> I've seen estimates of 1.2 mw per square km
from the cited article:
A single solar plant has the potential to generate minimum of 1250GW and maximum of 2000GW per square meter
Both figures are complete BS. Solar constant is about 1.36 kW/m^2 at 1 AU from the sun. Realistic over all electric peak powers might be in the 200 W/m^2 ballpark. This can only be harvested in orbit, however. On a planetary (or lunar) surface under a day-night cycle you get up to 1/4 of that, up to 1/2 for a sparse installation with sun-tracking.