[Sanzig]

Indeed, space based solar power is always one of those ideas that sounds great until you sit down for fifteen minutes with a pencil and a piece of paper.

The antenna aperture size for effective wireless power transmission in any band with a reasonable atmospheric window needs to be utterly massive. And you can't escape the aperture requirement with a phased-array, either, since you lose a bunch of power to grating lobes (see the "thinned-array curse").