By heat pump I mean this: http://en.wikipedia.org/wiki/Heat_pump.

These are not popular in the US & UK mainly due to the initial cost, but are often used in 'Minergy' (low energy) houses in Switzerland. They function like a refrigerator in reverse extracting heat from either the outside air or from the ground, usually by deep bore hole. The heat pump somehow manages to produce 4 times the energy is uses as it moves heat but does not create it...