Solar-Thermal Feasibility Study Farm #5 Boutique Winery

Transcription

1 Solar-Thermal Feasibility Study Farm #5 Boutique Winery Mirko Slivar Stantec Consulting Ltd. Suite nd Avenue, Kamloops, B.C.

2 Prepared for: Prepared by: Stantec Consulting Ltd. Suite nd Avenue Kamloops, B.C. V2C 5W1 Contact: Mirko Slivar, P.Eng., CEM Tel: Project # July 17,

3 TABLE OF CONTENTS LIST OF FIGURES AND TABLES EXECUTIVE SUMMARY SITE INFORMATION FARM OPERATION LOCATION EQUIPMENT UTILITY INFORMATION THERMAL LOAD CALCULATIONS HOT WATER CHILLED WATER HEATED AIR SOLAR-THERMAL SYSTEM SELECTION SOLAR HOT WATER SOLAR-THERMAL SYSTEM SIZING SOLAR HOT WATER MANUAL METHOD RETSCREEN METHOD NOTE ON MANUAL VERSUS RETSCREEN RESULTS FINANCIAL ANALYSIS SCENARIO #1: MINIMUM PRICE OF FUEL REQUIREMENT SCENARIO #2: CAPITAL FUNDING REQUIREMENT SCENARIO #3: RENEWABLE HEAT INCENTIVE REQUIREMENT APPENDIX A DETAILED CALCULATION OF HOT WATER USAGE APPENDIX B MANUAL CALCULATIONS OF SOLAR POTENTIAL APPENDIX C RETSCREEN RESULTS FOR SOLAR HOT WATER APPENDIX D FINANCIAL ANALYSIS DATA

4 LIST OF FIGURES AND TABLES Figure 1. Energy Demand Profile of Natural Gas Use for Farm # Figure 2. Schematic of Closed-Loop Solar Hot Water System for Farm # Figure 3. Monthly Radiation - Incident and Usable for Farm # Figure 4. Hot Water Demand Versus Solar Hot Water Output for Farm # Table 1. RETScreen Solar Hot Water Inputs for Farm # Table 2. Comparison Between Manual and RETScreen Results for Farm # Table 3. Scenario #1: Minimum Price of Fuel Requirement for Farm # Table 4. Scenario #2: Capital Funding Requirement for Farm # Table 5. Scenario #3: Renewable Heat Incentive Requirement for Farm # Table 6. Summary of Monthly Radiation - Incident and Usable for Farm # Table 7. Detailed Monthly Radiation Data for Farm # Table 8. RETScreen Solar Hot Water Model for Farm # Table 9. Financial Analysis Data for Farm #

5 1 EXECUTIVE SUMMARY B.C.'s agricultural sector consumes significant quantities of energy. Renewable energy from the sun present agricultural operators with an opportunity to decrease their utility costs, become more energy independent and reduce the environmental impacts of their operations. This study looked at the potential of using solar-thermal systems (namely hot water, chilled water and heated air) for heating and cooling at a boutique winery, located in the Okanagan Valley. The winery produces over 50,000 cases of wine annually and operates a wine shop and a full-service restaurant that seats about 114 guests and is open daily for lunch and dinner. There is a potential for using solar-thermal hot water, chilled water and heated air at this winery only if the restaurant is taken into consideration. While the winemaking process uses some hot water for barrel washing, most of the hot water demand at this operation is for the restaurant. The restaurant uses about 9,080 litres of water at 60 C per day, which is heated by an 80 per cent efficient natural gas boiler. Installing a 54-collector solar hot water system at an estimated cost of $225,000 will reduce the restaurant's annual energy use for hot water from about 960 GJ to 557 GJ for an annual saving of about $3,600. Due to the low cost of natural gas this study concludes that to make the proposed solar hot water system financially viable, one of the following conditions must be met: 1) The price of natural gas would need to increase from $8.87/GJ to $21.50/GJ based on a 10 per cent return on investment; or 2) A one-time capital cost rebate of $100,200 (equivalent to $800 per square metre of solar collector or 45 per cent of total installed cost) is needed based on a 5 per cent return on investment; or 3) A renewable heat incentive of $0.032/kWh of heat energy produced over a 25-year period is needed based on a 10 per cent return on investment. The chilled water demand at this operation is for the winemaking process. Jacketed fermentation tanks are used to control the temperature of the wine during primary and secondary fermentation. These tanks flow a liquid (in this case glycol) around the outside of the tank to control the temperature of the wine inside of the tank. During fermentation the wine is cooled to maintain a final temperature of 10 to 20 C, or 2 C depending on the style of wine being made. This equates to a chilled glycol temperature demand of 3 to 10 C. Solar chilled water systems are limited to delivering down to a temperature of 7 C; therefore this type of system is not suitable for this operation. There is no demand for preheating of ventilation air for the winemaking process or its buildings. However, there is demand for ventilation air for the restaurant's kitchen, and this demand is yearround. Based on a high level assessment of the restaurant operation considering the amount of ventilation air required (830 cubic feet per minute), installing a 19 square metre solar heated air system at an estimated cost of $5,700 will save the operation about $272 per year. This works out to a simple payback of 21 years. This study concludes that solar heated air is not financially viable, and therefore is not a suitable technology for this application. Budget estimates provided in this study are generalized costs. The above findings are based on current figures and current industry practices and as such can change with time, with location and with physical on-site findings. Hence, these findings may prove to be more or less viable upon a detailed engineering design and competitive pricing. This paper is part of the Benchmarking of Solar-Thermal Technologies in B.C.'s Agricultural and Agri- Food Operations (a.k.a. main feasibility study) and should be referenced as such. Other agricultural and agri-food operators can use this paper to determine the suitability of using solar-thermal systems at their own operations. Stantec Consulting Ltd. 5

6 2 SITE INFORMATION In the Okanagan, grape harvest usually starts late September and finishes by mid-november. At the beginning of the winemaking process a bit of heat is required to start the fermentation process and after that cooling is required. September to November the grapes are harvested, crushed and placed in fermentation tanks. To start the fermentation the 2 C crush is heated up to a final temperature of 10 to 15 C. During fermentation the wine is cooled to maintain a final temperature of 10 to 20 C, or 2 C depending on the style of wine being made. After primary fermentation the wine is transferred to secondary fermentation storage for maturation (November to February) and maintained at desired temperatures (15 to 20 C), and then bottled according to various production schedules. The winemaking building is unheated. During fermentation, unheated ventilation air is used to rid the building of carbon dioxide produced during fermentation. 2.1 FARM OPERATION The winery produces over 50,000 cases of wine annually and operates a wine shop and full-service restaurant that seats about 114 guests and is open daily (11:30 a.m. to 9:00 p.m.) for lunch and dinner. The restaurant is closed for three weeks in January. 2.2 LOCATION West Kelowna, B.C. Latitude 48.5 degrees and longitude degrees. The winery, located in the Okanagan Valley, is situated on a south-facing slope above Okanagan Lake and has good southern exposure to capture the sun with no shading issues from buildings, trees or mountains. There are four closely spaced flat roofed buildings on the property that house the winemaking operation, wine storage, wine store, restaurant and offices. There is limited space available on the roofs to mount collectors due to existing air handling equipment. Ground mounted collectors are not an option, as roadways front the buildings on two sides and the vineyard takes up the other sides. 2.3 EQUIPMENT Two 80 per cent efficient natural gas boilers supply hot water at 60 to 66 C (for winery and restaurant). Two hot water storage tanks (65-inches long by 27-inches in diameter). Fifty-one jacketed fermentation tanks with glycol heating and cooling. Natural gas forced air furnace for space heating of restaurant, wine shop and offices. Gas cooking equipment. 2.4 UTILITY INFORMATION In 2011, the winery used about 860,000 kwh of electricity at a total cost of about $62,600. This electrical consumption was used to operate winery equipment, fermentation cooling equipment, restaurant equipment, air conditioning equipment, lights, ventilation and other electrical equipment. In addition, the winery used about 5,020 GJ of natural gas at a total cost of about $16,600. This natural gas consumption was used for hot water, space heating and cooking in restaurant. The operation does not use propane. Stantec Consulting Ltd. 6

7 Figure 1. Energy Demand Profile of Natural Gas Use for Farm #5 Figure 1 shows the energy demand profile of natural gas for the years 2008 to As can be seen from the profile, there is a 200 GJ per month base demand for natural gas during the months of June, July, August and September. During these months there is no space heating demand and minimal demand for hot water for barrel washing. Therefore, this base load can be assumed to be for the restaurant, for hot water and cooking. Stantec Consulting Ltd. 7

8 3 THERMAL LOAD CALCULATIONS There is a potential for using solar-thermal hot water, chilled water and heated air at this winery only if the restaurant is taken into consideration. While the winemaking process uses some hot water for barrel washing, most of the hot water demand at this operation is for the restaurant. There is a demand for chilled water for the winemaking process. Furthermore, while there is no demand for preheated ventilation air for any of the winemaking buildings, there is a demand for preheated ventilation air for the restaurant's kitchen. 3.1 HOT WATER In order to design a solar hot water system the winery will need to know its daily hot water usage in litres per day. In this example, the operator does not know his hot water usage, so it was calculated using the natural gas utility bill and the equation: Q = 500 x gpm x T Where: Q is the heat energy (Btu/h). gpm is the flow rate (US-gallon/minute). T is the temperature rise (F). We are given: Monthly natural gas consumption 200 GJ (used in restaurant for hot water and cooking). Winery operation uses an 80 per cent efficient natural gas boiler to make hot water. Hot water usage 10 hours per day. Hot water temperature 60 C. Incoming supply water temperature 4 C. Calculated: Winery restaurant uses about 9,080 litres of water at 60 C per day. For a step-by-step calculation see Appendix A. 3.2 CHILLED WATER The chilled water demand at this operation is for the winemaking process. Jacketed fermentation tanks are used to control the temperature of the wine during primary and secondary fermentation. These tanks flow a liquid (in this case glycol) around the outside of the tank to control the temperature of the wine inside of the tank. During fermentation the wine is cooled to maintain a final temperature of 10 to 20 C, or 2 C depending on the style of wine being made. This equates to a chilled glycol temperature demand of 3 to 10 C. Solar chilled water systems are limited to delivering down to a temperature of 7 C; therefore this type of system is not suitable for this operation. 3.3 HEATED AIR There is no demand for preheating of ventilation air for the winemaking process or its buildings. However, there is demand for ventilation air for the restaurant's kitchen, and this demand is yearround. Based on a high level assessment of the restaurant operation considering the amount of ventilation air required (830 cubic feet per minute), installing a 19 square metre solar heated air system at an estimated cost of $5,700 will save the operation about $272 per year. This works out to a simple payback of 21 years. Stantec Consulting Ltd. 8

9 This study concludes that solar heated air is not financially viable, and therefore is not a suitable technology for this application. Amount of ventilation air required 830 ft 3 /minute (ASHRAE standard) Calculated collector area required = 830 ft 3 /minute divided by 4 = 207 ft 2 (19 m 2 ) Calculated potential annual energy savings = (207 ft 2 divided by 500) x 74 = 30 GJ Calculated potential natural gas savings = 30 GJ x $8.87/GJ = $272 Total cost to install solar heated air system = $5,700 (19 m 2 x budget $300 per square metre of collector). Stantec Consulting Ltd. 9

10 4 SOLAR-THERMAL SYSTEM SELECTION Of the potential solar-thermal systems explored in this study (namely hot water, chilled water and heated air), solar hot water is most suitable for this operation. 4.1 SOLAR HOT WATER The winery in this study has an ideal application for solar hot water in its restaurant operations because it is open year-round; has a steady hot water demand during daylight hours; and has good southern exposure for collectors with no shading issues from buildings, trees or mountains. Winery operating parameters: Latitude 48.5 degrees and longitude degrees. Hot water usage of 9,080 litres per day. Incoming supply water temperature 4 C. Hot water temperature 60 C. Year-round use (system requires freeze protection). Steady demand throughout day between 11:30 a.m. and 9:00 p.m. Given the above requirements a closed-loop solar hot water system was chosen for this case study. Figure 1 illustrates the operation of a closed-loop system. When the sun is out the collector heats up and the controller turns on the pump to transfer heat from the collector to the storage tank via the heat transfer fluid. In B.C., all solar hot water systems that operate during the winter require some sort of antifreeze protection. This can be achieved by installing a closed-loop system with a water-propylene glycol solution as the heat transfer fluid. The expansion tank minimizes pressure changes in the system due to volume change of the heat transfer fluid as the system heats up. Solar collector performance varies amongst manufacturers and the type of collector. For solar hot water systems collectors are divided into flat plate and evacuated tube. Both types of collectors are suitable for this application. However, there are two advantages to choosing a flat plate collector over an evacuated tube collector: 1) Flat plate collectors cost less than evacuated tube collectors (about $900 per collector and $3,500 per collector respectively); and 2) In cold weather a flat plate collector has the ability to melt snow and continue to operate, whereas an evacuated tube collector will not melt snow and will not operate when covered. Refer to the main feasibility study for a detailed discussion on how solar hot water systems work. Stantec Consulting Ltd. 10

11 Figure 2. Schematic of Closed-Loop Solar Hot Water System for Farm #5 Stantec Consulting Ltd. 11

12 5 SOLAR-THERMAL SYSTEM SIZING 5.1 SOLAR HOT WATER Sizing of solar hot water system for this case study was done using two methods: manual calculations and then again using RETScreen (a free software program used to review renewable energy projects). It is not anticipated that an agricultural operator will perform manual calculations. This method is included for benchmarking and informational purposes. It is expected agricultural operators will either retain a suitable solar consultant or use a software program such as RETScreen MANUAL METHOD The general procedure for carrying out the manual calculations is: 1) Determine monthly hot water demand (refer to Appendix A). 2) Determine monthly solar radiation available (refer to Appendix B). 3) Calculate amount of usable solar radiation based on operating parameters (refer to Appendix B). 4) Determine the number of solar collectors required. For this case study, the energy input from the sun to a square metre of south-facing collector is about 1,572 kwh annually; and the energy output of a square metre of south-facing collector is about 714 kwh annually. Figure 3 shows the energy input (green line) and usable energy (red line) for this site. Peak production occurs in July with 100 kwh per square metre of collector, and production drops to a low of 17 kwh per square metre of collector in December. Figure 3. Monthly Radiation - Incident and Usable for Farm #5 Stantec Consulting Ltd. 12

13 Generally, solar hot water systems are sized to supply 60 to 70 per cent of the annual hot water demand so that the likelihood of over sizing the system during summer peak solar intensities is minimized. Based on winery's monthly energy demand for hot water of 80 GJ (22,222 kwh) about 84 collectors could be installed as calculated: Monthly hot water demand = natural gas used x efficiency of hot water boiler = 22,222 kwh x 0.80 = 17,800 kwh/month Annual hot water demand = 17,800 kwh/month x 12 month/year = 213,600 kwh Assume a load saving of 65 per cent due to solar = 213,600 kwh x 0.65 = 138,840 kwh Annual usable solar from collector from Table 6 = 714 kwh/m 2 Area of collector required = 138,840 kwh divide by 714 kwh/m 2 = 194 m 2 Number of collectors = 194 m 2 divided by standard collector aperture 2.32 m 2 = 84 However, based on the available rooftop area, only about 54 collectors can be installed. These 54 collectors would produce about 322 GJ of annual solar hot water energy, which is about 42 per cent of the annual hot water energy required. Figure 4 shows the hot water demand (green line) versus the solar hot water output for a 54-collector system (red line). As shown, it is possible to use the sun to provide useful preheating of water throughout the year, especially during the summer. Figure 4. Hot Water Demand Versus Solar Hot Water Output for Farm #5 The proposed 54-collector solar hot water system will reduce the winery's annual energy use for hot water from about 960 GJ to 557 GJ for an annual saving of about $3,600 as calculated: Annual solar hot water energy = 54 collectors x standard collector aperture 2.32 m 2 x 714 kwh/m 2 x GJ/kWh = 322 GJ Natural gas offset = annual solar hot water energy divided by efficiency of hot water boiler = 322 GJ divided by 0.80 = 403 GJ Annual natural gas savings = 403 GJ x $8.87/GJ = $3,600 Stantec Consulting Ltd. 13

14 5.1.2 RETSCREEN METHOD RETScreen is a useful tool when it comes to making a decision about whether or not it is financially viable to use renewable energy technologies like solar hot water. Some of the user inputs are technical in nature so we have included user inputs and helpful comments, shown in Table 1, to assist agricultural producers who want to perform their own feasibility analysis using this program. A more detailed explanation of user inputs can be found in the main feasibility study. See Appendix C for RETScreen solar hot water energy model results for this case study. Table 1. RETScreen Solar Hot Water Inputs for Farm #5 Variable Input Comment Daily hot water use 9,080 litres/day Calculated from utility bill Hot water temperature 60 C Temperature set on boiler # of days per week solar water heater use 7 Restaurant open daily Supply temperature method formula Solar tracking mode fixed Typical installation in B.C. Slope of solar collector 40 Rule of thumb for B.C. Azimuth 0 Collectors pointed directly south Type of collector glazed Efficient for this application Manufacturer of collector Viessmann Leading manufacturer of solar collectors Model of collector Vitosol 100-F SV1 Efficient collector # of collectors 54 Estimated Miscellaneous solar heater losses 7% Typical value Storage yes Require hot water in the evening when the solar collector is no longer generating heat so need storage to hold hot water for later use Storage capacity per collector area 70 litres/m 2 60 to 80 litres/m 2 for intermittent usage generally allows flexibility for finding off the shelf tanks, is able to handle most overheating situations and has been verified by industry associations Heat exchanger yes Year-round system requires antifreeze protection (part of closed-loop system) Heat exchanger efficiency 95% Typical value Miscellaneous system losses 7% Typical value Pump power per collector 15 W/m 2 Typical value Electricity rate $/kwh Used by the program to calculate the cost of electricity used to operate the solar system Fuel type natural gas Fuel used to heat the water in your facility Seasonal efficiency 80% Typical value Fuel rate RETScreen Inputs $8.87/GJ Cost of fuel used to heat the water in your facility Stantec Consulting Ltd. 14

15 5.1.3 NOTE ON MANUAL VERSUS RETSCREEN RESULTS As a comparison, Table 2 is a summary of the calculation results for both the manual and RETScreen method. As shown, the results are very similar. Table 2. Comparison Between Manual and RETScreen Results for Farm #5 Manual vs RETScreen Results Variable Manual Calculations RETScreen Calculations Number of panels % of annual hot water energy offset by solar Estimated annual $ saved $3,600 $3,680 Estimated annual GJ saved Stantec Consulting Ltd. 15

16 6 FINANCIAL ANALYSIS To supply and install a solar hot water system can budget on spending $1,800 per square metre of flat plate collector. This budget cost is an established industry standard from numerous installations and includes materials, labour and permitting for a fully operational system as follows: Flat plate collectors 35 per cent Storage tanks 15 per cent Controls 10 per cent Miscellaneous (pumps, insulation, mixing valve, mark up and profit) 40 per cent The above price percentages are for a typical installation and may change depending on each installation s characteristics. The financial analysis that follows is based on the installation of a 54-collector solar hot water system at a total cost of $225,000 (54 collectors x standard collector aperture 2.32 square metre x budget $1,800 per square metre of flat plate collector). To determine the incentive required to make the proposed solar hot water system financially viable three scenarios were investigated: 1) What does the minimum price of fuel have to be? 2) What one-time upfront capital payment does there need to be? 3) What renewable heat incentive does there need to be? The return on investment for scenarios one and three above was set at 10 per cent and for the capital payment scenario a 5 per cent return on investment was deemed reasonable in relation to operator's reduced capital cost and the associated risks. For this study a Chabot profitability index of 0.3 was used and is defined as the net present value of the sum of the discounted energy bills over n years of operation divided by the initial investment cost (refer to the main feasibility study for a more detailed discussion on financial analysis and the use of the Chabot profitability index.) For reference see Appendix D for the calculated net present values over 25 years (analysis period) of the discounted energy bills, cost of maintenance and cost of electricity needed to operate the solar hot water system. 6.1 SCENARIO #1: MINIMUM PRICE OF FUEL REQUIREMENT This scenario looked at what the minimum energy price, by fuel type, would need to be to make the proposed solar hot water system financially viable today. Table 3 is a summary of the findings. For the winery in this study the cost of natural gas would need to increase by 142 per cent from $8.87/GJ to $21.50/GJ. However, if the winery didn't have access to natural gas and had been using either electricity or propane to heat water, the financial analysis tells us it would be viable today to install a solar hot water system based on the local price of electricity and propane ($0.084/kWh and $0.55/L respectively). Stantec Consulting Ltd. 16

17 Table 3. Scenario #1: Minimum Price of Fuel Requirement for Farm #5 Scenario 1 Summary Fuel Type Variable Current Cost of Energy Required Cost of Energy Natural Gas ($/GJ) Utility Rate $ 8.87 $ Electric ($/kwh) Utility Rate $ $ Propane ($/L) Utility Rate $ 0.55 $ SCENARIO #2: CAPITAL FUNDING REQUIREMENT This scenario looked at the one-time capital payment, by fuel type, that would be required to make proposed solar hot water system financially viable given today's energy prices. Table 4 is a summary of the findings. The winery in this study would need a one-time capital incentive of $100,200 for a 54-collector system. This capital incentive amounts to 45 per cent of the total cost of installing a solar hot water system. However, if the winery didn't have access to natural gas and had been using either electricity or propane to heat water, the financial analysis tells us it would be viable today to install a solar hot water system based on the local price of electricity and propane ($0.084/kWh and $0.55/L respectively). Table 4. Scenario #2: Capital Funding Requirement for Farm #5 Fuel Type Scenario 2 Summary Variable Current Capital Cost ($/m 2 ) Required Capital Grant ($/m 2 ) Natural Gas Capital Cost $ 1,800 $ 800 Electric Capital Cost $ 1,800 not required Propane Capital Cost $ 1,800 not required 6.3 SCENARIO #3: RENEWABLE HEAT INCENTIVE REQUIREMENT This scenario looked at the renewable heat incentive, by fuel type, that would be required over a 25- year period to make the proposed solar hot water system financially viable given today's energy prices. In other words, an incentive based on the amount of energy saved through on-site heat production. Table 5 is a summary of the findings. The winery in this study would need a renewable heat incentive of $0.045/kWh of heat energy produced over a 25-year period based on the local price of natural gas of $8.87/GJ. This amounts to the government paying the winery about $4,020 per year on heat energy produced. Stantec Consulting Ltd. 17

18 However, if the winery didn't have access to natural gas and had been using either electricity or propane to heat water, the financial analysis tells us it would be viable today to install a solar hot water system based on the local price of electricity and propane ($0.084/kWh and $0.55/L respectively). Table 5. Scenario #3: Renewable Heat Incentive Requirement for Farm #5 Fuel Type Natural Gas ($/GJ) Electric ($/kwh) Propane ($/L) Variable Renewable heat incentive Renewable heat incentive Renewable heat incentive Scenario 3 Summary Current Cost of Energy Current Cost of Energy ($/kwh) Required Incentive on Fuel Saved Equivalent Incentive on Fuel Saved ($/kwh) $ $ $ $ $ not required not required $ $ not required not required Stantec Consulting Ltd. 18

19 APPENDIX A DETAILED CALCULATION OF HOT WATER USAGE To calculate hot water usage using natural gas utility bill and the equation: Q = 500 x gpm x T Where: Q is the heat energy (Btu/h). gpm is the flow rate (US-gallon/minute). T is the temperature rise (F). We know for Farm #5: Monthly natural gas consumption 200 GJ (used in restaurant for hot water and cooking). Winery operation uses an 80 per cent efficient natural gas boiler to make hot water. Hot water usage 10 hours per day (300 hours per month). Hot water temperature 60 C. Incoming supply water temperature 4 C. Calculate Q heat energy 1) Calculate the natural gas used in restaurant for hot water. Consumption, typically 40 per cent is used for hot water and 60 per cent is used for cooking (US Department of Energy Data Book 2003 Food Service Industry). Hence, amount of natural gas used monthly in restaurant for hot water = 200 GJ/month x 0.4 = 80 GJ/month. 2) Monthly energy to heat water for restaurant operation = natural gas used x efficiency of natural gas boiler = 80 GJ x 0.80 = 64 GJ/month 3) Convert GJ to Btu = 64 GJ/month x 947,817 Btu/GJ = 60,660,288 Btu/month 4) Q = 60,660,288 Btu/month divided by 300 hours/month of water usage = 202,200 Btu/h Calculate T temperature rise 1) T = hot water temperature minus incoming supply water temperature = 60 C 4 C = 56 C 2) Convert C to F = 56 C x 1.8 F/C = 100 F Calculate gpm flow rate Where: 1) From equation Q = 500 x gpm x T Q = 202,200 Btu/h T = 100 F Therefore: gpm = 202,200 divided by (500 x 100) = 4.0 gpm Stantec Consulting Ltd. 19

20 Calculate daily hot water usage 1) Daily hot water usage = 4.0 gpm x 600 minutes = 2,400 US-gallons 2) Convert US-gallons to litres = 2,400 US-gallons x 3.78 litres/us-gallon = 9,072 litres Restaurant uses about 9,080 litres of 60 C water a day. Stantec Consulting Ltd. 20

21 APPENDIX B MANUAL CALCULATIONS OF SOLAR POTENTIAL Table 6. Summary of Monthly Radiation - Incident and Usable for Farm #5 Farm #5 Month Incident Solar Usable Solar kwh/m 2 -day kwh/m 2 -month kwh/m 2 -month % A B C D E Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec KWh/m 2 -yr: GJ/m 2 -yr: Column A: Month Column B: The daily averaged solar radiation incident on an equator-pointed 34 tilted surface (relative to the horizontal) (NASA data) Column C: The monthly averaged solar radiation incident on an equator-pointed 34 tilted surface (relative to the horizontal) (column B x # of days in month) Column D: The monthly averaged solar radiation captured and usable on an equator-pointed 34 tilted surface (relative to the horizontal) Column E: The percentage of incident solar radiation captured and usable For this site, the energy input from the sun to a square metre of south-facing collector is about 1,572 kwh annually; and the energy output of a square metre of south-facing collector is about 714 kwh annually. The average annual operating efficiency of the collector (Viessmann flat plate model Vitosol 100-F SV1) is about 45 per cent. Results would be similar for other brands of flat plate collectors. Stantec Consulting Ltd. 21

22 Table 7. Detailed Monthly Radiation Data for Farm #5 The monthly solar potential is site specific and is calculated using NASA solar radiation incident data, NRCan weather data and operating performance for Viessmann flat plate collector (model Vitosol 100-F SV1). Results would be similar for other brands of flat plate collectors. Farm #5 Monthly System Output Daily System Output System Efficiency Factor Critical Intensity T Collector Inlet Water Temp. Incident Solar Average Daytime Air Temp. Collector Heat Loss Factor Collector Optical Efficiency Month Efficiency W/m 2 -C C kwh/m 2 -day C C W/m 2 Efficiency kwh/m 2 -day kwh/m 2 -month A B C D E F G H I J K L Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Column A: Month Column B: Optical efficiency is the fraction of solar radiation which passes through the outside collector glass and reaches the absorber and is actually absorbed for a Viessmann flat plate collector Column C: Collector heat loss factor is a property of the collector chosen Columd D: Average monthly daytime temperature (NRCan data) Column E: The daily averaged solar radiation incident on an equator-pointed 34 tilted surface (relative to the horizontal) (NASA data) Column F: Approximate average fluid temperature entering the collector (calculated value) Column G: Temperature difference between fluid entering collector and average daytime temperature (column F - column D) Column H: The critical intensity is indicative of the length of time in each day during which the collector produces energy (calculated value) Column I: This factor is an extension of column H and involves the critical intensity and the period of collector operation (calculated value) Column J: The percentage of incident solar radiation captured and usable (calculated value) Column K: The daily averaged solar radiation captured and usable on an equator-pointed 34 tilted surface (relative to the horizontal) (column E x column J) Column L: The monthly averaged solar radiation captured and usable on an equator-pointed 34 tilted surface (relative to the horizontal) Stantec Consulting Ltd. 22

23 APPENDIX C RETSCREEN RESULTS FOR SOLAR HOT WATER Table 8. RETScreen Solar Hot Water Model for Farm #5 Technology Load characteristics Application Swimming pool Hot water Solar water heater Unit Base case Proposed case Load type Other Daily hot water use L/d 9,080 9,080 Temperature C Operating days per week d 7 7 Percent of month used Month Supply temperature method Formula Water temperature - minimum C 4.3 Water temperature - maximum C 12.1 Unit Base case Proposed case Energy saved Heating MWh % Incremental initial costs Resource assessment Solar tracking mode Fixed Slope 40.0 Azimuth 0.0 Show data Daily solar radiation - horizontal Daily solar radiation - tilted Solar water heater Type Manufacturer Model Glazed Viessmann Vitosol 100-F SV1 Gross area per solar collector m² 2.49 Aperture area per solar collector m² 2.34 Fr (tau alpha) coefficient 0.78 Fr UL coefficient (W/m²)/ C 4.43 Temperature coefficient for Fr UL (W/m²)/ C² Number of collectors Solar collector area m² Capacity kw Miscellaneous losses % 7.0% Balance of system & miscellaneous Storage Yes Storage capacity / solar collector area L/m² 70 Storage capacity L 8,826.3 Heat exchanger yes/no Yes Heat exchanger efficiency % 95.0% Miscellaneous losses % 7.0% Pump power / solar collector area W/m² Electricity rate $/kwh Summary Electricity - pump MWh 4.3 Heating delivered MWh 92.3 Solar fraction % 46% Heating system Project verification Base case Proposed case Energy saved Fuel type Natural gas - GJ Natural gas - GJ Seasonal efficiency 80% 80% Fuel consumption - annual GJ GJ Fuel rate $/GJ $/GJ Fuel cost $ 8,020 4,338 Stantec Consulting Ltd. 23

24 APPENDIX D FINANCIAL ANALYSIS DATA Table 9. Financial Analysis Data for Farm #5 Offset Consumption Natural Gas as Primary Fuel Electricity as Primary Fuel Propane as Primary Fuel Electricity Maintenance Year Energy Saved Cost per unit of energy Annual Savings Present Value of Annual Savings Energy Saved Cost per unit of energy Annual Savings Present Value of Annual Savings Energy Saved Cost per unit of energy Annual Savings Present Value of Annual Savings Energy Consumed Cost per unit of energy Annual Costs Present Value of Annual Costs Annual Costs Present Value of Annual Costs (kwh) ($/kwh) ($) ($) (kwh) ($/kwh) ($) ($) (kwh) ($/kwh) ($) ($) (kwh) ($/kwh) ($) ($) ($) ($) A B C D E F G H I J K L M N O P Q R S 0 $ $ - $ $ $ - $ $ $ - $ $ $ 8.99 $ $ $ $ $ $ $ $ $ $ $ $ 0.85 $ 0.77 $ 9.60 $ $ $ $ $ $ $ $ $ $ $ $ 0.86 $ 0.71 $ $ $ $ $ $ $ $ $ $ $ $ 0.88 $ 0.66 $ 9.79 $ $ $ $ $ $ $ $ $ $ $ $ 0.90 $ 0.61 $ $ $ $ $ $ $ $ $ $ $ $ 0.92 $ 0.57 $ $ $ $ $ $ $ $ $ $ $ $ $ 0.94 $ 0.53 $ $ $ $ $ $ $ $ $ $ $ $ 0.95 $ 0.49 $ $ $ $ $ $ $ $ $ $ $ $ $ 0.97 $ 0.45 $ $ $ $ $ $ $ $ $ $ $ $ 0.99 $ 0.42 $ $ $ $ $ $ $ $ $ $ $ $ $ 1.01 $ 0.39 $ $ $ $ $ $ $ $ $ $ $ $ 1.03 $ 0.36 $ $ $ $ $ $ $ $ $ $ $ $ $ 1.05 $ 0.34 $ $ $ $ $ $ $ $ $ $ $ $ 1.08 $ 0.31 $ $ $ $ $ $ $ $ $ $ $ $ $ 1.10 $ 0.29 $ $ $ $ $ $ $ $ $ $ $ $ 1.12 $ 0.27 $ $ $ $ $ $ $ $ $ $ $ $ $ 1.14 $ 0.25 $ $ $ $ $ $ $ $ $ $ $ $ 1.16 $ 0.23 $ $ $ $ $ $ $ $ $ $ $ $ $ 1.19 $ 0.21 $ $ $ $ $ $ $ $ $ $ $ $ 1.21 $ 0.20 $ $ $ $ $ $ $ $ $ $ $ $ $ 1.23 $ 0.18 $ $ $ $ $ $ $ $ $ $ $ $ 1.26 $ 0.17 $ $ $ $ $ $ $ $ $ $ $ $ $ 1.28 $ 0.16 $ $ $ $ $ $ $ $ $ $ $ $ 1.31 $ 0.15 $ $ $ $ $ $ $ $ $ $ $ $ $ 1.34 $ 0.14 $ $ $ $ $ $ $ $ $ $ $ $ 1.36 $ 0.13 $ $ 1.12 Column A Year. Column B Annual energy that can be saved by the solar thermal system per m 2 of collector area. Column C Cost per unit of natural gas in $/kwh escalated at 2% annual inflation. Column D Annual offset savings of natural gas (column B x column C). Column E Present value of annual offset savings (present value of column D). Column F Annual energy that can be saved by the solar thermal system per m 2 of collector area. Column G Cost per unit of electricity in $/kwh escalated at 2% annual inflation. Column H Annual offset savings of electricity (column F x column G). Column I Present value of annual savings (present value of column H). Column J Annual energy that can be saved by the solar thermal system per m 2 of collector area. Column K Cost per unit of propane in $/kwh escalated at 2% annual inflation. Column L Annual offset savings of prpane (column J x column K). Column M Present value of annual savings (present value of column L). Column N Annual energy required to operate pumps, increased at 2% annually for "wear and tear". Column O Cost per unit of electricity in $/kwh escalated at 2% annual inflation. Column P Annual operating cost of electricity (column N x column O). Column Q Present value of annual cost (present value of column P). Column R Annual maintenance cost based on one maintenance visit every 2 years, per m 2 of collector area. Column S Present value of maintenance costs (present value of column R). Stantec Consulting Ltd. 24