It's funny, I never thought of electricity as being a big issue for a moonbase. There are so many ways to store potential energy - you could, for example, put a

It's funny, I never thought of electricity as being a big issue for a moonbase. There are so many ways to store potential energy - you could, for example, put a bunch of moon rock/dust on a platform and run electric motors to raise it for 14 days, and then, during the lunar night, allow the platform to lower and generate electricity. But the remarkable 300 deg temp swing is a dream for power generation, although the OP is right that you'd need a medium (e.g. lots of water) to harness it as a carnot engine. Still, fun to think about since it's a hard, but not unsolvable problem.