On mars you have a day not too different from ours and solar looks attractive. On the moon you really need nuclear because the night lasts two weeks. It is so bad people are thinking about reversing O’Neills idea and microwave beaming power from the Earth to the Moon.
Why would you need to do that? Just put solar arrays at the poles. There might be some practical limitations with power transmission to other parts of the moon, but extremely high-voltage power should be easier to do there than on Earth, since there's no oceans in the way, nor any atmosphere (so no problems with discharge from the high voltage wires).
