Over two-thirds of the nation’s electrical energy and over 40% of natural gas consumption is used in buildings. Space heating and cooling and water heating account for over 40% of the electric power used in residential and commercial buildings. By decreasing or offsetting the amount of energy needed for space conditioning and water heating, the nation has a major energy-saving opportunity.

GHPs, also known as GeoExchangeSM systems, move the heat from the earth (or a groundwater source) into the home in the winter, and pull the heat from the house and discharge it into the ground in the summer. The underground (or underwater) piping loops serve as a heat source in the winter and a heat sink in the summer. In essence, it’s the same heat-exchanging process used by the common refrigerator or air conditioner.

While many parts of the country experience seasonal temperature extremes— from scorching heat in the summer to sub-zero cold in the winter—a few feet below the earth’s surface the ground remains at a relatively constant temperature.

Because a GHP system is so efficient, it uses a lot less energy to maintain comfortable indoor temperatures. This means that less energy—often created from burning fossil fuels—is needed to operate a GHP. According to the EPA, geothermal heat pumps can reduce energy consumption— and corresponding emissions—up to 44% compared to air-source heat pumps and up to 72% compared to electric resistance heating with standard air-conditioning equipment for residential applications.