It seems that a nuclear thermoelectric generator was used to power spacecrafts for some exploration missions. Can a thermopile that harvest the light/shade temperature difference on Earth's orbit be used to power a small satellite? What about a Mercury satellite, would it be more reliable and efficient than solar panels which could melt on those conditions?
-
5$\begingroup$ MESSENGER's solar panels haven't melted. $\endgroup$ – Mark Adler Apr 27 '14 at 2:58
There's no theoretical reason why not. The main reason why they aren't used is practical: the best solar panels convert about 22% of available energy to electricity, while the best thermoelectric generators operate at about 8% of Carnot efficiency, which for a reasonable temperature gradient works out to converting about 4% of available energy.