There are a bunch of things that are better about the Moon: - no atmosphere in the way - no weather or clouds in the way - no buildings or other stuff competing

There are a bunch of things that are better about the Moon: - no atmosphere in the way - no weather or clouds in the way - no buildings or other stuff competing for the land area (yet) There's no shortage of places to put solar panels, and nothing that will reduce the amount of light getting to them (except the rotation of the Moon itself), so actual efficiency isn't that important.