Geothermal Explained How Geothermal Heat Pumps use the Earth to Heat and Cool Your Home Geothermal Technology Geothermal heat pumps use the earth as a heat source in the winter and as a heat storage source in the summer. The ground loop components of a geothermal heating and cooling system can last up to 50 years! Ground and water temperatures, 6 feet below the earth's surface, stay relatively constant throughout the year. This allows the system to provide extremely efficient heating or cooling all year long in virtually any climate. Sometimes the term "environmental comfort system" is used to describe a geothermal heat pump. This happens because a heat pump absorbs or rejects heat from the earth and has absolutely no impact on the environment.