re: steam power
Sterling is great, maybe a little more complex to make than a simple steam turbine mounted on the shaft of an alternator that doesn't try to be very efficient - it dumps heated steam that could do more work. Until I spend some time researching, I don't really know if high pressure was required. I'm sure there is a formula that will tell me what pressure and volume is required to drive a certain horsepower motor. The little research I've done suggests it might work - without high pressures or high temps.