Flying wind turbines

As found on Inhabitat, this is again a very impressive sustainable energy idea:

We’ve seen wind turbines fit for backyards, balconies, even oceans- and now pioneering wind-power engineers are looking to take wind turbines to new heights—15,000-30,000 feet in the air! Harvesting just 1% of the energy from jet-stream winds could produce enough power for everybody on the planet. Sky WindPower and Magenn Power are just two of the companies in the race to develop flying generators for high-altitude winds