Preliminary Conceptual Design for Geothermal Space Heating Conversion of School District 50 Joint Facilities at Pagosa Springs, Colorado. GTA Report No. 6

摘要

This feasibility study and preliminary conceptual design effort assesses the conversion of Colorado School District 50 facilities - a high school and gym, and a middle school building - at Pagosa Springs, Colorado to geothermal space heating. A preliminary cost-benefit assessment made on the basis of estimated costs for conversion, system maintenance, debt service, resource development, electricity to power pumps, and savings from reduced natural gas consumption concluded that an economic conversion depended on development of an adequate geothermal resource (approximately 150 exp 0 F, 400 gpm). Material selection assumed that the geothermal water to the main supply system was isolated to minimize effects of corrosion and deposition, and that system-compatible components would be used for the building modifications. Asbestos-cement distribution pipe, a stainless steel heat exchanger, and stainless steel lined valves were recommended for the supply, heat transfer, and disposal mechanisms, respectively. A comparison of the calculated average gas consumption cost, escalated at 10% per year, with conversion project cost, both in 1977 dollars, showed that the project could be amortized over less than 20 years at current interest rates. In view of the favorable economics and the uncertain future availability and escalating cost of natural gas, the conversion appears economicaly feasible and desirable. (ERA citation 07:021639)