It gets dark in the stratosphere too, and the UK already has a power grid connecting it with the Spanish power grid which doesn't rely on 20km cables into the sky...
Outer space gets dark too you not sure which orbit will get you 100 sun time solar synced orbits still get 50% night time. Maybe some geosync high polar orbit but then you have issues with transmition.
Space solar makes very little sense you only get twice the solar power at 50% efficiency rate at best.
