Open loop geothermal heating and cooling. Well water is used to heat and cool the house and then it's discharged into the pond.
I *wish* I could do that! Our well does not have near enough flow rate to pull that one off, and it is too risky to try another well to find it doesn't have enough flow. Buried loops and excavation just cost way too much, as does getting the house retrofitted with duct work.
The cost of propane may just make it seem like a steal soon though. $3.59 a gallon! Arg!
