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HomeMy WebLinkAboutSolar Hot Water Costworksheet Renewable Energy Fund RFA AEA 09-004 Application Cost Worksheet revised 9/26/08 Page 1 Application Cost Worksheet Please note that some fields might not be applicable for all technologies or all project phases. Level of information detail varies according to phase requirements. 1. Renewable Energy Source The Applicant should demonstrate that the renewable energy resource is available on a sustainable basis. Annual average resource availability. This project will assess the feasibility of solar hot water heating systems on residential units in the Northwest Arctic Borough, as well as commercial and public buildings. Unit depends on project type (e.g. windspeed, hydropower output, biomasss fuel) On average, the daily solar radiation flux for Northwest Alaska ranges between 2 to 3 kWh/sq. meter. For solar space heating, the most economic time of year in Northwest Alaska would be around the equinoxes of September and March. These are times of year when there are 12 hours of daylight per day, and the average air temperature in Northwest Alaska is cold enough to justify space heating. 2. Existing Energy Generation a) Basic configuration (if system is part of the Railbelt1 grid, leave this section blank) i. Number of generators/boilers/other The hot water heaters in the buildings of the Northwest Arctic Borough School District ar e part of a heating plant, which is separated from the main building. An example of this is the Kotzebue school, where water is heated indirectly with hot glycol from a boiler module, which also provides space heating. The boiler water heats the schools two huge plate and frame heat exchangers where the schools glycol/water -heating medium is heated. Hot glycol is then circulated through a plate type heat exchanger (for 115 degree water) and an Amtrol hot water maker for 140-degree hot water. During the warmest months of the school year, the school must run a boiler to make hot water. One boiler contains 385 gallons of water, the piping that connects it with the plate and frame heat exchangers contain approximately 200 gallons. Thus there are times when the school does not need space heating, but does need hot water. ii. Rated capacity of generators/boilers/other iii. Generator/boilers/other type iv. Age of generators/boilers/other v. Efficiency of generators/boilers/other 1 The Railbelt grid connects all customers of Chugach Electric Association, Homer Electric Association, Golden Valley Electric Association, the City of Seward Electric Department, Matanuska Electric Association and Anchorage Municipal Light and Power. Renewable Energy Fund RFA AEA 09-004 Application Cost Worksheet revised 9/26/08 Page 2 b) Annual O&M cost (if system is part of the Railbelt grid, leave this section blank) i. Annual O&M cost for labor ii. Annual O&M cost for non-labor c) Annual electricity production and fuel usage (fill in as applicable) (if system is part of the Railbelt grid, leave this section blank) i. Electricity [kWh] ii. Fuel usage Diesel [gal] Other iii. Peak Load iv. Average Load v. Minimum Load vi. Efficiency[kwh/gal] vii. Future trends d) Annual heating fuel usage (fill in as applicable) i. Diesel [gal or MMBtu]  800-1000 gallons/year for 700 sq foot home;  4000 sq ft commercial building approximately 3000 gallons/year ii. Electricity [kWh] iii. Propane [gal or MMBtu] iv. Coal [tons or MMBtu] v. Wood [cords, green tons, dry tons] vi. Other 3. Proposed System Design Solar hot water heating could be practical in Northwest Alaska for up to nine months of the year. About 50% of annual hot water heating needs in Kotzebue could be met by solar. Solar photovoltaic (PV) power generation also could be practical during late spring and summer, and is being studied for applications in Northwest Alaska by the Alaska Village Electric Cooperative. Solar thermal power generation (using steam turbines) is not likely to be practical in Northwest Alaska. For mounting solar collector panels, a vertical panel surface (a 90° angle from the ground) would be best in Northern Alaska. Such a vertical mounting mitigates the accumulation of snow or ice. South -facing walls on existing buildings can be adapted for this purpose. Our proposed design would be for solar radiation for flat plate collectors facing south at a fixed tilt (uncertainty of (+-9%). a) Installed capacity The thermal requirements are 40-50,000 btu/per residence. Assuming water must be heated from 35° to 120°F. b) Annual renewable electricity generation Renewable Energy Fund RFA AEA 09-004 Application Cost Worksheet revised 9/26/08 Page 3 i. Diesel [gal or MMBtu] 125-175 gallons of displaced fuel (25-30% displacement for solar hot water heating) Hot water heating constitutes approximately 50% of a households annual heating diesel fuel use. ii. Electricity [kWh] iii. Propane [gal or MMBtu] iv. Coal [tons or MMBtu] v. Wood [cords, green tons, dry tons] vi. Other 4. Project Cost a) Total capital cost of new system Assumed at $8-10,000 per home. Approximately $10,000-50,000 for a commercial building on scale with what is found in NW Alaska. b) Development cost Development cost is assumed to be 5-15% of capital costs. c) Annual O&M cost of new system Approximately $500/year on a commercial building; Negligible on residential unit d) Annual fuel cost A 700 sq ft home uses approximately 1000 gallons/yr of diesel fuel. Assuming the price of home heating fuel in Noatak, that amounts to $8,500/yr in total ($4,250 for hot water heating and $4,250 for space heating) for a residence. 5. Project Benefits a) Amount of fuel displaced for i. Electricity ii. Heat For a residential unit, it is estimated that a solar hot water system can displace 25- 30% of heating fuel needs (assume 50% of domestic heating oil is used for hot water and 50% is used for home heating; and 1000 gallons annual home heating) Using these parameters, a hot water solar system can displace 125-150 gallons/yr per home. This technology can save targeted households approximately $800- 1200/yr depending on the price of fuel. iii. Transportation b) Price of displaced fuel Price of displaced fuel anywhere from $3.80 in Deering to - 8.50 in Noatak. Assuming a 20 year lifecycle of the installed unit, price of fuel at $8.49, a 3.5% inflation rate on the price of fuel, the proposed technology could save $36,000 over the life of the Renewable Energy Fund RFA AEA 09-004 Application Cost Worksheet revised 9/26/08 Page 4 project. c) Other economic benefits The project also has the benefit of reducing spills and other environmental benefits. d) Amount of Alaska public benefits 6. Power Purchase/Sales Price a) Price for power purchase/sale N/A 7. Project Analysis a) Basic Economic Analysis Project benefit/cost ratio 1.9 Payback 13 years