GeoThermal. Ground source heat pumps. In Wisconsin, we are talking about the same thing. Geo meaning Earth and thermal meaning heat. Heat from the earth. Free energy. (Really? Are you trying to pull my leg? Get outta here! Nothing is free.). But it is. And by the time that I am done explaining, my hope is that you will have a clear understanding of how this can be true.
Go to the Refrigeration Process page for a step-by-step explanation of how a geothermal heat pump can make your home warm from ground that is only 50 degrees!
Please come back as I do intend to keep adding information!