soooo i just "happen" to have a stirling engine laying around. we made it in school (M.E. program) you know if you run it back wards it acts like a fridge? any one ever tried this before? be easy to run with a 25watt solar panel, and dc motor. would work during the hottest part of the day the best. only trick i think is what plastic to plumb the water. what conducts heat the best?