Earth-based wind power is becoming rather passe. The future is in the jet stream, where winds blow at 150 miles per hour. An unmanned turbine flying 30,000 feet above the ground has the potential to generate 50 times the amount of watts that ground-based turbines can.

What would one of these high-flying turbines look like? Plenty of designs have been proposed, from balloons to blimps to kites, with all manner of rotating appendages to collect energy. Discovery News blogger Alyssa Danigelis has a great round up here of technology being worked on by companies including Joby Energy, Makani Power, Sky WindPower and Magenn Power.

But what many of them have in common is a long nanotube tether that relays captured energy from on high to where it's needed on the ground. NASA is using a $100,000 federal grant and the talents of aerospace engineer Mark Moore to figure out which of these futuristic schemes is best. That means they'll have to also consider airspace allocations — how to share the sky with other flying vehicles.

The jet stream's high wind speeds are used by large international flights to save fuel and shorten travel time, making the region somewhat of an in-demand resource. But even at lower altitudes, wind turbines and their tethers could get in the way — each turbine would likely need a 2-mile-wide restricted area to keep it out of collisions. Such a patchwork of “do” and “do not fly” zones would take some expert planning to work in busy airspace.

As he explains in a press release, Moore thinks one part of the answer may be to deploy the wind devices offshore, where there is little demand for low-flying airspace from commercial crafts. That would help eliminate most potential hazards below the jet stream. It would also avoid taking up land for the tethers and would not add any cost, since the flying turbines wouldn't need expensive platforms or towers to support them.

Leaders in the wind power industry and other government agencies, including the Department of Energy and the National Renewable Energy Laboratory, have been talking to NASA while it researches turbines. Moore says in the same press release that the other parties “welcome this study because they've never dealt with flying systems and NASA has.”