While the air outside changes at a moment’s notice, the earth remains fairly constant and warmer than above ground. Geothermal heating is one of the most energy-efficient ways to heat a house as it delves deep into the earth to harness that heat. It uses small amounts of electricity and water to transport that heat back up. Although pricey, this system has proven to be a gamechanger on the utility bill which means it pays for itself over a period of time, roughly estimated to be eight years. With a 300 to 600 percent efficiency rating, it’s definitely worth the consideration.