[elhigh]

About 20 years ago I read of a built-in refrigerator that used an ammonia absorption loop to cool a heavily insulated compartment. During the day, heat from the sun would drive the ammonia off the wet end of the loop outside the house, to a reservoir inside the cooler box. During the night, the ammonia would boil off from the loop inside the box and condense with the water. Next day lather, rinse, repeat.

This cooler design used about 1/2 kwh per year - to run the light.

If heat moves through dry earth at about 16' / 6mos, then the right place for your ground source loops is directly under your own basement floor, about 16 feet down. In the middle of January, all the heat you dumped in there for cooling back in July ought to be just about creeping its way back up to you -