New Ways to Combine Solar Thermal with Geothermal
Abstract
A more efficient and less costly method for heating and cooling of buildings is possible using any of several types of solar thermal collectors along with a geothermal or ground source heat pump (GSHP). This paper considers only shallow earth geothermal, as opposed to deep earth geothermal typically used for electricity generation. Although a variety of solar assisted ground source heat pump (SAGSHP) systems have been described in the literature in past years, none of these have become commercially viable products. It is possible that with a more optimum design, this general approach could become more cost-effective than conventional ground source heat pump systems and thereby become commercially viable. The general consideration is that there is a trade-off between the size and cost of a solar thermal collector array and the ground loop for the geothermal portion of the system. For parts of the world where the cost of drilling and installing ground loops is high, it is likely that the added cost of a solar thermal array (or possibly an air to liquid heat exchanger) will be lower than the cost of the portion of the ground loop which is eliminated. This could lead to commercial viability for a system such as described herein.
Keywords
Solar thermal collector, Ground source heat pump, Geothermal