Solar Energy System Performance Evaluation, Design Construction, Bigfork, Montana, October 1979-April 1980

摘要

The Design Construction site is a single-family residence in Bigfork, Montana equipped with an active solar energy system. The solar energy system consists of an array of 792 square feet of Revere, Sun Roof flat-plate, liquid (water drain-down) collectors and a 1400 gallon water storage tank located centrally on the first floor. Heat from the storage tank is transported to a 65 gallon DHW heater equipped with an auxiliary electric heating element. Hot water from the storage tank also passes through an auxiliary electric boiler and then through a four zone baseboard radiator system to provide space heating for the home. There is also a special hydro-heater fireplace built into the side of the storage tank which is used as an auxiliary. The Design Construction solar energy system supplied 35% of the space heating and 27% of the domestic hot water required for this house during the heating season of October 1979 through April 1980. The quantity of collected solar energy that was used was 81% and the collector array efficiency was 28%. (This efficiency is based on the total solar radiation incident on the array.) Solar energy saved 7415 kwh of electricity for the seven-month period. The solar energy system functioned consistently throughout the heating season providing significant amounts of solar energy to the space heating and DHW subsystems. The solar fraction of 35% was somewhat lower than the design goal of 50%. The main reason for this was that the insolation was well below the long-term average for this period (October 1979 through April 1980). (ERA citation 06:000528)