Geothermal engine

[jbanes]

> You could however run one in reverse and use
> it as a heater, though I don't think that's
> terribly practical either.

Actually, that should work. I spoke with a contractor at a church
event who does geothermal installations. They basically drill a hole
200 feet down into the ground, throw some piping down there, then
circulate water. The amount of energy spent moving the water is minor
compared to the amount of heat which is extracted from that depth.
(At least during winter months.)

He claimed that due to the fact that temperatures at that depth are
relatively constant, these installations can keep a house at an even
temperature year-round.

[ting_says]

Huh, I didn't think of that, but that sounds pretty sweet. It makes a lot of sense, all the constancy of a cave and it's massive volume without the cave bit. The earth as a cold sink, as in the reverse of a heat sink.

Well that's good to know, but you probably don't want to embark on that project without professional help.