a structure analogous to the one of PVsyst Import projectshetl restores whole projects either from exported structures or simply from a set of the filesl84 of a project in a single subdirectory without structure This is especially useful for re importing your old projects from a previous version of PVsyst The concerned files are dispatched into the local data structure Export Database Components copies all or chosen database components created or modified by the user These files are dispatched into an external directory usually named PVsyst_ExtData as a structure analogous to the one of PVsyst You can chose the desired categories and files to be exported as you like Import Database Components dispatchs a set of PVsyst database elements from an external data structure to each convenient folder in the working Data structure The source data may be either a set of individual files or an Ext_Data structure created by the previous tool There are sophisticated options for replacing only older files or replacing the files only when

4 - SoDa Service

Contents

Download Pdf Manuals

Related Search

Related Contents