There’s a neat article about the upcoming use of Sterling Engines to create some highly effecient solar energy conversion in the California desert. I first read about this some time back, and have since been quietly obsessed with the idea of using the external combustion engine (yes, that’s correct and NOT a typo) in a huge variety of places. It only requires a thermal gradient – the really small ones will run off your palm (and do correspondingly little), but just THINK of the places where this could be really effective!
I don’t know how much gradient is really needed to be effective, but if you could get some micro-power generation just from the difference between the ground temp and the air temp, that would be pretty darn cool!
Rhonabwy 