A friend of mine found TEG Power. These are devices that produce electricity from a heat source and they seem to be pretty efficient. Does anyone know anything about this company or the nature of thermoelectric generators? I like the idea of this device that sits on your wood stove and generates electricity. If you want ways to trickle-charge a bank of batteries and it's winter time and PV cells aren't working because they're covered with snow, this might be ideal.