[AnthonyMouse]

> The whole problem is difficulty getting grid connections on Earth. If you can just hook up to the grid then why not just use it for everything.

Because you already need inverters and batteries for backup power and then using solar + batteries for ordinary operations and the grid for backup is cheaper than the other way around.

Which is also why you may not even need the grid connection. Suppose you have diesel generators to use in case you have some kind of a fault in the solar system, the same as was traditionally done in case of a failure of a grid connection, and then use those for the one week every two years when solar generation is too low.