Well, sun can be around 1kw/m^2 in midday, although there are many factors. Not only weather, but latitude. And of course time of day other than peak hours is less. Solar cell efficiency has gone as high as 30%, in practice, 25% for the best of the best.
Space-based solar cells get more sun. I don't recall exactly, I think it was maybe 30%.
The costs of putting it into space and microwaving it down are pretty ridiculous, compared to just putting them on the ground. Ground stuff faces problems of dirt and hail, but that's nothing compared to space debris and charged particles. It's like 100k times cheaper to replace cells on the ground.
Many web pages dedicated to power a house with solar. Big problem is storing power for the night or cloudy days. A single lead-acid deep cycle battery is only around 1.2kw-hr, and lasts maybe 5 yrs at best. If you have very low consumption, this can work. If you keep a desktop computer (300w) or lights on all the time, or use an air conditioner, it becomes impractical.