TAKING SOLAR POWER TO NEW HEIGHTS: NASA Invests In Satellites That Beam Power Down to Earth.

As spaceborne energy-harvesting schemes go, this one seems faintly possible — an array of curved mirrors directing sunlight toward solar cells, their energy production microwaved down to Earth. It’s so realistic, actually, that NASA is providing funding for a proof-of-concept study. . . .

It would consist of a modular array of movable thin-film mirrors, which could be taken into space using current cargo ships and assembled piece by piece. This would be less expensive than building a gigantic array and launching it. These curved mirrors would redirect sunlight toward an internal collection of photovoltaic panels, and the solar energy would be converted into microwaves. Then the Earth-facing portion, or the bottom of the margarita glass in the image at top, would transmit low-frequency, low-intensity waves toward Earth. At the receiving end, power plants would convert the microwave energy into electricity, adding it to the power grid.

Build enough orbital solar plants and you can supply earth’s power needs effectively. Build more and you can use the extra electricity to split water into hydrogen for vehicle fuel.