Google, going beyond its investments in clean energy, has bought an intriguing wind-power company called Makani Power and brought it into the fold of its mysterious Google X research program. Founded in 2006 by some entrepreneurial kite surfers, Makani makes flying wind turbines. They’re essentially giant robot-piloted kites that fly in circles, collecting energy using wing-mounted turbines and transferring it back to earth using a conductive tether. It’s a clean-energy drone.

Airborne wind power has a couple theoretical advantages over old-fashioned windmills. For one, wind is stronger and more consistent the higher up you go. The tallest windmills are about 600 feet tall, but the first generation of Makani planes will fly at heights between 800 and 1,950 feet.

Second, the autopilot finds the windiest spots and then flies in circles, so the whole wing moves at the speed of the tip of a windmill’s blade—its most productive part. Makani, based in Alameda, California, claims that this allows its planes to produce power more efficiently in low winds than conventional windmills, making them more reliable sources of energy. The planes also take far less material to make than a windmill, so the company says they’ll be faster to produce and deploy.

These advantages become clearer in the case offshore wind power, which seems to be the company’s focus. The wind is stronger offshore, and about half the world’s population lives on the coast, so less energy would be lost in transmission. But it’s really hard to put a windmill in the ocean: you have to anchor it to the floor, so you’re stuck in shallow water, and corrosion from salt water and damage from waves make maintenance expensive. If you could launch these things from, say, a floating buoy, you could solve a lot of problems at once. Also, as the company points out, you could fly them out of sight of land, eliminating the aesthetic concerns that have dogged offshore windmills in the past.

On May 9, one of Makani's wings completed its first autonomous flight—launching, circling, and landing on its own. That version produces 30 kilowatts, but Makani hopes future versions will be larger, generating 600 kilowatts and eventually making wind competitive with fossil fuels. It’ll be interesting to see what the company does as part of Google X.