Geothermal heating isn't as complex as you would think. You drill some holes, sink some pipe and circulate water through the ground below the frost line which is a constant six degrees Celsius. That water goes through a ground source heat pump which is really just a larger, fancier version of the heat pump in your fridge. It strips three degrees off of that water, compresses it, raises the temperature to 65 degrees celsius and provides hot water and space heating like a regular furnace. See Green Energy Futures video, blog and photos: http://www.greenenergyfutures.ca/episode/06/geothermal-101
