Hi Jeremy,

With Peltier heating/cooling your electric bill and the cost of the things would put a dent in Bill Gates wealth. Joking of course but the cost and implementation would be prohibitive.

Would take a pretty big chiminea to generate enough heat.

One BTU raises 1 pound of wate r1 deg F. Therefore 15000 gal at 7.5 pounds per gallon takes about 112,000 BTU assuming no heat loss due to evaporation or other factors.

I have about a 22,000 gal IG pool and a homebew solar in the back field. Made some PVC manifolds to split the feeds for 12 100' sections of 1/2" black poly pipe layed out on about an 8x50 base made of black rolled roofing. If I remember right I think I can get 40,000 BTU/Hr from the thing. It's nowhere near the theoretical heat output because the pipes aren't spaced tightly as would be the case of a solar mat. But....it was CHEAP and I have the space and when the grass grows you can't see it.

Another source of heat is the home air conditioner. You could add a water-freon heat exchanger to capture the heat removed from the house. However, the bad part if usually when you have to cool the house the pool is already warm enough you don't need to add heat.

Sounds like you want to experiment and I can assure you it can be fun.
Al