Geothermal
The newest home heating (and cooling) technology is called a Geothermal Heat Pump (GHP). Heat pumps work like a refrigerator that can run in reverse. Heat is taken from one source and deposited in another location. With ground loop geothermal systems, heat is taken from or deposited to the earth by use of a ground loop pipe.
The EPA states that a Geothermal Heat Pump can save 30 to 70 percent on home heating and 20 to 50 percent on home cooling costs over conventional systems. But these systems are not cheap.
An excellent overview of Geothermal Heat Pumps including cost, manufacturers and details on this technology can be found at Toolbase.org Geothermal Heat Pumps.
