Here is an idea i had when in school after seeing a small stirling engine
that operated by placing it on top of a mug of hot coffee... after you
helped the engine overcome starting torque, it kept itself quite nicely.
Ignoring feasibility (I did major in math, we're allowed to do that), my
idea was to build quite a few stirling engines along those lines but upside
down.. (ie, the cooling section is on the bottom). Now, bury the cooling
section and leave the part you must heat above ground in a sunny place. Onc=
e
the temperature differential is in the right place, give them a start. So,
on each engine we put a small generator and trickle charge our batteries.
 Go ahead, I'm ready for all the many things I haven't thought of that make
this a bad idea:p
 James
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