I would start with insulating the ductwork in the crawl space. This should be done whether you change to a geo system or not. You have a huge heat loss there.
Next, look into any tax rebates on installing a geo system.
Last, I question why you would use a well and the electricity to run a well pump when you have a pond.
Don't let anyone try to sell you a "passive" water heater for your geo system. They cost 5 times as much as a standard electric water heater, which will work just as well. You can just not wire it up, or wire it for emergencies and cut the breaker off.
Hey Moe, I'm trying to think but nuthin's happening!
