Performance analysis and cost optimization of a solar-assisted heat pump system

A solar-assisted heat pump system with a conventional backup unit was simulated for a 93 m2 (1000 ft2) house in Rhode Island using quasi-dynamic computer models. The performance of the system as a function of collector area and thermal storage volume was evaluated to determine the fraction of the space heating and domestic hot water load that was supplied by the solar-assisted system. This information was used to compute the payback time, based on cumulative costs, for each variation of the system\u27s parameters when compared to a conventional system. The optimal combination of system components which had a payback time less than the mortgage life was determined. For the given initial costs of solar panels and storage reservoir, this optimal combination was found to be insensitive to the variations in mortgage and fuel cost growth rates presented in this report. © 1978