The renewable energy source is heat - heat that is stored in the earth! It is amazing that we can take heat from 40 to 55 degree F dirt and heat our houses toasty warm. Geothermal heat pumps move heat out of the ground and into the house in the winter, and back into the ground from inside our houses in the summer. Instead of burning something to make new heat for our homes, we take heat that's already there and reuse it. It's renewable energy!
The earth's surface is kept warm by the sun's energy being absorbed into it. This heat can be removed from the earth and used to heat your home. Although there are many skeptics, the proof is plentiful. With a little help from a geothermal heat pump, we can move the heat from the earth into your home. A geothermal heat pump gathers up the earth's heat and squeezes it into a smaller 'ball' until it is hot enough to heat your home. It is so good at compressing the heat and moving it into your home, it can move 4 times as much heat as the energy it takes to move it.
And since the earth is cooler than your home in the summer it is a breeze to cool it with the earth's cool temperature. It is done by reversing the process: gathering up heat from the building and putting it back into the earth.