It's conceivable that in a world where solar panels are incredibly expensive and there's an extreme collapse in the cost of launching objects to space, you might want to maximize your energy per panel by putting them above the atmosphere. But panels are cheap, and even if we assume pretty steep drops in the cost of space launch, the numbers don't add up. This becomes especially clear when you start to think about maintenance. Try to imagine acres upon acres of glass panels in space, regularly hit by intense radiation and bits of space debris while enduring the extreme heat of constant sunlight. They'll have to be repaired and cared for either by astronauts or an army of advanced robots. Solar panels in Australia can be cleaned by a teenager with a spray bottle and a cloth.