Imagine 2,500 spaceborne magic carpets flying side-by-side in tight formation, covering an area of 3.5 square miles (9 square kilometers) in Earth orbit or 1,670 football fields, capturing the sun’s energy and beaming it down to Earth to make electricity. That's actually what NASA/JPL and Northrup Grumman propose to collect solar energy with an array of space-based panels to beam back to Earth, claiming it's not a pipe dream. http://climate.nasa.gov/news/2426/
Sounds like NASA is seriously considering killing off any ground based astronomy, as well as disrupting Intelsat geostationary satellite telecom.
If you are going to do that, just use orbiting mirrors to light cities directly. (Most power used by cities at night goes towards lighting.) No need for the extra step.
