text: The main advantage of locating a space power station in geostationary orbit is that the antenna geometry stays constant, and so keeping the antennas lined up is simpler. Another advantage is that nearly continuous power transmission is immediately available as soon as the first space power station is placed in orbit, LEO requires several satellites before they are producing nearly continuous power.
  Power beaming from geostationary orbit by microwaves carries the difficulty that the required optical aperture sizes are very large. For example, the 1978 NASA SPS study required a 1 km diameter transmitting antenna and a 10 km diameter receiving rectenna for a microwave beam at 2.45 GHz. These sizes can be somewhat decreased by using shorter wavelengths, although they have increased atmospheric absorption and even potential beam blockage by rain or water droplets. Because of the thinned array curse, it is not possible to make a narrower beam by combining the beams of several smaller satellites. The large size of the transmitting and receiving antennas means that the minimum practical power level for an SPS will necessarily be high; small SPS systems will be possible, but uneconomic.
  A collection of LEO (low earth orbit) space power stations has been proposed as a precursor to GEO (geostationary orbit) space-based solar power.