South Dakota School of Mines, Keystone, South Dakota solar-energy-system performanceevaluation, June 1980-April 1981

The South Dakota School of Mines site is the Mount Rushmore National Memorial Visitor's Center in Keystone, South Dakota. The active solar energy system is a retrofit designed to supply 45% of the heating load and 53% of the observation room cooling load. The system is equipped with 2000 square feet of flat-plate collector panels double-glazed with a black chrome absorber surface; 3000 gallons of water in an insulated tank for sensible heat storage; a two-stage fuel oil furnace for auxiliary heating; and direct expansion electric air conditioning units for auxiliary cooling. The actual heating and cooling provided are 42% and 12% respectively. The solar fraction, solar savings ratio, conventional fueld savings, electrical energy expense, system performance factor, and solar system coefficient of performance are among the performance data listed. A control problem is reported that kept the collector pump running 24 hours a day for 18 days. Performance data are given for each subsystem as well as for the overall system. Typical system operation and the system operating sequence for a day are given. The system's use of solar energy and the percentage of losses are given. Also included are a system description, performance evaluation techniques and equations, long-term weather data, chemical analysis of the antifreeze solutions, sensor technology, and typical weather and performance data for a month. (LEW