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Solar Water Heating Project Model

1. SWH 14 RETScreen Solar Water Heating Project Model Fr tau alpha coefficient The user enters the Fr tau alpha coefficient for the collector under consideration For detailed information Technical Note 1 should be consulted The user can consult the RETScreen Online Product Database for more information Values typically range from 0 50 to 0 90 The higher end of the range is applicable to unglazed collectors the middle range to glazed collectors while the lower end is applicable to evacuated collectors Wind correction for Fr tau alpha If Unglazed collector type is selected the user enters the wind correction coefficient for Fr tau alpha in s m For detailed information Technical Note 1 should be consulted The user can consult the RETScreen Online Product Database for more information Values of the wind correction for Fr tau alpha are typically between 0 030 and 0 050 s m Fr UL coefficient The user enters the Fr UL coefficient in W m 2 C For detailed information Technical Note 1 should be consulted The user can consult the RETScreen Online Product Database for more information Values typically range from 10 00 to 15 00 W m C for unglazed collectors from 3 50 to 6 00 W m C for glazed collectors and from 0 70 to 3 00 W m C for evacuated collectors Wind correction for Fr UL If Unglazed collector type is selected the user enters the wind correction coefficient for Fr UL i
2. cescceseeseeseeeeeeeeeeeeeeeees 51 55 60 Travel and accommodation 0cc00 45 46 48 Type of analysis nanan nia 40 82 83 Type of poolse iman pies i aeoe iosa 36 U Units Symbols amp Prefixes s es 7 Use GHG analysis sheet cc eeecesecseeeecneeeeeeeeeees 82 Use Of COVED sie Aisin ar E E E 37 Use sensitivity analysis sheet 0 0 ee eeeeeeeeeeees 92 WwW Water Heating Load Calculation ee 11 34 SWH 110 RETScreen Solar Water Heating Project Model Water heating system seasonal efficiency 12 Weather Data cccccccccccceesssseceeees 5 10 29 33 102 Wind correction for Fr tau alpha eee 15 Wind correction for Fr UL ceccecceesseeseeereeeeeeeees 15 Wind sheltering coefficient cece eeeeeeee 36 37 Y Yearly Cash FIOWS cescceeseeeeseeceereeeneees 65 79 80 Year to positive cash flOW ee eeeeeseeeeeees 77 93 SWH 111 RETScreen Software Online User Manual Notes SWH 112 www retscreen net
3. eee eeeeeseeeeeeeeeneeeeee 74 Debt ratiO ecct ccc etn eh R ceneester heck cess 69 96 Debt Service COVETASC eee eeeeeseeeeteceeeecnereeeneeeees 79 Debt teikas ennaa A ES 69 97 Depreciation method ssseeeeseeeeeeeesesrsrsrrerererseee 70 Depreciation period ssessssesssseeesseserseeseesesseeerssese 71 Depreciation rate e seseeeseeesseeeesseserserseserseeessese 71 Depreciation tax Dasis cescceseeseceseceeeeneeeeeeneees 71 Desired load temperature ee eeeceeeeeeseeceeeeeeneeeee 11 Desired pool temperature eeeeeeeesecteeeeeeeeeees 37 Desired water temperature eeeeeeeeecseeeeeeeeeees 36 Deyel pment meieni nann 40 47 51 73 Disclaimer and Indemnification 0 0 0 0 cece 105 DISCOUNE Tate crna e ct eaten in eee bes 68 Distribution graph cee eeesceseeeeeeceeeeecneeeeeseeeees 99 E Effective income tax rate eeeeeseseeseteeeeeeeeeees 70 Electricity neenotne 12 27 62 66 74 81 83 Electricity required seeeeeeeeeeeeeeeeeeeeesrsesrrerererseee 66 End of project life eee eeeeseeeeeeeeeeeeees 63 70 75 End of project life Cost Credit cece eeeseeeeees 75 End use annual energy delivered seseseseeeeeseeeee e 91 Energy cost escalation rate ss eseeeseeeeeseeeereeerreeees 68 Energy demand for months analysed 11 27 39 Energy equipment s sesesssseesssesrsereseisesssssrtsesceeireess 73 Energy Equipment eeceeceseeseeeecneeeeeeeenees 17
4. SWH 18 RETScreen Solar Water Heating Project Model Pipe Diameter Collector Aperture Area mm inch m 8 3 8 Oto 14 12 44 7 to 23 20 G4 18 to 48 25 1 35 to 80 Suggested Copper Pipe Diameters for Service Hot Water Systems Small pipe diameters 6 mm 14 or less are not recommended because of the risks of blocking and requiring a high pressure head pump The pipe diameter choice will depend on the required flow rate in the solar loop which is proportional to the collector aperture area The maximum recommended flow rate to minimise excess noise in a 25 mm 1 pipe is around 45 L min 10 GPM Based on a fluid temperature increase of 15 C through the collector for average solar radiation and typical temperature levels the maximum collector area used on a 25 mm 1 solar loop is estimated to be around 80 m For larger systems gt 80 m it is recommended to use more than one solar loop to limit pipe diameter to 25 mm 1 A modular system using 25 mm 1 piping diameter is often less costly to install than a single system with a larger pipe diameter In general it is also easier to control and operate Pumping power per collector area The user enters the pumping power per unit of collector aperture area in W m This value is used to calculate the electricity required to operate the SWH system This value shall be set to zero for the following systems e Thermosiphon systems as a solar loop pump is n
5. officers employees or agents makes any warranty in respect to this report or assumes any liability arising out of this report ISBN 0 662 41076 9 Catalogue no M39 122 2005E PDF Minister of Natural Resources Canada 1997 2005 RETScreen Solar Water Heating Project Model TABLE OF CONTENTS Brief Description and Model Flow Chart cccsccsssscsssssccsssccesssscssseccssssccesseccssssccsssccssssscssseed Solar Water Heating Project Model sssssssssssssssssssssssssessssssscssssssssssscssssssssscssssssssscsssssosseD Bimmer ry WIEN sa desis di cc ctlexas tues tude couse tos ceawesaacies eussdssncedubastacnedeeusddasucs cues tues svdusasssatvcusunscdseeeveseserendusese kU Solar Resource and Heating Load Calculation ccscccsssscsssscsssccssssccsssscssseccssseccssseccssnsee 29 MSE PATNALY SIS 55 2s E E EE E E E E E Financi l SUMAN NN ALY cases ceed dcasc save adaceeacas cede acco cdsaeesdes coho cdeacoustaenn susan be aseadesevuetvevascocccdesidec veneer gt Greenhouse Gas GHG Emission Reduction AnallySsis ccsccccssscsssssccssssccsssccssssscssssceseee DL Sensitivity and Risk Analysis sisesescsesesssscscsvecesessesssostessensessoncssvennsvsncsoseansdenaveseenceonessesssonsevecevervnce J2 Product Datatisccssscisssssessineacesstonssensiesnssedscuqssiensaaaenal oovancseounceedessss easshoacesoepansvonsbonseedssogoncvoxseneusoasen LOL DAUTA TA DAU REA E connscceanssuenscsiansndesesss tonadouseddcaesast
6. For new construction where a site visit is not normally required estimate 2 to 4 hours to obtain drawings and required information Solar water heating system expert fees typically range from 40 h to 100 h SWH 45 RETScreen Software Online User Manual Preliminary design A preliminary design is required in order to determine the size layout and potential energy output of the solar water heating system After the solar water heating system is sized draft drawings which consider system component integration into the building such as structures piping and other equipment are prepared The preliminary design is used to prepare a more detailed cost estimate The time required to prepare the preliminary design and detailed cost estimate typically falls between 5 and 50 hours at fees between 40 h to 100 h Small scale projects with standard and or simple structural requirements are at the low end of this range Special design and or large scale projects requiring optimisation and more difficult structural integration into existing buildings will be at the high end of this range When preliminary design is not required the user may enter 0 Report preparation A summary report should be prepared which describes the feasibility study its findings and recommendations The written report will contain data summaries charts tables and illustrations that clearly describe the proposed project This report should be in sufficient detail
7. SWH 32 RETScreen Solar Water Heating Project Model 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 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 kKWh m7 d Data in MJ m d should be divided by 3 6 to be converted to kWh m d Data in BTU ft should be divided by 317 and data in cal cm or Langleys should be divided by 86 to be converted to kWh m 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 m7 d in temperate 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 solar collectors the energy requirement of outdoor swimming pools and the cold mains water temperature The user can consult the RETScreen Online Weather Database for more information Monthly average relative humidity The user enters the average relative humidity for the month in This value is used to estimate the evaporation losses for outdoor swimming pools The user can consult the RETScreen Online Weather Database for more inf
8. 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 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 of future cash flows Net Present Value NPV The model calculates the net present value of the project NPV 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
9. 000 Note that the metallic components of these heating systems are exposed to corrosion because they are in contact with chlorinated water A well installed high quality UV stabilised solar collector system can have a longer lifetime than a conventional heating system especially first generation heat pumps For a SWH system using an antifreeze protection the price for antifreeze mixture can be entered here The cost of food grade thermally and chemically stabilised propylene glycol mixed 50 50 with distilled water will be about 3 50 L to 6 00 L Typically a system uses about 10 to 100 L of the mixture depending on the solar collector area SWH 56 RETScreen Solar Water Heating Project Model If the solar pump is driven by a photovoltaic PV module the cost for this PV module can be entered here The required PV module rating Wp is about twice the nominal power rating of the circulator pump Small scale PV module costs including a regulator are between 10 Wp to 20 Wp As an example the cost of a 20 Watt 12 Volt PV module is about 400 Balance of System The balance of system for a SWH project typically includes the equipment that can be supplied by local suppliers the solar collector array support structure and the interconnection plumbing and control In addition the installation labour for the entire SWH system and the various components are included under this heading including the solar loop installation and the
10. 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 ei users computer or server RETScreen MyFiles WIND3 xls RETScreen Download Procedure SWH 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 SWH 8 RETScreen Solar Water Heating Project Model Solar Water Heating Project Model The RETScreen International Solar Water Heating Model can be used world wide to easily evaluate the energy production life cycle costs and greenhouse gas emissions reduction for three basic applications domestic hot water industrial process heat and swimming pools indoor and outdoor ranging in size from small residential systems to large scale commercial institutional and industrial systems
11. 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 the miscellaneous costs that occur during a project and have not been taken into account in the previous sections For SWH projects these costs can include training and contingencies Training When the installation is complete the system must be commissioned by the system designer often in the presence of the building owner The commissioning involves a trip to the job site This trip normally includes the final inspection and necessary training for the operation of the system The adequate training of operators and maintenance personnel is fundamental to the SWH 60 RETScreen Solar Water Heating Project Model successful deployment of any technology This cost is usually small for SWH systems given their relative simplicity A 4 to 8 hours training session by a SWH system expert should be sufficient for the client to operate the SWH system properly Rates for SWH system experts range from 40 h to 100 h Contingencies The allowance made for contingency costs depends on the level of accuracy of the cost estimates Contingencies are estimated bas
12. analysed The model calculates the energy demand MWh of the SWH system for the months used in the Solar Resource amp Heating Load SR amp HL worksheet and it is copied automatically to the Energy Model worksheet This is the energy required to heat main water to the required hot water temperature in the case of service hot water or the energy required to maintain the pool at the desired load temperature in the case of swimming pools Note that the annual energy demand is calculated for the season of use of the SWH system only that is if the solar heating system is turned off for some months of the year or for fractions of months the energy demand for the corresponding period is not taken into account in the calculation of the Energy demand for months analysed To specify the season of use of the solar heating system see months Fraction of month used in the Solar Resource amp Heating Load SR amp HL worksheet System Characteristics The system characteristics associated with estimating the annual energy production of a solar water heating system are detailed below Some other system characteristics can be found in the Water Heating Load Calculation section of the Solar Resource amp Heating Load SR amp HL worksheet SWH 11 RETScreen Software Online User Manual Application type The user selects the solar water heating application type in the Solar Resource amp Heating Load SR amp HL worksheet and it is cop
13. 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 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 tco MWh Base Case Heating System Baseline The base case heating system or baseline system represents the system to which the solar water heating system is compared The base case heating system is defined in terms of its fuel types its emissions of GHG and its conversion efficiencies The base case system is normally referred to as the reference or baseline option in standard economic analysis Fuel type The fuel type of the base case heating system entered by the user in the Energy Model worksheet is transferred to the GHG Analysis worksheet Fuel mix The base case heating system is assumed to be fuelled by a single source of energy and the fuel mix is therefore set to 100 SWH 87 RETScreen Software Online User Manual C
14. 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 appearing 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 SWH 42 RETScreen Solar W
15. 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 Contingencies A contingency may be included to account for unforeseen annual expenses This may include costs for replacement of solar collectors due to vandalism if this item is not covered by the insurance policy and other potential cost items However due to the durability of the SWH system these costs will likely be minimal A contingency allowance of 1 to 5 of total solar collector and balance of system cost per year is reasonable and will depend upon the project location Electricity In most cases the SWH system uses a low
16. 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 Yellow 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 SWH 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 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
17. eeeseeseeeecneeeeeeeeeees 30 31 Makeup water ratio cece eecssecssecesecseesecsereeeaeeees 37 Maximum within level of confidence 000 99 Medi atts eener en a r ioe 99 Minimum within level of confidence 00 99 Miscellaneous ccccccccceesseeesseeeceesseceessececeenes 60 73 Model Flow Chai t cccecceceesceceessececssceeeeesneeensaee 4 Monthly average daily radiation in plane of solar CONE COR hencp en tense nieces 33 Monthly average daily radiation on horizontal surface bohidi Sevevantenscees sis eepacdee A eee sme S Ra 33 Monthly average relative humidity eee 33 Monthly average temperature eee eeeeee 33 Monthly average wind speed ee eeeeeseeeeeeeeees 33 Monthly Inputs 200 eeeeeeene eee 32 36 37 38 39 Months SWH system in Use 38 N NASA Global Satellite Data eee ceesteees 102 Nearest location for weather data 0 10 29 Net GHG emission reduction cccccssceereeeseeeee 66 Net GHG emission reduction credit duration 66 Net GHG emission reduction project life 66 Net Present Value NPV cccccceccccceeeeeeneeee 77 93 Number of collectors 0 cccceccceesseceeeseeeeenee 16 17 Number of floors from mechanical room to collector PA EE E AAE cule oie 21 53 Number of months analysed esceeseeseeereeeeees 11 Number of units ccccecssscessceessecsseeeesseceseeeesseeees 35 O ORM Soest ios R iee
18. energy consumption pump Electrical energy consumption is calculated in the Energy Model worksheet The user will enter the cost for electricity used This cost should be based upon the rate paid by the building owner SWH 62 RETScreen Solar Water Heating Project Model Note No allowance for a credit is made to account for the reduction in peak power after the installation of a SWH system Periodic Costs Credits This section is provided to allow the user to specify the periodic costs associated with the operation of the energy 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 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 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
19. 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 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
20. in substantial cost savings for users and increased market opportunities for industry while allowing governments and industry to evaluate regional energy resource potential SWH 102 RETScreen Solar Water Heating Project Model 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 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 selec
21. 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 Engineering The engineering phase includes costs for the SWH system design structural design tenders and contracting and construction supervision The costs are detailed below SWH system design The SWH system design consists of the time required to prepare drawings and specifications excluding structure including identifying the final configuration of the SWH system the sizing of all SWH system equipment the exact physical placement of the solar modules the storage tank th
22. investments and are therefore fully expensed in the year they are incurred End of project life Cost Credit The value of the 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 1 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 Feasibility 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
23. 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 SWH 40 RETScreen Solar Water Heating Project Model 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 Pro
24. 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 SWH 77 RETScreen Software Online User Manual Benefit Cost B C ratio 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 GHG reduction cost The user indicates by selecting fro
25. of buildings or loads can be selected from the drop down list House Apartment Hotel Motel Hospital Office Fast food Restaurant School School w showers Laundry Car wash Industrial Aquaculture and Other Depending on the selection the model will use different algorithms to estimate the load For the last three choices no estimate is made and the load volume as well as temperature has to be calculated manually on a case by case basis Number of units The user enters the maximum number capacity of occupants units rooms beds persons meals served per day students or cars washed per day for the facility depending on the type of load selected For Laundry the user enters the number of washers installed in the laundry the model assumes a standard usage ASHRAE of a commercial washer 173 L d of hot water This item is used if the Building or load type is not Industrial Aquaculture or Other Rate of occupancy The user enters the percentage of the capacity specified under the Number of units item that is used on average during the season of use of the solar water heating equipment This item is used if the Building or load type is not Industrial Aquaculture or Other Estimated hot water use at approx 60 C The model calculates the daily hot water use of the facility The user should use this estimate as a guide for determining the next item in the worksheet Hot wa
26. of the cost of doing work in isolated communities and the range of cost so variable it is advisable to contact a travel agent with experience in arranging such travel Accommodation rates are SWH 46 RETScreen Solar Water Heating Project Model 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 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 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 solar water heating p
27. on distance and will be based on a volume weight formula Handling charges for the material at the receiving end should be considered In isolated areas many communities receive bulk shipments only once a year either by barge ice road or sometimes only by air Logistical control is extremely important here Shipping costs should be obtained from shipping agents when the scope of the project equipment and materials are determined As an example typical dimensions in m of a 2 3 m single glazed solar collector are 0 9 1 2 x 2 4 x 0 15 and weight is about 60 85 kg A 270 L storage tank is about equivalent to a volume of in m 0 6 x 0 6 x 1 7 and weighs about 40 kg Pump and heat exchanger assembly with interconnections for a medium size SWH system 20 m can reach 40 kg with a volume of in m 0 6 x 0 6 x 0 3 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
28. on the pool The model assumes that the cover is on predominantly at night and that 90 of the pool is covered by the blanket Enter 0 if no cover is used If the pool is open n hours per day and a cover is used whenever the pool is closed enter 24 n for example if a community pool is open 8 hours a day enter 16 Desired pool temperature The user enters the desired minimum temperature of the pool This is the temperature set point of the pool heater Typical values range from 22 C for competitive swimming to 27 C for recreational swimming to 35 C for therapeutic pools whirlpools and spas Makeup water ratio The user enters the percentage of pool water renewed every week not including the addition of water to compensate for evaporation This amount is representative of pool activity level It includes compensation for water lost when swimmers exit the pool and periodic water renewal done for hygienic reasons backwash cleaning of filtration system using reverse water flows This value is typically between 5 and 10 Generally the lower value will be used for a residential pool with low activity level and the higher value for public pools with high activity level Note that the model can accept higher ratio values for example more than 25 if the user wants to represent the case of a municipal pool where water is completely renewed every month for hygienic reasons or even higher than 100 in the case of a therapeutic or balne
29. 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 solar water heating 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 SWH 76 RETScreen Solar Water Heating Project Model 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 inflation 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
30. 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 In the case of an outside swimming pool with no back up water heater a credit can be entered to take into account the installed cost of an equivalent conventional pool water heater system The credit amount will be based on the value of the conventional water heater system displaced or avoided Typically the cost of a conventional residential pool heating system ranges from 800 for an electric heater to 2 000 for a natural gas propane or oil heater including the fuel tank installation and 2 500 to 4 000 and more for an electric heat pump Depending on the location and the competitiveness of local markets these prices can increase by more than 1
31. potential to actual power plant 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 NO 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 power plant output gigajoules of electricity Fuel types which emit no GHGs e g solar have a default value of 100 The default values provided by the model are given in the Default Emission Factors and Conversion Efficiencies table SWH 86 RETScreen Solar Water Heating Project Model 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 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 The model calculates the weighted average of the T amp D losses of the global electricity mix on the
32. regarding costs performance and risks to enable project lenders and other decision makers to evaluate the merits of the project The cost of the 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 a feasibility study report takes between 2 and 16 hours at a rate of between 40 h and 100 h When a report is not required the user may enter 0 Travel and accommodation This cost item includes all travel related costs excluding time required to prepare 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 For local travel a supplier may not charge for time and expenses For projects in isolated communities where air travel is time consuming and expensive it is better to include more than one potential project in the feasibility study to spread the site visit costs over a number of projects and not just one This is especially important where the projects being evaluated are small in size with resulting small solar water heating systems In the case of isolated communities rates for air travel will vary considerably Airfares are typically twice those for similar distances in populated areas Since travel is a large component
33. 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 SWH 98 RETScreen Solar Water Heating Project Model 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 that the financial indicator will fall outside this confidence interval The limits of the confidence interval are automatically calculated based on th
34. required to help arrange the client project financing In the case of an ESCO developed project much more effort will likely be required to arrange financing negotiate an energy services contract with the solar water heating system owner and prepare legal documents The cost to obtain project financing will range from 8 and 24 hours at a rate of between 60 h and 180 h The lower end of the range is for owner product supplier developed projects The higher end of the range applies to ESCO type projects When project financing is not required the user may enter 0 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 are also included as part of the solar water heating project management cost item here However public relations is not normally a big issue with most SWH systems as the projects are usually building mounted and have little or no negative environmental impact The project development management time will usually take between 10 and 40 hours at rates of between 50 h to 100 h When project management is provided directly by the end user or the supplier installer the user may enter 0 Travel and accommodation This cost item includes all travel related costs excluding time required to develop the project SWH 48 RETScreen Solar Water Heating Project Model Other These
35. savings The model escalates the avoided cost of heating energy yearly according to the energy cost escalation rate starting from year 1 and throughout the project life Note that the avoided cost of energy unit for propane is expressed in terms of liquefied propane 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 reduction 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 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 GHG credit escalation rate The user enters the GHG credit escalation rate which is the projected annual average
36. system typically falls between 20 and 30 years SWH 68 RETScreen Solar Water Heating Project Model 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 In cases where the solar water heating system cost is incorporated into the cost of a house or building and tied to its mortgage the debt ratio will likely be between 50 and 75 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 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 financi
37. 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 with 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 heat purchase or energy service agreement Although the model can analyse project life s up to 50 years the project life of a well designed solar water heating
38. the range defined by the width of each bar The value corresponding to the middle of each range is plotted on the X axis SWH 99 RETScreen Software Online User Manual 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 SWH 100 RETScreen Solar Water Heating Project Model 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 Collector type selected by the user in the Energy Model worksheet From the dialogue box the user selects the Region followed by the Supplier and Model The data can be pasted from the dialogue box to the spreadsheets by clicking on the Pas
39. 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 CO which is assigned a reference value of 1 1 e the GWP of CO is 1 and the GWP of N20 is 310 The default values are those defined by the Revised Intergovernmental Panel on Climate Change IPCC Guidelines for Greenhouse Gas Inventories 1996 SWH 82 RETScreen Solar Water Heating Project Model Base Case Electricity System Baseline To perform the RETScreen GHG emission reduction analysis for the SWH 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 Note Defining the Base Case Electricity System carefully is more important if the base case heating system fuel type defined in the Energy Model worksheet is electricity Otherwise this analysis applies only to the electricity used for the pump which represents a relatively small amount of energy For example in North America when preparing a GHG emission reduction analysis for a SWH project where central grid electricity is used it is often reasonable to assume that a combined cycle
40. volume Storage tanks to be installed inside the mechanical room will have to pass through the doors of the building Storage tanks should be manipulated easily by the installers otherwise cranes and or hoists will have to be rented The user may choose a storage tank with an internal coil only if he has already selected Yes from the drop down list for Heat exchanger antifreeze protection in the Energy Model worksheet If the user has selected a storage tank with an internal coil or a tank in tank 0 will be entered in the Heat exchanger cost box For large process hot water solar heating systems requiring pressurised tanks multiple 450 L storage tanks can be used to obtain the required volume Contact a local supplier for the price of SWH 52 RETScreen Solar Water Heating Project Model a custom made pressurised storage tank custom tank costs are typically twice the costs for multiple standard tanks of the same volume For very large solar water heating systems industrial commercial a configuration using non pressurised solar storage tanks typically made of concrete or polyethylene could be more cost effective Use the following table to estimate the approximate costs of non pressurised tanks 300 to 10 000 Polyethylene Insulation 0 18 to 0 50 2 000 to 20 000 Fibre glass Insulation 1 10 to 2 80 10 000 to 30 000 Concrete Insulation Underground 0 28 to 0 45 Cost of Non Pressurised SWH Storage Tanks Polyethy
41. worker and 40 h to 70 h for a professional plumber Roof modifications e g openings through roof must be done by a professional roofing contractor at a labour cost between 40 h and 75 h Pipe preparation and cutting pipe insulation and jacketing and pipe support can be done by a non specialised worker Pipe soldering must be done by a professional plumber The user enters a m price per unit of solar loop length Costs range between 4 m and 15 m for a service hot water solar system depending primarily upon the installation accessibility the site labour hourly rate the number of connections per pipe meter the number of openings to make through walls etc Openings through walls and the roof can be time consuming It is usually easier to attach pre insulated piping along an exterior wall or to use large existing ducts Costs range between 2 m and 6 m for a swimming pool solar water heating system where there are no pipe insulation no jacket and generally no openings to make SWH 58 RETScreen Solar Water Heating Project Model Use the lower value for simple ground installations where there is only one wall opening no roof opening and easy access The higher value would be more appropriate in complex retrofit installations where there are many obstructions to avoid and for larger pipe diameters Auxiliary equipment installation Auxiliary equipment installation refers to hot water storage tanks heat exchangers pump
42. 51 Energy Model9 10 11 12 29 39 51 52 53 54 55 57 62 65 66 67 82 83 87 89 91 92 93 101 Engineering asr no eran aia va iiaea 49 73 SWH 108 RETScreen Solar Water Heating Project Model Estimated hot water use at approx 60 C 35 36 F Feasibility Stud y cccceescesseesceseceseceeeceeeeneeeeeeeeees 72 Feasibility Study oo eeseceesecseeeeceeeeeeeeeneeeees 45 73 Financial Feasibility 0 0 0 eeeeeeeecseeeeeeeeees 65 75 Financial Parameters c ccccccccessseceeesseeeeene 65 66 Financial Summary 9 12 27 28 65 66 72 79 81 82 91 94 95 96 97 99 Foreign AMOuN1 ceecceeeceeseeceeeeeeneeeeee 43 44 103 Fr tau alpha coefficient ceeeeseeseeseereeeeeees 15 Fr UL coefficient ccccccccesccceessececesseeecnseeeeens 15 Fraction of month used cccccceesseceeeseeeeeee 11 32 Fuel conversion efficiency c ceeeee 86 89 90 Fuel MX 00 0 cceccccecesececeessececesseeeeenteeeeeaes 85 87 89 Fueltype ntek aana 84 86 87 89 G GHG credit escalation rate 000sseeee000e000000e 67 75 GHG emission factor 81 85 86 87 88 89 90 91 GHG emission reduction COSt ccccceessceeeseeeees 78 GHG emission reduction credit 67 75 78 97 98 GHG Emission Reduction Summaty 81 90 GHG reduction credit duration cccceee 66 67 GHG reduction income duration cccc
43. AE ASHRAE Applications Handbook SI Service Water Heating 1995 Chabot B Personal Communication 1999 The Danish Energy Agency Engerstatistics 1995 1999 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 Leng G RETScreen International A Decision Support and Capacity Building Tool for Assessing Potential Renewable Energy Projects UNEP Industry amp Environment 3rd Quarter 2000 Marbek Resource Consultants Solar Water Heaters A Buyers Guide report prepared for Energy Mines and Resources Canada 1986 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 Ross M and Royer J Photovoltaics in Cold Climates James and James Ltd 1999 Sandor R Walsh M and Leblanc A Creating a Market for Carbon Emissions Gas Industry Opportunities published in Natural Gas June 1999 SWH 107 RETScreen Software Online User Manual Index A After taxX ere 76 79 94 After tax IRR and ROU ceeeeecseeeecneeeeeeeeeees 94 Annual average temperature eee eee eeeeeeeeee 10 Annual average wind speed c ceseeceesseeseeeeeees 11 Annual COStS ccicecescccedesvesseeseleccdesssup
44. Database for more information Solar water heating collector model The user enters the name of the solar water heating collector model This is for reference purposes only The user can consult the RETScreen Online Product Database for more information Gross area of one collector The user enters the gross area of one collector in m Gross area is the total area occupied by the collector including its frame For detailed information Technical Note 1 should be consulted The user can consult the RETScreen Online Product Database for more information In RETScreen all calculations including collector efficiency are based on gross area except SWH system capacity storage pump energy suggested pipe diameter and heat exchanger cost which are based on aperture area Aperture area of one collector The user enters the aperture area of one collector in m Aperture area is the maximum area of the collector over which useful direct solar radiation can be collected For detailed information Technical Note 1 should be consulted The user can consult the RETScreen Online Product Database for more information In RETScreen all calculations including collector efficiency are based on gross area except SWH system capacity storage pump energy suggested pipe diameter and heat exchanger cost which are based on aperture area Typical aperture collector areas range from 1 to 5 m Aperture area is always less than or equal to gross area
45. Heat exchanger costs depend primarily on their thermal capacity and efficiency on the material used for its construction copper stainless steel etc and on the type of construction shell and single wall tube shell and double wall tube plate exchanger etc The user enters a kW price where kW is for the heat exchanger thermal power rating The model automatically calculates the thermal rating of the heat exchanger this parameter is not a thermal engineering value and must be evaluated more precisely under the final SWH system design task The thermal rating value of the heat exchanger characterises the thermal power generated by the total collector area working under an average solar radiation conditions and at typical temperature levels on the load side and not at the desired hot water temperature Consult the table below to help estimate the cost of standard heat exchangers The lower end of the range is for shell and single wall tube The higher end of the range applies to shell double wall tube and stainless steel plate heat exchangers Local plumbing codes may require stainless steel or double wall for leak detection purposes heat exchangers when the system is connected to the main water supply Costs for a custom made heat exchanger can be more than twice the price of a standard exchanger For small systems under 15 kW the cost of the heat exchanger will rarely be lower than 150 SWH system manufacturers and or suppliers may off
46. O2 CH4 and N20 emission factors Custom analysis For the base case heating system the user enters the CO CH and N O emission factors corresponding to the heating fuel type selected If the heating fuel type is electricity emission factors of the base case electricity mix are used CO CH and N20 emission factors represent the mass of greenhouse gas emitted per unit of energy generated Emission factors will vary for different types and qualities of fuels and for different types and sizes of heating equipment For each fuel type selected units are given in kilograms of gas emitted per gigajoule of heating energy 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 CO2 CH4 and N20 emission factors Standard analysis For the base case heating system the model provides the CO2 CH and NO emission factors corresponding to the heating fuel type selected If the heating fuel type is electricity emission factors of the base case electricity mix are used CO CH and NO emission factors represent the mass of greenhouse gas emitted per unit of energy generated Emission factors will vary for different types and qualities of f
47. RETScreen International Clean Energy Decision Support Centre RETScreen Software Online User Manual Solar Water Heating Project Model Canada 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 person Neither Canada nor its ministers
48. Six worksheets Energy Model Solar Resource and Heating Load Calculation Solar Resource and Heating Load Cost Analysis Greenhouse Gas Emission Reduction Analysis GHG Analysis Financial Summary and Sensitivity and Risk Analysis Sensitivity are provided in the Solar Water Heating Project Workbook file The Energy Model and Solar Resource amp Heating 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 order to help optimise the design of the solar water heating 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 Solar Water Heating 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 w
49. TScreen allows such equations to be entered However the algorithm used internally by RETScreen requires a linear equation so quadratic equations are linearized by the program When available it is best to use linear efficiency equations rather than quadratic efficiency equations The efficiency of all collectors in the RETScreen Product Database is given in linear form Efficiency equations in European format Some test laboratories particularly in Europe report collector efficiencies with linear or quadratic equations similar to those shown above 1 2 except that DT is the temperature differential between the average collector temperature and the outdoors All collector efficiency equation of that form in the RETScreen product database were converted to the linear form using the temperature differential between inlet temperature and the outdoors If the user needs to input a collector efficiency either linear or quadratic in European format the current version of RETScreen will not properly account for the fact that the coefficients were measured using average rather than inlet collector temperature A rough workaround is simply to reduce collector efficiency by about 3 This is best done by increasing the Losses due to snow and dirt in the Balance of System subsection by 3 Wind dependent efficiency equations for unglazed collectors Equation 1 is also used to model unglazed collectors However the following points should b
50. WH 79 RETScreen Software Online User Manual 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 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 SWH 80 RETScreen Solar Water Heating 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 common GHG emission reduction analysis worksheet contains four main sections 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 represent
51. age 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 estimated debt interest rate value The higher the percentage the SWH 96 RETScreen Solar Water Heating Project Model 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 pro
52. al viability of a energy 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 For solar water heating systems installed in private homes and paid for by the home owner it is likely that the user would select No given all cash flows would come from after tax money 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 magnitude as the corresponding costs and fall under a different depreciati
53. alent of CO emission per megawatt hour of end use heating energy delivered tco 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 system SWH 90 RETScreen Solar Water Heating Project Model 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 water heating energy delivered for the base case system Units are given in tonnes equivalent of CO emission per megawatt hour of end use heating energy delivered tco MWh Proposed case GHG emission factor The model transfers the solar water heating GHG emission factor calculated in the proposed case heating system section This value represents the amount of GHG emitted per unit of water heating energy delivered if the solar water heating system is installed Units are given in tonnes equivalent of CO emission per megawatt hour of end use heating energy delivered tco MWh End use annual energy delivered The model displays the end use annual energy delivered as calculated in the Energy Model worksheet Units are given in megawatt hours of end use heating energy delivered MWh Annual GHG emission reduction The model calculates the annual reduction in GHG emissions estimat
54. an 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 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 energy project 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 N O emission Fuel conversion factor factor factor efficiency kg GJ kg GJ kg GJ Diesel 2 oil Geothermal Biomass wood Small hydro Wind Solar Propane Default Emission Facto
55. and engineering are then included in the price of the system However because SWH 41 RETScreen Software Online User Manual each building has different characteristics the user should verify the cost of anchoring the collector structure to the roof For a better understanding of components mentioned in this section the user should consult Technical Note 2 Typically the cost for an installed residential domestic SWH system using a glazed flat plate collector ranges from 2 000 to 4 000 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 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
56. arly 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 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 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 S
57. art of the RETScreen Clean Energy Project Analysis Software the Cost Analysis worksheet is used to help the user estimate costs associated with a solar water heating 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 from the drop down list 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 for 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
58. as well as sizing elements that will enable the model to estimate the energy requirements of the system Application type The user selects the solar water heating application type The options from the drop down list are Service hot water and Swimming pool Service hot water includes domestic hot water heating systems and industrial process heating systems Swimming pool includes indoor and outdoor swimming pools System configuration The user selects the configuration of the system from the two options in the drop down list With storage and Without storage Systems with storage should be considered for domestic hot water applications or for industrial applications requiring the solar water heating system to provide a significant part of the water heating load Thermosiphon systems can also be evaluated using the configuration with storage as their thermal performance is typically similar to those of pumped systems Systems without storage are typically industrial applications as a rule of thumb the solar energy in a system without storage should represent no more than 15 of the load and the load should be continuous during daytime SWH 34 RETScreen Solar Water Heating Project Model Building or load type The user selects the type of building or load under consideration This is used in the model to suggest in some cases an estimated load in Estimated hot water use at approx 60 C Several types
59. ater Heating Project Model 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 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 l
60. ater heating project has been identified through the RETScreen pre feasibility analysis process a more detailed feasibility analysis study may be required for larger solar water heating projects Feasibility studies typically include such items as site investigations preliminary project design and report preparation including a detailed cost estimate Travel costs may also be incurred These costs are detailed in the section below For small projects the cost of the feasibility study relative to the cost of the solar water heating 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 In some cases a client may not require a feasibility study and will only ask for a proposal from the supplier relying on the supplier s energy saving estimates and price quotation This is common practice for Standard design off the shelf projects which the user can select as an option at the beginning of the Cost Analysis worksheet in RETScreen Note The RETScreen Clean Energy Project Analysis Software can also be used to prepare the Feasibility Study Site investigation When a solar water heating system is being considered for an existing building a site visit is often required to evaluate the site conditions and suitability of installing the SWH system If the SWH system is for a new building or is to be ground mounted then a s
61. ations 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 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
62. auxiliary equipment installation Collector support structure This item refers to the total cost of the equipment required to provide a support for the solar collectors The cost of the structure will vary considerably depending upon whether the system is to be mounted on the building wall on a flat roof on an inclined roof or whether it is to be ground mounted These costs can be related to the area covered by the solar collectors which is calculated in the Energy Model worksheet Total gross collector area The user enters a m cost For simple solar water heating systems where the collectors are flush mounted to the building roof or wall the structure costs are minimal The user would enter 0 m2 to 10 m for a solar pool heating system using flush mounted unglazed collectors and up to 40 m for service hot water applications using a custom designed support structure For more elaborate structures such as on flat roof commercial buildings support structure costs could range from 70 m to 200 m The cost can be higher if the roof has to be modified If the system is to be ground mounted some site work will have to be done and those costs should be added to the Other category Especially if sophisticated anchoring features need to be installed through the roof membrane cost of support structure may increase by more than 50 Plumbing and control The interconnection plumbing involves the plumbing interface between the solar loo
63. bable based on a normal distribution 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 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 w
64. 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 MWh means that the RE delivered could take any value between 36 MWh and 44 MWh Since 40 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 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 initial costs could take For example a range of 10 for initial costs of 3 000 means that the initial costs could take any value between 2 700 and 3 300 Since 3 000 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 t
65. ciency equations considered by RETScreen Please note that all the efficiency equations used by RETScreen are based on gross area not aperture area Generic linear efficiency equation Typically the performance of a glazed or evacuated solar collector is modelled by the following equation eta Fr tau alpha Fr UL DT G 1 where eta is the collector efficiency dimensionless Fr tau alpha is a parameter used to characterise the collector s optical efficiency dimensionless Fr UL is a parameter used to characterise the collector s thermal losses W m C DT is the temperature differential between the working fluid entering the collector and the outdoors C G is the global incident solar radiation on the collector W m7 Parameters Fr tau alpha and Fr UL are determined from standard tests and are available for most collectors on the market The larger Fr tau alpha is the more efficient the collector is at capturing the energy from solar radiation The smaller Fr UL is the better the collector is at retaining the captured energy instead of losing it through convection and conduction to the ambient air SWH 22 RETScreen Solar Water Heating Project Model Quadratic efficiency equation Some manufacturers or test laboratories also include a quadratic term in the efficiency equation eta Fr tau alpha Fr UL DT G Fr UL_T DT G 2 where Fr UL_T is the temperature coefficient of Fr UL RE
66. copper plastic and diameter on the insulation type and thickness and on the type of jacket used The user enters a m price The model calculates the solar piping length loop m from values entered for Number of floors from mechanical room to collector and Horizontal distance from mechanical room to collector in the Energy Model worksheet Use the following table to help estimate the cost of the solar loop SWH 53 RETScreen Software Online User Manual Pipe Diameter Description mm Copper pipe 9 3 8 With fitting and insulation 8 to 10 13 1 2 With fitting insulation R7 and aluminium jacket 17 to 21 19 G 4 With fitting insulation R7 and aluminium jacket 20 to 24 25 1 With fitting insulation R7 and aluminium jacket 25 to 29 Plastic pipe with unglazed collectors 38 1 12 ABS with fitting no insulation 3 to6 38 1 12 PVC with fitting no insulation 6to 10 51 2 ABS with fitting no insulation 6to9 51 2 PVC with fitting no insulation 9 to 14 Cost of Solar Loop Typical Piping Circulating pump s The cost of the circulating pump depends on its capacity on the material used for its construction cast iron for closed loop systems bronze or stainless steel for open loop systems on the type of power supply AC DC solar circulator and on the type of construction flanged circulators are more expensive The user enters a W price In the Energy Model worksheet the user defines the pump powe
67. 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 the O amp M cost required by the base case energy system The model uses the O amp M cost to calculate the total annual costs and the yearly cash flows Electricity The annual cost of electricity to run the solar water heating system is transferred from the Cost Analysis worksheet It represents the cost of electricity required to run auxiliary equipment such as pumps 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 heat power producer or an energy services company these savings will be viewed as income It is dire
68. ctly related to the avoided cost of heating energy derived from implementing the project Heating energy savings income The model calculates the heating energy savings which represent the additional cost that would have been incurred if this heating energy had been delivered by the base case energy system The heating energy savings are equal to the product of the heating energy delivered the cost and heating value of the heating energy avoided divided by the base case system seasonal heating efficiency The yearly value of heating energy savings is escalated at the energy cost escalation rate SWH 74 RETScreen Solar Water Heating Project Model 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 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
69. cts No if there is no heat exchanger In this case service hot water or pool water is assumed to circulate through the collector loop and the system should be turned off whenever freezing conditions are encountered SWH 17 RETScreen Software Online User Manual Heat exchanger effectiveness The user enters the effectiveness of the heat exchanger in This entry is available only if the Heat exchanger antifreeze protection option is set to Yes Heat exchanger effectiveness ranges from 50 to 85 depending on the type of heat exchanger selected As a typical starting point value for analysis 80 is suggested Note that the heat exchanger effectiveness is not related to the heat losses of a heat exchanger generally negligible A higher effectiveness characterises the ability of the heat exchanger to transfer the same amount of heat from the solar loop to the service hot water but with a narrower temperature difference The higher the effectiveness is the higher will be the seasonal yield of the SWH system Suggested pipe diameter The model calculates the suggested nominal diameter of the solar collector piping in mm This value is calculated based on the collector aperture area The nominal value is suggested mainly for service hot water systems where copper piping is considered for installation Swimming pool heating systems typically use the same 35 mm 11 2 plastic tubing as the filtration system Values range fro
70. der to find the most financially viable collector area for the specific application Note that collector efficiency varies with season of use Evacuated collectors for example are more efficient than unglazed collectors in the winter but the situation is reversed in the summer For this reason depending on the climatic conditions and the season of use the number of collectors suggested in the model may be larger with evacuated collectors than with unglazed collectors despite the fact that evacuated collectors are on average more efficient The suggested number of collectors may vary from one for small residential systems to several hundred for large commercial or industrial applications N A may appear if the model is unable to suggest the number of collectors In this case the user should choose a number of collectors in an iterative process to obtain a desirable solar fraction or financial optimum Note The maximum suggested solar collector gross area is limited within the software to equal the pool area This is a rule of thumb used in the industry Number of collectors The user enters the actual number of collectors for the solar water heating system As a first pass use the Suggested number of collectors calculated by the RETScreen model then vary the value of the number until a financial optimum is found The number of collectors may vary from one for small residential systems to several hundred for large commercial o
71. drain back system In large indirect loop pumped SWH systems with storage and an external heat exchanger see Technical Note 2 point 3 A ii use 1 5 to 2 times the estimate given in the previous table as there are typically two pumps required to operate the system Piping and solar tank losses The user enters a value accounting for heat losses from the pipes and or the tank to the surrounding environment Heat losses are represented as a fraction of renewable energy delivered This fraction depends on several factors e n systems without storage the only losses for this item are piping losses which depend on the length of piping Enter 1 or 2 if there is a short distance relative to collector area between the collector and the rest of the system and between 4 and 8 otherwise Use the lower values for well insulated piping and the higher values for poorly insulated piping e In systems with storage additional heat losses from the tank have to be taken into account Enter an additional 5 to 10 for tank losses e The values above can be lowered if the system is used only during summer months or hot water tanks are installed in a warm mechanical room often overheated in commercial buildings Lower values may be used because losses to the environment are lower and because systems can sometimes offset some of the losses by collecting extra energy that would otherwise be wasted However note that some of the heat losses from the ta
72. e noted e For unglazed collectors G also includes long wave radiative losses to the sky e For most unglazed collectors efficiency coefficients are adjusted depending on wind speed Fr tau alpha becomes Fr tau alpha Fr tau alpha wind V and Fr UL becomes Fr UL Fr UL wind V SWH 23 RETScreen Software Online User Manual where Fr tau alpha wind and Fr UL wind are two corrective coefficients expressed in s m and J m 3 C respectively and V is the wind velocity experienced by the collector C Differences between gross and aperture area Collector tests report efficiency relative to gross collector area aperture area or both e Gross area is the total area occupied by the collector including its frame It is simply the product of the outside length and width dimensions of the collector e Aperture area is the maximum area of the collector over which useful direct solar radiation can be collected For most unglazed collectors gross and aperture areas are identical For glazed collectors aperture area is equal to gross area minus the area occupied by the frame For evacuated tube collectors aperture area is the area covered by the tubes themselves whereas gross area includes the area between tubes RETScreen expects collector efficiencies expressed in terms of gross area If the efficiency is expressed in terms of aperture area the following conversion can be used eta_g eta_a Aa A
73. e heat exchanger the control unit pipes and the liquid handling unit The drawing and specifications should also determine how the SWH system will be integrated with the existing plumbing system Liaison will also be required with the SWH system designer s the architect engineer of the building the roof contractor of the building and the plumber responsible to achieve an optimum design Since both engineering time and drafting time are required use a weighted average for the engineering and drafting rates and time The time required to prepare the SWH system design and detailed drawings falls between 6 and 24 hours at fees of 40 h to 100 h A standard system using generic installation drawings falls at the lower end of the time range For small projects generic installation drawings can often be used and there may not be a separate charge for design In such cases the user may enter 0 Structural design From a SWH system design standpoint the simplest structural designs are vertical wall mounted and flush mounted roof systems such as unglazed flat plate collectors used in a swimming pool system where little or no structural work is required When the project is a large retrofit to a SWH 49 RETScreen Software Online User Manual building or when 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 installat
74. e 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 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 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
75. e 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 1 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 project costs 2 000 to eval
76. e system purchases are at the higher end of this price range Note that the prices will vary depending on the manufacturer Solar storage tank The cost of the solar hot water storage tank depends on its volume on the material used steel with or without glass lining stainless steel etc on the insulation thickness and quality on the use or not of internal coil or other type of integrated heat exchanger such as tank in tank design and on the number of inlets and outlets The user enters a L price The user defines the solar hot water storage tank volume L in the Energy Model worksheet The table below gives approximate costs of pressurised solar hot water storage tanks Note that the volume and cost of the solar storage tank is 0 for swimming pool SWH systems and SWH systems without storage pL Insulation glass lined standard 0 95 to 1 50 Insulation stainless steel internal coil 6 10 to 7 80 Insulation glass lined standard 0 85 to 1 30 Insulation stainless steel internal coil 5 55 to 6 65 Insulation glass lined standard 1 10 to 1 40 Insulation stainless steel internal coil 5 00 to 6 10 Insulation glass lined standard 1 45 to 1 70 Insulation stainless steel internal coil 4 45 to 5 55 Cost of Pressurised SWH Storage Tanks A custom made pressurised tank can be used for very large solar water heating systems but it is generally more expensive than an equivalent number of smaller standard tanks with the same combined
77. e tank ee eeeeeeeeeeeeeeeseensees 52 55 Solar water heating collector manufacturer 14 Solar water heating collector model eee 14 Solar Water Heating Project Model eeeeeeees 9 Specife yield seri ea a EEs 27 Standard eee 6 42 44 45 82 85 86 88 90 Storage e rE ge macdi asia bey 17 52 53 Storag CAPACI eee eeesesesesescsetenceseeoeesentseetenes 17 Structural design ee eee eeeeeeeeeeeeeeeeeeees 49 50 Suggested number of Collectors eeeeeseeeeeeeeeees 16 Suggested pipe diameter ee eeeeecseeeeeseeeeeeeees 18 SWH system capacity cece eeesecseeeeceeeeeeeeees 14 26 SWH system design 49 55 System Characteristics 11 27 System configuration eeseeseeeeeeeeeereesrereereeeerersrees 34 System efficiency ossosa cieri nnii a e i in 27 T Tax holiday available ceeeeeseeseeeceeneeeeeeneees 72 Tax holiday duration ccceseeseeseeseeeeeeeeeeeeeeeeees 72 Technical Note 1o cccccececccccecsesssseeeeeeeees 14 15 21 Technical Note 2 0 ccceee 17 19 20 24 42 54 Temperature coefficient for Fr UL eee 15 Tenders and contracting ce seeseseeeceeeeeeeeeeeees 50 Terms of US tei isaac aen aaa 105 Threshold iien i ea E i tan 93 Total gross collector area 16 57 Tr ningen eiar a riai 60 104 Training and Support esseseeeeseeeeeeseersrsrrererereses 104 Transmission and distribution losses eeee 87 Transportation
78. e year the user should set the calculation method to User defined and set the minimum and the maximum values equal to the well temperature Months SWH system in use The model calculates the number of months for which the equipment is used from data entered by the user in the Monthly Inputs section of the Solar Resource and Heating Load Calculation worksheet SWH 38 RETScreen Solar Water Heating Project Model Energy demand for months analysed The model calculates the annual energy demand for water heating in MWh This is calculated based on the months of use of the energy equipment specified in the Monthly Inputs section This value is copied to the Energy Model worksheet The energy demand of service hot water systems is determined from cold water temperature load temperature and hot water use specified by the user For swimming pools the energy demand is determined through an energy balance between pool losses due to evaporation convection radiation conduction and fresh water supply and passive solar gains 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 This value is for reference purposes only and is not required to run the model Note The user should return to the Energy Model worksheet SWH 39 RETScreen Software Online User Manual Cost Analysis As p
79. eating PLOJOCt e eea E bole stebenseethbes 89 Pumping energy electricity s es 26 Pumping power per collector area 19 26 54 R Rate Ist currency 2nd currency 43 Rate Of OCCUPANCY ee eeeeeeeesecseeeeeseceeesecereeeeaeeees 35 Ratio of storage capacity to collector area 17 Renewable energy delivered 27 28 65 95 Report preparation cee ceesecseeeeceeeeeceeeeeeeseeneeees 46 Retail price of electricity 0 eee eee eeeeecseeeeeeeeees 68 S Saving a File voei isene etene iuter i rok 7 Second Currency ssssseseeeeeeeeeeeeeeeee 6 42 43 44 103 Sensitivity and Risk Analysis 0 0 0 0 ceeeeseeeerees 9 92 SeEMSItIVILY rapen noni iei me e teh 93 Simple Payback cise oos asic uan oree ino 76 Site CONGIIONS ssassn Aene aro 10 27 Site investigation eeeseeseseeeseeseeeesesrsesrereerseserreeeees 45 Site Latitude and Collector Orientation 29 Slope of solar collector 0 cece eeeeeceeeeeeeeeeeeeeeeee 29 Solar collector asennan ns A 51 58 Solar Collectot miserans sine a 13 21 26 31 Solar fraction e ae a AE E 27 Solar loop installation eseeeeeeeeeeeeeeeeeeereersesereeerees 58 Solar loop piping materials sseseeeeeeeeeee seeren 53 Solar radiation horizontal cccccccecssceeseesseeeeees 33 Solar radiation tilted surface cceeeeeeeee 27 34 Solar Resource and Heating Load Calculation 9 10 29 38 Solar storag
80. ed for the installation of the solar collectors and structure however for larger systems cranes and hoists can be used to save site labour cost for the rental of a crane is around 400 h The user enters a m price per unit of solar collector gross area These costs range between 10 m and 100 m primarily depending upon the structural requirements as described above and the site labour hourly rate The lower value is for a simple installation using unglazed collectors directly on a roof with a low labour cost The higher value is for commercial installations on high rise buildings using a more elaborate structure These costs are typical when labour hourly rates are 20 h to 40 h for a non specialised worker and 40 h to 75 h for a professional roofing contractor Note that all modifications on a roof must be done by a professional roofing contractor Installations during the winter period are more expensive due to costs associated with snow removal difficulties working in cold conditions with gloves etc Solar loop installation Solar loop installation refers to the labour required on the site to install the pipes on the solar loop side including the pipe insulation and jacketing the pipe supports and all openings through walls and roof if required from the mechanical room to the solar collectors Interconnection to equipment is not included in this item Typically the labour cost is between 20 h to 40 h for a non specialised
81. ed on a user selected percentage of the sub total of all project 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 of 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 SWH systems it is certainly possible that the RETScreen user experienced with SWH project developments could estimate costs in the range of 5 to 20 of the total initial project costs Annual Costs Credits There may be some annual costs associated with SWH projects but they are likely to be very small compared to the overall system cost These may include property taxes insurance and O amp M labour In addition costs for contingencies and parasitic electricity consumption will also be incurred These costs are detailed below O amp M Property taxes Insurance Generally SWH systems should not increase property taxes In some cases a community may provide a tax incentive for SWH installations The SWH system owner may choose to insure the cost of the system Th
82. ed 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 annual energy delivered 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 SWH 91 RETScreen Software Online User Manual 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 section 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 workshe
83. eeee 75 Global Warming Potential of GHG ee 82 Greenhouse Gas Emission Reduction Analysis 9 Gross area of one collector 0 eee eeececeeseeeeeeeeeees 14 Ground Monitoring Stations Data 00 0 eee 102 H Heat exchanger seseeeeeeeeeeeeeereeerseseseee 17 18 52 55 Heat exchanger effectiveness eeeeneeeeeeereeee 18 Heat exchanger antifreeze protection 17 18 52 55 Heating energy savings iNCOMe ce eeeeeeeeeeeees 74 Heating fuel displaced 00 0 eee eeeetecseeeecneeeeeeeeees 66 Heating fuel type eee ee eeeeecseeeeeeecnereeeneeees 12 67 Horizontal distance from mechanical room to COUCCIOR A E thc Radice Westen dake toes teehee 21 53 Hot water USC cc cccccccecssssssececececsesseeeeeeees 11 35 36 I Inipact raph nesie a O E 98 Incentives Grants cccccseccccceceessseceeececeensaeeeeees 73 Income tax analysis cs eesssecseeseeecsceeecteeeeeeeeeees 69 Inflation s 2i3 a e a a S hehe e 68 Initial COStS n e RE Eai 94 95 initial COosts ccccccecccccceessececeeeeceenseeeeeenes 44 70 72 Initial Costs Credits cccccccecssecessceesseceeeeeeseeees 44 L Latitude of project location 29 Leveliof risky cicdese cesses feecdgg dc A E 99 License AgreeMent ce eeeeceseeeestecreeeeeneeeeeeaees 106 Loss carryforward 0 0 ceescseeceseeeeeeceeeecneeeeeeeenees 70 Losses due to snow and or dirt c cccceeceeeeseeeees 20 M Magnetic declination cc
84. el at the back They are good at capturing the energy from the sun and their thermal losses to the environment are relatively low Glazed collectors are commonly used for applications requiring energy delivery at moderate temperatures domestic SWH 21 RETScreen Software Online User Manual hot water space heating and process heating applications at 50 C or less in medium to cold climates They can be operated year round with freeze protection e g glycol drain back design The efficiency of glazed collectors is independent of wind 3 Evacuated collectors have a selective coating enclosed in a sealed evacuated glass tubular envelope They are good at capturing the energy from the sun their thermal losses to the environment are extremely low Systems presently on the market use a sealed heat pipe on each tube to extract heat from the absorber a liquid is vaporised while in contact with the heated absorber heat is recovered at the top of the tube while the vapour condenses and condensate returns by gravity to the absorber Evacuated collectors are good for applications requiring energy delivery at moderate to high temperatures domestic hot water space heating and process heating applications typically at 60 C to 80 C depending on outside temperature in cold climates They can be operated year round with freeze protection The efficiency of evacuated collectors is independent of wind B Different types of collector effi
85. encctees vovssdenes 79 96 Annual Costs Credits ccccccccccssccesseesseeeeeeeesseeee 61 Annual Costs and Debt eee ceeeereeeeeeee 74 Annual Energy Balance eee eeeeeeeeeeeeeeeeee 65 Annual Energy Production for months analysed 26 Annual GHG emission reduction 91 Annual Life Cycle Savings eseeeeceseeeeeeeeneeeee 77 Annual Savings or INCOMe sseeeeeeeeeeeeeeeererrreeeeee 74 Annual solar radiation tilted surface 10 Aperture area of one collector eeeeeeeeee 14 17 Application type ceceeeesseecssecreesecsereeeeeeeees 12 34 Auxiliary equipment installation eee eeeeeeeeee 59 Average temperature eee eee eeeecse cree cneeeeeeeeeees 34 Average Wind speed ceceeeccsseseessecreeeecnereeenaeeees 34 Avoided cost of heating energy 0 0 0 seen 67 94 Azimuth of solar collector ee ceeeeeeeeceeneeeeeeeeeees 30 B Background Information 81 82 Balance Of SYSteM eeeeseseeeseceeesecneeseceeeeeceeeeeeees 73 Balance of System cesceeseeeeeees 17 23 26 57 Bar frapi iee snr ar ree a EEE EE EE 100 Base Case Electricity System Baseline 83 Base case GHG emission factor 0 0 0 eeeeeeeeeereeees 91 Base Case Heating System Baseline 0 87 Base Case Water Heating System 12 Benefit Cost B C ratio ccccecesccesseesseceseeeesseeees 78 Bibliography ciiiissiseete techie taal ese 107 Blank Worksheets 3 c ccccssscessc
86. er an optimal heat exchanger capacity for their systems Cost Bk 13 to 20 13 to 18 12 to 14 10 to 12 8 to 11 7to 10 7Fto 10 Cost Estimates for SWH Heat Exchangers Transportation Transportation costs for equipment and materials will vary considerably depending upon the mode of transport 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 Handling charges for the material at the receiving end should be considered In isolated areas many communities receive SWH 55 RETScreen Software Online User Manual bulk shipments only once a year either by barge ice road or sometimes only by air Logistical control is extremely important here Shipping costs should be obtained from shipping agents when the scope of the project equipment and materials are determined As an example typical dimensions in m of a 2 3 m single glazed solar collector are 0 9 1 2 x 2 4 x 0 15 and weight is about 60 85 kg A 270 L storage tank is about equivalent to a volume of in m 0 6 x 0 6 x 1 7 and weights about 40 kg Pump and heat exchanger assembly with interconnections for a medium size SWH system 20 m can reach 40 kg with a volume of in m 0 6 x 0 6 x 0 3 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
87. et 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 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 SWH 92 RETScreen Solar Water Heating Project Model Project location The u
88. etary 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 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 switch 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 solar water heating project are detailed below The major categories may include costs for preparing a feasibility study performing the project development functions completing the necessary engineering purchasing and installing the energy equipment the balance of system and costs for any other miscellaneous items SWH 44 RETScreen Solar Water Heating Project Model Feasibility Study Once a potential cost effective solar w
89. f the GHG credit in equivalent tonnes of CO tco2 resulting from the implementation of the project instead of the base case or baseline 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 system instead of the base case or baseline heating system This value is calculated by multiplying the net annual GHG emission reduction by the life of the project 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 building owner vs energy service company ESCO SWH 66 RETScreen Solar Water Heating Project Model Avoided cost of heating energy The user enters the avoided cost of heating energy For exemple if the user chose natural gas m3 as the Heating fuel type in the Energy Model worksheet then the user would simply enter the local natural gas price in m3 for the avoided cost of heating energy The avoided cost of heating energy is used in conjunction with the renewable energy delivered the heating value and the base case heating seasonal efficiency appearing in the Energy Model worksheet to calculate the annual heating energy
90. 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 SWH 4 RETScreen Solar Water Heating 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 el File Edit Yiew Insert Format Tools Data Window Help RETScreen E se 6a PI S Oy a a Online User Manual Onine Product Database 2 Online Weather Database ARCHER 2 Decision Support Centre Arial gt 10 B I uU Z A22 RETScreen menu ee Training and Support Internet Forums RETScreen Marketplace floating RETScreen toolbar _
91. g where eta_g is the efficiency based on gross area eta_a is the efficiency based on aperture area Ag is the gross area and Aa is the aperture area Example An evacuated tube collector has a gross area of 2 140 m and an aperture area of 1 412 m2 The efficiency equation of the collector based on aperture area is eta_a 0 813 1 32 DT G 0 035 DT G Then the efficiency equation based on gross area is obtained by multiplying the coefficients of the equation above by 1 412 2 140 hence the efficiency equation based on gross area is eta_g 0 536 0 871 DT G 0 023 DT G Technical Note 2 Preheating System Configurations for Service Hot Water Applications 1 Thermosiphon systems e A simple and reliable system design widely used for domestic hot water throughout the world and for seasonal use in cold climates SWH 24 RETScreen Solar Water Heating Project Model e Thermosiphon systems are generally direct loop systems e No circulator is required the water circulates naturally in the solar loop under the action of heat generated in the solar collectors Heated water becomes lighter than the cold water in the tank gravity then pulls heavier cold water down from the tank and into the collector inlet e The storage tank needs to be placed above the collector array level at the roof level Hot water is accumulated with a natural stratification which means that hot water accumulates first at the top
92. g on the project size this task can take between 8 to 24 hours at rates of 40 h to 100 h Travel costs should be included in the Development section above If the SWH project is installed directly by the end user and or the supplier of the energy equipment the user may enter 0 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 Energy Equipment The energy equipment as defined here includes all the equipment that is typically supplied by the solar water heating system manufacturer the solar collector the solar hot
93. he building are usually required by the architect engineer of the building to approve the load weight distribution on the roof A roofing contractor should be consulted to approve all modifications to be done to the roof SWH 47 RETScreen Software Online User Manual e g roof penetrations This is required to maintain the roof warranty all modifications done on a roof must be done by a professional roofing contractor 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 solar water heating project the permit acquisition and approval process could take between 2 and 8 hours at rates of between 40 h and 100 h for project development staff The user can also add to the number of hours or unit costs an amount to cover the actual permit itself Permit costs are usually minor relative to the total project cost When permits or approvals are not required the user may enter 0 Project financing The time and effort required to arrange project financing will vary depending upon the project developer and client relationship In most cases where the client is the owner and the developer is the product supplier the project financing costs attributable to the project are minimal The solar water heating system owner will usually finance the project out of capital or O amp M budgets and the product supplier will provide in kind support as
94. he time range Mounting Angle Engineering Drafting h h Vertical on wall 0to4 Oto 8 Horizontal on roof 0 to 16 Oto 8 Tilted on roof 15 to 30 20 to 40 Tilted on ground with no contour work 20 to 40 20 to 40 Tilted on ground with contour work 22 to 44 30 to 60 Structural Design Time Estimates for SWH Collectors 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 If bid documents are required 10 to 40 hours at rates of 40 h to 100 h are common If the SWH project is installed directly by the end user and or the supplier of energy equipment the user may enter 0 Construction supervision The construction supervision cost item summarises the estimated costs associated with ensuring that the project is constructed as designed The consultant overseeing the project the equipment SWH 50 RETScreen Solar Water Heating Project Model supplier or the project manager can each act as the construction supervisor Construction supervision involves regular visits to the job site to inspect the installation Dependin
95. he user should enter a range of 0 SWH 95 RETScreen Software Online User Manual Annual costs The annual cost is transferred automatically from the Financial Summary worksheet to the Sensitivity worksheet but does not include debt payments 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 80 means that the annual cost could take any value between 72 and 88 Since 80 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 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 percent
96. ictewasesanessoudsceouveseousssoosasooensess LUE OSU DACA PEAST ATA LUD Training and Support eeessoessoesssccssocescocesoosesocessecesocesocesoossssesssocesocssoosssoessseessocesoosssosssssssseessoe L04 AKSIE E DE E E E E A OT EEEN UO Mer Bibliography sisisectaacetaschancscatinessnccleussdastanueticceavacsncadestaceatediestactetidstanseabtionsiuacaaisumlabaataaasaansaclOT TRON A TAE A ETEEN ATOE A EEEE UO SWH 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 Solar Water Heating 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 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
97. ied automatically to the Energy Model worksheet There are four basic applications service hot water with storage service hot water without storage indoor swimming pool and outdoor swimming pool Base Case Water Heating System This sub section contains information that describes the energy system displaced by the installation of the solar water heating system Heating fuel type The user selects the type of heating energy displaced by the solar water heating system This entry will be used to calculate annual heating energy savings in the Financial Summary worksheet A list of common heating fuel types is provided in the drop down list The table below provides the heating value for various fuel types Heating Energy Avoided Fuel Heating Value Natural gas 37 2 Mim 10 33 k Whim Propane 26 6 MIL 7 39 kWhiL Gasoline 33 7 MIL 9 36 kWhiL Kerosene 36 6 MU L 10 16 kWhiL Diesel 2 oil 38 7 MU L 10 74 kWh L 6 oil 40 5 MIL 11 25 kWh L Electricity 1 0kWhkWh Other 1 0 Fuel Heating Value Note 1 The gallon gal unit used in RETScreen refers to US gallon and not imperial gallon 2 Propane gal and Propane L are expressed in terms of liquefied propane Water heating system seasonal efficiency The user enters the average efficiency of the conventional water heating system over the season of use This value is used to calculate the financial value of the system It has no influence on the calculation of the annua
98. ing energy is automatically transferred from the Financial Summary worksheet to the Sensitivity worksheet The user enters the avoided cost of heating energy range The range is a percentage corresponding to the uncertainty associated with the estimated avoided cost of heating 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 SWH 94 RETScreen Solar Water Heating Project Model For example a range of 10 for an avoided cost of energy of 0 09 kWh means that the avoided cost of heating energy could take any value between 0 081 kWh and 0 099 kWh Since 0 09 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 avoided cost of heating 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
99. ing 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 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 represent the fuels and the emissions that are being displaced by the proposed project For example if dispatch information shows that the fuel used on the margin is natural gas 85 of the SWH 83 RETScreen Software Online User Manual 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 c
100. ing no heat exchanger and no storage tank will be almost 0 In this case the interconnecting cost will only be estimated for two to three connections solar loop filtration system and motorised valve Electrical installation costs for SWH systems are relatively small A rough estimate of total costs for electrical installation ranges between 0 to 400 including electrical equipment The lower end of the range is for thermosiphon systems or an outdoor pool SWH system using a filtration pump unit as a circulator and no electrical equipment Electrical installation costs may also be 0 if a standard solar handling unit kit is used the pump is already electrically connected to the controller and installed near an electric plug a standard 115 V AC line can normally be used to supply electricity to the low energy consumption solar pump The higher end of the range is for a custom designed system all electrical connections are to be made between the electrical equipment an electrical line needs to be installed between the solar controller and the existing breaker panel etc The cost for the rental of cranes and hoists may be considered to facilitate handling of larger storage tanks SWH 59 RETScreen Software Online User Manual Transportation Transportation costs for equipment and materials will vary considerably depending upon the mode of transport available and the location of the project site In many instances the cost will depend
101. ing on the energy analysis of the system It is used in the Cost Analysis worksheet to estimate the cost of running vertical piping to the collector Values typically range from O in the case of a collector installed on a structure outside the mechanical room to 20 floors in the case of taller buildings e g apartment buildings Technical Note 1 Performance of Solar Collector Technologies used in the RETScreen SWH Project Model A Types of collectors available in RETScreen The three types of collectors available in RETScreen are as follows 1 Unglazed collectors are usually made of a black polymer They do not have a selective coating and do not include a frame and insulation at the back they are usually simply laid on a roof or on a wooden support They are good at capturing the energy from the sun but thermal losses to the environment increase rapidly with water temperature particularly in windy locations Unglazed collectors are commonly used for applications requiring energy delivery at low temperatures pool heating make up water in fish farms process heating applications etc they are often operated in the summer season only because of the high thermal losses of the collector Unglazed collectors are sensitive to wind and often the efficiency of such collectors include a wind dependent term 2 Glazed collectors often have a selective coating and are fixed in a frame between a glass cover at the front and an insulation pan
102. ing 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 solar water heating 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 CH4 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 Earth 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 N O these gases are considered in the RETScreen GHG emission reduction a
103. ion Some SWH system suppliers propose pre engineered structures that can be sized to accommodate the required number of solar collectors The pre engineered structures are less expensive but may not be appropriate depending on the building Liaison with the architect engineer load on building and the roof contractor roof modifications are required when performing the final structural design and anchoring between the structure and the roof When the roof membrane has to be replaced in the coming years structural design should allow membrane replacement without need to dismantle the solar collector structure The time required to prepare the SWH system structural design and detailed drawings will depend on the simplicity of the structural layout chosen Since both engineering time and drafting time are required use a 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 Consult the table below to estimate the structural design time engineering time can be 0 or very low if the structure is pre engineered Simple wall or flush mounted roof systems and small scale projects with standard and or simple structural requirements fall at the lower end of the time range Allow O for most small projects Special design and or large scale projects requiring optimisation and more difficult structural integration into the building will be at the higher end of t
104. is cost can be estimated by contacting an insurance broker O amp M labour SWH systems typically require minimal maintenance Usually the solar collector is designed to last over twenty years A water glycol mixture used as a transfer fluid needs to be replaced about every four to seven years The liquid handling unit pump and the controller will require an annual maintenance inspection Because of its simplicity the inspection of relatively small solar water heating system can be performed by the system owner SWH 61 RETScreen Software Online User Manual The cost range for annual maintenance inspection of a SWH system is between 0 and 200 Use the lower value if the inspection is done by the owner The higher value would be more appropriate if the maintenance inspection is performed by a system expert on a large and complex SWH system Rates for system experts range from 40 h to 100 h The replacement of water glycol mixture should be done by a professional plumber at a cost between 40 and 80 for the labour and between 4 L and 6 L for the fluid to be replaced In the case of seasonal swimming pool SWH systems the maintenance is limited to the drainage of the system before annual freezing occurs As this operation applies to any other conventional heater there is no incremental cost for this operation and the user should enter 0 for O amp M labour cost Other These input cells are provided to allow the user to enter
105. ite visit is usually not required since the analysis can be done from architectural or engineering and or land survey drawings Site visit time includes time required to arrange meetings survey the site obtain the necessary information and any travel time but not travel expenses see Travel and accommodation For existing building installations a solar water heating project expert should normally 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 SWH system can be designed The site will be inspected to determine a possible location for the solar collectors piping control liquid handling unit and storage tanks if needed Questions such as municipal regulations regarding installation of structures on the roof roof membranes scheduled replacement or warranty conditions should be clarified at this stage as they may affect the system design and the cost of the structure 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 will suffice to conduct the feasibility study for the vast majority of retrofit projects The cost of a site visit will be influenced by the planned duration and travel time 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 4 and 8 hours
106. ith 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 SWH 97 RETScreen Software Online User Manual If the GHG emission reduction 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 graph are calculated using these results and updated each time the user clicks on the button Click here to Calculate Risk Analysis The risk analysis calcul
107. ject Analysis Software can be used to prepare both the initial pre feasibility analysis and the more detailed feasibility analysis re tender estimate t i Be st accuracy wit 10 All tenders received cost accuracy within 5 12 tt ty Final cost Ba o 0 9 a s Constructo 0 8 al r o7 of sibility study cost accuracy wit 15 to 2 0 6 sa Pre leasibility study ost ac racy within 40 to 50 Time Accuracy of Project Cost Estimates Gordon 1989 By selecting Pre feasibility initial costs for the feasibility study development and engineering items for the solar water heating system will be assumed to be 0 For example this selection may be appropriate for the implementation of a small residential solar DHW system or a simple swimming pool solar water heating system By selecting Feasibility the user will enter costs in all the standard initial costs categories described below This selection is more appropriate for larger solar water heating systems and or for projects requiring a more difficult structural integration into the existing building It is worth noting that for small SWH projects capital cost less than 10 000 manufacturers and retailers may offer pre engineered systems based on an off the shelf concept If this is the case the user should select the Pre feasibility option the costs of feasibility study development
108. l renewable energy production Typical values range from 50 for conventional fossil fuel fired water heaters to nearly 100 for electric heaters If a heat pump is used as a base case e g for swimming pool applications the user will select Electricity as the heating fuel type and may enter values higher than 100 to reflect the heat pump coefficient of performance COP e g enter 225 if seasonal COP is 2 25 SWH 12 RETScreen Solar Water Heating Project Model Typical values of residential heating system efficiencies are tabulated below The efficiencies of commercial and industrial water heating systems can vary significantly depending on size age technology condition installation specifics etc and these are not specifically included here However the user may use the efficiencies of residential water heating systems as a reference for similar larger systems Typical Seasonal Residential Water Heating System Type Efficiency Typical Water Heating System Seasonal Efficiencies Note The efficiency of residential water heating systems is commonly expressed in terms of the Energy Factor EF For the purposes of the model it is assumed that the two measures are essentially the same except that EF is expressed as a decimal The values in the above table are in fact EF values that were converted to percentages Seasonal Efficiency is used here because it is a more generic term and more applicable to commercial and ind
109. lene tanks can be placed underground or aboveground They can reach temperatures higher than 50 C They can be thermally insulated or not depending on storage temperature Use lower cost values for large insulated tanks The higher values are for smaller insulated tanks Contact your local supplier for confirmation and for more specific technical data on temperature and structural resistance Fibreglass tanks can be placed underground or aboveground They can reach temperatures higher than 100 C They can be thermally insulated or not depending on storage temperature Use lower cost values for large insulated tanks The higher values are for smaller insulated tanks Contact your local supplier for confirmation and for more specific technical data on temperature and structural resistance Concrete tank costs are based on the costs for commercial septic tanks This kind of tank can be used only if it is installed underground otherwise the tank walls can break when full of water A concrete tank can generally withstand a rise in temperature of up to 100 C but not a continuous temperature increase Contact your local supplier for confirmation and for more specific technical data on temperature and structural resistance Solar loop piping materials The solar loop piping materials refer to the piping the fittings the pipe supports the insulation and the jacket The cost of the solar piping loop depends on the length used on the pipe material
110. 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 negative 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 fo
111. lity 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 SWH 72 RETScreen Solar Water Heating Project Model 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 ca
112. llector and the Number of collector entered in the Balance of System and Solar Collector sub sections SWH 26 RETScreen Solar Water Heating Project Model of the System Characteristics section This value is transferred to the Cost Analysis worksheet to calculate the Electricity annual costs of the SWH system in the Financial Summary worksheet Specific yield The model calculates the amount of energy delivered by the solar collector per unit of gross collector area for the months analysed in kWh m This value depends on the technology used climatic conditions the use or not of an heat exchanger the daily hot water usage etc This value is typically in the 200 to 800 kWh m range for a system that operates for 12 months of a year System efficiency The model calculates the system efficiency for the months analysed System efficiency is the ratio of Renewable energy delivered to Solar radiation tilted surface Note that the system efficiency does not take into account the parasitic pumping energy For service hot water applications the annual SWH system efficiency are typically between 30 to 50 depending on climate system size and water heating load Generally the greater the solar fraction the lower the system efficiency to obtain high solar fractions the collector area is increased and the system operates more often at high temperature with a lower efficiency Swimming pool systems may show higher efficiencie
113. m 8 mm 3 8 for small solar collector area up to 25 mm 1 for larger collector area Note that a flag or N A will advise the user when a large system will require a solar loop diameter greater than 1 inch The user will then have to calculate piping cost manually in the Cost Analysis worksheet or consider splitting the solar loop in several parallel loops Hence the cost of piping should then be multiplied by the number of loops in parallel Pipe diameter The user enters the actual pipe diameter in mm This is used to estimate the cost of piping installation in the Cost Analysis worksheet typically the larger the pipe the higher the costs Note that it is assumed in the model that the value entered has no influence on the annual energy production Values ranging from 8 mm 3 8 to 25 mm 1 are acceptable As a first pass use the Suggested pipe diameter or 35 mm 11 2 plastic tubing for swimming pool systems For swimming pool SWH systems it is common to use plastic pipes with diameters ranging from 35 to 50 mm 1 to 2 inches which are easily adaptable to existing pool filtration pipes For SWH thermosiphon systems the solar loop should be as short as possible with a larger pipe diameter A minimum pipe diameter of 34 inch is required even for a small residential thermosiphon system For other solar water heating systems installers usually use copper pipe from 8 to 25 mm 3 8 to 1 as recommended in the following table
114. m 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 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 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 Project location The user defined project location is entered for reference purposes only in the Energy Model worksheet Renewable energ
115. m 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 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 calculati
116. metimes adjusted for convenience in the site and building drawings SWH 30 RETScreen Solar Water Heating Project Model Example Collector faces 45 SW in Northern Hemisphere Azimuth of Solar Collector 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 place 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 SWH 31 RETScreen Software Online User Manual 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
117. 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 Solar Water Heating 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 to indicate that they are not used for energy calculations For example if the system under consideration is for service hot water then monthly average relative humidity is not required it is needed only for outdoor pools to calculate the rate of evaporation from the pool Note It is important to revisit this table to check that all required inputs are filled in if the user changes any of the following parameters which modify the cells that are greyed out application type solar collector type type of pool or method for calculating cold water temperature 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
118. n J m C For detailed information Technical Note 1 should be consulted The user can consult the RETScreen Online Product Database for more information Values of the wind correction for Fr UL typically range from 3 00 to 15 00 J m3 C Temperature coefficient for Fr UL If Glazed or Evacuated collector type is selected the user enters the temperature coefficient of Fr UL i e the quadratic term of the efficiency equation if there is one for the collector under consideration in W m C For detailed information Technical Note 1 should be consulted The user can also consult the RETScreen Online Product Database for more information Note that when both a linear and a quadratic efficiency equations are available the linear equation should be used since quadratic equations are linearized by RETScreen If a linear efficiency equation is used set the temperature coefficient of Fr UL to 0 SWH 15 RETScreen Software Online User Manual Values typically range from 0 000 to 0 010 this last value corresponding to collectors where thermal losses increase significantly with temperature Suggested number of collectors The model calculates the suggested number of collectors This value depends on the energy load collector type climatic conditions and season of use The suggested number of collectors is used as a Starting point only It is important to vary the actual number of collectors see Number of collectors in or
119. nalysis The GHG Analysis worksheet of each RET Workbook file has been developed with a common framework so as to simplify the task of the user in analysing the viability of different RET 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 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 SWH 81 RETScreen Software Online User Manual Use GHG analysis sheet The user indicates by selecting from the drop down list whethe
120. 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 solar water heating 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 Resources Canada the user would select the follow
121. nk and inside piping can provide space heating during winter months Losses due to snow and or dirt The user enters the percentage of energy lost due to the obstruction of the solar collector by snow and or dirt The value of this parameter depends on local climatic conditions on the tilt angle of the collector and on the presence of personnel on site to remove the snow or clean the collector SWH 20 RETScreen Solar Water Heating Project Model Depending on local conditions use 2 to 5 for evacuated tube collectors rack mounted on flat surfaces or well maintained collectors and 3 to 10 for other collectors Horizontal distance from mechanical room to collector The user enters the horizontal distance between the mechanical room and the solar collector in metres m It is assumed in the model that this parameter has no bearing on the energy analysis of the system This parameter is used in the Cost Analysis worksheet to estimate the cost of running horizontal piping to the collector Values typically range from 5 m in the case of a solar collector installed on the roof of a house to 20 m for industrial systems where solar collectors can be located on a structure outside the building or on the roof of another building Number of floors from mechanical room to collector The user enters the number of floors through which piping has to be installed to reach the solar collector The model assumes that this parameter has no bear
122. nlet water heater inlet A B Solar hot Solar hot water tank Cold water Cold water supply supply Coil in tank Side arm system heat exchanger To conventional water heater inlet Secondary A Cold water gt supply Larger system configuration Typical Heat Exchanger Configurations for Service Hot Water Solar Systems with Antifreeze Protection Annual Energy Production for months analysed This section summarises the annual energy production of the solar water heating project Note All energy values summarised here are calculated for the part of the year when the SWH system is in use Months during which the solar water heating system is not used are not taken into account in this analysis SWH system capacity The model calculates the SWH system capacity in kW as defined by the number of collectors and the aperture area of one collector Units switch The user can choose to express the capacity in different units by selecting among the proposed set of units MW million Btu h boiler hp ton cooling hp W This value is for reference purposes only and is not required to run the model Pumping energy electricity The model calculates the approximate amount of electricity MWh necessary to run the pumps of the solar water heating system during the months of use This value depends on solar radiation and is proportional to the Pumping power per collector area the Aperture area per co
123. nual solar radiation incident on the solar collector in MWh m2 from monthly data entered by the user in the Solar Resource amp Heating Load SR amp HL worksheet Annual average temperature The model calculates the annual average temperature in C from monthly data entered by the user in the Solar Resource amp Heating Load SR amp HL worksheet The annual average temperature typically ranges from 20 to 30 C depending upon the location SWH 10 RETScreen Solar Water Heating Project Model Annual average wind speed The model calculates the annual average wind speed in m s from monthly data entered by the user in the Solar Resource amp Heating Load SR amp HL worksheet Desired load temperature The user enters the desired load temperature C of the water delivered by the SWH system in the Solar Resource amp Heating Load SR amp HL worksheet and it is copied automatically to the Energy Model worksheet Hot water use If the user selects Service hot water as the application type then the value entered for Hot water use in the Solar Resource amp Heating Load SR amp HL worksheet is copied here It indicates the daily volume of hot water required at the desired temperature Number of months analysed The model calculates the number of months for which the equipment is used from monthly data entered by the user in the Solar Resource amp Heating Load SR amp HL worksheet Energy demand for months
124. ocated 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 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 the 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 selecti
125. 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 SWH 75 RETScreen Software Online User Manual 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 organisation 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 ROD or the time adjusted rate of return It is calculated by
126. of the reservoir e For better performance the solar loop must be as short as possible and made of a larger pipe diameter than pumped systems 19 mm or 34 inch minimum even in small residential DHWS Note that well designed thermosiphon systems may have similar heat performance to pumped systems and can be considered in a pre feasibility analysis using RETScreen 2 Direct loop pumped systems e System with no heat exchanger service hot water circulates directly in the solar loop e Simple low cost design suitable for warm climates or seasonal applications in cold climates Note that unglazed solar outdoor pool heaters are direct loop systems connected in line with the filtration system 3 Indirect loop pumped systems e Possible use of an antifreeze mixture in the solar loop e Requires a heat exchanger A external 1 external with natural circulation side arm type operating like a thermosiphon avoids the use of a secondary circulator in smaller systems following figure example B and ii external with a secondary loop using a secondary circulator the only configuration with 2 pumped circuits is a common design for larger systems 15 m and above following figure example C B coil in tank also called internal coil following figure example A and C wrap around or tank in tank SWH 25 RETScreen Software Online User Manual To conventional To conventional water heater i
127. 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 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 ey ee es ee ee 2 m a Se ee ee ee L a E O person year pra E e _pound force square inch psi second s a es er ee List of Units Symbols and Prefixes SWH 6 RETScreen S
128. oftware Online User Manual Training and Support The user can obtain current information on the RETScreen Training amp Support at the following Website address www retscreen net e training SWH 104 RETScreen Solar Water Heating Project Model 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 watranties 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 losses costs including solicitor and client costs damages actions suits or proceedings arising out of related to or occasioned by any use of RETScreen Internati
129. olar Water Heating Project Model Some currency symbols 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 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 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 MyFiles directory automatically set by the RETScreen installer program on the hard drive The download procedure is presented in the next 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
130. ology centre with non chlorinated ocean or spring water where water is renewed continuously However in this latter case it is recommended to validate the results by comparing the results with those obtained when the model is set for Service hot water application type with aquaculture as the Building or load type Wind sheltering coefficient The user enters a coefficient characterising the attenuation of wind speed near the pool due to obstacles such as buildings trees and fences The wind speed values entered in the Monthly Inputs section are typically measured at a height of 10 m They are multiplied by the wind sheltering coefficient prior to evaluating evaporative losses from the pool Recommended values are between 0 1 for a very sheltered pool to 0 3 for an open air pool Higher values of the wind sheltering coefficient can be considered only for very exposed locations SWH 37 RETScreen Software Online User Manual Note that the wind sheltering coefficient has a significant influence on the estimated energy requirement for heating the pool Evaporative losses are strongly dependent on wind speed at the pool surface and can represent up to 60 of all energy losses of the pool It is usually safer to consider a larger wind shelter coefficient 0 3 than a smaller one 0 1 to estimate the amount of energy displaced by the solar heating system because smaller values will tend to under estimate the energy requirements of the
131. on 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 SWH 43 RETScreen Software Online User Manual 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 Second 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 mon
132. on 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 SWH 78 RETScreen Solar Water Heating Project Model 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 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 dividing 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 Ye
133. on schedule for tax purposes SWH 69 RETScreen Software Online User Manual 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 offset any o
134. onal 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 SWH 105 RETScreen Software Online User Manual 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 that the Centre may periodically inform the user of product upgrades and be able to report on the global use of RETScreen SWH 106 RETScreen Solar Water Heating Project Model Bibliography American Society of Heating Refrigerating and Air Conditioning Engineers ASHR
135. onel 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 SWH 101 RETScreen Software Online User Manual 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 for reference purposes only Data entered using the online weather database 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 the NASA sa
136. orksheets can be used to enter more details about the project to prepare graphs and to perform a more detailed sensitivity analysis SWH 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 Heating Load Calculation worksheets are used to help the user calculate the annual energy production for a solar water heating system 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 solar water heating system are detailed in the following sections 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 user 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 and Heating Load worksheet and it is copied automatically to the Energy Model worksheet Note At this point the user should complete the Solar Resource amp Heating Load SR amp HL worksheet Annual solar radiation tilted surface The model calculates the total an
137. ormation Monthly average wind speed The user enters the average wind speed for the month in m s This value is used to estimate the energy requirements of outdoor swimming pools and the performance of unglazed solar collectors The user can consult the RETScreen Online Weather Database for more information Monthly average daily radiation in plane of solar collector The model calculates the amount of solar radiation received on average during one day on a tilted surface at the site in kKWh m d Typical values calculated by the model range from 0 to 10 kWh m d 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 SWH 33 RETScreen Software Online User Manual 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 season of use Average wind speed The model calculates the average wind speed in m s for the entire year and for the period season of use Water Heating Load Calculation Water heating load characteristics are entered by the user in this section This includes the type of application service hot water or swimming pool
138. ot required e Systems with photovoltaic powered pumps as the required electric energy is produced by photovoltaic panels e Outdoor swimming pool systems when the filtration system pump can be used for the solar loop when solar loop requires a high head e g collectors placed too high above pool level a booster pump may be required and e Industrial type systems where water is simply diverted through the collectors before being delivered to the load In direct loop SWH systems Technical Note 2 only one pump is generally required to circulate water from the tank through the solar collectors Values ranging from 3 to 22 W m are typical Use higher values if the solar loop diameter is small or length is long in proportion to solar collector aperture area The following table provides power requirements for typical circulators SWH 19 RETScreen Software Online User Manual Collector Aperture Area Solar Pump Specific Pump Power Range m W W im 2 to 6 20 to 45 to 12 85 12 to 35 185 35 to 60 205 Typical Solar Pumps Used Depending on Collector Array Size With indirect loop SWH systems using an antifreeze mixture and operated in cold climates it is important to note that the pump power has to be greater than direct systems operated in mild climates This to compensate when the system starts for the high viscosity of the colder transfer fluid in outdoor piping or the head required to fill the solar loop of a
139. 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 system 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 exempt from sales taxes Users will have to consider these costs for their region when preparing their evaluations For example if in a particular region sales tax is applicable to the cost of a solar water heating 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 item represents the sum of the costs incurred to assess the feasibi
140. p the solar pump liquid handling unit the heat exchanger and the storage tank s and or to the load Interconnecting plumbing also includes all the required complementary plumbing to finalise the SWH system installation such as strainer balancing or globe valves gates and check valves pressure temperature relief valves and expansion tank A controller may also be required to activate the solar pump when there is sufficient heat available from the solar collectors The cost of material for the interconnection plumbing interface will depend on the pipe diameter and on the complexity of the interface plumbing number of heat exchangers to be connected number of storage tanks to be connected etc Costs for the interconnecting plumbing can be estimated roughly to be equal to 1 3 to 1 2 of the solar loop costs The cost for the SWH 57 RETScreen Software Online User Manual complementary plumbing accessories is between 70 project to 500 project depending on the solar water heating system size on the pipe diameter used and on the number of solar hot water tanks to be interconnected The cost for a service hot water system controller is about 150 to 220 A pool controller cost is about 200 and a motorised valve is about 200 to 250 Collector installation Solar collector installation refers to all the site labour required to install the solar collectors including the collector structure Special equipment is not generally requir
141. pool Pool covers are used primarily for this reason Pool shading factor The user enters a coefficient characterising the average shading of direct solar radiation on the pool itself over the season of use of the SWH equipment This is used by the model to reduce direct passive gains of a standard pool Note that pools located in a non heated greenhouse can not be simulated using RETScreen Typical values range from 0 for a pool without any obstacles to 50 for a pool surrounded by trees and buildings No shading factor shall be considered for the use of a pool blanket even opaque Cold water temperature minimum and maximum The user selects the type of method used to specify cold mains water temperature The options from the drop down list are Auto and User defined If Auto is selected the model automatically calculates the temperature of the cold water from temperature data specified in the Monthly Inputs section The corresponding yearly minimum and maximum are shown in the next two lines If User defined is selected the minimum and maximum cold water temperature values are entered by the user In the Northern Hemisphere the model assumes that the minimum temperature occurs in February and the maximum in August a sinusoidal temperature profile is used for other months The situation is reversed in the Southern Hemisphere If mains water comes from a deep well of which the temperature is nearly constant throughout th
142. r industrial applications Note The maximum suggested solar collector area is limited within the software to equal the pool area This is a rule of thumb used in the industry Total gross collector area The model calculates the total gross area of the collectors in m The total gross collector area may range from a few square meters for a residential hot water system to up to hundreds of square meters for large commercial or industrial applications Note that the user may be limited by space available on the roof of the building in the case of a roof mounted system SWH 16 RETScreen Solar Water Heating Project Model Storage This sub section deals with the characteristics of the storage tank Ratio of storage capacity to collector area The user enters the desired number of litres of storage per square meter aperture area of solar collector L m The larger the storage the better the system will be at going through long periods with little sunshine although this will increase stand by losses and initial equipment costs The nominal value should be 75 L m typical values range from 37 5 to 100 L m Note that Ratio of storage capacity to collector area is to be modified if the user wants to keep the same storage volume in a sensitivity analysis on collector aperture area otherwise storage will vary proportionally to collector aperture area Storage capacity The model calculates the capacity of the hot water s
143. r 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 is entered for reference purposes only in the Energy Model worksheet and it is copied automatically to the GHG Analysis 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 GHG Analysis worksheet Global Warming Potential of GHG The model indicates the global warming potential of methane CH4 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
144. r per collector aperture area W m Current costs for standard circulating pumps in commercial systems range from 1 0 W to 5 W The lower end of this price range is for larger projects If the SWH system configuration considered includes a secondary loop see Technical Note 2 the consumption of the second pump is already considered if the wattage indicated under Quantity for the circulating pump if the user included it under the Pumping power per collector area item in the Energy Model worksheet The table below shows typical costs for circulating pumps Circulating pump costs can exceed 30 W in residential systems using low power high efficiency pumps If a photovoltaic PV powered pump is used use at least twice the suggested cost as DC pump are generally more expensive than AC pumps and a power conditioner is required to avoid overheating of the motor at low solar radiation levels Collector Aperture Area Circulating Pump Circulating Pump m W S W 2 to 6 20 to 45 to 12 85 12 ta 35 185 35 to 60 205 Costs of Typical Circulating Pumps SWH 54 RETScreen Solar Water Heating Project Model Heat exchanger The user enters a heat exchanger cost only under the two following conditions Heat exchanger antifreeze protection has been selected in the Energy Model worksheet and the Solar storage tank cost does not already include a heat exchanger which is the case if an internal heat exchanger is used
145. r project technology and or regional differences not specifically covered in the generic information provided SWH 63 RETScreen Software Online User Manual 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 SWH 64 RETScreen Solar Water Heating 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 strea
146. 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 SWH 67 RETScreen Software Online User Manual Retail price of electricity The retail price of electricity is transferred from the Cost Analysis worksheet This value is used in conjunction with the electricity required to run the pumps of the solar water heating system in order to calculate the system annual cost of fuel electricity This value 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 retail price of electricity yearly according to the energy cost escalation rate starting from year 1 and throughout the project life 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 life of the project This permits the user to apply rates of inflation to fuel electricity 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 Inflation The user enters the inflation rate which is the projected annual average rate of inflation over
147. 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 N O emission factors for a number of fuels are included on pages 1 35 and 1 36 of the IPCC Reference Manual CO2 CH4 and N20 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 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 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 For more information on determining GHG emission factors see the revised IPCC Guidelines for National Greenhouse Gas Inventories CO emission factors for man
148. rmal 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 collector 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 following figure If two walls are being used the average of the absolute values for the orientation should 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 so
149. ro CO2 CH and NO emission factors Units are given as a percentage of actual water heating energy output gigajoules of heating energy to primary heat potential gigajoules of heat or electricity GHG emission factor The model calculates the GHG emission factor for the base case heating system 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 heating energy delivered tco MWh Proposed Case Heating System Solar Water Heating Project The proposed case heating system or mitigation system is the solar water heating system It is defined in terms of its fuel types its emissions of GHG and its conversion efficiencies Note that in all cases the pumps if any of the solar water heating system are assumed to be electricity driven using the base case electricity system The proposed case system is normally referred to as the mitigation option in standard economic analysis Fuel type The fuel type of the solar water heating system is assumed to be solar electricity is used to drive the pumps Fuel mix The fuel mix of the solar water heating system is assumed to come from two sources i e solar and electricity totalling 100 SWH 89 RETScreen Software Online User Manual CO2 CH4 and N20 emission factors Custom analysis The user enters the CO CH and N O emission factors co
150. roject has been identified through the feasibility study or sometimes just a pre 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 SWH projects there are a number of possible project developers Currently a common approach is for the client to be the building owner with the developer being the local solar water heating system product supplier who provides complete design build services General contractors may also be the developers purchasing the solar water heating system on behalf of the building owner It is also possible that an Energy Services Company ESCO could be the project developer The ESCO purchase the solar water heating system and install it on a building owned by a third party in return receiving a portion of the annual energy savings production Estimating the costs of development phase will depend on the particular development arrangement established Items here include costs for permits and approvals project financing development phase project management and any development related travel costs These costs are detailed below Permits and approvals A building and electrical permit may be required for the construction of the project Drawings done in the preliminary design showing the structural integration into t
151. rresponding to the solar energy provided by the solar water heating system The model provides the electricity emission factors corresponding to the electricity mix of the base case electricity system For each fuel type selected units are given in kilograms of gas emitted per gigajoule of primary heat used by the solar water heating system kg GJ CO2 CH4 and N20 emission factors Standard analysis The model provides the CO CH and N O emission factors corresponding to the fuel type i e solar and electricity for the solar water heating system The electricity values correspond to the electricity mix of the base case electricity system For each fuel type selected units are given in kilograms of gas emitted per gigajoule of primary heat used by the solar water heating system kg GJ Fuel conversion efficiency Fuel conversion efficiencies for both the solar energy and electricity are set to 100 This value is used in conjunction with the CO CH and NO emission factors to calculate the aggregate GHG emission factor for the solar water heating system Units are given as a percentage of actual water heating energy output gigajoules of heating energy to primary input gigajoules of heat GHG emission factor The model calculates the GHG emission factor for the proposed project Values are calculated based on the individual CO CH and N O emission factors and the fuel conversion efficiency Units are given in tonnes equiv
152. rs and Conversion Efficiencies SWH 84 RETScreen Solar Water Heating Project Model Fuel mix The user enters the fuel mix of the base case electricity system for each fuel type Units are given as percentages of total electricity supplied Note that the user should verify that the sum of all fuel types listed in the fuel mix column equals 100 CO2 CH4 and N20 emission factors Custom analysis The user enters the CO 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 grid connected projects 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 each fuel type selected units are given in kilograms of gas emitted per gigajoule of heat energy generated kg GJ 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 more information on determining GHG emission factors see the
153. s liquid handling unit and controller installation including electrical connection and interconnection plumbing between this equipment and the solar loop This installation also includes all the required complementary plumbing accessories to be installed such as strainer balancing or globe valves gates and check valves pressure temperature relief valves and expansion tank Typically the labour cost is between 20 h to 40 h for a non specialised worker and 40 h to 75 h for a professional plumber and a professional electrician Pipe preparation and cutting pipe insulation and jacketing and pipe support can be done by a non specialised worker Pipe soldering and connection to equipment must be done by a professional plumber The user enters a single amount for the entire project The cost range for auxiliary equipment installation is between 6 m and 20 m of pipe length depending primarily upon the number of complementary plumbing accessories required such as strainer valves etc the number of connections per pipe meter the installation accessibility pipe and equipment installation facility the pipe diameter and the site labour hourly rate Plumbing length depends on the number of pieces of equipment and distance between each one Typically the pipe length for a SWH system including a circulator one heat exchanger and one storage tank is 6 to 20 m For example auxiliary equipment installation cost for a pool SWH system requir
154. s up to 60 Solar fraction The model calculates the fraction of the water heating load for the months analysed see Energy demand for months analysed in the Site Conditions section met by the solar water heating system For service hot water applications the annual energy needs covered by a SWH system the solar fraction are typically between 10 to 70 of the annual water heating load depending on climate system size and load The optimal size in terms of system cost effectiveness is generally obtained for solar fractions between 30 to 50 on a 12 months operation basis e For most service hot water systems without storage this value should not exceed 15 e For service hot water systems with storage this value can range anywhere from 10 to 70 SWH systems designed for year long operation in temperate climates will have solar fractions typically between 30 and 50 e For swimming pools this value can range from 10 to 100 generally 70 to 100 in the case of seasonal outdoor pools SWH 27 RETScreen Software Online User Manual Renewable energy delivered The model calculates the amount of energy delivered by the solar water heating system for the months analysed in MWh Typical values depend on the type of application considered This value is transferred to the Financial Summary worksheet Units switch The user can choose to express the energy in different units by selecting among the proposed set of uni
155. se equipment Balance of system The balance of system 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 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 For example in Canada the Renewable Energy Deployment Initiative REDI may provide a 25 contribution for certain renewable energy systems used for heating and cooling applications The contribution is 40 for systems installed in Canada s remote communities More information may be obtained from the REDI Website or by calling 1 877 722 6600 SWH 73 RETScreen Software Online User Manual 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 the fuel electricity costs and debt payments Note that the total annual
156. ser 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 percentage 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 b
157. te 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 Collector 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 watranty in respect to this database or assumes any liability arising out of this database Product manufacturers interested in having their products listed in the product database can reach RETScreen International at RETScreen International CANMET Energy Technology Centre Varennes Natural Resources Canada 1615 Li
158. te tierce Rhee ORE 48 61 62 74 O amp M labour aniren e nea reas 61 62 Other 35 47 49 51 56 57 60 62 63 84 101 SWH 109 RETScreen Software Online User Manual P Perform analysis On csssesecsseeseeeecnereeeneeees 92 93 Perform risk analysis t00 sesser 92 Periodic Costs Credits c ccccccccsseeesteceseeeeees 63 75 Permits and approvals ccscceseeeseeseeereeeeeeseeeeees 47 Pip diameter se eiie nies a ee ee Sos 18 Piping and solar tank losses 20 Plumbing and Control ee eceseeeeesecreeeecneeeeeneeees 57 P l ron nsere t e waves ascee 36 Pool shading factor ee eeesecseceeeeecneeeeeneeeees 36 38 Preliminary design oo eee sescsseeceesecreesecnereeeeeeeees 46 Pretax es scivtcavovennd a a r 75 79 Printing a Fil enres ine Soe r 8 Product Data 5 7 10 14 15 23 40 51 101 Project Costs and Savings 65 72 Projectdebt asrining nr rs 78 Project CQuIty css eesiei ion eri ara ies aAA 78 Project financii n i rene deine Gs aeih 48 Project Hite coteersestes eveeesseuie erie eee ieee ets 68 Project location ccscecceeseeeseeeseeeeeeees 10 65 82 93 Project management 0 eee ee eset ceee esac ceeeeeeeeees 48 Project Name cs cccsiee cetieeccnties creates 10 65 82 92 Property taxes Insurance e cee eee eseeeeeeeeeeees 61 Proposed case GHG emission factor eseeeeee 91 Proposed Case Heating System Solar Water H
159. teceeseeeeeeeeees 9 80 Brief Description and Model Flow Chart 4 Building or load type ee eeeeceeeeceeeeeeteeeeeees 35 37 G Calculate GHG reduction cost seesseeeeeeeeeeeeeeeee 78 Cell Colour Coding niise neii 5 Circulating pump S ssseeeeeeseeeeseeeeereresrrrererrersesreee 54 Click here to Calculate Risk Analysis 00 98 Click here to Calculate Sensitivity Analysis 93 Cold water temperature minimum and maximum 38 Collector installation cece eseeeectecneeeeeeeeeees 58 Collector support Structure 0 0 leet rere 57 Collector type eee eeeesecesecsecseesseeeneeeeeeeeees 13 101 Construction SUPETVISION ce eeeeeseeteeeeeeeeeees 50 51 Contingencies csacciie ieee denis 61 62 Copyright and Trademark ceeeeseeeeeeeeeeeeeee 105 Cost Analysis 6 9 14 17 18 21 27 40 42 45 65 68 69 70 72 74 75 103 COSt Dafa iere enne ea r E EE E EEES 103 Cost references ua e E EEA 6 42 43 Cumulative Te eane n E 65 79 80 Cumulative Cash Flows Graph eeseeeeeeeeeee 65 80 CUITENGCY ea a a A E RE 6 42 44 Currency Option Seisei ess aienea vea 6 CUSO surte 82 83 84 85 86 88 90 D Data amp Help Access s nsosseeeeeeeeeeeeeee 5 10 101 102 Days per week system is used 0 0 ceeeeeeeeeeeeeeeeeees 36 Debt interest rate ceccceecesceceesseeeenseeeeeenes 69 96 Debt payments eee eeeeeeeeeeeeeeeeees 74 78 79 Debt payments debt term
160. tellite 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 only 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
161. ter use This item is used if the Building or load type is not Industrial Aquaculture or Other Hot water use The user enters the daily hot water use L d averaged over the season of use of the solar water heating equipment If this value is known for example from energy bills it should be used here As a rule of thumb hot water use for a residential application is 1 3 of the total water use as shown on the water bill If it is not known the estimate from the previous item Estimated hot water use at approx 60 C can be entered For loads such as Industrial Aquaculture or Other the hot water use has to be estimated from energy bills through a manual calculation or from other data sources SWH 35 RETScreen Software Online User Manual Desired water temperature The user enters the temperature of the load in C This is used in the model to calculate the energy requirements of the system Values range from less than 12 C for aquaculture applications to 60 C or higher for domestic or industrial applications Note that if the value provided in the model for Estimated hot water use at approx 60 C is used as the Hot water use then the Desired water temperature should be set to 60 C Days per week system is used The user enters the number of days per week the SWH system is used during the season of use This value is used in the model to reduce the energy requirements of the system by a propor
162. ter 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 using 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 heating energy The avoided cost of heat
163. ther 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 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 a project profitable 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 SWH 70 RETScreen Solar Water Heating Project Model When None is selected the model assumes that th
164. tional amount Values range from 1 to 7 For example in the case of a school that is closed during the weekend enter 5 For a cottage used during weekends only enter 2 For a system used all week enter 7 Type of pool The user selects the type of the swimming pool from the two options in the drop down list Indoor and Outdoor Outdoor swimming pools experience climatic conditions defined in the Monthly Inputs section The wind speed is multiplied by the attenuation factor defined in the Wind sheltering coefficient item Direct solar radiation incident upon the pool is multiplied by the attenuation factor defined in the Pool shading factor item Sky temperature is calculated from the meteorological data entered by the user The following assumptions are made on the climatic conditions for the evaluation of indoor swimming pools in the model ambient temperature 27 C ambient relative humidity 60 inside air motion equivalent to a wind speed of 0 1 m s Generally there is no direct or diffuse solar radiation incident upon the pool Sky temperature is 27 C In addition a normal activity level in the pool is assumed Pool area The user enters the area of the pool in m Values range from 20 m for small residential pools to 1 000 m or more for city pools and aquatic parks SWH 36 RETScreen Solar Water Heating Project Model Use of cover The user enters the number of hours per day h d a cover blanket is put
165. torage tank in L This is calculated in the model as the product of Ratio of storage capacity to collector area Aperture area of one collector and Number of collectors Storage capacity is application dependent It can range from a few hundred litres for residential applications to several thousand litres for industrial applications For domestic hot water applications storage capacity is typically equal to the daily hot water use or a little less Balance of System This sub section deals with the characteristics of the balance of system which includes piping pumps and an optional heat exchanger In the Cost Analysis worksheet items generally supplied by the solar equipment manufacturer or directly related to the solar loop are considered as part of the Energy Equipment installation and materials locally purchased or supplied by the installer are listed as part of the Balance of System For a better understanding of the different components involved in different design configurations of a SWH system Technical Note 2 may be consulted Heat exchanger antifreeze protection The user selects whether or not an heat exchanger is used The user selects Yes if the collector loop is separated from the rest of the system by a heat exchanger If this is the case the model assumes that an antifreeze fluid such as glycol circulates through the collector loop thereby providing antifreeze protection to the system in the winter The user sele
166. ts GWh Gcal million Btu GJ therm kWh hp h and MJ This value is for reference purposes only and is not required to run the model SWH 28 RETScreen Solar Water Heating Project Model Solar Resource and Heating Load Calculation As part of the RETScreen Clean Energy Project Analysis Software the Solar Resource and Heating Load Calculation worksheet is used in conjunction with the Energy Model to calculate the energy load and energy savings of a solar water heating system The user can consult the RETScreen Online Weather Database for more information Site Latitude and Collector 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 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 are 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 more information The latitude of the closest weather location can be pasted to the spreadsheet from the online
167. ts 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 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 SWH 103 RETScreen S
168. uate feasibility study and develop and 8 000 to design engineering build install and commission the user could enter 80 as the depreciation tax basis in order to depreciate only the engineering energy equipment balance of system 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 SWH 71 RETScreen Software Online User Manual 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 number of years
169. uels and for different types and sizes of heating equipment The default factors provided are those which are representative of large heating plants For smaller plants and for greater accuracy the user may select the Custom type of analysis and specify the emission factors For each fuel type selected units are given in kilograms of gas emitted per gigajoule of primary heating energy 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 The default values provided by the model are given in the Default Emission Factors and Conversion Efficiencies table SWH 88 RETScreen Solar Water Heating Project Model Fuel conversion efficiency The base case heating system fuel conversion efficiency is entered by the user in the Energy Model worksheet and is transferred to the GHG Analysis worksheet The fuel conversion efficiency represents the annual average efficiency of energy conversion from primary heat potential to actual heating 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 ze
170. ustrial water heating systems for which EF ratings don t exist All shown efficiency values are approximate and typical values Solar Collector This sub section deals with the characteristics type and area of the solar collector Collector type The user selects the collector type from the three options in the drop down list Unglazed Glazed and Evacuated These three basic solar water heating collector technologies exhibit different performances under various climatic conditions and also present large differences in SWH 13 RETScreen Software Online User Manual cost per collector area For more information Technical Note 1 should be consulted There are other technologies available such as double glazed flat plate collectors concentrating collectors or collectors with integrated storage capacity However they are not included in the current version of RETScreen The user can consult the RETScreen Online Product Database for more information Note that different technologies have different costs unglazed collectors having the lowest cost and evacuated collectors having the highest costs A balance has to be reached between efficiency and cost this issue will be addressed in detail in the Cost Analysis worksheet Solar water heating collector manufacturer The user enters the name of the solar water heating collector manufacturer This is for reference purposes only The user can consult the RETScreen Online Product
171. utton 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 SWH 93 RETScreen Software Online User Manual Sensitivity Analysis for This section presents 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 heating 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 parame
172. water storage tank the solar loop piping materials the solar loop pump and the heat exchanger Transportation costs are estimated separately to allow for cost differentiation in 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 detailed below Solar collector The cost of the solar collector depends on the type of solar collector used and the total solar collector gross area required The user enters a m price The user enters the total array required m in the Energy Model worksheet Note that total area is based on the gross area of the solar collector The user can refer to the following table to help estimate the cost of the solar collector The user may refer to the RETScreen Online Product Database for supplier contact information in order to obtain prices or other information required SWH 51 RETScreen Software Online User Manual Solar Collector Description Cost Range Bian bm Plastic unglazed liquid flat plate solar collectors 50 to 90 Single glazed flat plate solar collectors 180 to 310 Evacuated tube solar collectors 900 to 1 100 Cost of SWH Collectors The lower end of these cost ranges is for large projects where volume purchase discounts may come into play In addition to single large systems this could include a volume purchase of multiple residential SWH systems Small singl
173. 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 Slope of solar collector The user enters the angle between the solar collector and the horizontal in degrees In most cases the slope of the collector 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 solar collector 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 solar collector in the summer 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 solar collector in the winter This slope is also recommended in cold climates to minimise snow accumulation or SWH 29 RETScreen Software Online User Manual e Equal to the slope of the roof on which the collector 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 Azimuth of solar collector The user enters the angle between the projection on a horizontal plane of the no
174. y delivered The Energy Model worksheet calculates the renewable energy delivered which is equivalent to the heating energy delivered MWh by the project This energy displaces the heating energy that would have otherwise been delivered by the conventional or base case system The renewable SWH 65 RETScreen Software Online User Manual energy delivered is used in conjunction with the avoided cost of heating energy and the base case heating system seasonal efficiency to calculate the heating energy savings Heating fuel displaced The heating fuel displaced is the type of heating energy displaced by the addition of the project The heating fuel type selected in the Energy Model worksheet is transferred here The heating fuel displaced is used in the calculation of the heating energy savings Electricity required The Energy Model worksheet calculates the electricity required MWh to run the pumps of the solar water heating system during the heating season Net GHG emission reduction The model calculates the net annual average GHG emission reduction in equivalent tonnes of CO per year tco yr resulting from the implementation of the system instead of the base case or baseline heating system This value is calculated in the GHG Analysis worksheet and is copied here automatically Net GHG emission reduction credit duration The model calculates the cumulative net greenhouse gas GHG emission reduction for the duration o
175. y fuels are included on page SWH 85 RETScreen Software Online User Manual 1 13 of the IPCC Reference Manual CH and N O 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 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 actual power plant 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 Units are given as a percentage of primary heat potential gigajoules of heat to actual power plant output gigajoules of electricity Fuel types which emit no GHGs e g solar 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

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