A
docm":2yg7dq8k said:One limiting factor with a Peltier-style device would be if the source were hot enough to break down the junction, though some work was recently reported on MIT's Technology Review site that could extend the operable range significantly. You also have to maintain a temperature differential across the junction to generate power, so radiators or some other mechanism is necessary.
Other possibile junction breakdown mechanisms could be ionizing radiation or neutron transmutation. Junction size & materials affect both of these.