Very interesting stuff... but a bit scary.

The article posted links to this article, which goes deeper into the details of how such a system would work.

A ground-based microwave receiver on Earth would be used to intercept the incoming radiofrequency energy and convert it back into useable electricity.

Imagine the implications of this (beyond having to reroute any air traffic; account for atmospheric spread; atmospheric warming; etc.) I'm thinking there will be more than just ground-based receivers. Ask yourself this: would it be theoretically possible to keep an unmanned aircraft aloft indefinitely, by continually beaming radiofrequencies to it? It might have to be done in stages: low Earth orbit plasma jet craft -> high altitude gliders -> lower altitude planes -> drones. We could be entering into a time when we have drones constantly swarming in our skies, without any need for downtime. That is, if the engineers can keep the radiofrequency beams tight enough, and always on their target.

That's the scary part; hopefully they just use this for cheap energy.