Geothermal Heat Pumps Produce Dramatic Savings

The widespread use of geothermal energy to reduce heating costs has been limited in part by the high initial cost of digging deep wells to obtain moderate temperature water (under 220 F) for direct-use industrial process and space heating applications. One approach now expanding the direct use of geothermal energy is coupling this energy resource with high temperature, industrial-type water-to water heat pumps. Such systems can tap geothermal energy in 50 F to 120 F water, normally available from many aquifers less than 3000 ft. deep, and amplifying this heat to the 120 F to 220 F range. An added advantage is such systems are nonpolluting and, in many cases, nonconsumptive. For these process, space and water heating direct use applications, geothermal heat pump systems can offer lower first and operating costs. This paper briefly describes three recent installations of this type system having dramatic savings in operating costs. Systems using the industrial heat pump can accelerate geothermal use by either (a) upgrading a geothermal source where the flow and/or temperature is inadequate or (b) obtaining higher temperatures without the expense or problems of drilling much deeper wells