The threads on water motors caused me to recall some other ways.
One inventor patented a convection motor -- simply put a big pipe loop up a mountain and let the 3 oF/1000 ft temperature lapse rate create a convection motor. Extending this idea, since water is most dense at 4 oC, how about a high column of 4 oC water with a small heat pump at the bottom splitting it into two streams, 6 oC and 2 oC and sending them back to the top where they mix back to 4 oC. Does that make any sense? Hoyt Stearns Scottsdale, Arizona http://members.cox.net/hoyt-stearns
