This document was prepared by Steven Forrester for DMA Engineering and discusses the problems with Geothermal (Ground Source Heat Pumps) and offers a solution. Use solar thermal in correlation with geothermal in a hybrid model.
The advantages of a hybrid model are that both systems are renewable energy systems, both do not use fossil fuels at the point of use, and there is outstanding synergy between the two technologies maximizing efficiency during summer and winter seasons.The ground heat exchanger in the geothermal model can be used as a “tank” to store the excess solar energy in the summer thus allowing the user to get 100% of their hot water heating from the solar system and then using the excess energy to heat other heating appliances.
Based on Colorado utility rates the geothermal system alone has a “payback” period of 9.4 years with the addition of the solar thermal system the payback time decreases to 8.2 years. The solar system alone has a payback of 15 years, if used in conjunction with geothermal the payback time decreases to 12 years.
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