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RETScreen - Photovoltaic Project Model

1. AC energy demand for months analysed The model calculates the AC energy demand in MWh for the season of use This is calculated from data entered in the Load Characteristics section of the Solar Resource amp System Load SR amp SL worksheet Water demand for months analysed The model calculates the water demand for the season of use in m3 This is calculated from data entered in the Load Characteristics section of the Solar Resource amp System Load SR amp SL worksheet Equivalent pumping energy demand The model calculates the amount of mechanical energy required to deliver the water demand over the season of use in MWh This is purely the mechanical energy necessary to lift water from the point of origin to the point of delivery and overcome fluid friction losses It does not include losses due to the inefficiency of the pump or the inefficiency of any electrical component of the system System Characteristics The system characteristics associated with estimating the seasonal energy production of a photovoltaic system are detailed below Some other system characteristics particularly those used to calculate the system load can be found in the Load Characteristics section of the Solar Resource amp System Load SR amp SL worksheet Application type The user enters the type of PV application in the Solar Resource amp System Load SR amp SL worksheet and it is copied automatically to the Energy Model worksheet The
2. 71 72 73 100 Cost Data secre iea e 100 Cost references cccccccceessscecessseeenseeeceeaee 6 41 42 Cumulative 0 0 ccccccccesccceececeessececeesseeeesesseeees 59 77 Cumulative Cash Flows Graph eee 59 77 CUITENCY a E EERE E TRE ER ees 6 40 42 Currency Opt ONS iiie n i ieies 6 CUStOM esanen n 80 81 82 83 84 86 D Daily water required sseseeeeeseeeeeeeereeeerereererrreerer 37 Daily water requirement seseeeeeeeeeeeeereeeererereerer 37 Data amp Help Access ceeeeeseeceereeeneeees 5 10 98 99 Days of autonomy required cc eeeeeeeeeeeee 17 19 Days of use per Week ceeeeeseeesesecseesecneeeeeneeeees 35 DC energy demand eeeeeeeeeee 11 19 24 35 61 DC energy demand for months analysed 11 Debt interest rate ccc ceecceccssceceesseceenseeeeeenee 66 93 Debt payment wise ateniesi sssi 71 76 Debt payments debt term ee ceeeeeseeceeeeeneeeeee 71 Debt 1E OLER EEE E AT 66 93 Debt service COVCLaQC e cesccesseeseceseceeeeeeeseeeneees 77 De Ditters Msi ostescishoosieszeste iiss eects 67 94 Depreciation method ceeesesecsecreeeecneeeeeeeeeees 68 Depreciation period 00 ceceeeccsseseeesecseeeecneeeeeeeeeees 69 Depreciation rate ceeecsesceeeeeeseceeesecneeeeeeeeees 69 Depreciation tax Dasis seeeceseseessecreesecneeeeeeeeeees 68 Description sonno rinen nn en a 33 36 Detailed load calculator off grid system 33 Deta
3. Components of a PV system more likely to need maintenance are batteries e g watering etc fossil fuel generators e g oil change etc and pumping equipment An annual visual inspection is recommended to check for loose wires structure solidity etc Components such as the controller or inverter should also be inspected on an annual basis although these components are more susceptible to fail completely instead of operating on an accelerated aging or wear and tear mode The inspection of PV systems can be performed by the system owner The cost range for annual maintenance inspection of a PV system is between 0 and 200 Use the lower value if the inspection is done by the owner Higher values would be more appropriate for larger and more complex PV systems where the maintenance inspection is performed by a paid technician or a system expert Rates for system experts range from 40 h to 100 h PV 56 RETScreen Photovoltaic Project Model Other These input cells are provided to allow the user to enter cost or credit items that are not included in the information provided in the above cost category The user must enter a positive numerical value in the Unit Cost column A cost item may be entered in the grey input cell as Other The user then selects Cost from the drop down list in the unit column The user can input both a quantity amount and unit cost This item is provided to allow for project technology and or regional
4. RETScreen International Clean Energy Decision Support Centre RETScreen Software Online User Manual AX z A e GEF SS Photovoltaic Project Model es aaa naturelles Canada Background This document allows for a printed version of the RETScreen Software Online User Manual which is an integral part of the RETScreen Software The online user manual is a Help file within the software The user automatically downloads the online user manual Help file while downloading the RETScreen Software Reproduction This document may be reproduced in whole or in part in any form for educational or nonprofit uses without special permission provided acknowledgment of the source is made Natural Resources Canada would appreciate receiving a copy of any publication that uses this report as a source However some of the materials and elements found in this report are subject to copyrights held by other organizations In such cases some restrictions on the reproduction of materials or graphical elements may apply it may be necessary to seek permission from the author or copyright holder prior to reproduction To obtain information concerning copyright ownership and restrictions on reproduction please contact RETScreen International Disclaimer This report is distributed for informational purposes and does not necessarily reflect the views of the Government of Canada nor constitute and endorsement of any commercial product or per
5. RETScreen Software Online User Manual Bibliography Barlow R McNelis B and Derrick A Solar Pumping An Introduction and update on the Technology Performance Costs and Economics Intermediate Technology Publications and The World Bank Washington D C 1993 Chabot B Personal Communication 1999 The Danish Energy Agency Engerstatistics 1995 1999 ECOTEC Research and Consulting Limited ECD Energy and Environment Newcastle Photovoltaics Applications Centre The Potential Market for PV Building Products report ETSU S P2 00277 00 00 1998 Fenhann J Personal Communication January 2000 Fenhann J Projections of Emissions of Greenhouse Gases Ozone precursors and Sulphur Dioxide from Danish Sources until 2010 The Danish Energy Agency December 1999 Johansson et al Renewable Energy Sources for Fuels and Electricity Island Press 1993 Leng G RETScreen International A Decision Support and Capacity Building Tool for Assessing Potential Renewable Energy Projects UNEP Industry amp Environment 3rd Quarter 2000 Leng G Dignard Bailey L Bragagnolo J Tamizhmani G and Usher E Overview of the Worldwide Photovoltaic Industry report 96 41 Al TR CANMET Energy Diversification Research Laboratory Natural Resources Canada Varennes June 1996 Leng G and Martin J Distributed Photovoltaic Demand Side Generation An Economic Evaluation For Electric Utilities I
6. This histogram provides a distribution of the possible values for the financial indicator resulting from the Monte Carlo simulation The height of each bar represents the frequency of values that fall in the range defined by the width of each bar The value corresponding to the middle of each range is plotted on the X axis Looking at the distribution of financial indicator the user is able to rapidly assess its variability In some cases there is insufficient data to properly plot the graph For example when the year to positive cash flow is immediate the result is not a numerical value and therefore these values cannot be plotted Bar graph The bar graph summarises the maximum and minimum financial indicator values that can be expected according to the level of risk defined by the user PV 97 RETScreen Software Online User Manual Product Data Some of the product data requirements for the model are provided in the RETScreen Online Product Database To access the product database the user may refer to Data amp Help Access The product database provides information on the equipment associated with the project From the online product database dialogue box the user may obtain product specification and performance data as well as company contact information The product database sorting routine starts by using the PV module type selected by the user in the Energy Model worksheet From the dialogue box the user s
7. Credit from the drop down list in the unit column The project may be credited for material and or labour costs that would have been spent on the base case or conventional energy system The user can input both a quantity amount and unit cost Note that the credit item is expressed as a negative value in the Amount column Development Once a potential photovoltaic project has been identified through the feasibility study to be desirable to implement project development activities follow For some projects the feasibility study development and engineering activities may proceed in parallel depending on the risk and return acceptable to the project proponent For photovoltaic projects there are a number of possible project developers Currently one common approach is for electric utilities to manage a program where a large number of PV systems are purchased for individual building home owners The utility may purchase the systems and then install them on the roof of the utility customer or near a utility substation In other programs the utility and or government provides a subsidy directly to the customer or product supplier to defray the initial cost of the PV system For these present day photovoltaic project development activities development costs typically include items such as permits and approvals project development management and travel costs These costs are detailed in the section below Permits and approvals A number of
8. The model calculates the net benefit cost B C ratio which is the ratio of the net benefits to costs of the project Net benefits represent the present value of annual revenues or savings less annual costs while the cost is defined as the project equity Ratios greater than 1 are indicative of profitable projects The net benefit cost B C ratio similar to the profitability index leads to the same conclusion as the net present value indicator Calculate energy production cost The user indicates by selecting from the drop down list whether or not the project energy production cost should be calculated The energy production cost could be used to either calculate the avoided cost of energy for the project to break even or the economic energy production cost In order to calculate the true economic not financial energy production cost a number of parameters such as the RE production credit GHG emission reduction credit avoided cost of capacity avoided cost of excess energy etc should be set to 0 In addition Income tax analysis should be set to No and other taxes and debt should also be set to zero This option is more applicable to economists as it requires a careful analysis of assumptions used PV 75 RETScreen Software Online User Manual Energy production cost The model calculates the energy production cost per kWh The energy production cost could be used to either calculate the avoided cost of energy for the
9. The user enters an estimate of the number of days during which the load is used per week d wk In the vacuum cleaning example if vacuuming is done on Mondays Wednesdays and Fridays the user should enter 3 DC energy demand The DC energy demand is the weekly averaged daily amount of DC energy required by all the individual loads This value is automatically calculated in the model if the detailed load calculator is used It must be entered manually by the user if the detailed load calculator is not used Values can range from zero if the entire load is AC to a few tens of kWh or more AC energy demand The AC energy demand is the weekly averaged daily amount of AC energy required by the load This value is automatically calculated by the model if the detailed load calculator is used It must be entered manually by the user if the calculator is not used Values can range from zero if the entire load is DC to a few tens of kWh or more AC peak load The AC peak load is the maximum power drawn at any time during one day by the load This value is automatically calculated by the model if the detailed load calculator is used It must be entered manually by the user if the calculator is not used Values can range from zero if the entire load is DC to a few kW or more The AC peak load is required to estimate the size the inverter If the detailed load calculator is used the AC peak load is obtained by summing all AC loads This may lead t
10. ccccccecssceeseeeeseeeeees 32 Solar radiation tilted surface ccccscesseeeseeeeeee 32 Solar Resource amp System Load Calculation 27 Solar load correlation ceceeseseeeeesecneeeeeneeeeeeaees 33 SOULCE i ssevscesiaeds hustendes en EEE ENKEN Toup ESEESE ESEESE Erebi 13 Specific fuel consumption sseseeseeeeeeeeeee e 13 23 72 Specie yield visio clei jase E e Eanna 25 Standard eee 6 41 42 80 82 83 84 86 Structural design cee eeeeceeseceseceeseceeeeeneseeeeaees 47 Suction h ad cnn cesta giesa penia Savane sees 37 Suggested genset Capacity cece eeeeeeceseeeeeeeeeee 23 Suggested inverter DC to AC capacity 16 24 Suggested nominal battery capacity eee 19 Suggested nominal PV array pOWel eeeeceeee 22 System Characteristics cccsescseeecsseecsseeeeeeeeaees 11 System installation eee seeeeecseeeecneeeecesesereeeaees 54 T Tax holiday available oo ees eeeeseeseeeecneeeeeeeeeees 69 Tax holiday duration 69 Tenders and contracting ceeseseeeeceeeeeeeeeeeees 48 Terms of Use 233 ansdsnialinindnesnite 102 PV 108 RETScreen Photovoltaic Project Model Threshold ireen arian steeds iaachesewsacabescaseetch 90 Total he dia sions cites elven Ars elas 38 54 Tr ning heata aeii ovea Aiki bestes 55 101 Training and Support sesseseeeeeeesseereresrsrsrrrrereerees 101 Transmission and distribution losses 85 87 Transportatio
11. then the risk analysis section will open and the user should complete the lower half of the worksheet The analysis will be performed on the financial indicator selected by the user in the Perform analysis on input cell at the top right The user will need to click on Calculate Risk Analysis button in the Risk Analysis section at the lower half of this worksheet to get the results Project name The user defined project name is entered for reference purposes only in the Energy Model worksheet and it is copied automatically to the Sensitivity worksheet PV 89 RETScreen Software Online User Manual Project location The user defined project location is entered for reference purposes only in the Energy Model worksheet and it is copied automatically to the Sensitivity worksheet Perform analysis on The user selects from three options in the drop down list the financial indicator to be used for both the sensitivity and risk analyses Modifying the selection in this cell will change the results in the worksheet Sensitivity range The user enters the sensitivity range which defines the maximum percentage variation that will be applied to all the key parameters in the sensitivity analysis results tables Each parameter is varied by the following fraction of the sensitivity range 1 1 2 0 1 2 1 This value is used in the sensitivity analysis section only The sensitivity range entered by the user must be a percenta
12. 45 Photovoltaic Project Model eceeeeeeeeeecneeeeeeeeeees 9 PIPES TESELVOINS nere e iiaae a iape EE aE eik 54 Power Conditioning eeeeeeseseeeeeeneeeeeneeeeeees 16 24 Preliminary design cccceesceesceesceeeceeeceteeeeeeeeeaes 44 Pressure headvess ccissceeststasessssesspesstissestesssenssseesteabes 38 PIO DED eB oes os AAE SEE esses earns 73 77 Printing a Fil s s s Aclwisig Sideiiiniinen sear 8 Product Data 5 7 10 20 22 39 49 98 Project Costs and Savings ceeeeseseeeeeeeeees 59 69 Project debDt 1 32 sc tt a ARs alt oh ties 76 Project CQUILY oo nii n a i 76 Project life sis sya chia eed oan las 66 Project location ceccesceesseeeeeteeeeees 10 59 80 90 Project management ee eee cess ceseceecseeeseeeees 46 Project NAMEC eeeeceeeeecsteceeeeeceeeeeeeeees 10 59 80 89 Property taxes Insurance 0 0 0 ee eee cee eee eeeeeeeeee 56 Proposed Case Electricity System Photovoltaic Project isc testis belies Bed hit eens Ree te 85 Proposed case GHG emission factor eee 87 Pump system efficiency ceeceeeecseeeeceecnereeeeeee 15 PV Array luann n e Arica ast 19 28 PV rray afed connie nennen unaa at 22 25 51 PV array controller narenn uninin unnta 21 PV array tracking mode sessessensseseseeeseesessreerseeeeee 27 PV energy absorption rate eee eeeeeeeeeeeeee 12 60 PV module manufacturer model e cesses 20 PV module type eee cece
13. 5 3 stand alone 0 5 3 hybrid 3 10 fend connected 11 24 grid connected 26 50 end connected PV Electrical Design Time Estimates Tenders and contracting Upon completion of the various engineering tasks tender documents may be required by the project developer They are prepared for the purpose of selecting contractors to undertake the work Once tenders are released the contracting process is required to both negotiate and establish contracts for the completion of the project The time required to produce a set of bid documents will vary depending upon the complexity and the size of the project A minimum 16 h for a 3 kWp system and 40 h for a 50 kWp system provides a reasonable range If the project is to be handled completely by one firm i e engineering design and construction then do not include any time for preparing bid documents Rates of 40 h to 100 h are possible Construction supervision The construction supervision cost item summarises the estimated costs associated with ensuring that the project is constructed as designed This cost item also includes final commissioning of the PV system Depending on the project size this task can take from 8 to 24 h at rates of 40 h to 100 h Travel time to the site for commissioning are in addition to the range given Travel costs should be entered in the Development section above For smaller projects especially at isolated sites commissioning will g
14. Online Weather Database aR GREG oi Decision Support Centre A22 RETScreen menu Training and Support Internet Forums l RETScreen x Marketplace floating RETScreen toolbar _ _ e 2 A Case Studies e Textbook RETScreen Menu and Toolbar The RETScreen Online User Manual or help feature is cursor location sensitive and therefore gives the help information related to the cell where the cursor is located Cell Colour Coding The user enters data into shaded worksheet cells All other cells that do not require input data are protected to prevent the user from mistakenly deleting a formula or reference cell The RETScreen Cell Colour Coding chart for input and output cells is presented below Input and Output Cells Model output calculated by the model User input required to run the model User input required to run the model and online databases available User input for reference purposes only Not required to run the model RETScreen Cell Colour Coding PV 5 RETScreen Software Online User Manual Currency Options To perform a RETScreen project analysis the user may select a currency of their choice from the Currency cell in the Cost Analysis worksheet The user selects the currency in which the monetary data of the project will be reported For example if the user selects all monetary related items are expressed in Selecting User defined allows the u
15. PV array power multiplied by the total hours in a year Renewable energy collected The model calculates the amount of electrical energy produced by the photovoltaic array during the season of use in MWh Depending on latitude and system size this value may range from a fraction of one MWh to several hundred MWh or more Renewable energy delivered The model calculates the annual renewable energy delivered MWh which is the amount of equivalent DC electrical energy actually delivered by the PV system to the load or the utility in the case of an on grid system This value is transferred to the Financial Summary worksheet as an input to conduct the financial analysis PV 25 RETScreen Software Online User Manual Units switch The user can choose to express the energy in different units by selecting among the proposed set of units GWh Gcal million Btu GJ therm kWh hp h and MJ These values are for reference purposes only and are not required to run the model Excess RE Renewable Energy available The model calculates the excess renewable energy available MWh which is the amount of renewable energy produced by the system that could not be used by the grid because of mismatches between PV output and utility energy demand see PV Energy absorption rate This value is transferred to the Financial Summary worksheet as an input to conduct the financial analysis PV 26 RETScreen Photovoltaic Pro
16. Since 20 years is the estimated value the risk analysis will consider this value as being the most probable and the minimum and maximum values as being the least probable based on a normal distribution If the debt term is known exactly by the user no uncertainty the user should enter a range of 0 GHG emission reduction credit The GHG emission reduction credit is automatically transferred from the Financial Summary worksheet to the Sensitivity worksheet The user enters the GHG emission reduction credit range The range is a percentage corresponding to the uncertainty associated with the estimated GHG emission reduction credit value The higher the percentage the greater the uncertainty The range specified by the user must be a percentage value between 0 and 50 The range determines the limits of the interval of possible values that the GHG emission reduction credit could take For example a range of 10 for a GHG emission reduction credit of 5 t o means that the GHG emission reduction credit could take any value between 4 5 tco and 5 5 tco Since 5 tco is the estimated value the risk analysis will consider this value as being the most probable and the minimum and maximum values as being the least probable based on a normal distribution If the GHG emission reduction credit is known exactly by the user no uncertainty the user should enter a range of 0 RE production credit The RE production credit is automatically t
17. The user then selects Credit from the drop down list in the unit column The project may be credited for material and or labour costs that would have been spent on the base case or conventional energy system The user can input both a quantity amount and unit cost Note that the credit item is expressed as a negative value in the Amount column Miscellaneous This category is for all of the miscellaneous costs that occur during a project and have not been taken into account in the previous sections For photovoltaic projects these costs can include training and contingencies Training The adequate training of operators and maintenance personnel is fundamental to the successful deployment of any technology This cost is usually very small for PV systems given their relative simplicity A 4 to 8 h training session by a PV system expert should be sufficient for the client to operate the PV system properly Rates for PV system experts range from 40 h to 100 h PV 55 RETScreen Software Online User Manual Contingencies The allowance made for contingency costs depends on the level of accuracy of the cost estimates Contingencies are estimated based on a user selected percentage of the sub total of all project costs excluding miscellaneous costs Note that contingencies are incremental in the sense that they are derived from project costs including any credits The allowance for contingency items should be based on the level o
18. Water Requirements table for more information of units The user enters the number of units for which water will be supplied For the example of the corn field that is 50 m wide by 100 m long the user should enter 0 5 note one hectare is 100 m x 100 m Water use per unit The user enters an estimate of the amount of water required by each unit on a daily basis Domestic People 3 WHO recommended minimum 30 Lid The following table can be used as a Average use Africa Asia 45 to 85 Lid guideline for estimating water requirements Average use Europe South America 250 Lid For corn field example the user would likely Hierage use A sone IVESTOC enter 45 m d ha Note that water Cow 40 Lid requirements vary widely with type of Sheep and goat 5 Lid irrigation system hence when precise data is ae a available it should be used in the place of Camel 20 Lid typical requirements suggested in the Irrigation Market gardening l m dha following table Rice 100 m2 dsha Cereals 45 mAdtha Sugar cane 65 m d ha Cotton 55 m d ha Typical Water Requirements l Data in this table from Royer J et al 1998 and United Nations Population Information Network PV 36 RETScreen Photovoltaic Project Model Daily water required The model calculates the daily water requirement in m d This value is based on the number of units and the water use per unit specified by the user For typical PV water pumping applicati
19. a new building or if it is to be ground mounted then a site visit is usually not required since the analysis can be done from architectural engineering and or land survey drawings PV 43 RETScreen Software Online User Manual For existing building installations a photovoltaic project expert should visit the site to meet with the client and other stakeholders assess the exact location of the proposed installation and gather data so that the PV system can be designed The site will be inspected to determine a possible location for the photovoltaic modules electrical conduit and inverter Preliminary data gathering which should build upon the initial pre feasibility analysis data should be conducted prior to and during the site visit A single site visit which usually requires one day on site will suffice to conduct the feasibility study for most projects The cost of a site visit will be influenced by the planned duration and travel time travel costs separate see below to and from the site The time required to gather the data prior to the site visit and during the site visit typically falls between 8 and 16 h travel time extra Photovoltaic expert fees typically range from 40 h to 100 h depending on their experience Preliminary design A preliminary design is required in order to determine the size layout and potential energy output of the PV modules After the PV system is sized draft drawings which also consider o
20. amount and unit cost Note that the credit item is expressed as a negative value in the Amount column PV 46 RETScreen Photovoltaic Project Model Engineering The engineering phase includes costs for the photovoltaic system structural and electrical design as well as tenders and contracting and construction supervision These costs are detailed below PV system design The PV system design includes the time required to specify and draw the exact physical placement of the PV modules at the project site Liaison will also be required with the structural and electrical designer to achieve an optimum design The time required to prepare the PV system design and detailed drawings falls between 12 and 24 h at fees of 40 h to 100 h Simple wall or flush mounted roof grid connected systems fall at the lower end of this scale in terms of time while large hybrid or grid connected systems will tend to fall on the higher end Structural design From a PV system design standpoint the simplest structural designs are flush roof mounted and vertical wall mounted systems where little structural work is required When the project is a large retrofit to a building and or where modules are not flush mounted to the building structure additional engineering time will likely be necessary to evaluate the structural and wind loading concerns for the installation The time required to prepare the PV system structural design and detailed drawings
21. applications as calculated in the Energy Model worksheet minus the T amp D losses for the grid vis a vis the proposed project For Off grid and Water pumping applications it is simply the amount of end use annual energy delivered to the load Note that for an Off grid application with a PV battery genset configuration the end use annual energy delivered corresponds to the sum of the renewable energy delivered and the genset energy delivered Units are given in megawatt hours of end use energy delivered MWh Annual GHG emission reduction The model calculates the annual reduction in GHG emissions estimated to occur if the proposed project is implemented The calculation is based on emission factors of both the base case and the proposed case system and on the end use energy delivered by the PV project on an annual basis Units are given in equivalent tonnes of CO emission per year tco2 yr Note At this point the user should complete the Financial Summary worksheet PV 88 RETScreen Photovoltaic Project Model Sensitivity and Risk Analysis As part of the RETScreen Clean Energy Project Analysis Software a Sensitivity and Risk Analysis worksheet is provided to help the user estimate the sensitivity of important financial indicators in relation to key technical and financial parameters This standard sensitivity and risk analysis worksheet contains two main sections Sensitivity Analysis and Risk Analysis Each sec
22. be calculated For example if one wall is 30 degrees west of south 30 and the other wall is 60 degrees east of south 60 enter 45 degrees Alternatively if one wall were due east 90 and the other due west 90 the average of the absolute values would be 90 Note that the azimuth must be entered with respect to true south and not magnetic south Compasses point to magnetic north the complement of magnetic south and azimuth directions based on this measure must be adjusted for the magnetic declination for more information refer to Magnetic declination If the azimuth direction is being determined from site drawings it should be determined what reference the site north is using Site north does not always correspond to true north as it is sometimes adjusted for convenience in the site and building drawings PV 29 RETScreen Software Online User Manual Example Collector faces 45 SW in Northern Hemisphere Azimuth of a Photovoltaic Array adapted from Ross 1999 Magnetic declination A magnetic compass does not normally point to true north In fact over most of the Earth it points at some angle east or west of true geographic north The direction in which the compass needle points is referred to as magnetic north and the angle between magnetic north and the true north direction is called magnetic declination The terms variation magnetic variation or compass variation are often used in plac
23. calculator assumes that all AC loads can occur simultaneously In practice some of the appliances may be on at varying times thus reducing the maximum power required from the inverter If this is the case the user may want to enter a lower value Zero should be entered if the PV system has no AC load Average inverter efficiency The user enters the combined efficiency expressed in of the electronic devices maximum power point tracker and inverter used to control the PV array and transform its DC output to AC Values between 80 and 95 are typical A value of 90 is suggested as a starting point Zero should be entered if the PV system has no AC load Miscellaneous power conditioning losses The user enters power conditioning losses if any not taken into account elsewhere For example this could include losses incurred in DC DC converters or in step up transformers In most cases this value will be zero Battery This sub section deals with the characteristics of the battery bank PV 16 RETScreen Photovoltaic Project Model Days of autonomy required The user enters the size of the battery expressed in days of autonomy d In other words this is the number of days that the system starting from a state of full charge would be able to meet the load using the batteries only Depending on site conditions and system characteristics values usually range from a couple of days to 10 days Systems with a few days of
24. crediting period the project will have to be validated after each 7 year period in order to receive CERs for the subsequent 7 years Thus in selecting a crediting period the benefits of the potentially longer crediting period of the renewable crediting period e g up to 21 years must be weighed against the additional transaction costs of re validating the project after each 7 year period and the risk of the project potentially not meeting validation requirements at that time PV 64 RETScreen Photovoltaic Project Model GHG credit escalation rate The user enters the GHG credit escalation rate which is the projected annual average rate of increase in the GHG emission reduction credit over the life of the project This permits the user to apply rates of inflation to the market price of GHG emission reduction credits which may be different from general inflation Avoided cost of excess energy The user enters the avoided cost of excess energy per kWh The avoided cost of excess energy may range from zero where there is no need for the excess energy to a value close to the local retail price for electricity For On grid applications to simulate reverse metering schemes the user must enter the utility buy back electricity rate as the avoided cost of excess energy Avoided cost of capacity The user enters the avoided cost of capacity per kW yr Unless the user knows this value it is safer to assume a zero for this ent
25. data the user can refer to the values in the table below Default maximum depth of dischar ge Lead acid car Lead acid gel Lead acid FV vented Nickel Cadruum Maximum Depth of Discharge for Rechargeable Batteries PV 17 RETScreen Software Online User Manual Charge controller DC to DC efficiency The user enters the average efficiency of the charge controller in A default value of 95 is suggested Because controllers often draw a fixed current from the system regardless of its size controller efficiency tends to be higher in larger systems and lower in smaller systems Battery temperature control The user enters the type of temperature control applied to the battery The options from the drop down list are Ambient Constant and Minimum This item is used to derate the battery capacity according to the temperature conditions it experiences The user may select Ambient if the battery is subject to fluctuations in outdoor temperature for example if the battery is located in a non insulated shed If the battery is kept at a constant temperature for example if it is located in the basement of a house the user may select Constant The user may select Minimum if the battery follows the fluctuations of outdoor temperature except when it falls below a certain level for example if the battery is located inside a phase change box or if the battery is heated This model does not consider battery freez
26. differences not specifically covered in the generic information provided A credit item may be entered in the grey input cell as Credit The user then selects Credit from the drop down list in the unit column The project may be credited for material and or labour costs that would have been spent on the base case or conventional energy system The user can input both a quantity amount and unit cost Note that the credit item is expressed as a negative value in the Amount column Contingencies A contingency allowance may be included to account for unforeseen annual expenses Grid connected PV systems generally require no maintenance as the PV cells are a solid state device without any moving parts and the modules are designed to last over 25 years A contingency allowance of 1 to 5 of total PV system and balance of equipment cost per year is reasonable and will depend upon the project location For off grid systems in isolated areas a larger contingency allowance is probably required Fuel In the case of hybrid PV systems that incorporate a genset the cost of fuel will be given in per unit of volume These costs will vary substantially depending on the type of fuel selected and the project location Transportation The user enters the cost associated with the transportation of the fuel to the site This is for the case where trips to the sites are required to specifically bring the fuel in If transportation costs are already inc
27. feasibility study performing the project development functions completing the necessary engineering purchasing and installing the energy equipment construction of the balance of equipment and costs for any other miscellaneous items Feasibility Study Once a potential cost effective photovoltaic project has been identified through the RETScreen pre feasibility analysis process a more detailed feasibility study may be required for larger photovoltaic projects greater than 3 kWp of PV Feasibility studies typically include such items as site investigations a preliminary project design and a final report with detailed cost estimates Feasibility study project management and travel costs are also normally incurred These costs are detailed in the section below For smaller projects the cost of the feasibility study relative to the cost of the PV system may not be justified In this case the project proponent may choose to go directly to the engineering stage combining some steps from the feasibility and development stages and enter 0 for cost items not applicable Note The RETScreen Clean Energy Project Analysis Software can also be used to prepare the Feasibility Study Site investigation When a photovoltaic system is being considered for an existing application or building a site visit is often required to evaluate the site conditions such as solar access and the requirements of installing the PV system If the PV system is for
28. for this level of analysis PV 51 RETScreen Software Online User Manual Inverters Grid tied Inverters Standalonelnvertes Stand alone Inverters Modified square wave sinewave i E bike lt 1kw 2 000 10 000 lto 10 kW 1 500 20 to 100 EW 1 250 gt 100 kW 1 000 Typical Cost of Inverters Note Inverter prices have been decreasing over time As technology advances better quality and lower cost inverters will be available on the market The user should contact suppliers for current prices Genset The user enters a kW AC cost nominal genset AC output Generator costs depend mainly on the size of the generator but also on the construction type i e domestic or heavy duty maintenance requirements fuel type manufacturers and integrated functions such as automatic starting As a first estimate the user can enter the costs indicated in the two following figures Generators made for domestic use for cottages for example can cost anywhere from 450 kW AC to 1 200 kW AC for capacities up to 7 5 kW As a general rule smaller or heavy duty type generators tend to be more expensive per kW AC Heavy duty generators such as those used for commercial industrial applications will typically cost between 500 kW AC and 1 700 kW AC for units up to 25 kW Domestic Use Generators 1250 Nominal Capacity KY Typical Costs of Domestic Use Generators per Nominal kW AC Output PV 52 RETScreen Photovoltaic Project Mod
29. lantern i e L year lanterns hours day days year L h For comparison purposes the user may consider that a typical kerosene lantern rated at 450 W would consume about 0 04 L h 34 g h and produce a light intensity of roughly 250 lumens about the equivalent of a 25 W incandescent bulb or a 5 W compact fluorescent bulb PV 14 RETScreen Photovoltaic Project Model N wn N in litre kh 10 25 50 75 100 of Load Diesel Genset Fuel Efficiency vs Capacity Used Royer 1999 PV Water Pump This sub section deals with the characteristics of the PV powered water pump Motor type The user enters the type of motor AC or DC used to drive the PV powered water pump The choice between a DC and an AC motor to drive the pump will depend on many factors including price reliability and technical support available DC motors are usually very efficient and are easier to match with the photovoltaic array however they may be more expensive and available only through a limited number of locations AC motors on the other hand are less expensive and more widely available but they require an inverter to be connected to the PV array Pump system efficiency The user enters the efficiency of the PV powered water pump system This efficiency should be understood to be the wire to water efficiency that is the ratio of mechanical power delivered to the water to the electrical pow
30. of future cash flows Net Present Value NPV The model calculates the net present value NPV of the project which is the value of all future cash flows discounted at the discount rate in today s currency NPV is thus calculated at a time 0 corresponding to the junction of the end of year 0 and the beginning of year 1 Under the NPV method the present value of all cash inflows is compared against the present value of all cash outflows associated with an investment project The difference between the present value of these cash flows called the NPV determines whether or not the project is generally a financially acceptable investment Positive NPV values are an indicator of a potentially feasible project In using the net present value method it is necessary to choose a rate for discounting cash flows to present value As a practical matter organisations put much time and study into the choice of a discount rate The model calculates the NPV using the cumulative after tax cash flows In cases where the user has selected not to conduct a tax analysis the NPV calculated will be that of the pre tax cash flows Annual Life Cycle Savings The model calculates the annual life cycle savings ALCS which is the levelized nominal yearly savings having exactly the same life and net present value as the project The annual life cycle savings are calculated using the net present value the discount rate and the project life Benefit Cost B C ratio
31. permits and approvals may be required for the construction of the project These include building and electrical permits from local authorities In addition when the PV system can supply energy into the existing electrical grid authorization from the local electric utility will likely be required Some equipment may be required to undergo testing by national standards associations and or laboratories PV 45 RETScreen Software Online User Manual The cost of acquiring the necessary permits and approvals is calculated based on an estimate of the time required to complete the necessary work For a typical PV project it normally takes between 4 and 8 h at rates of between 40 h and 100 h The user can also add to the number of hours or unit costs an amount to cover the actual permit itself Permit costs often range from 0 25 to 1 5 of electrical equipment materials costs depending on the jurisdiction and project scale Large scale projects which can supply significant energy to the electrical grid would take considerable more time to obtain approvals and permits Project management The project management cost item should cover the estimated expenses of managing all phases of the development of the project excluding construction supervision Public relations and project financing activities are also included as part of the PV project management cost item here However public relations is not normally a big issue with most PV systems
32. product database can reach RETScreen International at RETScreen International CANMET Energy Technology Centre Varennes Natural Resources Canada 1615 Lionel Boulet P O Box 4800 Varennes Quebec CANADA J3X 1S6 Tel 1 450 652 4621 Fax 1 450 652 5177 E mail rets nrcan gc ca PV 98 RETScreen Photovoltaic Project Model Weather Data This database includes some of the weather data required in the model To access the weather database the user may refer to Data amp Help Access While running the software the user may obtain weather data from ground monitoring stations and or from NASA s satellite data Ground monitoring stations data is obtained by making a selection for a specific location from the online weather database dialogue box NASA s satellite data is obtained via a link to NASA s Website from the dialogue box Ground Monitoring Stations Data From the dialogue box the user selects a region then a country then a sub region provinces in Canada states in the United States and N A in the rest of the countries and finally a weather station location The weather station usually corresponds to the name of a city town within the selected country From the dialogue box the data can be pasted to the spreadsheets by clicking on the Paste Data button Only data that are in bold are pasted to the spreadsheets all other data are provided for reference purposes only Data entered using the online weather da
33. project owner s The project equity is deemed to be disbursed at the end of year 0 i e the development construction year It is calculated using the total initial costs the initial cost incentives and the debt ratio Project debt The model calculates the project debt which is the portion of the total investment required to implement the project and that is financed by a loan The project debt leads to the calculation of the debt payments and the net present value It is calculated using the total initial costs and the project equity Debt payments The model calculates the debt payments which is the sum of the principal and interest paid yearly to service the debt Whereas debt payments are constant over the debt term the principal portion increases and the interest portion decreases with time In that respect it is similar to the yearly annuity paid to reimburse the mortgage of a house Debt payments are calculated using the debt interest rate the debt term and the project debt PV 76 RETScreen Photovoltaic Project Model Debt service coverage The model calculates the debt service coverage for each year of the project and reports the lowest ratio encountered throughout the term of debt The debt service coverage is the ratio of the operating benefits of the project over the debt payments This value reflects the capacity of the project to generate the cash liquidity required to meet the debt payments It is calculated by d
34. river based pumping systems the value is zero Discharge head The user enters the total vertical distance in meters that the water will be lifted from the centre of the pump to the point of free discharge or the surface of water in the storage tank see Pumping Head Nomenclature figure This value usually ranges from zero to a few tens of meters Pressure head The user enters the pressure head in meters at which the water exits the discharge point or enters into an irrigation system see Pumping Head Nomenclature figure For most systems such as non pressurized tanks or irrigation troughs this value will be zero it will be non zero for pressurized systems and irrigation sprinklers Friction losses The user enters an allowance for dynamic friction losses This value is expressed as a percentage of the total head Friction losses are the pressure losses caused by friction when water moves through the pipes and fittings This value is a function of the length of piping diameters of the pipes the material they are made of and the water flow In well designed systems the friction losses are kept below 10 of the total head Total head The model calculates the total equivalent vertical distance in metres that the pumped water will be lifted see Pumping Head Nomenclature figure This is the sum of the suction head the drawdown the discharge head the pressure head and the friction losses This value can range from 0 to a fe
35. the O amp M cost required by the base case electricity system The model uses the O amp M cost to calculate the total annual costs and the yearly cash flows Fuel For Off grid applications with PV battery genset system configuration the annual cost of fuel to run the system is transferred from the Cost Analysis worksheet This value represents the cost of fuel to run the genset Debt payments debt term The model calculates the debt payments which is the sum of the principal and interest paid yearly to service the debt Whereas debt payments are constant over the debt term the principal portion increases and the interest portion decreases with time In that respect it is similar to the yearly annuity paid to reimburse the mortgage of a house Debt payments are calculated using the debt interest rate the debt term and the project debt Annual Savings or Income The total annual savings represent the yearly savings realised due to the implementation of the project From the perspective of an independent power producer or service provider these savings will be viewed as income It is directly related to the avoided cost of energy derived from implementing the project It is an input in the calculation of the simple payback and the debt service coverage PV 71 RETScreen Software Online User Manual Energy savings income For On grid applications the annual energy savings are equal to the sum of the product of the R
36. the jurisdiction in which the system is installed The value entered is assumed to be representative of year 0 i e the development year prior to the first year of operation year 1 For tax purposes the RE production credit is treated as supplemental income The model escalates the RE production credit value yearly according to the RE credit escalation rate starting from year 1 and throughout the RE production credit duration Fuel Price L 105 Jf JV ALY f iA AL k PEA sA 100 AE AA Diesel Electrical Generation Avoided Cost of Energy Sigma 1985 40 RE production credit duration The user enters the renewable energy RE production credit duration year This value typically represents the number of years for which the project receives a RE production credit It is used to calculate the annual RE production credit income PV 63 RETScreen Software Online User Manual RE credit escalation rate The user enters the renewable energy RE credit escalation rate which is the projected annual average rate of increase in the renewable energy credit over the RE production credit duration This allows the user to apply rates of inflation to the value of renewable energy production credits which may be different from general inflation GHG emission reduction credit The user enters the GHG emission reduction credit per tonne of CO tco2 It is used in conjunction with the net GHG emission r
37. the source and the pump Hence in the grid extension case the specific fuel consumption expressed in kWh L allows the user to specify the number of kilowatt hours needed per litre of pumped water If the user is comparing PV to an existing pumping system the specific fuel consumption can be calculated by dividing the measured fuel consumption over a certain period in L of fuel or kWh of electricity by the amount of water pumped in that same period If the user does not have this data from an existing installation the specific fuel consumption for a fossil fuel generator system can be estimated by L of fuel L of water 9 81 total head Energy content of fuel genset efficiency pump efficiency where the total head in m is given in the Solar Resource amp System Load SR amp SL worksheet and the energy content of the fuel in J L is approximately 38 7 MJ L for diesel 26 6 MJ L for propane 33 7 MJ L for gasoline 37 2 MJ L for natural gas and 36 6 MJ L for kerosene The specific fuel consumption for grid extension can be estimated by kWh of electricity L of water 9 81 total head 3 600 000 pump efficiency where the total head in m is given in the Solar Resource amp System Load SR amp SL worksheet For lanterns the L year unit is used The user may calculate this value by multiplying the number of lanterns the number of hours of use per day the number of days per year and the number of litres of fuel per hour used by the
38. the user Inverter capacity The user enters the inverter capacity in kW AC that is the nominal output of the inverter By default the user will likely enter the Suggested inverter DC to AC capacity provided above Miscellaneous power conditioning losses The user enters power conditioning losses if any not taken into account elsewhere For example this could include losses incurred in DC DC converters or in step up transformers In most cases this value will be zero Annual Energy Production for months analysed This section summarises the annual energy production of the photovoltaic project Equivalent DC energy demand The model calculates the equivalent DC energy demand in MWh This is the sum of the DC demand and the AC demand divided by inverter efficiency over the season of use Energy from genset The model calculates the energy delivered by the genset over the season of use in MWh Equivalent DC demand not met The model calculates the electrical demand that is not met by the system over the season of use in MWh This quantity is expressed as an equivalent DC demand that is it is the amount of energy that the photovoltaic system is unable to provide to meet both DC and AC loads PV 24 RETScreen Photovoltaic Project Model This value provides an indication of whether the system is properly sized if it is the demand not met should be equal to zero However the user should refrain from using this
39. value to calculate a loss of load probability for the system that is the chance that the system will fail to meet the load over a given number of years The algorithms used in the RETScreen PV model have been chosen to provide a reasonable estimate of the energy delivered during a typical season but they are not designed to provide a detailed estimate of the loss of load probability Water delivered The model calculates the amount of water delivered in m3 over the season of use Specific yield The model calculates the specific yield in kWh m This is the renewable energy delivered by the PV system over one year divided by the PV array area Depending on PV array technology type climatic conditions latitude power conditioning efficiency and losses this value will likely be in the range 30 to 250 kWh m Overall PV system efficiency The model calculates the overall efficiency of the PV system in This value is the amount of renewable energy delivered divided by the amount of solar radiation incident on the photovoltaic array Typical values range from 3 to 13 depending on module type power conditioning efficiencies and solar radiation distribution PV system capacity factor The model calculates PV system capacity factor which represents the ratio of the average power produced by the system over a year to its nominal rated PV array power It is calculated as the ratio of the renewable energy delivered over the nominal
40. will depend on the simplicity of the structural layout chosen Since both engineering time and drafting time are required use weighted average for the engineering and drafting rates and time Structural design rates range from 40 h for drafting to 100 h for a professional engineer The user may refer to the table below to estimate the structural design costs Vertical on wall Flush mount horizontal or at roof tilt Tilted on roof Tilted on ground wath no contour work Tilted on ground vath contour work PV Structural Design Time Estimates Electrical design Electrical engineering design will be required to determine how the PV system will be integrated into the existing electrical system The electrical engineer will provide details for PV module and inverter connections fusing conductors and conduit routing as well as for other generator or electrical equipment required Co ordination between the PV system designer and the electrical engineer will be required they can also be the same person PV 47 RETScreen Software Online User Manual Electrical design time will vary with the size of the system Since both engineering time and drafting time are required use a weighted average for the engineering and drafting rates and time Electrical design rates range from 40 h for drafting to 100 h for a professional engineer The user may refer to the following table to estimate the electrical design costs PY System Size 0
41. 0 to evaluate feasibility study and develop and 8 000 to design engineering build install and commission the user could enter 80 as the PV 68 RETScreen Photovoltaic Project Model depreciation tax basis in order to depreciate only the engineering energy equipment balance of equipment and miscellaneous costs while the feasibility and development costs would be fully expensed during year 0 Depreciation rate The user enters the depreciation rate which is the rate at which the undepreciated capital cost of the project is depreciated each year The depreciation rate can vary widely according to the class of assets considered and the jurisdiction in which the project is located Depreciation period The user enters the depreciation period year which is the period over which the project capital costs are depreciated using a constant rate The depreciation period can vary widely according to the class of assets considered and the jurisdiction in which the project is located Tax holiday available The user indicates by selecting from the drop down list whether or not the project can benefit from a tax holiday If the user selects Yes the tax holiday applies starting in the first year of operation year 1 up to the tax holiday duration The income tax calculation for the development construction year year 0 is not affected Tax holiday duration The user enters the tax holiday duration year which is the numb
42. 5 72 A im th of PV arr y pispa 29 B Background Information s s s 79 80 Balance of equipment ssseeeseeseeeiererrersrsrerrerersees 70 Balance of Equipment s sseeeeseeeeeeeeeeereerersereerseee 50 Bat graphrnarenen r aS 97 Base Case Electricity System Baseline 81 Base case GHG emission factor sceeeeeeseeeeeeeeeees 87 Base Case Power and Pump System 0 0 13 Batteries aeiee Ea 17 53 Battery onrera i A A R 16 17 18 Battery efficiency sseesssneesseseessesersreseesessreressesees 17 Battery temperature control sseseeeesseeeseeeeeereeees 18 Benefit Cost B C ratio ccccesceeseesseseeeeesteeeeees 75 BibliGS raphy senean aren 104 Blank Worksheets 3 cccssecesssseceesteeeeesneeeees 9 78 Brief Description and Model Flow Chatt 4 C Calculate energy production cost s s s 75 Calculate GHG reduction cost s s s 76 Capacity savings INCOME s eseeeeeeeeeeeeererereeere 72 Cell Colour Coding ansin ai 5 Charge controller DC to DC efficiency 0 18 Charger AC to DC efficiency 22 Click here to Calculate Risk Analysis 0 95 Click here to Calculate Sensitivity Analysis 90 Constant battery temperature eee 18 Construction SUPCTVISION s 48 Contingencies p Sa a ea i a aa 56 57 Copyright and Trademark eeeeseeeeeeeeeeeeereeeeeeees 102 Cost Analysis 6 9 17 39 40 41 53 59 67 69 70
43. EEE First World Conference On Photovoltaic Energy Conversion December 1994 Leng G Distributed Photovoltaic Demand Side Generation An Economic Evaluation For Electric Utilities Master Degree Thesis University of Massachusetts Lowell November 1993 Martinot E and McDoom O Promoting Energy Efficiency and Renewable Energy GEF Climate Change Projects and Impacts October 1999 Pre Publication Draft Global Environment Facility 1999 Maycock P D Photovoltaic News February 2000 Ross M and Royer J Photovoltaics in Cold Climates James and James Ltd 1999 PV 104 RETScreen Photovoltaic Project Model Royer J Personal Communication Solener Inc 1999 Royer J Djiako T Schiller E and Sy B S Le pompage photovoltaique manuel de cours a l intention des ing nieurs et des techniciens Institut de l Energie des Pays ayant en commun l usage du Fran ais 56 rue Saint Pierre 3e tage Qu bec PQ GIK 4A1 Canada 1998 Sandor R Walsh M and Leblanc A Creating a Market for Carbon Emissions Gas Industry Opportunities published in Natural Gas June 1999 Sigma Engineering Ltd Energy Overview Study of Remote Communities in Canada prepared for the Remote Community Demonstration Program Energy Mines and Resources Canada March 1985 United Nations Framework Convention on Climate Change UNFCCC Clean Development Mechanism CDM Executive Board Annex B Indicative sim
44. ETScreen Software Online User Manual At the completion of each step a go or no go decision is usually made by the project proponent as to whether to proceed to the next step of the development process High quality but low cost pre feasibility and feasibility studies are critical to helping the project proponent screen out projects that do not make financial sense as well as to help focus development and engineering efforts prior to construction The RETScreen Clean Energy Project Analysis Software can be used to prepare both the initial pre feasibility analysis and the more detailed feasibility analysis i j _ X cost accuracy within 5 Pre teasibility study ost accuracy within 40 to 50 Time gt Accuracy of Project Cost Estimates Gordon 1989 Currency To perform a RETScreen project analysis the user may select a currency of their choice from the Currency cell in the Cost Analysis worksheet The user selects the currency in which the monetary data of the project will be reported For example if the user selects all monetary related items are expressed in Selecting User defined allows the user to specify the currency manually by entering a name or symbol in the additional input cell that appears adjacent to the currency switch cell The currency may be expressed using a maximum of three characters US etc To facilitate the presentation of monetary d
45. Energy Model worksheet and it is copied automatically to the Financial Summary worksheet For water pumping applications the equivalent pumping energy demand is calculated in the Energy Model worksheet and it is copied automatically to the Financial Summary worksheet Net GHG emission reduction The model calculates the net annual average GHG emission reduction in equivalent tonnes of CO per year tco2 yr resulting from the implementation of the energy system instead of the base case or baseline system This value is calculated in the GHG Analysis worksheet and is copied here automatically to the Financial Summary worksheet Net GHG emission reduction credit duration The model calculates the cumulative net greenhouse gas GHG emission reduction for the duration of the GHG credit in equivalent tonnes of CO tco2 resulting from the implementation of the project instead of the base or baseline case system This value is calculated by multiplying the appropriate net annual GHG emission reduction by the GHG reduction credit duration Net GHG emission reduction project life The model calculates the net project life GHG emission reduction in equivalent tonnes of CO tco2 resulting from the installation of the energy system instead of the base case or baseline system This value is calculated by multiplying the net annual GHG emission reduction by the life of the project Type of fuel displaced The type of fuel displaced is th
46. Isolated grid applications the following figure Sigma 1985 can be used to estimate the pall park avoided cost of energy for diesel fuel electric generation Note that the values presented in this figure include diesel plant maintenance at 20 of fuel costs As an example from that same figure within the normal operating efficiency of diesel generators and assuming diesel fuel costs of 0 60 L avoided costs of energy would range from approximately 200 MWh to 300 MWh The user needs to correct these values to kWh units by dividing by 1 000 Note that the avoided cost of energy unit for propane is expressed in terms of litres of liquefied propane PV 62 RETScreen Photovoltaic Project Model RE production credit The user enters the renewable energy RE production credit per kWh This value typically represents the amount that can be credited to the project in exchange of the production credit generated by the renewable energy delivered by the PV system It is used in conjunction with the renewable energy delivered to calculate the annual RE production credit income RE production credits are most common for electricity generation from renewable energy projects For example it is possible to receive a tax credit of 1 5 kWh in the USA for electricity produced from wind biomass or chicken manure Whether or not a given project would qualify to receive such payments depends on the rules of the specific programs in
47. MyFiles directory automatically set by the RETScreen installer program on the hard drive MyFiles The download procedure is presented in the following figure The user may also visit the RETScreen Website at www retscreen net for more information on the download procedure It is important to note that the user should not change directory names or the file organisation automatically set by RETScreen installer program Also the main RETScreen program file and the other files in the Program directory should not be moved Otherwise the user may not be able to access the RETScreen Online User Manual or the RETScreen Weather and Product Databases RETScreen Download Procedure WIND3 xls PV 7 RETScreen Software Online User Manual Printing a File To print a RETScreen Workbook file standard Excel printing procedures should be used The workbooks have been formatted for printing the worksheets on standard letter size paper with a print quality of 600 dpi If the printer being used has a different dpi rating then the user must change the print quality dpi rating by selecting File Page Setup Page and Print Quality and then selecting the proper dpi rating for the printer Otherwise the user may experience quality problems with the printed worksheets PV 8 RETScreen Photovoltaic Project Model Photovoltaic Project Model The RETScreen International Photovoltaic Project Model can be
48. PV system For equipment and materials transportation costs will vary considerably depending on the mode of transportation available and the location of the project site In many instances the cost will depend on distance and will be based on a volume weight formula Costs to handle the material at the receiving end should also be considered In isolated areas Many communities can receive bulk shipments at given periods of the year either by barge ice road or sometimes only by air Logistical control is extremely important here For many remote telecom sites a helicopter rental may have to be included in the transportation cost estimate Shipping costs should be obtained from shipping agents when the scope of the project equipment and materials are determined As an example a 4 kWp inverter has a weight of about 50 kg Other These input cells are provided to allow the user to enter cost or credit items that are not included in the information provided in the above cost category The user must enter a positive numerical value in the Unit Cost column A cost item may be entered in the grey input cell as Other The user then selects Cost from the drop down list in the unit column The user can input both a quantity amount and unit cost This item is provided to allow for project technology and or regional differences not specifically covered in the generic information provided A credit item may be entered in the grey input cell as Credit
49. ain a record of up to 8 different quantity and cost ranges that can be used in future RETScreen analyses and thus create a localised cost database PV 100 RETScreen Photovoltaic Project Model Training and Support The user can obtain current information on RETScreen Training amp Support at the following Website address www retscreen net e training PV 101 RETScreen Software Online User Manual Terms of Use Disclaimer and Indemnification RETScreen International is provided on an as is basis Natural Resources Canada nor does its minister officers employees or agents make any representations or warranties either expressed or implied arising by law or otherwise including but not limited to implied warranties of merchantability or fitness for a particular purpose or that the use of the software will not infringe any intellectual property rights of third parties In no event will Natural Resources Canada nor its minister officers employees or agents have any obligations or liability arising from tort or for loss of revenue or profit or for indirect special incidental or consequential damages as a result of your use of the software In consideration of the right to load execute and use RETScreen International the recipient Licensee shall indemnify and save harmless Natural Resources Canada Licensor and its employees and agents from and against and shall be responsible for all claims demands loss
50. and the GHG emission reduction credit value The yearly value of GHG emission reduction income is escalated at the GHG credit escalation rate Periodic Costs Credits The periodic costs and periodic credits entered by the user in the Cost Analysis worksheet are transferred here The model escalates the periodic costs and credits yearly according to the inflation rate starting from year and throughout the project life From an income tax perspective periodic costs and credits are treated as operating expenses rather than capital investments and are therefore fully expensed in the year they are incurred PV 72 RETScreen Photovoltaic Project Model End of project life Cost Credit The value of the energy project at the end of its life entered by the user in the Cost Analysis worksheet is transferred here This amount is also commonly referred to as the salvage value or disposal value The salvage value entered is assumed to be representative of year 0 i e the development construction year prior to the first year of operation year 1 The model escalates the salvage value yearly according to inflation rate starting from year and up to the end of the project life i e the schedule year reported in the model For tax purposes the difference between the project salvage value and its undepreciated capital costs at the end of the project life is treated as income if positive and as a loss if negative Financial Feasibilit
51. aner the user may enter Vacuum cleaner AC DC The user selects whether the load is direct current DC or alternating current AC For example if the load is a standard electric vacuum cleaner the user would select AC Solar load correlation The user selects the solar load correlation The three options from the drop down list are Negative Zero and Positive The solar load correlation is a qualitative estimate of how the load is correlated with the solar resource Negative i e negative correlation corresponds to cases where the load is very irregular or occurs mostly at night The model considers that the load is always met from the battery A light used exclusively at night for example falls into this category Zero i e zero correlation corresponds to steady loads The model considers that the load is constant throughout the day and is met partly from the battery partly directly by the photovoltaic array without going through the PV 33 RETScreen Software Online User Manual battery A cathodic protection system would fall into this category Positive i e positive correlation corresponds to loads that are turned on only when there is enough solar energy to power them directly The model then considers that the load is met directly by the photovoltaic array and the battery does not play a role A direct fan would fall into this category In most cases the solar load correlation will be Negative Only in v
52. ant here Shipping costs should be obtained from shipping agents when the scope of the project equipment and materials are determined As an example one 120 Wp polycrystalline PV module has dimensions mm of 1 227 length x 991 width x 50 thickness and a weight of 14 0 kg Likewise a typical 4 kWp inverter has a weight of 50 kg PV 49 RETScreen Software Online User Manual Other These input cells are provided to allow the user to enter cost or credit items that are not included in the information provided in the above cost category The user must enter a positive numerical value in the Unit Cost column A cost item may be entered in the grey input cell as Other The user then selects Cost from the drop down list in the unit column The user can input both a quantity amount and unit cost This item is provided to allow for project technology and or regional differences not specifically covered in the generic information provided A credit item may be entered in the grey input cell as Credit The user then selects Credit from the drop down list in the unit column The project may be credited for material and or labour costs that would have been spent on the base case or conventional energy system The user can input both a quantity amount and unit cost Note that the credit item is expressed as a negative value in the Amount column For PV in the Built Environment on grid applications the table below can be u
53. apacity The model calculates the suggested nominal capacity of the battery bank in Ah This is the capacity that would provide the system with the autonomy specified by the user in the Days of autonomy required given the temperature conditions experienced by the battery Values can range from less than one hundred Ah for small systems e g on board electricity for recreational vehicles to several thousand Ah for large systems requiring high availability e g radio repeaters The model assumes discharge rates typical of PV systems i e C 20 or slower The user should note that a faster than normal discharge rate will reduce the actual battery capacity Note The RETScreen PV model uses the daily average DC energy demand and the number of Days of autonomy required to calculate the suggested nominal battery capacity If this average is exceeded on certain days of the week the model may underestimate the battery capacity required for a specified level of autonomy For example in the case of a 2 day autonomy battery for a cottage PV system that is used on weekends only the model will suggest a battery capacity that is 2 7 of what is required The user can account for this by specifying a battery capacity larger than that suggested by the model Nominal battery capacity The user enters the actual nominal capacity of the battery bank in Ah By default the user will likely enter the value calculated in the model under Suggested nominal b
54. are all sections of the feasibility study by the various members of the feasibility study team These expenses include such things as airfare car rental lodging and per diem rates for each trip required In the case of isolated areas rates for air travel will vary markedly Airfares are typically twice those for similar distances in populated areas Since travel is a large component of the cost of PV 44 RETScreen Photovoltaic Project Model doing work in isolated areas and the range of cost is so variable the user should contact a travel agent with experience in arranging such travel Accommodation rates are typically twice the going rate for modest accommodation in populated areas Typical rates for modest hotel rooms can range from 180 to 250 per day in the more isolated areas Other These input cells are provided to allow the user to enter cost or credit items that are not included in the information provided in the above cost category The user must enter a positive numerical value in the Unit Cost column A cost item may be entered in the grey input cell as Other The user then selects Cost from the drop down list in the unit column The user can input both a quantity amount and unit cost This item is provided to allow for project technology and or regional differences not specifically covered in the generic information provided A credit item may be entered in the grey input cell as Credit The user then selects
55. aring on the screen display Cost references The user selects the reference from the Cost Analysis worksheet that will be used as a guideline for the estimation of costs associated with the implementation of the project This feature allows the user to change the Quantity Range and the Unit Cost Range columns The options from the drop down list are Canada 2000 None Second currency and a selection of 8 user defined options Enter new 1 Enter new 2 etc If the user selects Canada 2000 the range of values reported in the Quantity Range and Unit Cost Range columns are for a 2000 baseline year for projects in Canada and in Canadian dollars This is the default selection used in the built in example in the original RETScreen file Selecting None hides the information presented in the Quantity Range and Unit Cost Range columns The user may choose this option for example to minimise the amount of information printed in the final report If the user selects Second currency two additional input cells appear in the next row Second currency and Rate Ist currency 2nd currency In addition the Quantity Range and Unit Cost Range columns change to Foreign and Foreign Amount respectively This option allows the user to assign a portion of a project cost item in a second currency to account for those costs that must be paid for in a currency other than the currency in which the project costs are rep
56. arth s surface from escaping Instead this outgoing radiation is absorbed by the greenhouse gases and then partially re emitted as thermal radiation back to Earth warming the surface Greenhouse gases that are most relevant to energy project analysis are carbon dioxide CO2 methane CH4 and nitrous oxide NO these gases are considered in the RETScreen GHG emission reduction analysis The GHG Analysis worksheet of each Workbook file has been developed with a common framework so as to simplify the task of the user in analysing the viability of different projects Hence the description of each parameter is common for most of the items appearing in the worksheet One of the primary benefits of using the RETScreen software is that it facilitates the project evaluation process for decision makers The GHG Analysis worksheet with its emission related input items e g fuel mix fuel conversion efficiency and its calculated emission factor output items e g GHG emission factor allows the decision maker to consider various emission parameters with relative ease However the user should be aware that this ease of use may give a project developer a too optimistic and simplified view of what is required in setting a baseline for a proposed project As such it is suggested that the user take a conservative approach in calculating the baseline emission factor for the project particularly at the pre feasibility analysis stage In order to determine the net
57. as the projects are usually building mounted and have little or no negative environmental impact The elapsed time for the development of a PV project is relatively short An entire project can certainly be developed within a one year time period with actual construction time only taking a few days or weeks depending on the project scale The project development management time will usually take between 16 and 80 h at rates of between 50 h to 100 h Travel and accommodation This cost item includes all travel related costs excluding time required to develop the project Other These input cells are provided to allow the user to enter cost or credit items that are not included in the information provided in the above cost category The user must enter a positive numerical value in the Unit Cost column A cost item may be entered in the grey input cell as Other The user then selects Cost from the drop down list in the unit column The user can input both a quantity amount and unit cost This item is provided to allow for project technology and or regional differences not specifically covered in the generic information provided A credit item may be entered in the grey input cell as Credit The user then selects Credit from the drop down list in the unit column The project may be credited for material and or labour costs that would have been spent on the base case or conventional energy system The user can input both a quantity
58. ata this selection may also be used to reduce the monetary data by a factor e g reduced by a factor of a thousand hence k 1 000 instead of 1 000 000 PV 40 RETScreen Photovoltaic Project Model If None is selected all monetary data are expressed without units Hence where monetary data is used together with other units e g kWh the currency code is replaced with a hyphen kWh The user may also select a country to obtain the International Standard Organisation ISO three letter country currency code For example if Afghanistan is selected from the currency switch drop down list all project monetary data are expressed in AFA The first two letters of the country currency code refer to the name of the country AF for Afghanistan and the third letter to the name of the currency A for Afghani For information purposes the user may want to assign a portion of a project cost item in a second currency to account for those costs that must be paid for in a currency other than the currency in which the project costs are reported To assign a cost item in a second currency the user must select the option Second currency from the Cost references drop down list cell Some currency symbols may be unclear on the screen e g this is caused by the zoom settings of the sheet The user can then increase the zoom to see those symbols correctly Usually symbols will be fully visible on printing even if not fully appe
59. attery capacity However if the user has a specific battery model in mind the user should enter a multiple of the nominal capacity specified by the manufacturer Note The RETScreen PV model is not designed to analyse PV battery or PV battery genset systems that have less than one day of storage or more than 15 days of storage PV Array This sub section deals with the characteristics of the photovoltaic array PV module type The user selects the type of PV module considered for the application The seven options from the drop down list are mono Si poly Si a Si CdTe CIS spherical Si and User defined The Nominal Efficiencies of PV Modules table presents a comparative summary of the different types of modules PV 19 RETScreen Software Online User Manual The PV module type selected will depend on a number of factors including price from suppliers product availability warranties efficiencies etc Without further information either mono Si or poly Si may be used as a first selection as each have similar prices on a Wp basis and are the most common PV modules used today PV module manufacturer model The user enters the name of the PV module manufacturer or model number This is for reference purposes only The user can consult the RETScreen Online Product Database for more information Nominal PV module efficiency The user enters the nominal efficiency of the PV module under cons
60. autonomy will have a poor availability or rely more on the genset if there is one Systems with many days of autonomy will have greater availability or use the genset if there is one less often Note also that smaller batteries will tend to have a somewhat lower useful capacity see Average battery temperature derating and age faster than larger batteries see Batteries in the Cost Analysis worksheet Note The RETScreen PV model is not designed to analyse PV battery or PV battery genset systems that have less than one day of storage or more than 15 days of storage Nominal battery voltage The user enters the nominal voltage of the batteries to be used in V Usual battery voltages are 6 12 18 24 36 48 or 72 Volts The nominal battery voltage has no influence on the energy predictions of the model it is simply used to convert battery capacity from Ah to Wh according to the relationship Wh V x Ah Battery efficiency The user enters the average efficiency of the battery as specified at the nominal temperature of 25 C In the absence of information from the battery supplier an efficiency of 85 may be used Maximum depth of discharge The user enters the percentage of the rated battery capacity that can be withdrawn repeatedly without abnormal loss of battery life The maximum depth of discharge depends on the size and type of the battery In the absence of additional information for example from manufacturer s
61. average daily radiation on horizontal surface E E A E T 31 32 Monthly average temperature eee 31 32 Monthly Inputs oo eee eee ceseeesecneeeeeenee 27 31 Monthly solar fraction cesseesecseeseeeecseeeeeeeeeees 32 Motor type ci tscsiestinidcitvel ade 15 N NASA Global Satellite Data eee eeeeeeeeees 99 Nearest location for weather data 006 10 27 PV 107 RETScreen Software Online User Manual Net GHG emission reduction cccccscceeseeesseeeeees 61 Net GHG emission reduction credit duration 61 Net GHG emission reduction project life 61 Net Present Value NPV ccccccccccceesssseeeeees 75 90 NOCT TAs aa a ei Meh oven font feces a a eoeccs 20 Nominal battery capacity s es 19 53 Nominal battery voltage eee eeeeeeeeseeeeeee 17 53 Nominal PV array powel ccceee 22 24 49 61 Nominal PV module efficiency ce ceeeeeeeeeeeee 20 O OGM tice etcetera 56 57 71 O amp M labour sc cestode dihelaia Rie aines 56 Other 13 36 45 46 48 50 51 54 55 57 58 61 81 82 98 Other electrical equipment eee eeeeeteceeeeeeeeeee 54 Overall PV system efficiency 25 P Perform analysis ON sssseseeseeeeseeeeerereersesrrrrerees 89 90 Perform risk analysis t00 seseeeeeeeeeeereererrerereee 89 Periodic Costs Credits cccccccssceessecesteeeseeees 57 72 Permits and approvals ecceesceseeeceeeeeeeeeeeene
62. be used Genset This sub section deals with the characteristics of the genset Note that genset as defined here also includes thermoelectric generators TEGs Charger AC to DC efficiency The user enters the efficiency of the battery charger rectifier Values usually range between 80 and 95 If data from the manufacturer is not available a value of 80 will likely be a reasonable estimate PV 22 RETScreen Photovoltaic Project Model Suggested genset capacity The model calculates the suggested capacity of the genset in kW The genset is sized so that i it can always meet the AC load and ii it can nominally recharge the batteries in 8 h Suggested genset capacities usually range from very small values which should be considered as impractical to a few kW Genset capacity The user enters the genset capacity in rated kW for continuous operation By default the user will likely enter the Suggested genset capacity If the user has a specific genset in mind the nameplate capacity of that genset will likely be entered In the case of a retrofit situation where a PV system is added to an installation with an existing genset the nameplate capacity of the existing genset will likely be used The genset capacity will likely be within 25 of the suggested genset capacity significant deviations from the suggested value may affect battery operation and life expectancy Fuel type The user selects the typ
63. benefits of obtaining carbon finance for the project the user can evaluate the project twice once including the value of the carbon credits and the associated transaction costs and once without and then compare the results PV 79 RETScreen Software Online User Manual Use GHG analysis sheet The user indicates by selecting from the drop down list whether or not the optional GHG Analysis worksheet is used to conduct an analysis of GHG emission reduction If the user selects Yes from the drop down list then the user should complete the GHG Analysis worksheet Certain input fields will be added to the Financial Summary worksheet in order to calculate the GHG emission reduction income and cost If the user selects No from the drop down list then the user should go directly to the Financial Summary worksheet Type of analysis The user selects the type of analysis from the two options in the drop down list Standard and Custom Standard analysis uses many pre defined parameters in the calculations whereas Custom analysis requires that these parameters be entered by the user Background Information Project name The user defined project name for reference purposes only as entered in the Energy Model worksheet and it is copied automatically to the GHG Analysis worksheet Project location The user defined project location for reference purposes only as entered in the Energy Model worksheet and it is copied au
64. bility Study siaren ina 43 70 Financial Feasibility 0 00 ceeeeeeecseeeeeneeeeeeee 59 73 Financial Parameters cccccccssseceesseeeeessees 59 62 Financial Summary 9 25 26 59 60 61 62 69 77 79 80 88 91 92 93 94 96 Firm RE capacity cseecsesscseneesecseeeeeees 60 65 72 Foreign Amount ceceeeseesseereeeeeees 41 42 43 100 Fraction of month used cccecessceceesseceesseeeeeenee 31 Friction losses ccccccccessccceesseeceenseeecessceceenseeeeeenes 38 Fuel 13 14 15 23 57 71 82 83 84 85 86 Fuel conversion efficiency s es 84 86 Fuel 011 eee Poa ee E 83 86 Fuel typem iise 13 23 82 84 85 86 G Genset aisarsioss 12 13 14 15 22 23 52 60 81 Genset capacity earair EEn 23 60 GHG credit escalation rate 000 00000000000000 64 65 72 GHG emission factotr 79 83 84 85 86 87 GHG emission reduction cost ccccceesseceeeseeeeenee 76 GHG emission reduction credit 64 65 72 75 76 94 GHG Emission Reduction Summary 79 87 GHG reduction credit duration 0000000000000 61 64 GHG reduction income duration 0 cccceeee 72 Global Warming Potential of GHG eee 80 Greenhouse Gas Emission Reduction Analysis 9 Grid type snipe e e E scenes 12 Ground Monitoring Stations Data eee 99 H Hours of use per day arera r 35 I Impact graph vice eke ts 95 Incentives Gra
65. bols may be unclear on the screen e g this is caused by the zoom settings of the sheet The user can increase the zoom to see Nameofunit Symholforunit aT ao ee ee a ee a ee a ee ee sepor ip age Yo personday pd pesontip petri pesonyew evr pound b pound forcelsquare inch psi 2 ___ __ Name of Prefix bol for Prefix ae e Oo o ma O M ee List of Units Symbols and Prefixes PV 6 RETScreen Photovoltaic Project Model those symbols correctly Usually symbols will be fully visible on printing even if not fully appearing on the screen display Units Symbols amp Prefixes The previous table presents a list of units symbols and prefixes that are used in the RETScreen model Note 1 The gallon gal unit used in RETScreen refers to US gallon and not to imperial gallon 2 The tonne t unit used in RETScreen refers to metric tonnes Saving a File jou users computer or server RETScreen To save a RETScreen Workbook file standard Excel saving procedures should be used The original Excel Workbook file for each RETScreen model can not be saved under its original distribution name This is done so that the user does not save _ over the master file Instead the user should use the File Save As option The user can then save the file on a hard drive diskette CD etc However it is recommended to save the files in the
66. ceseceeceeeeeee 19 20 98 PV module s ennn nnar nnana 49 PV system capacity factot 0 cee eecseeeceeeeeeeeeeeee 25 PV system configuration ccceeseceeseeeeeeeeeeees 12 PV system desin oisin ronseis 47 PV temperature coefficient 0 0 eee eeeeeeeeees 20 21 PV Water Pump eee cece cseeeeeeeeeeseeeeseneeensees 15 R Rate Ist currency 2nd currency eects 41 42 100 RE credit escalation rate ccccceeeseeeeee 63 64 72 RE production credit 63 64 72 75 94 95 RE production credit duration 06 63 64 72 RE production credit income duration 72 Renewable energy collected 0 eee ee eeeeeeeee 25 Renewable energy delivered 25 60 72 92 Report preparation ceecceeecesecececseeeeeeseeeeeeenees 44 Risk Analysis for 2 ecesesssesecseeeeceeeeeceseeeeeseeneeees 91 S Saving a Filename e e a E 7 Second Currency ee eeeeeeeeeeseeceeeee 6 41 42 43 100 Sensitivity Analysis fOr cc eeeseeeeesecseeeeeneeeeeeeees 91 Sensitivity and Risk Analysis eeeeeeeeeenees 9 89 Sensitivity LANGE ose ee eeeeteceeee cette cneeeeeeaeneeeeeeaees 90 Simple Payback snurrat sarrien ei 74 Site Conditions sereisas oeii i 10 Site investigation seeseseeeeeeeeerereersesrrrrereerersesrsee 43 Site Latitude and PV Array Orientation 0 27 Slope Of PV array oenenncsivecoina ciate a 28 Solar radiation horizontal
67. d below PV module s The total cost of the PV module depends on the total PV array power kWp output required which is specified in the Energy Model worksheet as Nominal PV array power and the price per kWp for PV modules The user enters a kWp price Current costs for PV modules range from 5 500 kWp to 8 000 kWp The lower end of this price range is for larger projects 20 kWp or greater where volume purchase discounts come into play In addition to single large systems this could include a volume purchase of multiple residential PV systems e g an electric utility may purchase many systems of 2 kWp each Costs of smaller single systems 4 kWp or below are at the higher end of this price range It is important to note that over the last two decades PV module prices have continued to decrease This trend is expected to continue in the foreseeable future The user should obtain updated price information for PV modules Transportation Transportation costs for equipment and materials will vary considerably depending on the mode of transportation available and the location of the project site In many instances the cost will depend on distance and be based on a volume weight formula Costs to handle the material at the receiving end should also be considered In isolated areas many communities can receive bulk shipments at given periods of year either by barge ice road or sometimes only by air Logistical control is extremely import
68. d currency The exchange rate is used to calculate the values in the Foreign Amount column Note that this selection is for reference purposes only and does not affect the calculations made in other worksheets For example the user selects the Afghanistan currency AFA as the currency in which the monetary data of the project is reported i e selection made in Currency input cell this is the lst currency The user then selects United States currency USD from the Second currency input cell this is the 2nd currency The user then enters the exchange rate in the Rate AFA USD input cell i e the amount of AFA needed to purchase 1 USD Using this feature the PV 42 RETScreen Photovoltaic Project Model user can then specify what portion in the Foreign column of a project cost item s costs will be paid for in USD Foreign The user enters the percentage of an item s costs that will be paid for in the second currency The second currency is selected by the user in the Second currency cell Foreign Amount The model calculates the amount of an item s costs that will be paid for in the second currency This value is based on the exchange rate and the percentage of an items costs that will be paid for in the second currency as specified by the user Initial Costs Credits The initial costs associated with the implementation of a PV project are detailed below The major categories include costs for preparing a
69. d debt interest rate value The higher the percentage the greater the uncertainty The range specified by the user must be between 0 and 50 The range determines the limits of the interval of possible values that the debt interest rate could take For example a range of 10 for a debt interest rate of 20 means that the debt interest rate could take any value between 18 and 22 Since 20 is the estimated value the risk analysis will consider this value as being the most probable and the minimum and maximum values as being the least probable based on a normal distribution PV 93 RETScreen Software Online User Manual If the debt interest rate is known exactly by the user no uncertainty the user should enter a range of 0 Debt term The debt term is automatically transferred from the Financial Summary worksheet to the Sensitivity worksheet The user enters the debt term range The range is a percentage corresponding to the uncertainty associated with the estimated debt term value The higher the percentage the greater the uncertainty The range specified by the user must be a percentage value between 0 and the lowest percentage such that the debt term will always fall between 1 year and the project life The range determines the limits of the interval of possible values that the debt term could take For example a range of 10 for a debt term of 20 years means that the debt term could take any value between 18 and 22 years
70. d interactive connection A lower absorption rate can be entered to simulate a reverse or net metering scheme In this case the portion not absorbed is deemed to be sold back to the utility at a rate different from the avoided cost of energy In cases where the utility would not allow electricity to be fed back into the grid such a system is referred to as grid connected non grid interactive system the user should specify an isolated grid system and the absorption rate should be reduced to reflect the amount energy wasted For isolated grids experience and studies indicate that less than 5 of the electrical energy produced by the PV system will be wasted because of mismatches between PV output and utility energy demand For this reason the absorption rate will likely be greater than 95 being as high as 100 if the size of the PV system is small compared to the load on the grid PV system configuration The user selects from the drop down list the type of off grid system under consideration PV battery or PV battery genset PV battery should be used if the system does not include a back up generator Use PV battery genset if the system includes a generator genset Genset as defined here also includes thermoelectric generators TEGs The user will need to decide whether or not to include a genset in the PV system In some systems a genset is added to provide very high reliability without having to substantially oversize the PV ar
71. delivered The Energy Model calculates the annual renewable energy production MWh of the project This renewable energy delivered by the project also equates to the annual energy savings as compared with the base case electricity or pumping system For central grid applications the user can simulate a reverse metering scheme by entering the portion of solar energy fed back into the grid in the PV energy absorption rate cell of the Energy Model For example an absorption rate of 80 would be specified for a situation in which 80 of electricity produced is consumed on the premises and 20 is not fed back into the grid The user can then specify two different electricity rates by entering the utility rate in the Avoided cost of energy cell and the utility buy back rate in the Avoided cost of excess energy cell in the Financial Summary worksheet For isolated grid applications all the energy produced may not be absorbed by the grid due to a mismatch between energy demand and the energy supply The model does not consider storage of excess renewable energy For water pumping applications the renewable energy delivered corresponds to the mechanical pumping energy delivered by the PV pumping system Excess RE available For On grid applications the Energy Model calculates the excess renewable energy available MWh which is the energy from the system that is not absorbed by the load and therefore is available as a by product for heatin
72. e Foreign Amount column is Selecting User defined allows the user to specify the currency manually by entering a name or symbol in the additional input cell that appears adjacent to the currency switch cell The currency may be expressed using a maximum of three characters US etc To facilitate the presentation of monetary data this selection may also be used to reduce the monetary data by a factor e g reduced by a factor of a thousand hence k 1 000 instead of 1 000 000 If None is selected no unit of currency is shown in the Foreign Amount column The user may also select a country to obtain the International Standard Organisation ISO three letter country currency code For example if Afghanistan is selected from the currency switch drop down list the unit of currency shown in the Foreign Amount column is AFA The first two letters of the country currency code refer to the name of the country AF for Afghanistan and the third letter to the name of the currency A for Afghani Some currency symbols may be unclear on the screen e g this is caused by the zoom settings of the sheet The user can then increase the zoom to see those symbols correctly Usually symbols will be fully visible on printing even if not fully appearing on the screen display Rate 1st currency 2nd currency The user enters the exchange rate between the currency selected in Currency and the currency selected in Secon
73. e equipment Balance of equipment The balance of equipment item represents the sum of the purchasing construction and installation costs of all the elements of the energy system other than the equipment costs less any credits for not having to purchase or install base case equipment Miscellaneous The miscellaneous item includes all the costs not considered in any of the other initial costs categories that are required to bring a project to the operational stage PV 70 RETScreen Photovoltaic Project Model Incentives Grants The user enters the financial incentive this is any contribution grant subsidy etc that is paid for the initial cost excluding credits of the project The incentive is deemed not to be refundable and is treated as income during the development construction year year 0 for income tax purposes Annual Costs and Debt The total annual costs are calculated by the model and represent the yearly costs incurred to operate maintain and finance the project It is the sum of the O amp M costs fuel electricity costs and debt payments Note that the total annual costs include the reimbursement of the principal portion of the debt which is not strictly speaking a cost but rather an outflow of cash These costs are described briefly below O amp M The operation and maintenance O amp M costs are the sum of the annual costs that must be incurred to operate and maintain the energy system in excess of
74. e of fuel used by the genset A list of common fuels is provided in the drop down list Specific fuel consumption The user enters an estimate of the fuel consumption of the genset per unit kWh of electricity delivered Typical values can be found in the table below note that these values are for a generator running at full capacity and that they should be increased if the generator is running only at a fraction of its full capacity see also the Diesel Genset Fuel Efficiency vs Capacity Used graph Suggested value Natural gas 0 54 0 60 Fropanet 0 90 1 10 Diesel 2 ol 0 40 0 50 Kerosene 0 80 1 00 Gasoline 0 60 0 75 Average Genset Specific Fuel Consumption 1 Liquid propane at 15 C 1 97 L kg PV 23 RETScreen Software Online User Manual Power Conditioning This sub section deals with the characteristics of the power conditioning hardware Average inverter efficiency The user enters the combined efficiency expressed in of the electronic devices maximum power point tracker and inverter used to control the PV array and transform its DC output to AC Values between 80 and 95 are typical A value of 90 is suggested as a starting point Suggested inverter DC to AC capacity The model calculates the suggested capacity of the inverter in kW AC that is the nominal output of the inverter This value is calculated based on Nominal PV array power and Average inverter efficiency entered by
75. e of magnetic declination especially by mariners Natural Resources Canada s Geomagnetic Website provides a Magnetic Declination Calculator that can calculate the magnetic declination for any location given latitude longitude and year on the globe A chart of magnetic declination is provided for Canada based on the year 1995 Small changes from year to year do occur but can be ignored for the purposes of this model A magnetic declination of 10 W means that magnetic north is 10 west of true north for that location and time PV 30 RETScreen Photovoltaic Project Model Lines of Equal Magnetic Declination in Canada for 1995 Monthly Inputs Monthly mean weather data are entered by the user in this section The user also specifies the months or the fraction of months e g 0 25 if the system is used only one week in a month during which the solar energy equipment is used All energy and cost calculations in the remainder of the Photovoltaic Project workbook are performed for the period of use of solar energy only In other words months where no solar energy is used are not taken into account in the energy and financial analysis the rationale being that there is no energy displaced or solar savings to calculate for these months For months where equipment is used only for a fraction of the entire month the same fraction applies for that month to all energy calculations Some cells may be greyed out and written in italic to i
76. e primary fuel source displaced by the project The fuel type selected in the Energy Model worksheet is transferred here The type of fuel displaced is used in the calculation of energy savings Depending on the application the following types of fuels are available in the model Natural gas Propane Diesel 2 oil Gasoline Kerosene Grid mix and Other PV 61 RETScreen Software Online User Manual Financial Parameters The items entered here are used to perform calculations in this Financial Summary worksheet Values for each parameter will depend on the perspective of the user e g utility vs independent power producer or service provider Avoided cost of energy The user enters the avoided cost of energy This value typically represents either the average or the marginal unit cost of energy for the base case system and is directly related to the cost of fuel for the base case system The user is given the flexibility in the model to determine what the base case system is The avoided cost of energy is used in conjunction with the renewable energy delivered and for off grid and water pumping applications the specific fuel consumption entered in the Energy Model worksheet to calculate the annual energy savings The model escalates the avoided cost of energy yearly according to the energy cost escalation rate starting from year 1 and throughout the project life For example for on grid applications the base case energy cos
77. eduction to calculate the annual GHG emission reduction income Preliminary estimates predict the market price of GHG emission reduction credits in the USA will range from US 4 to US 95 per tonne of CO with 5 to 8 per tonne being the most likely range Sandor 1999 As of 2003 the global market price has typically been in the range of US 3 to US 5 per tonne of CO The value entered is assumed to be representative of year 0 i e the development year prior to the first year of operation year 1 The model escalates the GHG emission reduction credit value yearly according to the GHG credit escalation rate starting from year 1 and throughout the project life GHG reduction credit duration The user enters the GHG reduction credit duration year This value typically represents the number of years for which the project receives GHG reduction credits It is used to determine the annual GHG reduction income For Clean Development Mechanism CDM projects two options are available for the length of the crediting period i a fixed crediting period of 10 years or ii a renewable crediting period of 7 years that can be renewed twice for a maximum credit duration of 21 years If a crediting period of 10 years is selected once the project has been validated and registered Certified Emission Reductions CERs can be certified and issued for the 10 years of the project without revisiting the baseline However in the case of a renewable 7 year
78. el Heavy Duty Generators 1740 1500 1240 Cost 1000 RKA 750 500 250 0 10 15 20 Norrinal Capacity WM Typical Costs of Heavy Duty Generators per Nominal kW AC Output Batteries This item refers to the total cost of the battery bank required in off grid PV systems The battery cost will vary depending on the type of batteries selected This cost is related to the battery size selected in the Energy Model worksheet Nominal battery capacity and Nominal battery voltage The user inputs a kWh cost note that this is in kWh of battery capacity not accumulated kWh of energy stored and discharged through the battery over its lifetime The user should note that the lifetime of the battery and its maintenance are highly correlated to the type of batteries selected therefore this should also be reflected in the maintenance cost annual costs and battery replacement cost periodic costs as entered in the Cost Analysis worksheet The following table presents ranges of cost expected lifetime and need for maintenance for different types of batteries Cost range Lifetime Maintenance akWwh ears Lead acid automotive 75 125 1 3 Lead acid RV eolfcart 100 150 2 4 Lead acid vented industrial 175 400 5 12 Lead acid inexpensive gel or AGM 250 400 3 6 Lead acid industrial gel or AGM 350 1 000 5 12 Mickel cadtmum industrial 1 000 1 900 15 20 Cost Lifetime and Maintenance Requirements for Different Types of Batt
79. el calculates the GHG emission factor for the PV project Values are calculated based on the individual emission factors and the fuel conversion efficiency Units are given in tonnes equivalent of CO emission per megawatt hour of end use energy delivered tcoz2 MWh GHG Emission Reduction Summary Based on the GHG emission data entered the model calculates the annual reduction in GHG emissions when the base case system is displaced with the proposed case Base case GHG emission factor The model transfers the base case GHG emission factor calculated in the base case heating system baseline section This value represents the amount of GHG emitted per unit of end use energy delivered for the base case system Units are given in tonnes equivalent of CO emission per megawatt hour of end use energy delivered tcoz2 MWh Proposed case GHG emission factor The model transfers the PV project GHG emission factor calculated in the proposed case electricity system section This value represents the amount of GHG emitted per unit of end use energy delivered if the PV project is installed Units are given in tonnes equivalent of CO emission per megawatt hour of end use energy delivered tcoz MWh PV 87 RETScreen Software Online User Manual End use annual energy delivered The model calculates the end use annual energy delivered by the PV project which is the amount of PV energy delivered to the electricity grid for On grid
80. elects the Region Supplier Model and the Number of PV modules The data can be pasted from the dialogue box to the spreadsheets by clicking on the Paste Data button Only data that are in bold are pasted to the spreadsheets all other data are for reference purposes only Data entered using the product database may be overwritten i e the user may prefer to use other data and can manually enter values into the spreadsheets Other information such as product weight and or dimensions is provided to help the user prepare the study The product database contains a link to the Websites of some product suppliers In the case where the Website link cannot be activated the user should try using another browser or can contact the supplier by other means email etc Note To see all the suppliers listed in the product database and their contact information the user can choose Any from the User Defined PV Module Type input cell However if Any is selected then this information is not pasted to the spreadsheets The product database is distributed for informational purposes only and does not necessarily reflect the views of the Government of Canada nor constitute an endorsement of any commercial product or person Neither Canada nor its ministers officers employees or agents make any warranty in respect to this database or assumes any liability arising out of this database Product manufacturers interested in having their products listed in the
81. emperate climates during summer months Monthly average temperature The user enters the average temperature for the month in C This temperature is used to estimate the performance of the photovoltaic array as well as the efficiency of the battery The user can consult the RETScreen Online Weather Database for more information Monthly average daily radiation in plane of PV array The model calculates the amount of solar radiation received on average during one day on a tilted surface at the site in kWh m d Typical values calculated by the model range from 0 to 10 kWh m d Monthly solar fraction The model calculates the monthly fraction of the load met by the photovoltaic system off grid and water pumping systems only This value is calculated for reference purposes only The user first needs to complete the Load Calculation section as well as the Energy Modelworksheet in order for the Monthly solar fraction value to have meaning Solar radiation horizontal The model calculates the amount of solar radiation incident on a horizontal surface in MWh m2 for the entire year and for the period season of use Solar radiation tilted surface The model calculates the amount of solar radiation incident on the solar collector in MWh m2 for the entire year and for the period season of use Average temperature The model calculates the average ambient temperature in C for the entire year and for the period seas
82. en Software Online User Manual The direction of the horizontal bar positive or negative provides an indication of the relationship between the input parameter and the financial indicator There is a positive relationship between an input parameter and the financial indicator when an increase in the value of that parameter results in an increase in the value of the financial indicator For example there is usually a negative relationship between initial costs and the net present value NPV since decreasing the initial costs will increase the NPV In some cases there is insufficient data to properly plot the graph For example when the year to positive cash flow is immediate the result is not a numerical value and therefore these values cannot be plotted Median The model calculates the median of the financial indicator The median of the financial indicator is the 50 percentile of the 500 values generated by the Monte Carlo simulation The median will normally be close to the financial indicator value calculated in the Financial Summary worksheet Level of risk The user selects from the drop down list the acceptable level of risk for the financial indicator under consideration The options are 5 10 15 20 and 25 The level of risk input is used to establish a confidence interval defined by maximum and minimum limits within which the financial indicator is expected to fall The level of risk represents the probability t
83. enerally be assumed by the installer Other These input cells are provided to allow the user to enter cost or credit items that are not included in the information provided in the above cost category The user must enter a positive numerical value in the Unit Cost column A cost item may be entered in the grey input cell as Other The user then selects Cost from the drop down list in the unit column The user can input both a quantity amount and unit cost This item is provided to allow for project technology and or regional differences not specifically covered in the generic information provided PV 48 RETScreen Photovoltaic Project Model A credit item may be entered in the grey input cell as Credit The user then selects Credit from the drop down list in the unit column The project may be credited for material and or labour costs that would have been spent on the base case or conventional energy system The user can input both a quantity amount and unit cost Note that the credit item is expressed as a negative value in the Amount column Energy Equipment The energy equipment includes PV modules which produce direct current DC voltage and current Transportation costs are provided separately to allow cost differentiation for various regions The user may refer to the RETScreen Online Product Database for supplier contact information in order to obtain prices or other information required These costs are detaile
84. enewable energy delivered and Avoided cost of energy and the product of the Excess RE available and the Avoided cost of excess energy For Off grid applications the annual energy savings are equal to the product of the Renewable energy delivered Specific fuel consumption and Avoided cost of energy For water pumping applications the annual energy savings are equal to the product of the Water delivered Specific fuel consumption and Avoided cost of energy The yearly value of energy savings is escalated at the energy cost escalation rate Capacity savings income The annual capacity savings are equal to the product of the Firm RE capacity and the Avoided cost of capacity The yearly value of capacity savings is escalated at the inflation rate RE production credit income duration The model calculates the RE production credit income which represent the income or savings generated by the sale or exchange of the RE production credits during the RE production credit duration It is calculated from the renewable energy delivered and the RE production income value The yearly value of RE production credit income is escalated at the RE credit escalation rate GHG reduction income duration The model calculates the GHG emission reduction income which represents the income or savings generated by the sale or exchange of the GHG emission reduction credits It is calculated from the annual net GHG emission reduction
85. er defined project location is given for reference purposes only Nearest location for weather data The user enters the weather station location in the Solar Resource amp System Load worksheet and it is copied automatically to the Energy Model worksheet Note At this point the user should complete the Solar Resource amp System Load SR amp SL worksheet Latitude of project location The user enters the latitude of the project location in the Solar Resource amp System Load SR amp SL worksheet and it is copied automatically to the Energy Model worksheet Annual solar radiation tilted surface The model calculates the total annual solar radiation incident on the PV array in MWh m from monthly data entered by the user in the Solar Resource amp System Load SR amp SL worksheet Annual average temperature The model calculates the annual average temperature in C This is calculated from monthly data entered by the user in the Solar Resource amp System Load SR amp SL worksheet PV 10 RETScreen Photovoltaic Project Model The annual average temperature typically ranges from 20 to 30 C depending upon the location The temperature at standard conditions is 15 C DC energy demand for months analysed The model calculates the DC energy demand in MWh for the season of use This is calculated from data entered in the Load Characteristics section of the Solar Resource amp System Load SR amp SL worksheet
86. er of years over which the tax holiday applies starting in the first year of operation year 1 For example in India certain renewable energy projects are given a five year tax holiday Project Costs and Savings Most of the summary items here are calculated and or entered in the Cost Analysis worksheet and transferred to the Financial Summary worksheet Some calculations are made in the Financial Summary worksheet Initial Costs The total initial costs represent the total investment that must be made to bring a project on line before it begins to generate savings or income The total initial costs are the sum of the estimated feasibility study development engineering energy equipment balance of equipment and miscellaneous costs and are inputs in the calculation of the simple payback the net present value and the project equity and debt It is important to note that the range of possible costs listed throughout RETScreen do not include sales taxes In a number of jurisdictions clean energy project costs are often exempt from sales taxes Users will have to consider these costs for their region when preparing their PV 69 RETScreen Software Online User Manual evaluations For example if in a particular region sales tax is applicable to the cost of a PV project then the user must add the amount of sales tax to the cost of the project chosen from the proposed range of values Feasibility study The feasibility study ite
87. er to the motor The following table can be used to obtain an estimate of pump efficiency for different kinds of pumps Note that the wire to water efficiencies reported in this table are for well matched systems Efficiencies may be lower if the pump is poorly matched to the water head Efficiencies may also be lower if the PV array operates under low light conditions or if the pump system is not well matched to the type of controller used PV 15 RETScreen Software Online User Manual Suggested pump type Wir e to water efficiency wg Surface centrifugal Surface centrifugal Submersible centrifugal multi stage Submersible centrifugal multi stage Displacement pumps Pump System Efficiency 1 Some new pumps have been reported to have efficiencies as high as 75 Power Conditioning This sub section deals with the characteristics of the power conditioning hardware Suggested inverter DC to AC capacity The model calculates the suggested capacity of the inverter in kW AC that is the nominal output of the inverter This value corresponds to the AC peak load Inverter capacity The user enters the inverter capacity in kW AC that is the nominal output of the inverter By default the user will likely enter the Suggested inverter DC to AC capacity calculated above If the detailed load calculator in the Solar Resource amp System Load SR amp SL worksheet is used the AC peak load may be overestimated because the load
88. eries adapted from Ross 1999 PV 53 RETScreen Software Online User Manual Water pump The user enters a cost per water pump This may also include electric cable suited for use in water if supplied with the pump The cost of a water pump depends on the type of pump used its design size capacity quality and built in features Because it depends on so many different aspects the cost of the pump can range anywhere from 300 to 3 500 per unit The user should consult a supplier for more accurate estimates A well matched pump for the application is key to an efficient system Pipes reservoir This item refers to the total cost of reservoir and pipes hoses required This includes the pipes running from the bottom of the well to the reservoir as well as the pipes used for distribution of water The cost of these items will vary depending on the application type of material used and size required See Total head in the Solar Resource amp System Load SR amp SL worksheet for an initial estimate of length required additional pipes hoses will be required if the storage tank is not near the well Often reservoirs are made of polyvinylchloride PVC or cement The cost of reservoirs made of local material such as cement will be highly dependent on labour costs the user should obtain information on local suppliers For piping the most popular material is polyethylene and piping will cost between 0 75 m and 3 00 m depending
89. ersion e g hydro have a default value of 100 Fuel conversion efficiency Standard analysis The model provides the fuel conversion efficiency for the selected fuel type The fuel conversion efficiency is the efficiency of energy conversion from primary heat potential to actual useful energy output This value is used to calculate for each fuel type the aggregate GHG emission factor and therefore is only relevant for fuel types which actually produce greenhouse gases i e with non zero CO2 CH and N O emission factors For example a typical coal fired power plant could have a fuel conversion efficiency of 35 which indicates that 35 of the heat content of the coal is transformed into electricity fed to the grid PV 84 RETScreen Photovoltaic Project Model Units are given as a percentage of primary heat potential gigajoules of heat to actual useful energy output gigajoules of electricity lighting energy or pumping energy Fuel types which do not involve a thermal to electrical conversion e g hydro have a default value of 100 The default values provided by the model are given in the Default Emission Factors and Conversion Efficiencies table Transmission and distribution losses The user enters the transmission and distribution T amp D losses of the base case electricity system which includes all energy losses between the power plant and the end user This value will vary based on the voltage of transpo
90. ery particular cases such as the ones given in the example will the solar load correlation be Zero or Positive In the vacuum cleaning example the user will likely enter Negative Load The user enters an estimate of the load in kW The following table provides an estimate of typical loads encountered in an household In the vacuum cleaning example the user would enter 0 8 800 W converted to kW 800 1 000 0 8 Appliance Estimated Power Rating AC appliances Block heater 500 Coffee maker 1 000 Clothes washer excl hot water 440 Computer desktop 200 Dishwasher excl hot water 1 200 Hair dryer iron 1 000 Light 24 W incandescent 25 Light 10 W fluorescent 10 Light 40 W fluorescent 40 Microwave oven a00 Fower tools 250 1 000 Radio 30 Refrigerator 330 Televison BW 200 Televison col or 330 Toaster 1 000 Vacuum cleaner a00 Video cassette recorder 30 Water heater electric 5 000 DC appliances Computer laptop 25 Fan ceiling 25 Fan 38 15 Refrigerator 65 Security system fi Telephone cellular standby 0 02 Telephone radio standby 25 Televison B amp W 10 20 Televison col or 45 60 Typical Loads in a Household PV 34 RETScreen Photovoltaic Project Model Hours of use per day The user enters an estimate of the number of hours that the load is used during a typical day h d For example if it takes one half hour to vacuum the house the user would enter 0 5 Days of use per week
91. es costs including solicitor and client costs damages actions suits or proceedings arising out of related to or occasioned by any use of RETScreen International by the Licensee The Licensor shall have the right to defend any such action or proceeding with counsel of its own selection Copyright and Trademark The RETScreen International Clean Energy Project Analysis Software and the accompanying manual and databases are copyright of the Minister of Natural Resources Canada 1997 2005 Duplication in any manner is forbidden without prior written permission which may be obtained by contacting RETScreen International CANMET Energy Technology Centre Varennes Natural Resources Canada 1615 Lionel Boulet P O Box 4800 Varennes Quebec CANADA J3X 1S6 Tel 1 450 652 4621 Fax 1 450 652 5177 E mail rets nrcan gc ca Minister of Natural Resources Canada 1997 2005 RETSCREEN is a registered trademark of the Minister of Natural Resources Canada PV 102 RETScreen Photovoltaic Project Model License Agreement The use of RETScreen International is subject to the terms detailed in the RETScreen Software License Agreement which is available at the following Website address www retscreen net license html The user is encouraged to properly register at the RETScreen Website so the Centre may periodically inform the user of product upgrades and be able to report on the global use of RETScreen PV 103
92. esents the results of the sensitivity analysis Each table shows what happens to the selected financial indicator e g After tax IRR and ROI when two key parameters e g Initial costs and Avoided cost of energy are varied by the indicated percentages Parameters are varied using the following fraction of the sensitivity range 1 1 2 0 1 2 1 Original values which appear in the Financial Summary worksheet are in bold in these sensitivity analysis results tables Results which indicate an unviable project as defined by the user threshold will appear as orange cells in these sensitivity analysis results tables All parameter values used for the calculations are taken from the Financial Summary worksheet and all the sensitivity variations are evaluated at the level of that worksheet This is a partial limitation of this sensitivity analysis worksheet since some parameter values are calculated from inputs in other worksheets but those inputs are not changed However for most cases this limitation is without consequence If required the user can use the blank worksheets Sheet1 etc to perform a more detailed analysis Risk Analysis for This section allows the user to perform a Risk Analysis by specifying the uncertainty associated with a number of key input parameters and to evaluate the impact of this uncertainty on after tax IRR and ROL year to positive cash flow or net present value NPV The risk analysis is performed usin
93. f accuracy associated with the RETScreen pre feasibility estimate of the project costs Typically a pre feasibility level cost analysis should be accurate within 40 to 50 However this accuracy will depend on the expertise of the study team the scale of the project being considered the level of effort put forward to complete the pre feasibility study and the availability of accurate information Given the relative simplicity of PV systems it is certainly possible that the RETScreen user experienced with PV project developments could estimate costs in the range of 5 to 40 of the total initial project costs Annual Costs Credits There may be some annual costs associated with PV systems but they are likely to be relatively small compared to the overall system cost and other electric power generation technologies For hybrid PV systems the cost of fuel for the fossil fuel gensets can represent a substantial annual cost These costs are detailed below O amp M Property taxes Insurance Generally PV systems should not increase property taxes In some cases a community may provide a tax incentive for PV installations The PV system owner may choose to insure the cost of the system This cost can be estimated by contacting an insurance broker O amp M labour PV systems typically require little maintenance Usually the PV modules will last more than 25 years and will need minimal maintenance e g occasional cleaning in dusty areas etc
94. fe of the project This permits the user to apply rates of inflation to electricity or fuel costs which are different from general inflation for other costs For example North American electric utilities currently use energy cost escalation rates ranging anywhere from 0 to 5 with 2 to 3 being the most common values PV 65 RETScreen Software Online User Manual Inflation The user enters the inflation rate which is the projected annual average rate of inflation over the life of the project For example inflation for the next 25 years in North America is currently forecasted to range between 2 and 3 Discount rate The user enters the discount rate which is the rate used to discount future cash flows in order to obtain their present value The rate generally viewed as being most appropriate is an organisation s weighted average cost of capital An organisation s cost of capital is not simply the interest rate that it must pay for long term debt Rather cost of capital is a broad concept involving a blending of the costs of all sources of investment funds both debt and equity The discount rate used to assess the financial feasibility of a given project is sometimes called the hurdle rate the cut off rate or the required rate of return The model uses the discount rate to calculate the annual life cycle savings For example North American electric utilities currently use discount rates ranging anywhere from 3 to 18 w
95. g a Monte Carlo simulation that includes 500 possible combinations of input variables resulting in 500 values of after tax IRR and ROI year to positive cash flow or net present value NPV The risk analysis allows the user to assess if the variability of the financial indicator is acceptable or not by looking at the distribution of the possible outcomes An unacceptable variability will be an indication of a need to put more effort into reducing the uncertainty associated with the input parameters that were identified as having the greatest impact on the financial indicator Avoided cost of energy The avoided cost of energy is automatically transferred from the Financial Summary worksheet to the Sensitivity worksheet The user enters the avoided cost of energy range The range is a percentage corresponding to the uncertainty associated with the estimated avoided cost of energy value The higher the percentage the greater the uncertainty The range specified by the user must be between 0 and 50 The range determines the limits of the interval of possible values that the avoided cost of energy could take For example a range of 10 for an avoided cost of energy of 0 09 kWh means that the avoided cost of energy could take any value between 0 081 kWh and 0 099 kWh Since 0 09 kWh is PV 91 RETScreen Software Online User Manual the estimated value the risk analysis will consider this value as being the most probable and the mini
96. g or other uses in the case of isolated grid or is fed and sold back into the grid in the case of a central grid Firm RE capacity The firm RE capacity refers to the guaranteed electrical power kW that a renewable energy electric power project can deliver For PV projects which are inherently intermittent the user enters an avoided cost of capacity that is agreed upon with may need to be negotiated the local electric utility This avoided cost of capacity credit will depend upon the profile of the local electrical demand and energy supply conditions In the most conservative cases due to the intermittent nature of solar energy resources the firm renewable energy capacity value would equal zero Application type The application type is selected in the Solar Resource amp System Load SR amp SL worksheet and it is copied automatically to the Financial Summary worksheet Genset capacity For Off grid applications the genset capacity kW of the project is entered in the Energy Model worksheet and it is copied automatically to the Financial Summary worksheet PV 60 RETScreen Photovoltaic Project Model Nominal PV array power For Off grid applications the nominal PV array power kW of the project is entered in the Energy Model worksheet and it is copied automatically to the Financial Summary worksheet Equivalent energy demand For Off grid applications the equivalent DC energy demand is calculated in the
97. ge the greater the uncertainty The range specified by the user must be between 0 and 50 The range determines the limits of the interval of possible values that the initial costs could take For example a range of 10 for initial costs of 300 000 means that the initial costs could take any value between 270 000 and 330 000 Since 300 000 is the estimated value the risk analysis will consider this value as being the most probable and the minimum and maximum values as being the least probable based on a normal distribution If the initial costs are known exactly by the user no uncertainty the user should enter a range of 0 Annual costs The annual cost is transferred automatically from the Financial Summary worksheet to the Sensitivity worksheet but does not include debt payments PV 92 RETScreen Photovoltaic Project Model The user enters the annual cost range The range is a percentage corresponding to the uncertainty associated with the estimated annual costs value The higher the percentage the greater the uncertainty The range specified by the user must be between 0 and 50 The range determines the limits of the interval of possible values that the annual costs could take For example a range of 10 for an annual cost of 800 means that the annual cost could take any value between 720 and 880 Since 800 is the estimated value the risk analysis will consider this value as being the most probable and the minim
98. ge value between 0 and 50 Threshold The user enters the threshold value for the financial indicator selected The threshold is the value under which for the After tax IRR and ROI and Net Present Value NPV or over which for Year to positive cash flow the user considers that the proposed project is not financially viable Results which indicate an unviable project as defined by the user threshold will appear as orange cells in the sensitivity analysis results tables This value is used in the sensitivity analysis section only Click here to Calculate Sensitivity Analysis The Click here to Calculate Sensitivity Analysis button updates the sensitivity analysis calculations using the input parameters specified by the user i e Perform analysis on and Sensitivity range input cells The sensitivity analysis tables are updated each time the user clicks on this button The sensitivity analysis calculations can take up to 15 seconds to run depending on the Excel version and the speed of the computer When the sensitivity analysis is updated the button disappears If the user makes any changes to the input parameters or navigates through any of the other worksheets the button will reappear The user will then have to click on the button to update the sensitivity analysis calculations so that the results reflect the changes PV 90 RETScreen Photovoltaic Project Model Sensitivity Analysis for This section pr
99. gs given in the Financial Summary worksheet which reflect amounts valid for year zero are thus escalated one year in order to determine the actual costs and savings incurred during the first year of operation i e year 1 Cumulative The model calculates the cumulative cash flows which represent the net after tax flows accumulated from year 0 It uses the net flows to calculate the cumulative flows Cumulative Cash Flows Graph The cumulative cash flows are plotted versus time in the cumulative cash flows graph These cash flows over the project life are calculated in the model and reported in the Yearly Cash Flows table PV 77 RETScreen Software Online User Manual Blank Worksheets 3 These worksheets are provided to allow the user to prepare a customised RETScreen project analysis For example the worksheets can be used to enter more details about the project to prepare graphs to perform a more detailed sensitivity analysis and to create a custom database The user may also use these worksheets to develop a companion model to RETScreen PV 78 RETScreen Photovoltaic Project Model Greenhouse Gas GHG Emission Reduction Analysis As part of the RETScreen Clean Energy Project Analysis Software a GHG Analysis worksheet is provided to help the user estimate the greenhouse gas emission reduction mitigation potential of the proposed project This GHG emission reduction analysis worksheet contains four main sect
100. hat the financial indicator will fall outside this confidence interval The limits of the confidence interval are automatically calculated based on the median and the level of risk and are shown as Minimum within level of confidence and Maximum within level of confidence It is suggested that the user select a level of risk of 5 or 10 which are typical values for standard risk analysis Minimum within level of confidence The model calculates the Minimum within level of confidence which is the lower limit of the confidence interval within which the financial indicator likely falls It is the percentile of the distribution of the financial indicator corresponding to half the level of risk defined by the user For example for a Minimum within level of confidence value of 15 IRR a level of risk of 10 means that 5 half the level of risk of the possible IRR values are lower than 15 Maximum within level of confidence The model calculates the Maximum within level of confidence which is the upper limit of the confidence interval within which the financial indicator likely falls It is the percentile of the distribution of the financial indicator corresponding to 100 minus half the level of risk For PV 96 RETScreen Photovoltaic Project Model example for a Maximum within level of confidence value of 25 IRR a level of risk of 10 means that 95 of the possible IRR values are lower than 25 Distribution graph
101. hat the project is fully capitalised at inception is not depreciated through the years and therefore maintains its undepreciated value throughout its life When Declining balance is selected the model assumes that the capitalised costs of the project as specified by the depreciation tax basis are depreciated at the depreciation rate The portion of initial costs not capitalised is deemed to be expensed during the year of construction i e year 0 When Straight line is selected the model assumes that the capitalised costs of the project as specified by the depreciation tax basis are depreciated with a constant rate over the depreciation period The portion of initial costs not capitalised is deemed to be expensed during the year of construction i e year 0 For both declining balance and straight line depreciation the model assumes that the full depreciation allowed for a given year is always taken Also the model does not incorporate the half year rule used in some countries and according to which depreciation is calculated over only half of the capitalised cost during the first year of operation of the equipment Depreciation tax basis The user enters the depreciation tax basis which is used to specify which portion of the initial costs are capitalised and can be depreciated for tax purposes The remaining portion is deemed to be fully expensed during the year of construction year 0 For example if a PV project costs 2 00
102. he GHG Analysis worksheet For Standard projects if the user selects one of the fuel types from the drop down list default emission factor and fuel conversion efficiency values will be inserted into the row inputs of the table The default emission factors and conversion efficiencies of various fuel types are given in the table below Fenhann J 1999 Fenhann J 2000 and The Danish Energy Agency 1999 For Custom projects if a specific fuel type is not included in the drop down list the user may choose Other and manually enter values for the remainder of the row inputs The order in which reference fuels or power plants are listed in this table is irrelevant CO emission CH emission MO emission Fuel conversion factor factor factor efficiency kg GJ kg GJ kg GJ Large hydro 4 oil Diesel 2 oil Geothermal Biomass wood Small hydro Wind Solar Propane Default Emission Factors and Conversion Efficiencies PV 82 RETScreen Photovoltaic Project Model Fuel mix For On grid projects for applications where the base case power energy source is Grid extension the user enters the fuel mix of the base case electricity system for each fuel type For Off grid and Water pumping applications that do not use Grid extension as the base case power energy source there is a single fuel type displaced and the fuel mix is thus set to 100 Units are given as percentages of total end u
103. ideration The user can consult the RETScreen Online Product Database for more information Module efficiency depends primarily on the type of cell used mono Si poly Si a Si CdTe CIS spherical Si However within each of these categories there are wide variations in module efficiency from manufacturer to manufacturer depending on the manufacturing processes used Keeping this in mind in the absence of other data the following values may be used Cel type Default efficiency Default tanperature coefficient 1 Nominal Efficiencies of PV Modules NOCT Nominal Operating Cell Temperature The model calculates the Nominal Operating Cell Temperature NOCT in C NOCT is defined as the module temperature that is reached when the PV module is exposed to a solar radiation level of 800 W m a wind speed of 1 m s an ambient temperature of 20 C and no load In the case where the user selects sperical Si or User defined under PV module type the user enters the Nominal Operating Cell Temperature NOCT The NOCT can usually be found in the datasheets provided by the PV module manufacturer PV temperature coefficient The model calculates the PV temperature coefficient In the case where the user selects User defined under PV module type the user enters the temperature coefficient of the PV module The efficiency of photovoltaic cells varies with their PV 20 RETScreen Photovoltaic Project Model operating tempera
104. iled load calculator water pumping system 35 Development ceeeeeereees 39 45 48 64 70 105 Discharge h ad iccsvinineniso inira iini 38 Disclaimer and Indemnification 0 0 0 cece 102 Discount fate i6 n r ERER 66 Distribution graph cee eeeecsseeeeseceeeeecneeeeeeeeeees 97 Drawdown eat enoet epes nen roa aea e 38 PV 106 RETScreen Photovoltaic Project Model E Effective income tax rate eee eeeeeceeeeeceeeeeeeeneeee 67 Electrical design tis s ii tances Rees 47 48 End of project life 58 68 73 End of project life Cost Credit cece eeeeeeteeeee 73 End use annual energy delivered 0 0 0 ee eeeeeeeee 88 Energy cost escalation rate eee eee eee cee creeeee 65 Energy equipment ioaren inini rnis 70 Energy Eq ipment issen irantan 49 Energy from genset sseeeeseeeseeiereessesrereerereerees 24 59 Energy Model 9 10 11 27 32 35 49 51 53 59 60 61 62 80 81 82 86 88 89 90 98 Energy production Cost s ssesseeseseeeeerersersrereererersees 76 Energy savings iNCOME ccessseeeeesecreeeecnereeeeeees 72 Egin ernt rsen teaei 47 70 105 Equivalent DC demand not met eee eeeeeeeeee 24 Equivalent DC energy demand ce ceeeeeeeeeeeee 24 Equivalent energy demand cee eeeeeeeeeeeee 38 61 Equivalent pumping energy demand 00 11 Excess RE available 0 ccccccccesseceesseeeeessees 60 72 F Feasibility Study nesre 43 70 Feasi
105. iments errr renner E AEE E bd OSE AEA PEE ET EEE AE E LUO Training and Support ssesssesssocesocesoosesoccssecesocescossoocesocessocesocesoosesocessecssocesocssoosessesssesesosssosesssees LOL Vermis Of U T A ESA LOZ License Agreement sssssssssisiessssoisossssissosssiasssrossissessossissasssissnssa sssessss scesscssitorsseis ssssssi sessin siss LOO PSUS EA PAY io dasa cnceieees cadena taicnaceaboesacatanSscacnicedacsdadecd ccenueaadedsuceiGinedetasetadenicasncessaelaneeutenisetaaubisseiaaen U4 MINOR EEEE E EREE cosacsdesecacsoscosssedoecsescoesececsdaccuecesasasesesancssscsasetecesasssscece LUG PV 3 RETScreen Software Online User Manual Brief Description and Model Flow Chart RETScreen International is a clean energy awareness decision support and capacity building tool The core of the tool consists of a standardised and integrated clean energy project analysis software that can be used world wide to evaluate the energy production life cycle costs and greenhouse gas emission reductions for various types of energy efficient and renewable energy technologies RETs Each RETScreen energy technology model e g Photovoltaic Project etc is developed within an individual Microsoft Excel spreadsheet Workbook file The Workbook file is in turn composed of a series of worksheets These worksheets have a common look and follow a standard approach for all RETScreen models In addition to the software the tool includes product
106. ing In cases where batteries are subject to freezing the user may select Constant or Minimum In the absence of information on the freezing point of lead acid batteries 10 C may be considered as the lower limit note that this varies with the state of charge of the battery Constant battery temperature The user enters the constant temperature at which the battery is kept in C For example if the battery is located in a basement a value of 18 C is appropriate Minimum battery temperature The user enters the minimum temperature at which the battery is kept in C For example if the battery temperature is kept above the freezing point of water enter 0 C If lead acid batteries are chosen this value should be higher than 15 C to prevent the batteries from freezing Average battery temperature derating The model calculates the loss of nominal 25 C battery capacity resulting from temperature conditions experienced by the battery in C This value is averaged over the season of use Battery derating depends mainly on the temperature at which the battery operates Lower temperatures result in a larger temperature derating PV 18 RETScreen Photovoltaic Project Model If the battery is kept at a constant temperature of 25 C year round the battery temperature derating is zero It can reach as high as 30 or more if the battery operates part of the year at very low temperatures Suggested nominal battery c
107. ions Background Information Base Case System Baseline Proposed Case System Project and GHG Emission Reduction Summary The Background Information section provides project reference information as well as GHG global warming potential factors The Base Case Electricity System and the Base Case Heating System sections provide a description of the emission profile of the baseline system representing the baseline for the analysis The Proposed Case Heating System section provides a description of the emission profile of the proposed project i e the PV project The GHG Emission Reduction Summary section provides a summary of the estimated GHG emission reduction based on the data entered by the user in the preceding sections and from values entered or calculated in the other RETScreen worksheets e g annual energy delivered Results are calculated as equivalent tonnes of CO avoided per annum This is an optional analysis inputs entered in this worksheet will not affect results reported in other worksheets except for the GHG related items that appear in the Financial Summary and Sensitivity worksheets Greenhouse gases include water vapour carbon dioxide CO2 methane CH3 nitrous oxide N20 ozone O3 and several classes of halo carbons that is chemicals that contain carbon together with fluorine chlorine and bromine Greenhouse gases allow solar radiation to enter the Earth s atmosphere but prevent the infrared radiation emitted by the E
108. ith 6 to 11 being the most common values Project life The user enters the project life year which is the duration over which the financial feasibility of the project is evaluated Depending on circumstances it can correspond to the life expectancy of the energy equipment the term of the debt or the duration of a power purchase agreement Although the model can analyse project life s up to 50 years the project life of a well designed PV project typically falls between 20 and 30 years Debt ratio The user enters the debt ratio which is the ratio of debt over the sum of the debt and the equity of a project The debt ratio reflects the financial leverage created for a project the higher the debt ratio the larger the financial leverage The model uses the debt ratio to calculate the equity investment that is required to finance the project For example debt ratios typically range anywhere from 0 to 90 with 50 to 90 being the most common Debt interest rate The user enters the debt interest rate which is the annual rate of interest paid to the debt holder at the end of each year of the term of the debt The model uses the debt interest rate to calculate the debt payments For example at a minimum the debt interest rate will correspond to the yield of government bonds with the same term as the debt term A premium is normally added to this rate the spread to reflect the perceived risk of the project PV 66 RETScree
109. its output its output capacity and other integrated functions such as battery charging or genset automatic starting Here the user enters a kW AC price For on grid PV systems the cost of inverters is in the 1 000 kW AC to 1 500 kW AC range where bigger units are on the lower end of this range and smaller units on the higher end A high volume purchase of small units may bring the cost in the middle range Note that some PV module manufacturers are offering AC PV modules for grid intertie systems These modules have a small built in inverter In this case the user will not include an inverter cost here For off grid PV systems the cost of inverters ranges from 1 000 kW AC to 2 000 kW AC The lower end of this price range is for larger inverters or lower output quality inverters modified square wave while the costs of smaller or higher quality sine wave units will be at the higher end of this price range Small less than 1 kW pure sine wave inverter are still relatively new on the market and can easily exceed this price range depending on their quality and application they are built for The following table presents the costs according to inverter size and type Note that for stand alone sine wave inverters of less than 1 kW a large price range exists kW AC refers to the nominal output of the inverter Technically this should read kVA but for simplicity purposes it is referred to as kW This should not make a difference
110. ity Range and Unit Cost Range columns The user may choose this option for example to minimise the amount of information printed in the final report If the user selects Second currency two additional input cells appear in the next row Second currency and Rate Ist currency 2nd currency In addition the Quantity Range and Unit Cost Range columns change to Foreign and Foreign Amount respectively This option allows the user to assign a portion of a project cost item in a second currency to account for those costs that must be paid for in a currency other than the currency in which the project costs are reported Note that this selection is for reference purposes only and does not affect the calculations made in other worksheets If Enter new 1 or any of the other 8 selections is selected the user may manually enter quantity and cost information that is specific to the region in which the project is located and or for a different cost base year This selection thus allows the user to customise the information in the Quantity Range and Unit Cost Range columns The user can also overwrite Enter new 1 to enter a specific name e g Japan 2001 for a new set of unit cost and quantity ranges The user may also evaluate a single project using different quantity and cost ranges selecting a new range reference Enter new 1 to Enter new 8 enables the user to keep track of different cost scenarios Hence the user may ret
111. ividing net operation income net cash flows before depreciation debt payments and income taxes by debt payments principal and interest The debt service coverage is a ratio used extensively by the potential lenders for a project to judge its financial risk The model assumes that the cumulative cash flows are used to finance a sufficient debt service reserve before any distributions to the shareholders Yearly Cash Flows Pre tax The model calculates the net pre tax cash flows which are the yearly net flows of cash for the project before income tax It represents the estimated sum of cash that will be paid or received each year during the entire life of the project Note that the initial costs are assumed to occur at the end of year 0 and that year 1 is the first year of operation of the project Annual costs and savings given in the Financial Summary worksheet which reflect amounts valid for year zero are thus escalated one year in order to determine the actual costs and savings incurred during the first year of operation i e year 1 After tax The model calculates the net after tax cash flows which are the yearly net flows of cash for the project after income tax It represents the estimated sum of cash that will be paid or received each year during the entire life of the project Note that the initial costs are assumed to occur at the end of year O and that year 1 is the first year of operation of the project Annual costs and savin
112. ject Model Solar Resource amp System Load Calculation As part of the RETScreen Clean Energy Project Analysis Software the Solar Resource amp System Load Calculation worksheet is used in conjunction with the Energy Model worksheet to calculate the energy load and energy savings of a photovoltaic system The first two sections of this worksheet Site Latitude and PV Array Orientation and Monthly Inputs are used to calculate monthly and annual average daily radiation in the plane of the photovoltaic array by using the orientation of the array the latitude of the site and values of monthly average daily radiation on a horizontal surface for the twelve months of the year The third section Load Characteristics is used to specify the type of system under consideration on grid off grid or water pumping and the characteristics of the load Site Latitude and PV Array Orientation Site conditions and system characteristics associated with estimating the annual solar energy resource are detailed below Nearest location for weather data The user enters the weather station location with the most representative weather conditions for the project This is used for reference purposes only The user can consult the RETScreen Online Weather Database for more information Latitude of project location The user enters the geographical latitude of the project site location in degrees measured from the equator Latitudes north of the equator a
113. l type The fuel type of the PV project is assumed to be entirely solar except for Off grid applications for which the PV batteries genset configuration has been selected In this case the fuel mix will be the percentage of the energy supplied by each fuel type i e solar and genset fuel type Fuel mix The fuel mix of the PV project is assumed to be entirely solar except for Off grid applications for which the PV batteries genset configuration has been selected In this case the fuel mix will be the percentage of the energy supplied by each fuel type i e solar and genset fuel type CQO2 CH and N2O emission factors Custom analysis The user enters the CO2 CH and NO emission factors corresponding to the fuel type i e the proposed system Units are given in kilograms of gas emitted per gigajoule of end use energy kg GJ CO CH and NO emission factors Standard analysis The model provides default values for the CO2 CH and N O emission factors corresponding to the fuel type i e the proposed system The default values provided by the model are given in the Default Emission Factors and Conversion Efficiencies table Units are given in kilograms of gas emitted per gigajoule of end use energy kg GJ Fuel conversion efficiency If the user selects Standard type of analysis the solar energy conversion efficiency is set to 100 for all applications except Water pumping For water pumping applications the fuel conver
114. luded in the price of the fuel or in the previous O amp M section do not duplicate here Periodic Costs Credits This section is provided to allow the user to specify the periodic costs associated with the operation of the system over the project life Grey input cells are provided to allow the user to enter the name of a periodic cost and periodic credit item The user must enter a positive numerical value in the Unit Cost column PV 57 RETScreen Software Online User Manual A periodic cost represents recurrent costs that must be incurred at regular intervals to maintain the project in working condition A periodic cost item is entered in the grey input cell The user then selects Cost from the drop down list in the unit column The interval in years over which the periodic cost is incurred is entered in the period column The amount of the cost incurred at each interval is entered in the unit cost column The energy project may also be credited for periodic costs that would have been incurred over the project life of the base case or conventional energy system The periodic credit item is entered in the grey input cell The user then selects Credit from the drop down list in the unit column The interval in years over which the periodic credit is incurred is entered in the period column The amount of the credit incurred at each interval is entered in the unit cost column Note that the credit item is expressed as a negati
115. m represents the sum of the costs incurred to assess the feasibility of a project It is net of any credits for not having to develop the base case project Considerable detail is provided in the Cost Analysis worksheet for estimating the sub costs for feasibility studies This is done because it will help the project proponent better estimate the costs of the next investment required which is the investment in a feasibility study However for smaller projects the RETScreen analysis may be sufficient to move to the development and engineering phase or to construction Note The RETScreen Clean Energy Project Analysis Software can also be used to prepare the Feasibility Study Development The development item typically represents the sum of the costs incurred to bring a project to the detailed design and construction stage once its feasibility has been proven It is net of any credits for not having to develop the base case project Engineering The engineering item typically represents the sum of the costs of the design activities required to go from the development stage to the construction stage of a project It also includes costs for construction supervision It is net of any credits for not having to develop the base case project Energy equipment The energy equipment item typically represents the sum of the purchasing and installation costs of the energy equipment less any credits for not having to purchase or install base cas
116. mum and maximum values as being the least probable based on a normal distribution If the avoided cost of energy is known exactly by the user no uncertainty the user should enter a range of 0 Renewable energy delivered The RE delivered is transferred automatically from the Financial Summary worksheet to the Sensitivity worksheet The user enters the RE delivered range The range is a percentage corresponding to the uncertainty associated with the estimated RE delivered value The higher the percentage the greater the uncertainty The range specified by the user must be between 0 and 50 The range determines the limits of the interval of possible values that the RE delivered could take For example a range of 10 for a RE delivered of 40 000 MWh means that the RE delivered could take any value between 36 000 and 44 000 MWh Since 40 000 MWh is the estimated value the risk analysis will consider this value as being the most probable and the minimum and maximum values as being the least probable based on a normal distribution If the RE delivered is known exactly by the user no uncertainty the user should enter a range of 0 Initial costs The total initial cost is transferred automatically from the Financial Summary worksheet to the Sensitivity worksheet The user enters the initial costs range The range is a percentage corresponding to the uncertainty associated with the estimated initial costs value The higher the percenta
117. n ccccceecceesceeseeeeceseeeseenseenes 49 55 57 Travel and accommodation cccecceeeeseeee 44 46 Type of analysis s es 39 80 81 Type of fuel displaced eee eeeeccssecreeeeceeeereeees 61 U Umit eeit 36 41 45 46 48 50 55 57 58 100 Units Symbols amp Prefixes ee ecceseeseeeecneeeeeneenees T Use detailed load calculator ceeeesceeeeesteceeees 33 Use GHG analysis sheet e eee eeeceseceeeeeeeeeee 80 Use sensitivity analysis sheet ee ceeeeeeeeeeeeeee 89 W Water delivered cccccccccssccecssceceessseeeesseeees 25 72 Water demand for months analysed 06 11 Water pump 22 33 36 54 81 82 83 86 88 Water pumping application cece eeeeeeteeeeeeee 36 Water USE Pper UDI vis sersniihe teetestoeiecte a niae 36 Weather Data cccccccccccceseesseseeeeees 5 10 27 32 99 Y Yearly Cash FIOWS 0 ccceceeccescesecesecnsecnseenee 59 77 Year to positive cash flOW ee eeeeeseeeeeeees 74 90 PV 109 RETScreen Software Online User Manual Notes PV 110 RETScreen Photovoltaic Project Model PV 111 www retscreen net
118. n Photovoltaic Project Model Debt term The user enters the debt term year which is the number of years over which the debt is repaid The debt term is either equal to or shorter than the project life Generally the longer the term the more the financial viability of a project improves The model uses the debt term in the calculation of the debt payments and the yearly cash flows The term of the debt normally falls within a 1 to 25 year range It should not exceed the estimated project life Income tax analysis The user indicates by selecting from the drop down list whether or not income tax should be factored into the financial analysis If the user selects Yes certain input fields will be added to allow the user to customise the income tax analysis according to the specific circumstances of the project In some situations the after tax return of a project can be more attractive than its pre tax return The income tax analysis allows the model to calculate after tax cash flows and after tax financial indicators In all cases the model assumes a single income tax rate valid throughout the project life and applied to net income Note that the analysis is based among others on net initial and annual costs i e any credits entered in the Cost Analysis worksheet for these two categories are not treated separately This leads to a reasonably accurate tax analysis unless the initial and or annual credits are of the same order of magnit
119. n Instead the IRR obtained is specific to the project and applies to all investors in the project The model uses the pre tax yearly cash flows and the project life to calculate the internal rate of return After tax Internal Rate of Return and Return on Investment The model calculates the after tax internal rate of return which represents the true interest yield provided by the project equity over its life It is also referred to as the return on investment equity ROI or the time adjusted rate of return It is calculated by finding the discount rate that causes the net present value of the project to be equal to zero Hence it is not necessary to establish the discount rate of an organisation to use this indicator An organisation interested in a PV 73 RETScreen Software Online User Manual project can compare the internal rate of return of the project to its required rate of return often the cost of capital The IRR is calculated on a nominal basis that is including inflation If the internal rate of return of the project is equal to or greater than the required rate of return of the organisation then the project will likely be considered financially acceptable assuming equal risk If it is less than the required rate of return the project is typically rejected An organisation may have multiple required rates of return that will vary according to the perceived risk of the projects The most obvious advantage of using
120. n for most of the items appearing in the worksheet One of the primary benefits of using the RETScreen software is that it facilitates the project evaluation process for decision makers The Financial Summary worksheet with its financial parameters input items e g avoided cost of energy discount rate debt ratio etc and its calculated financial feasibility output items e g IRR simple payback NPV etc allows the project decision maker to consider various financial parameters with relative ease A description of these items including comments regarding their relevance to the preliminary feasibility analysis is included below Annual Energy Balance The summary items here are calculated and or entered in the Energy Model and GHG Analysis worksheets and transferred to the Financial Summary worksheet Project name The user defined project name is entered for reference purposes only in the Energy Model worksheet and it is copied automatically to the Financial Summary worksheet Energy from genset The energy delivered by the genset MWh over the season of use is calculated in the Energy Model worksheet and it is copied automatically to the Financial Summary worksheet Project location The user defined project location is entered for reference purposes only in the Energy Model worksheet and it is copied automatically to the Financial Summary worksheet PV 59 RETScreen Software Online User Manual Renewable energy
121. ndicate that they are not used for energy calculations For example if the month of January is not considered in the analysis thus Fraction of month used is set to zero for January then Monthly average daily radiation on horizontal surface and Monthly average temperature are not required for January Hence the corresponding cells are greyed out to indicate that the information is not required to run the model Fraction of month used The user enters the months for which the energy equipment is used Months during which the energy equipment is not used are not taken into account in the energy and financial analysis For each month the user enters a value between 0 and 1 0 is entered if the energy equipment is not used during a month 0 5 if it is used 50 of the time and 1 if it is used 100 of the time PV 31 RETScreen Software Online User Manual Monthly average daily radiation on horizontal surface The user enters the amount of solar radiation received on average during one day on a horizontal surface at the site in kWh m7 d Data in MJ m d should be divided by 3 6 to be converted to kWh m d Data in BTU ft d should be divided by 317 and data in cal cm d or Langleys should be divided by 86 to be converted to kWh m7 d The user can consult the RETScreen Online Weather Database for more information The values range from 0 during polar night months in the polar regions to values around 8 5 kWh m d in t
122. nflation on the costs On the other hand the payback period is often of great importance to smaller firms that may be cash poor When a firm is cash poor a project with a short payback period but a low rate of return might be preferred over another project with a high rate of repayment but a long payback period The reason is that the organisation may simply need a faster return of its cash investment The model uses the total initial costs the total annual costs excluding debt payments and the total annual savings in order to calculate the simple payback The calculation is based on pre tax amounts and includes any initial cost incentives Year to positive cash flow The model calculates the number of years to positive cumulative cash flow which represents the length of time that it takes for the owner of a project to recoup its own initial investment out of the project cash flows generated The year to positive cash flow considers project cash flows following the first year as well as the leverage level of debt of the project which makes it a better time indicator of the project merits than the simple payback The model uses the year number and the cumulative after tax cash flows in order to calculate this value PV 74 RETScreen Photovoltaic Project Model The year to positive cash flow differs from the discounted payback indicator in that it considers the nominal value of future cash flows rather than the discounted value
123. nical pumps such as hand pump or animal driven pumps with a photovoltaic system A final option Other can be selected for cases not falling in one of the above categories Although the drop down list contains no genset battery system or cycle charger option this type of system can be simulated by adjusting the fuel consumption to account for losses in the battery and charger With Genset selected as the base case power source the specific fuel consumption input is set to the specific fuel consumption of the genset alone divided by the efficiency of the battery and the efficiency of the charger In cases where the source being displaced is not an electrical system the user should be careful when comparing conventional energy sources such as lanterns or hand pumps with PV systems as the latter may have a higher value convenience productivity safety etc For example a PV lantern may give a better quality light than a kerosene lamp and an electric water pump may free a person s time allowing them to accomplish other tasks Such aspects must be considered in the decision process Fuel type The user selects the type of fuel displaced by the PV system A list of common fuel types are provided in the drop down list The fuel options address the replacement of conventional fossil fuel generators and engine driven pumps Natural gas Propane Diesel 2 oil Gasoline Kerosene or fossil fuel lanterns Kerosene Propane with a photov
124. nts iise die eneit irese ne Rote 71 Income tax analysis ei eesecseeseeseceeeeecneseeeeeeeees 67 Inflation ie ies niece E Cake 66 Initial COStS 0 22 68 Ha eek tderk tacks Sek estate erie 91 92 Initial Costero ni 43 67 69 Initial Costs Credits cccccccecssecsesceesseceseeeesseee 43 vertei ens ne Retr hese 16 24 51 52 Inverter Capacity iise ie enan e Eia es 16 24 L Latitude of project location eee eeeeeeeeees 10 27 Level of risk se 2 3 stsigaiennih del ie lett 96 License Agreement ee eeeeceseeeesecreeeeeneeeeeeeees 103 Load eee 9 10 11 14 16 27 32 33 34 54 60 Load Characteristics 0 ccccccccssceessseeeeeee 11 27 33 Loss carryforward oc eeeeesceseeeeeecneeeecnetseeeeeees 67 M Magnetic declination ceeeseeseeeecneeeeeeeeeees 29 30 Maximum depth of discharge c ceesseeseereereees 17 Maximum within level of confidence 96 Medi n sci ara earet araar EE rae oep tE aE 96 Minimum battery temperature 0 0 0 0 cee eeeteeneeeee 18 Minimum within level of confidence 0 96 Miscellaneous cccccceceeseeeeereees 16 21 24 55 70 Miscellaneous power conditioning losses 16 21 24 Miscellaneous PV array losses c cceceeeseereeeeees 21 Model Flow Chat t eee eeceeceesecesecsecssesnseeseenees 4 Module support structure eee eeeeeeeeeeeee 51 Monthly average daily radiation in plane of PV array PEA ERREA T 32 Monthly
125. o an overestimation of the total AC peak load in systems where not all AC loads occur simultaneously For example if the system comprises both a TV and a vacuum cleaner the user may choose to turn the TV off when vacuuming If this is the case a smaller inverter size than the one proposed by the model in the Energy Model worksheet can be selected In other words the user should select an inverter with capacity to meet the maximum AC load with selected AC devices operating simultaneously Detailed load calculator water pumping system The user enters a detailed description of the various water pumping loads that the PV system will have to meet PV 35 RETScreen Software Online User Manual Description The user enters a description of the load This if for reference purposes only For example if the water will be used to irrigate a field of corn the user may enter Corn field Water pumping application The user selects the water pumping application under consideration The four options from the drop down list are Domestic Livestock Irrigation and Other For the example of the corn field the user would select Irrigation Unit Based on the water pumping application selected the model displays the unit used to calculate the daily water required If Other is selected as the water pumping application no units are displayed For the example of the corn field the units displayed are ha hectares See the Typical
126. oltaic system A final fuel option Other can be selected for cases not falling in one of the above categories For water pumping applications if the source of power energy being displaced is set to Grid extension then the fuel type is automatically set to Grid mix Specific fuel consumption Depending on the Application type being evaluated the user enters the amount of fuel consumed by the base case system to either provide a given amount of electrical energy kWh or PV 13 RETScreen Software Online User Manual provide a given amount of water L litres of water pumped or to produce a given amount of light over a certain period year Note that for fossil fuel generators the efficiency is a function of its operational point A small generator running at full load will be more efficient than a larger one running at half load Typical values can be found in the Average Genset Specific Fuel Consumption table note that these values are for a generator running at full capacity and that they should be increased if the generator is running only at a fraction of its full capacity The next graph shows genset fuel efficiency vs capacity used for various sizes of diesel generators in the absence of additional data this figure can be used to estimate fuel efficiency as a function of the average operational point of the genset For water pumping applications the specific fuel consumption encompasses the efficiencies of both
127. on of use PV 32 RETScreen Photovoltaic Project Model Load Characteristics The load characteristics of the PV system are entered by the user in this section The user specifies the type of application on grid off grid or water pumping as well as load details that will enable the model to estimate the energy requirements Application type The user selects the type of application under consideration The three options from the drop down list are On grid Off grid and Water pumping On grid applications cover both central grid and isolated grid systems with no batteries Off grid applications include both stand alone systems that have a photovoltaic array and batteries but no back up energy system and hybrid systems which include a photovoltaic array batteries and a fossil fuel generator Water pumping PV systems do not include batteries Use detailed load calculator The user selects whether or not the detailed load calculator is to be used If Yes is selected the detailed load calculator can be used to specify the load on an item by item basis If No is selected then the user must enter global estimates of the load Detailed load calculator off grid system The user enters a detailed description of the various loads that the system will have to meet Description The user enters a description of the load This is for reference purposes only For example if the load in question is an electric vacuum cle
128. on the location size material and quantity Other electrical equipment Other electrical equipment may be required such as conduit and fittings required to connect the PV modules to the inverter and the inverter to an existing breaker panel and includes such items as lightning protection or special electric cable for water pumping systems Each system will also require circuit protection and a disconnect so as to be able to isolate the inverter The input value has been estimated on a kWp basis rated PV array power The user enters a kWp price These costs can range from 700 kWp for simple and more standard residential PV systems up to 1 500 kWp for industrial scale systems System installation System installation refers to all the site labour required to install the PV systems including the PV modules inverter genset batteries structure and electrical equipment Special equipment is not generally required for the installation of the system however for larger systems cranes and hoists can be used to save site labour The input value has been estimated on a kWp basis rated PV array The user enters a kWp price These costs range between 900 kWp and 2 500 kWp depending primarily upon the structural requirements as described above PV 54 RETScreen Photovoltaic Project Model Transportation The user enters the cost of transportation for material and or personnel required to complete the installation of the
129. ons values can range from a fraction of a cubic meter per day to several hundred cubic meters per day Daily water requirement The model calculates the total daily water requirement in m d This value is automatically calculated in the model if the detailed load calculator is used It must be entered manually by the user if the calculator is not used For typical PV water pumping applications values can range from a fraction of a cubic meter per day to several hundred cubic meters per day Suction head The user enters the vertical distance in meters from the centre of the pump to the water surface when the pump is located above water and no water is being pumped see the figure below There is no suction head for floating and submerged pumps This value can range from zero for immersed pumps and should not exceed 8 m for hydraulic considerations Pressure head Discharge head Pump Suction head Pumping Head Nomenclature PV 37 RETScreen Software Online User Manual Drawdown The user enters the vertical distance in meters between the static water level to the actual or drawdown water level when water is pumped from the source see Pumping Head Nomenclature figure For wells this value is best determined by test pumping The drawdown depends on the rate of pumping and the ability of the surrounding aquifers to replenish the well If no test data is available use 1 m For immersed pumps or for
130. or cost over runs and how does it compare financially with other options These are very difficult to answer with any degree of confidence since whoever prepared the estimate would have been faced with two conflicting requirements e Keep the project development costs low in case funding cannot be secured or in case the project proves to be uneconomic when compared with other energy options e Spend additional money and time on engineering to more clearly delineate potential project costs and to more precisely estimate the amount of energy produced or energy saved To overcome to some extent such conflicts the usual procedure is to advance the project through the following four stages e Pre feasibility analysis e Feasibility analysis e Development including financing and engineering e Construction and commissioning Each stage could represent an increase of a magnitude or so in expenditure and a halving of the uncertainty in the project cost estimate This process is illustrated for hydro projects in the Accuracy of Project Cost Estimates figure Gordon 1989 A reminder to the user that the range of values for cost items mentioned in the manual are for a 2000 baseline year in Canadian dollars Some of this data may be time sensitive so the user should verify current values where appropriate The approximate exchange rate from Canadian dollars to United States dollars and to the Euro was 0 68 as of January 1 2000 PV 39 R
131. order to help optimise the design of the photovoltaic project from an energy use and cost standpoint In addition to the worksheets that are required to run the model the Introduction worksheet and Blank Worksheets 3 are included in the Photovoltaic Project Workbook file The Introduction worksheet provides the user with a quick overview of the model Blank Worksheets 3 are provided to allow the user to prepare a customised RETScreen project analysis For example the worksheets can be used to enter more details about the project to prepare graphs and to perform a more detailed sensitivity analysis PV 9 RETScreen Software Online User Manual Energy Model As part of the RETScreen Clean Energy Project Analysis Software the Energy Model and Solar Resource and System Load Calculation worksheets are used to help the user calculate the annual energy production for a photovoltaic project based upon local site conditions and system characteristics Results are calculated in common megawatt hour MWh units for easy comparison of different technologies Site Conditions The site conditions associated with estimating the annual energy production of a photovoltaic project are detailed below Project name The user defined project name is given for reference purposes only For more information on how to use the RETScreen Online User Manual Product Database and Weather Database see Data amp Help Access Project location The us
132. ort structure will vary considerably depending on whether the system is to be mounted on the building wall or roof or whether it is to be ground mounted These costs can be related to the area covered by the PV modules which is calculated in the Energy Model worksheet PV array area The user inputs a m cost For simple PV systems where the PV modules are flush mounted to the building roof or wall the structure costs are minimal and will typically be included as part of the PV module price In this case the user enters 0 For more elaborate structures such as on flat roof commercial buildings support structure costs could be as high as 200 m For systems using tracking devices the cost per unit of area will vary depending of the type of tracker used passive tracking or electrical drives its complexity one two axis or azimuth tracking and size Trackers can cost anywhere between 300 m and 1 200 m2 As a general rule the lower end of this price range is for simpler and larger trackers up to about 11 m while the higher end will reflect the cost of small units with full tracking two axis capability For arrays exceeding 11 m multiple tracking units may be required If the system is to be ground mounted fixed or tracking some site work will have to be done and those costs should be added in the Other category provided Inverter The cost of the inverter depends on the application it is used for the quality waveform of
133. orted Note that this selection is for reference purposes only and does not affect the calculations made in other worksheets If Enter new 1 or any of the other 8 selections is selected the user may manually enter quantity and cost information that is specific to the region in which the project is located and or for a different cost base year This selection thus allows the user to customise the information in the Quantity Range and Unit Cost Range columns The user can also overwrite Enter new PV 41 RETScreen Software Online User Manual 1 to enter a specific name e g Japan 2001 for a new set of unit cost and quantity ranges The user may also evaluate a single project using different quantity and cost ranges selecting a new range reference Enter new 1 to Enter new 8 enables the user to keep track of different cost scenarios Hence the user may retain a record of up to 8 different quantity and cost ranges that can be used in future RETScreen analyses and thus create a localised cost database Second currency The user selects the second currency this is the currency in which a portion of a project cost item will be paid for in the second currency specified by the user The second currency option is activated by selecting Second currency in the Cost references drop down list cell This second unit of currency is displayed in the Foreign Amount column If the user selects the unit of currency shown in th
134. plified baseline and monitoring methodologies for selected small scale CDM project activity categories December 2002 United Nations Population Information Network Population and Water Resources http www un org popin specialized fao html PV 105 RETScreen Software Online User Manual Index A AC energy demand ee eeeeeeeeeeeenees 11 35 AC energy demand for months analysed 11 AC peak load siot iii 16 35 ACIDC ean n aE a a ooisiice wad 33 After taR esee ENESE ences 73 77 91 After tax IRR and ROL 91 Annual average temperature esseeeseeerereeeereereeee 10 Annual Costs aasan Ee betes Hasson icdese 71 92 Annual Costs Credits cccccccccsscsssceesseeseeesseeeeees 56 Annual Costs and Debt eee ceeeceeeceecneeeeee 71 Annual Energy Balance eeseeeeeceeeeneeeeeeeee 59 Annual Energy Production for months analysed 24 Annual GHG emission reduction eceseeeeeeeereee 88 Annual Life Cycle Savings seese 75 Annual Savings or INCOME s src 71 Annual solar radiation tilted surface 00000000000 10 Application type ssseseseeeeessersesereeerereeeees 11 13 33 60 Average battery temperature derating 17 18 Average inverter efficiency 16 24 Average temperature sceitse resser 32 Avoided cost of Capacity ce ceeeeeseseeereneeeeeens 65 72 Avoided cost of energy ccecceseerees 60 62 72 91 Avoided cost of excess energy u s 60 6
135. project may be credited for material and or labour costs that would have been spent on the base case or conventional energy system The user can input both a quantity amount and unit cost Note that the credit item is expressed as a negative value in the Amount column PV 58 RETScreen Photovoltaic Project Model Financial Summary As part of the RETScreen Clean Energy Project Analysis Software a Financial Summary worksheet is provided for each project evaluated This common financial analysis worksheet contains six sections Annual Energy Balance Financial Parameters Project Costs and Savings Financial Feasibility Yearly Cash Flows and Cumulative Cash Flows Graph The Annual Energy Balance and the Project Costs and Savings sections provide a summary of the Energy Model Cost Analysis and GHG Analysis worksheets associated with each project studied In addition to this summary information the Financial Feasibility section provides financial indicators of the project analysed based on the data entered by the user in the Financial Parameters section The Yearly Cash Flows section allows the user to visualise the stream of pre tax after tax and cumulative cash flows over the project life The Financial Summary worksheet of each Workbook file has been developed with a common framework so the task of the user in analysing the viability of different project types is made simpler This also means the description of each parameter is commo
136. project to break even or the economic energy production cost Hence it is the value that when assigned to the avoided cost of energy results in a NPV of zero and thus the after tax IRR is equal to the discount rate The energy production cost is calculated assuming that all financial parameters other than the avoided cost of energy are kept constant Calculate GHG reduction cost The user indicates by selecting from the drop down list whether or not the project GHG emission reduction cost should be calculated In order to calculate the true economic not financial cost of GHG emission reductions a number of other parameters such as the GHG emission reduction credit debt ratio etc should be set to 0 In addition Income tax analysis should be set to No and other taxes should also be set to 0 This option is more applicable to economists as it requires a careful analysis of assumptions used GHG emission reduction cost The model calculates the GHG emission reduction cost The GHG emission reduction cost is calculated by dividing the annual life cycle savings ALCS of the project by the net GHG emission reduction per year averaged over the project life For projects with a net increase in GHG emission the GHG emission reduction cost is irrelevant and hence not calculated Project equity The model calculates the project equity which is the portion of the total investment required to finance the project that is funded directly by the
137. r more information on determining GHG emission factors see the revised IPCC Guidelines for National Greenhouse Gas Inventories CO emission factors for many fuels are included on page 1 13 of the IPCC Reference Manual CH and NO emission factors for a number of fuels are included on pages 1 35 and 1 36 of the IPCC Reference Manual The default values provided by the model are given in the Default Emission Factors and Conversion Efficiencies table Fuel conversion efficiency Custom analysis For On grid projects and for applications where the base case power energy source is Grid extension the user enters the fuel conversion efficiency for the selected fuel type The fuel conversion efficiency is the efficiency of energy conversion from primary heat potential to useful energy output This value is used to calculate for each fuel type the aggregate GHG emission factor and therefore is only relevant for fuel types which actually produce greenhouse gases i e with non zero CO CH and N O emission factors For example a typical coal fired power plant could have a fuel conversion efficiency of 35 which indicates that 35 of the heat content of the coal is transformed into electricity fed to the grid Units are given as a percentage of primary heat potential gigajoules of heat to actual useful energy output gigajoules of electricity lighting energy or pumping energy Fuel types which do not involve a thermal to electric conv
138. ransferred from the Financial Summary worksheet to the Sensitivity worksheet PV 94 RETScreen Photovoltaic Project Model The user enters the RE production credit range The range is a percentage corresponding to the uncertainty associated with the estimated RE production credit value The higher the percentage the greater the uncertainty The range specified by the user must be a percentage value between 0 and 50 The range determines the limits of the interval of possible values that the RE production credit could take For example a range of 10 for a RE production credit of 0 05 kWh means that the RE production credit could take any value between 0 045 kWh and 0 055 kWh Since 0 05 kWh is the estimated value the risk analysis will consider this value as being the most probable and the minimum and maximum values as being the least probable based on a normal distribution If the RE production credit is known exactly by the user no uncertainty the user should enter a range of 0 Click here to Calculate Risk Analysis The Click here to Calculate Risk Analysis button updates the risk analysis calculations using the input parameter ranges specified by the user Clicking on this button starts a Monte Carlo simulation that uses 500 possible combinations of input variables resulting in 500 values of the selected financial indicator The impact graph the median the minimum and maximum confidence levels and the distribution g
139. raph are calculated using these results and updated each time the user clicks on the button Click here to Calculate Risk Analysis The risk analysis calculations can take up to 1 minute to run depending on the Excel version and the speed of the computer When the risk analysis is updated the button disappears If the user makes any changes to the input range values or navigates through any of the other worksheets the button will reappear The user will then have to click on the button to update the risk analysis calculations so that the results reflect the changes Impact graph The impact graph shows the relative contribution of the uncertainty in each key parameter to the variability of the financial indicator The X axis at the bottom of the graph does not have any units but rather presents a relative indication of the strength of the contribution of each parameter The longer the horizontal bar for a given input parameter the greater is the impact of the input parameter on the variability of the financial indicator The input parameters are automatically sorted by their impact on the financial indicator The input parameter at the top Y axis contributes the most to the variability of the financial indicator while the input parameter at the bottom contributes the least This tornado graph will help the user determine which input parameters should be considered for a more detailed analysis if that is required PV 95 RETScre
140. ray and the battery bank If the batteries become depleted for example after a long period with little sun the genset quickly recharges the batteries and the delivery of energy to the load remains uninterrupted In other systems usually with a lower reliability a genset is not used due to environmental noise fumes convenience fuel transportation or cost considerations In a third case the use of a genset providing a significant portion of the load may prove more financially viable the extra cost of the genset and its fuel being offset by the lower cost of the photovoltaic array This configuration may also apply to the case of retrofit installations where PV modules are added to displace energy produced by an existing genset PV 12 RETScreen Photovoltaic Project Model Base Case Power and Pump System This sub section deals with the definition of the base case scenario For water pumping applications the base case power system includes the pump system The base case is used for financial calculations and does not have any bearing on the energy calculations for the energy system Source The user selects from the drop down list the source of power energy being displaced The options available address the replacement of conventional electrical sources genset thermoelectric generator grid extension or non rechargeable batteries light source non electric lantern and mechanical sources engine driven pump or other mecha
141. ray power aims at providing 100 of the load for the worst month for hybrid systems PV battery genset the suggested power aims at providing 25 of the load for the worst month and no more than 75 of the load for the best month values are approximate Nominal PV array power The user enters the nominal power of the PV array in kWp For Off grid or Water pumping applications as a first guess the user will likely enter the Suggested nominal PV array power then enter lower or higher values to perform a sensitivity analysis of the system The value entered by the user may be slightly different from the suggested value to match the output of PV modules available from specific manufacturer The user can consult the RETScreen Online Product Database for more information PV array area The model calculates the area that will be covered by the PV array in m This is simply the nominal PV array power divided by the nominal module efficiency The user should verify the value calculated by the model If the PV array is mounted on a wall the required array area should not exceed the surface available on the wall For roof mounted systems the size should not exceed approximately half the total roof area For ground mounted systems the size is limited only by the available land area If the calculated area exceeds the available space a smaller system size should be specified under Nominal PV array power or higher efficiency modules should
142. rces Canada the user would select the following fuel types and associated fuel mix coal with 78 of the fuel mix large hydro with 9 6 oil with 5 natural gas with 5 and biomass with 3 of the fuel mix and T amp D losses of 8 for all fuel types For Off grid applications the user selects the base case electricity system in the Energy Model worksheet from the following list of available power sources Genset Thermoelectric generator Grid extension Non rechargeable batteries Lantern and Other For Water pumping applications the user selects the base case electricity system in the Energy Model worksheet from the following list of available power sources Genset Grid extension Engine driven pump and Other mechanical pump Some users may prefer to perform a much more detailed analysis of the GHG reduction potential of the project e g an economist working for a public utility commission The model allows for a more detailed analysis regarding T amp D losses and using the Custom option under the Type of analysis drop down list the user can prepare an even more detailed analysis regarding emission factors etc If the user has access to dispatch information from the local utility the Base Case Electricity System table can be used to model the marginal fuel use on the grid which may more accurately PV 81 RETScreen Software Online User Manual represent the fuels and the emissions that are being displaced by the p
143. re are three basic applications On Grid applicable to systems without batteries and connected to a utility grid Off Grid applicable to systems with batteries and gensets and Water Pumping applicable to photovoltaic water pumping systems without batteries PV 11 RETScreen Software Online User Manual Grid type The user selects the type of grid from the two options in the drop down list Central grid and Isolated grid Central grid is recommended for systems where the size of the grid and the load it satisfies is so large that the utility will always be able to use all the energy produced by the PV system Isolated grid should be chosen for smaller local grids for which some of the electricity produced by the PV system will be wasted because of mismatches between PV output and utility energy demand In this case the PV energy absorption rate should be specified PV energy absorption rate The user enters the PV energy absorption rate This is the amount of energy produced by the PV system that will actually be delivered to the utility The remaining energy is available for other potential uses or possibly wasted because of mismatches between PV output and utility energy demand For central grid connected systems the absorption rate will typically be 100 that implies that electricity can be sent back to the grid This will be the case of a central PV generation plant or distributed generation PV systems with a gri
144. re entered as positive values and latitudes south of the equator are entered as negative values The user can consult the RETScreen Online Weather Database for this information The latitude of the closest weather location can be pasted to the spreadsheet from the online weather database If the user knows the latitude for the project location this value should be entered in the spreadsheet by overwriting the pasted value PV array tracking mode The user selects the type of sun tracking device upon which the PV system is mounted The options from the drop down list are Fixed One axis Two axis and Azimuth If the PV array is mounted on a fixed structure the user may select Fixed The remaining choices may be selected if the PV array is mounted on a tracker A tracker is a device supporting the photovoltaic array which moves the array in a prescribed way to minimize the angle of incidence of beam radiation on the array s surface Hence incident beam radiation i e solar energy collected is maximized PV trackers may be classified as follows PV 27 RETScreen Software Online User Manual One axis trackers track the sun by rotating around an axis located in the plane of the array The axis can have any orientation but is usually horizontal east west horizontal north south or parallel to the earth s axis Azimuth trackers have a fixed slope and rotate about a vertical axis and Two axis trackers always position their su
145. rface normal to the beams of the sun by rotating about two axes The next figure illustrates the three tracking types defined above One Axis Tracking Azimuth Tracking Two Axis Tracking Sun tracking Devices Depending on whether or not a tracking device is used the following parameters also need to be entered in the PV model Tracking Mode Parameter s required No tracking Slope and azimuth of FV array l amis tracking Slope and azimuth oftracking axis Z axis tracking None Azimuth tracking Slope oftracking azis PV Array Tracking Mode Slope of PV array The user enters the angle between the photovoltaic array and the horizontal in degrees In most cases the slope of the PV array will be e Equal to the absolute value of the latitude of the site This is the slope which in general maximises the annual solar radiation in the plane of the photovoltaic array This is adequate for systems working year round e Equal to the absolute value of the latitude of the site minus 15 This is the slope which in general maximises the solar radiation in the plane of the photovoltaic array in the summer PV 28 RETScreen Photovoltaic Project Model e Equal to the absolute value of the latitude of the site plus 15 This is the slope which in general maximises the solar radiation in the plane of the photovoltaic array in the winter This slope is also suggested in cold climates to minimise snow accumulation e For fi
146. roposed project For example if dispatch information shows that the fuel used on the margin is natural gas 85 of the time and fuel oil 15 of the time the user would enter these details into the base case table along with the corresponding GHG coefficients The resulting baseline is often referred to as the operating margin Another baseline option referred to as the build margin can be calculated by modeling recent capacity additions for example the 5 most recent plants that have been added to the grid The build margin can be modeled in the base case table by entering recent capacity additions along with their relative generating capacities scaled to total 100 and appropriate GHG coefficients It is suggested that the user take a conservative approach in calculating the baseline emission factor for the project particularly at the pre feasibility analysis stage Fuel type For On grid projects and for applications where the base case power energy source is Grid extension the user selects the fuel type from the options in the drop down list The RETScreen software can model the GHG emissions of any electricity supply system The fuel type is the fuel s or power plant s which will be displaced by the proposed project For Off grid and Water pumping applications that do not use Grid extension as the base case power energy source the user selects the fuel type in the Energy Model worksheet and it is copied automatically to t
147. rt lines the distance from the site of energy production to the point of use peak energy demands ambient temperature and electricity theft In addition T amp D system type e g AC vs DC and quality may also influence losses The model calculates the weighted average of the T amp D losses of the global electricity mix on the bottom row of the table Units are given as a percentage of all electricity losses to electricity generated It is reasonable to assume T amp D losses of 8 to 10 in modern grids in industrialised countries and 10 to 20 in grids located in developing countries GHG emission factor The model calculates the GHG emission factor for each reference fuel type Values are calculated based on the individual emission factors the fuel conversion efficiency and the T amp D losses if any For On grid projects and for applications where the base case power energy source is Grid extension the weighted GHG emission factor for the total electricity mix is calculated on the bottom row of the table Units are given in tonnes equivalent of CO emission per megawatt hour of end use electricity delivered tego MWh Proposed Case Electricity System Photovoltaic Project The proposed case electricity system or mitigation system is the proposed project The proposed case system is normally referred to as the mitigation option in standard economic analysis PV 85 RETScreen Software Online User Manual Fue
148. ry as this number is often incorporated into the avoided cost of energy value If the project being evaluated has a zero Firm RE capacity then this item is hidden in the spreadsheet The value of avoided cost of capacity typically represents either the average or the marginal unit cost of capacity for a base case power system This value is directly related to the cost of generation capacity for the base case electricity system Avoided cost of capacity calculations for electric power generation usually requires a relatively detailed analysis For on grid electric power generation electric utilities will normally calculate this value for their service area This value may also be the amount that utilities will pay IPPs for electric capacity provided to the utility Utilities may assign a higher value where distributed generation benefits are obtainable to account for Transmission and Distribution T amp D capacity attributes Leng 1994 A more detailed description is beyond the scope of this manual for a more detailed description see Johansson 1993 As a brief example a New England electric utility has valued avoided capacity costs at roughly 100 kW yr for a proxy gas turbine and marginal avoided T amp D costs at 250 kW yr for central grid applications Leng 1993 Energy cost escalation rate The user enters the energy cost escalation rate which is the projected annual average rate of increase for the cost of energy over the li
149. se energy supplied Note that the sum of all fuel types listed in the fuel mix column should equal 100 CO CH and N20 emission factors Custom analysis The user enters the CO2 CH and NO emission factors for the different fuel types They represent the mass of greenhouse gas emitted per unit of energy Emission factors will vary for different types and qualities of fuels and for different types and sizes of power plants For On grid projects and for applications where the base case power energy source is Grid extension the user should enter factors representative of large generating plants On the electricity mix row at the bottom of the table the model calculates the equivalent emission factors for the global electricity mix and per unit of electricity delivered The electricity mix factors thus account for a weighted average of the fuel conversion efficiencies and T amp D losses of the different fuel types For the global electricity mix shown on the bottom row of the table units are given in kilograms of gas emitted per gigajoule of end use electricity delivered For Off grid and Water pumping applications the user should enter emission factors representative of the power source for the system specified e g emission factors typical of internal combustion engines should be entered for systems that include the use of a genset For each fuel type selected units are given in kilograms of gas emitted per gigajoule of heat energ
150. sed it is often reasonable to assume that a combined cycle natural gas power plant is the proxy plant In this case the user need only select Natural gas as the fuel type with a 100 fuel mix and use the default T amp D losses of 8 For the case of an isolated grid a diesel genset would likely be the proxy power plant with Diesel 2 oil chosen as the fuel type It is also possible to define the grid and the mix of the different power plants with their respective fuels fuel mix and different T amp D losses e g distributed generators such as photovoltaics will have lower T amp D losses This information is usually available through the local electric utility the utility regulator and or through government For example the United States Environmental Protection Agency US EPA provides The Emissions amp Generation Resource Integrated Database called E GRID This is a database featuring environmental characteristics of electric power generation in the US including fuel mix This database is available free of charge at the E GRID Website To illustrate this alternative analysis method for a PV project based in Nova Scotia Canada the provincial government might determine the baseline to be the weighted average of the current generation mix This can be calculated by simply entering the current fuel mix into the grid along with the appropriate emissions coefficient For this example and with information provided by Natural Resou
151. sed to estimate possible credit amounts for PV modules versus conventional building materials PY Product m Conventional Material m Standarc sized PY modules 1 400 Aluminium pitched roof oa 1 800 Stone wall cladding Glassfelass module for curtain walling PY arrayincorporated into a tracking shading system Grate faced pre cast pale concrete 2 600 Shading system PY wall claddine 1 400 Rarscreen overclad dine Double glazed class cl ass PY modutes F roof tiles 1 200 Double glazed class cl ass PY modules Garth higher 2 200 quality support for fa ade 2 000 Double glazing Roofales fconcrete of clay Glazing with hi cher quality support Cost of PV Products Compared With Conventional Building Materials adapted from ECOTEC 1998 Balance of Equipment The balance of equipment or Balance of Systems BOS for a PV project typically includes the PV module array support structure the inverter a genset for hybrid systems batteries a water pump and pipes reservoirs for water pumping applications and the various electrical components such as fuses switches conductors and conduit In addition the installation labour for the entire PV system and for the various components is included under this section PV 50 RETScreen Photovoltaic Project Model Module support structure This item refers to the total cost of the equipment required to provide a support for the PV modules The cost of the supp
152. ser to specify the currency manually by entering a name or symbol in the additional input cell that appears adjacent to the currency switch cell The currency may be expressed using a maximum of three characters US etc To facilitate the presentation of monetary data this selection may also be used to reduce the monetary data by a factor e g reduced by a factor of a thousand hence k 1 000 instead of 1 000 000 If None is selected all monetary data are expressed without units Hence where monetary data is used together with other units e g kWh the currency code is replaced with a hyphen k Wh The user may also select a country to obtain the International Standard Organisation ISO three letter country currency code For example if Afghanistan is selected from the currency switch drop down list all project monetary data are expressed in AFA The first two letters of the country currency code refer to the name of the country AF for Afghanistan and the third letter to the name of the currency A for Afghani For information purposes the user may want to assign a portion of a project cost item in a second currency to account for those costs that must be paid for in a currency other than the currency in which the project costs are reported To assign a cost item in a second currency the user must select the option Second currency from the Cost references drop down list cell Some currency sym
153. set any other year taxable income If the user selects Flow through losses are not carried forward but rather used in the year in which they occur and applied against profits from sources PV 67 RETScreen Software Online User Manual other than the project or qualify and generate a refundable tax credit thereby reducing the income tax owed in the years in which losses occur Whether losses must be carried forward or not will depend on the tax laws in the jurisdiction in which the project is located The Flow through situation is typically the most advantageous for the project owner and can contribute to make profitable a project which would not appear financially attractive on a pre tax basis The model does not allow losses to be carried backward and does not set a limit on the number of years for carryforwards Depreciation method The user selects the depreciation method from three options in the drop down list None Declining balance and Straight line This selection of the yearly depreciation of assets is used in the model in the calculation of income taxes and after tax financial indicators The user should select the method accepted by the tax departments in the jurisdiction of the project The difference between the End of project life value and its undepreciated capital costs at the end of the project life is treated as income if positive and as a loss if negative When None is selected the model assumes t
154. sion efficiency equals the PV pump system efficiency specified in the Energy Model worksheet For PV battery genset configurations the genset fuel conversion efficiency is calculated from the specific fuel consumption as entered in the Energy Model worksheet For Custom type of analysis the user enters the solar energy conversion efficiency The fuel conversion efficiency is used in conjunction with the CO CH and NO emission factors and the transmission and distribution losses if any to calculate the aggregate GHG emission factor for the proposed project PV 86 RETScreen Photovoltaic Project Model Transmission and distribution losses The user enters the transmission and distribution T amp D losses of the proposed case PV project which includes all energy losses between the point at which the power plant is connected to the grid and the end user This value will vary based on the voltage of transport lines the distance from the site of energy production to the point of use peak energy demands ambient temperature and electricity theft In addition T amp D system type e g AC vs DC and quality may also influence losses Units are given as a percentage of all electricity losses to electricity generated As a first estimate it is reasonable to assume T amp D losses of 8 to 10 in modern grids in industrialised countries and 10 to 20 in grids located in developing countries GHG emission factor The mod
155. son Neither Canada nor its ministers officers employees or agents makes any warranty in respect to this report or assumes any liability arising out of this report ISBN 0 662 40023 2 Catalogue no M39 115 2005E PDF Minister of Natural Resources Canada 1997 2005 RETScreen Photovoltaic Project Model TABLE OF CONTENTS Brief Description and Model Flow Cha t ccsssccssssscssssscssssccssscccssccssssscsssssscssssccssscscssescssses F Photovoltaic Project Model e sseoesoseccoccsoossooocsocecossesoesoocossocccosscoossososssoossocccosscssessseesosossssessssesse Enersy WO ed siscciniadecetuccseetssisdccadecasectibisdadedudassetiscadscssucasscscvisdetetecsatestddasssvenssissvledecoceamtssnsdacceve LO Solar Resource amp System Load Calculation ccsscccssssscsssscssssccssssccsssscessssssssscssssssosssssess 27 COOSE A TAL VSS AEAEE EIE EAEE wer elon eam te aE Fi ancial SUMMATY sies une Re REP aes sosopo scsssdo kastede otadia deesse dosso EY BONNY eT RES AMP RSON SUN OLESRENAT PMTARTE ON Greenhouse Gas GHG Emission Reduction Analysis sccsssccsssssssssscesssscssssscssssscessescess 79 Sensitivity and Risk AMALYSIS scsdssesdscecccssvccebvedecssvecsvedenssdecasvespecsovendecacedapeedepnadeccendsivescesedescevecneseeo DI Prod ct Data stass Lisiedecedsecseedses sdcctds sassuasbs sdadasutinsedisccdscaoussssesevisdebobesincadesiulescsaseveassdiadedesseivatesasdacdeas DO BALEA oe D E I PAESE E heen
156. tabase may be overwritten i e the user may prefer to use other data and can manually enter values into the spreadsheets As an alternative the user can use resource maps or the NASA satellite data particularly for the case when the project location is not close to the given weather station location NASA Global Satellite Data A link to the NASA Surface meteorology and Solar Energy Data Set Website is provided in the online weather database dialogue box The user is able to select the data required for the model by clicking on a region on the world map illustrated on the NASA Website The location is narrowed down to a cell within a specified latitude and longitude The user may simply copy and paste this data to the RETScreen spreadsheets or manually enter these values NASA and CETC Varennes are co operating to facilitate the use of NASA s global satellite solar data with RETScreen and to develop a new global weather database see Surface meteorology and Solar Energy Data Set for the tool This work is sponsored as part of NASA s Earth Science Enterprise Program and is being carried out at the NASA Langley Research Center and at CETC Varennes This collaboration provides RETScreen users access free of charge to satellite data e g the amount of solar energy striking the surface of the earth global temperatures and wind speeds simply by clicking on links in either the RETScreen software or the NASA Website These data had previously onl
157. the internal rate of return indicator to evaluate a project is that the outcome does not depend on a discount rate that is specific to a given organisation Instead the IRR obtained is specific to the project and applies to all investors in the project The model uses the after tax yearly cash flows and the project life to calculate the internal rate of return Simple Payback The model calculates the simple payback year which represents the length of time that it takes for an investment project to recoup its own initial cost out of the cash receipts it generates The basic premise of the payback method is that the more quickly the cost of an investment can be recovered the more desirable is the investment For example in the case of the implementation of a photovoltaic project a negative payback period would be an indication that the annual costs incurred are higher than the annual savings generated The simple payback method is not a measure of how profitable one project is compared to another Rather it is a measure of time in the sense that it indicates how many years are required to recover the investment for one project compared to another The simple payback should not be used as the primary indicator to evaluate a project It is useful however as a secondary indicator to indicate the level of risk of an investment A further criticism of the simple payback method is that it does not consider the time value of money nor the impact of i
158. ther system components such as inverter s structures and other electrical equipment are then prepared The preliminary design is then used to prepare a more detailed cost estimate The time required to prepare the preliminary design and detailed cost estimate typically falls between 20 and 60 h at fees between 40 h to 100 h Smaller scale projects with simple structural requirements are at the low end of this time range Larger scale projects requiring more difficult structural integration into existing buildings will be at the high end of this time range Report preparation A summary report should be prepared which describes the feasibility study its findings and recommendations The report will contain data summaries charts tables and illustrations which clearly describe the proposed project In addition the report should be in sufficient detail regarding costs performance and risks to enable project lenders and other decision makers to evaluate the merits of the project The cost of the summary report preparation is calculated based on an estimate of the time required by a professional to complete the necessary work and should also include the time required to manage the overall feasibility study preparation Preparing the report and managing the feasibility study takes between 8 and 16 h at a rate of between 40 h and 100 h Travel and accommodation This cost item includes all travel related costs excluding time required to prep
159. tion provides information on the relationship between the key parameters and the important financial indicators showing the parameters which have the greatest impact on the financial indicators The Sensitivity Analysis section is intended for general use while the Risk Analysis section which performs a Monte Carlo simulation is intended for users with knowledge of statistics Both types of analysis are optional Inputs entered in this worksheet will not affect results in other worksheets Use sensitivity analysis sheet The user indicates by selecting from the drop down list whether or not the optional Sensitivity and Risk Analysis worksheet is used to conduct a sensitivity analysis of the important financial indicators If the user selects Yes from the drop down list the sensitivity analysis section will open and the user should complete the top part of the worksheet The user will need to click on Calculate Sensitivity Analysis button to get the results Perform risk analysis too The user indicates by selecting from the drop down list whether or not the optional risk analysis section is used to conduct a risk analysis of the important financial indicators in addition to the sensitivity analysis In the risk analysis section the impact of each input parameter on a financial indicator is obtained by applying a standardised multiple linear regression on the financial indicator If the user selects Yes from the drop down list
160. tomatically to the GHG Analysis worksheet Global Warming Potential of GHG The model indicates the global warming potential of methane CH and nitrous oxide N20 If the user selects the Custom type of analysis different values from the default values provided may be entered by the user Researchers have assigned Global Warming Potentials GWPs to greenhouse gases to allow for comparisons of their relative heat trapping effect The higher the global warming potential of a gas the greater the contribution to the greenhouse effect For example nitrous oxide is 310 times more effective than carbon dioxide at trapping heat in the atmosphere GWPs of gases are defined as a unit multiple of that given to carbon dioxide CO2 which is assigned a reference value of 1 i e the GWP of CO is 1 and the GWP of NO is 310 The default values are those defined by the Revised Intergovernmental Panel on Climate Change IPCC Guidelines for Greenhouse Gas Inventories 1996 PV 80 RETScreen Photovoltaic Project Model Base Case Electricity System Baseline To perform the RETScreen GHG emission reduction analysis for the PV project the user will need to define the baseline also called base case or reference case electricity system Often this will simply imply defining a proxy plant and its associated fuel For example in North America when preparing a GHG emission reduction analysis for a PV project where central grid electricity is u
161. ts efficiency will be lower The MPPT is often combined with other electronic devices such as the charge controller for off grid systems on grid systems include a MPPT as part of the inverter When this is the case the efficiency of the device in question should include the efficiency of the MPPT In cases where the MPPT is not combined with another device its efficiency should be accounted for separately for example in the Miscellaneous power conditioning losses Miscellaneous PV array losses The user enters array losses from miscellaneous sources not taken into account elsewhere in the model This includes for example losses due to the presence of dirt or snow on the modules Typical values range from zero to a few percent In some exceptional circumstances e g very harsh environment this value could be as high as 20 PV 21 RETScreen Software Online User Manual Suggested nominal PV array power The model calculates the suggested nominal power of the PV array expressed in kWp kilowatt peak The nominal power of the array is expressed under an irradiance of 1 000 W m a temperature of 25 C and an air mass of 1 5 This value can range from a few hundred Wp to many kWp depending on the type of system under consideration The value calculated by the model provides a reasonable estimate for the purposes of a preliminary feasibility analysis study For stand alone systems PV battery the suggested nominal PV ar
162. ts being avoided may be for a new combined cycle natural gas fired power plant established as a proxy or baseline reference case by the local utility The user will need to determine this value For off grid and water pumping applications the avoided cost of energy will be the price of fuel where fossil fuel generators are defined as the Base Case Power System Avoided cost of energy calculations for on grid electric power generation usually require a relatively detailed analysis Leng 1993 For electric power generation electric utilities will normally calculate this value for their service area This value may also be the amount that utilities may pay independent power producers IPP for electricity produced by the IPP Utilities may assign a higher value where distributed generation benefits are obtainable Leng 1994 A more detailed description is beyond the scope of this manual for a more detailed description see Johansson 1993 However a brief description of possible values follows The range of values for avoided cost of energy for on grid electric power generation will depend upon a number of factors As an example for a recently constructed 10 kW PV project in North America the local utility pays a building owner approximately 12 kWh 0 12 kWh for electricity sold to the utility for a central grid application Under net metering schemes the avoided cost of energy would probably equal the retail price of electricity For
163. ture Most cell types exhibit a decrease in efficiency as their temperature increases The PV temperature coefficient u expressed in C is defined in the RETScreen PV model as n T Tres 1 W T Tres where n T the efficiency of the solar cell at temperature T 1 Tref the efficiency of the cell at temperature Tref T the operating temperature of the module and Tref the reference temperature usually 25 C The value of u depends primarily on the type of cell used It is often fairly difficult to find this value on manufacturer datasheets therefore in the absence of this information the default values found in the Nominal Efficiencies of PV Modules table may be used PV array controller The user selects from the drop down list the type of PV array controller that is used to interface the PV array to the rest of the system MPPT and Clamped A Maximum Power Point Tracker MPPT is an electronic device used to maintain the operating voltage of the array at a value that maximises array output regardless of changes in load impedance or changes in array operating conditions due to variations in temperature or insolation If the user selects MPPT the efficiency of the array will be optimal A Clamped PV array controller is a direct connection between the array and the batteries in this configuration the array operates at the voltage set by the battery This may not be the optimal voltage for the array and therefore i
164. ude as the corresponding costs and fall under a different depreciation schedule for tax purposes Effective income tax rate The user enters the effective income tax rate which is the effective equivalent rate at which the net income derived from the project is taxed For example in most jurisdictions this would correspond to the combined federal provincial state and or local income tax rates for businesses Net taxable income is derived from the project cash inflows and outflows assuming that all revenues and expenses are paid at the end of the year in which they are earned or incurred The effective income tax rate is assumed to be constant throughout the project life Note that sales tax should be considered in the Initial Costs section of the Cost Analysis worksheet and that property tax should be considered in the Annual Costs section Loss carryforward The user indicates by selecting from the drop down list whether or not losses are carried forward i e whether or not a loss a negative taxable income in a given year can be used to lower taxes owed in that same year or can be deferred to offset profits from future years If the user selects Yes losses are carried forward and applied against taxable income in the following years thereby reducing the income tax owed up to the accumulated losses years after the losses occur If the user selects No losses are not carried forward but rather lost and thereby never used to off
165. um and maximum values as being the least probable based on a normal distribution If the annual costs are known exactly by the user no uncertainty the user should enter a range of 0 Debt ratio The debt ratio is automatically transferred from the Financial Summary worksheet to the Sensitivity worksheet The user enters the debt ratio range The range is a percentage corresponding to the uncertainty associated with the estimated debt ratio value The higher the percentage the greater the uncertainty The range specified by the user must be a percentage value between 0 and the lowest percentage such that the debt ratio will always fall between 0 and 100 The range determines the limits of the interval of possible values that the debt ratio could take For example a range of 10 for a debt ratio of 70 means that the debt ratio could take any value between 63 and 77 Since 70 is the estimated value the risk analysis will consider this value as being the most probable and the minimum and maximum values as being the least probable based on a normal distribution If the debt ratio is known exactly by the user no uncertainty the user should enter a range of 0 Debt interest rate The debt interest rate is automatically transferred from the Financial Summary worksheet to the Sensitivity worksheet The user enters the debt interest rate range The range is a percentage corresponding to the uncertainty associated with the estimate
166. used world wide to easily evaluate the energy production life cycle costs and greenhouse gas emissions reduction for three basic PV applications on grid off grid and water pumping For on grid applications the model can be used to evaluate both central grid and isolated grid PV systems For off grid applications the model can be used to evaluate both stand alone PV battery and hybrid PV battery genset systems For water pumping applications the model can be used to evaluate PV pump systems Six worksheets Energy Model Solar Resource amp System Calculation Solar Resource amp System Load Cost Analysis Greenhouse Gas Emission Reduction Analysis GHG Analysis Financial Summary and Sensitivity and Risk Analysis Sensitivity are provided in the Photovoltaic Project Workbook file The Energy Model and Solar Resource amp System Load worksheets are completed first The Cost Analysis worksheet should then be completed followed by the Financial Summary worksheet The GHG Analysis and Sensitivity worksheets are optional analyses The GHG Analysis worksheet is provided to help the user estimate the greenhouse gas GHG mitigation potential of the proposed project The Sensitivity worksheet is provided to help the user estimate the sensitivity of important financial indicators in relation to key technical and financial parameters In general the user works from top down for each of the worksheets This process can be repeated several times in
167. ve value in the Amount column End of project life The user enters the value of the project at the end of its life This amount is also commonly referred to as the salvage value or disposal value If the salvage value of the project at the end of its life is positive then the user selects Credit from the drop down list in the unit column in order to express this item as a negative value However if the costs of remediation or decommissioning that must be incurred at the end of the project life exceed the salvage value then the user must select Cost from the drop down list The user must enter a positive numerical value in the Unit Cost column Note At this point the user should go to the optional GHG Analysis worksheet Other These input cells are provided to allow the user to enter cost or credit items that are not included in the information provided in the above cost category The user must enter a positive numerical value in the Unit Cost column A cost item may be entered in the grey input cell as Other The user then selects Cost from the drop down list in the unit column The user can input both a quantity amount and unit cost This item is provided to allow for project technology and or regional differences not specifically covered in the generic information provided A credit item may be entered in the grey input cell as Credit The user then selects Credit from the drop down list in the unit column The RET
168. w tens of meters Equivalent energy demand The model calculates the mechanical energy corresponding to moving water from the source to the point of discharge in kWh d This quantity does not include energy lost because of inefficiencies of the pump or of the motor For typical PV water pumping applications this value can range from a fraction of one kWh d to tens of kWh d depending on the system configuration PV 38 RETScreen Photovoltaic Project Model Cost Analysis As part of the RETScreen Clean Energy Project Analysis Software the Cost Analysis worksheet is used to help the user estimate costs associated with a PV project These costs are addressed from the initial or investment cost standpoint and from the annual or recurring cost standpoint The user may refer to the RETScreen Online Product Database for supplier contact information in order to obtain prices or other information required Type of analysis The user selects the type of analysis by clicking on the appropriate radio button For a Pre feasibility analysis less detailed and lower accuracy information is typically required while for a Feasibility analysis more detailed and higher accuracy information is usually required To put this in context when funding and financing organisations are presented with a request to fund an energy project some of the first questions they will likely ask are how accurate is the estimate what are the possibilities f
169. weather and cost databases an online manual a Website an engineering textbook project case studies and a training course Model Flow Chart Complete each worksheet row by row from top to bottom by entering values in shaded cells To move between worksheets simply click on the tabs at the bottom of each screen or on the blue underlined hyperlinks built into the worksheets The RETScreen Model Flow Chart is presented below Five Step Standard Analysis Sensitivity amp Risk Analysis click on blue hyperlinks or floating icon to access data Project Cash Flows Ready to make a decision RETScreen Model Flow Chart PV 4 RETScreen Photovoltaic Project Model Data amp Help Access The RETScreen Online User Manual Product Database and Weather Database can be accessed through the Excel menu bar under the RETScreen option as shown in the next figure The icons displayed under the RETScreen menu bar are displayed in the floating RETScreen toolbar Hence the user may also access the online user manual product database and weather database by clicking on the respective icon in the floating RETScreen toolbar For example to access the online user manual the user clicks on the icon X Microsoft Excel sal File Edit view Insert Format Tools Data Window Help RETScreen IG SCH EaRY y magja Ca y Online User Manual aria glio B iu 5 Online Product Database
170. xed arrays equal to the slope of the roof on which the photovoltaic array is to be installed This does not necessarily represent an optimum in terms of energy production but can reduce significantly installation costs by eliminating the need for a support structure or may be more desirable from an aesthetics standpoint or e For fixed arrays equal to 90 This corresponds to a photovoltaic array mounted on the fa ade of a building This never corresponds to a optimum in terms of energy production but can reduce significantly installation costs by eliminating the need for costly cladding and a support structure or may be more desirable from an aesthetics standpoint Azimuth of PV array The user enters the angle between the projection on a horizontal plane of the normal to the surface and the local meridian with zero due south for the purpose of this model the sign has no importance The preferred orientation should be facing the equator in which case the azimuth angle is 0 in the Northern Hemisphere and 180 in the Southern Hemisphere In the case of a PV array mounted directly on the roof of a building the azimuth is equal to that of the roof which should be chosen to be as close to equator facing as possible For example a solar collector in the Northern Hemisphere facing south west would have an azimuth angle of 45 see next figure If two walls are being used the average of the absolute values for the orientation should
171. y The results provide the decision maker with various financial indicators for the proposed project Pre tax Internal Rate of Return and Return on Investment The model calculates the pre tax internal rate of return which represents the true interest yield provided by the project equity over its life before income tax It is also referred to as the return on investment equity ROD or the time adjusted rate of return It is calculated by finding the discount rate that causes the net present value of the project to be equal to zero Hence it is not necessary to establish the discount rate of an organisation to use this indicator An organisation interested in a project can compare the internal rate of return of the project to its required rate of return often the cost of capital The IRR is calculated on a nominal basis that is including inflation If the internal rate of return of the project is equal to or greater than the required rate of return of the organisation then the project will likely be considered financially acceptable assuming equal risk If it is less than the required rate of return the project is typically rejected An organisation may have multiple required rates of return that will vary according to the perceived risk of the projects The most obvious advantage of using the internal rate of return indicator to evaluate a project is that the outcome does not depend on a discount rate that is specific to a given organisatio
172. y been available from a limited number of ground monitoring stations and are critical for assessing the amount of energy a project is expected to produce The use of these data results in substantial cost savings for users and increased market opportunities for industry while allowing governments and industry to evaluate regional energy resource potential PV 99 RETScreen Software Online User Manual Cost Data Typical cost data required to prepare RETScreen studies are provided in the RETScreen Online Cost Database and in the Online Manual This database is built into the right hand column of the Cost Analysis worksheet Data are provided for Canadian costs with 2000 as a baseline year The user also has the ability to create a custom cost database The user selects the reference from the Cost Analysis worksheet that will be used as a guideline for the estimation of costs associated with the implementation of the project This feature allows the user to change the Quantity Range and the Unit Cost Range columns The options from the drop down list are Canada 2000 None Second currency and a selection of 8 user defined options Enter new 1 Enter new 2 etc If the user selects Canada 2000 the range of values reported in the Quantity Range and Unit Cost Range columns are for a 2000 baseline year for projects in Canada and in Canadian dollars Selecting None hides the information presented in the Quant
173. y generated kg GJ For more information on determining GHG emission factors see the revised IPCC Guidelines for National Greenhouse Gas Inventories CO emission factors for many fuels are included on page 1 13 of the IPCC Reference Manual CH and NO emission factors for a number of fuels are included on pages 1 35 and 1 36 of the IPCC Reference Manual CQ2 CH and N2O emission factors Standard analysis The model provides the CO CH and N O emission factors which represent the mass of greenhouse gas emitted per unit of energy Emission factors will vary for different types and qualities of fuels and for different types and sizes of power plants The default factors provided are those which are representative of large power plants that feed a central electricity grid On the electricity mix row at the bottom of the table the model calculates the equivalent emission factors PV 83 RETScreen Software Online User Manual for the total electricity mix and per unit of electricity delivered The electricity mix factors thus account for a weighted average of the fuel conversion efficiencies and T amp D losses if any of the different fuel types For each fuel type selected units are given in kilograms of gas emitted per gigajoule of heat energy generated kg GJ For the total electricity mix shown on the bottom row of the table units are given in kilograms of gas emitted per gigajoule of end use electricity delivered Fo

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