Why doesnt Gimme recommend geothermal systems generally?
Geothermal heating systems (groundwater heat source pumps) can be 2 or 3 times the cost of very efficient gas fired furnaces or boilers and depend on the relatively inefficient (15% overall!) electrical grid to supply their power. This is usually not taken into account when their efficiency is computed. In addition, conventional production of electricity by coal- or gas-fired plants has serious environmental consequences that must be factored into the choice of heating options. Groundwater heat source pumps are efficient compared to other electrical heating devices, but when they are compared to high-efficiency modulating gas fired boilers or furnaces, they are less impressive. They are actually most efficient in the cooling mode so buildings with large cooling loads, such as commercial buildings, are better candidates for this technology.
