The 5 Best High Flying Wind Power Projects
by Brian Merchant, Brooklyn, New York 
on 11.10.09
Image via IO9
The Kites, Blimps, and Copters that Could Power the World
Tapping into the jet stream--the fast-flowing air currents in the atmosphere--to harness high speed wind power is one of the most compelling ideas in the renewable energy world. How compelling, you ask? Some researchers figure that by successfully tapping into just 1% of the jet stream, we could power all of civilization. At about 6 miles up, the jet stream creates some 200 trillion watts--world energy demand is estimated to be between 2 and 2.5 trillion--the problem, of course, is bringing that stuff down to earth.
Here are the 5 most promising high altitude wind power projects designed to do exactly that.
1. Sky WindPower: Giant Helicopters in the Sky
One of the oldest entries in the quest to tap the jet stream, Sky WindPower's Flying Electric Generator was one of Time magazine's best inventions of 2008. The craft rises like a helicopter from the ground, drawing power from a ground source. Steady winds then keep it aloft, the blades spin like autogyres, and power is sent back down a tether. Here's a video of the test run for the small, 15 ft version of this 'rotorcraft':
Each rotor pictured has a diameter of 35 ft, helping the FEG to steadily capture 240 kW of electricity--at least four times as much as a ground based wind turbine. It's designed to soar to heights of 15,000 ft or higher. Find more detailed information at the company's (mildly confusing) website: Sky WindPower.
2. Magenn Floating Wind Turbines: Heading for MARS
Another classic high altitude wind power generator design, the Magenn Air Rotor has been piquing interest for years now. Its simple concept has drawn widespread acclaim--the Rotor stays afloat via helium, and makes use of the Magnus effect. The company explains: "For the Magnus airship and hence the patented Magenn Air Rotors System (MARS), we have proven that as wind speed increases, rotation increases, lift increases, drag will be minimized because of reduced leaning, and stability increases."
Magenn has designed both single home wind rotor units, and much longer, blimp-sized rotors for industrial power use. These are nearing viability, and full-sized test models of the 30 ft Air Rotor have been successfully floated. It's capable of generating 100 kW, while the smaller rotor does 4. Both are a ways off from the jet stream--they're designed to float some 1,000 ft in the air. But they're making strides, and a success with MARS could lead to higher aspirations.
3. Makani Wind Kites: Elegant Wind Power
Makani Wind takes a different tack with high altitude wind power: they look to kites. The company's innovation attracted some high profile investors--Google among them--and they've since made the prospect of flying wind power-generating kites high in the sky a reality.
A full 10 kW, enough to power a handful of homes, can be created by a kite roughly the size of a piano. But Makani is also working on much bigger kites--ones that fly as high as 2,000 ft and that generate electricity in the megawatt range. In the video below, CEO Saul Griffith shows the kites in action, and explains how we could meet all of the US's power needs in 10 years with such kites alone.
4.The 30,000 Ft. Laddermill
Taking the concept of using kites to harness high altitude wind power a step further, plans are in motion to build a towering 'Laddermill', a series of connected 'kitewings' that rotate in a loop which generates energy, which is then sent down below through a tether. The concept is being brought to life by researchers and students at the Netherlands' Delft University. From the project description:
The kites used in the laddermill, generally called "kiteplanes", combine the ascension characteristics of kites with the descension characteristics of aircraft. By creating a large loop of kiteplanes ascending and descending, a rotation can be created. In turn, this rotation can be coupled to a generator to create energy. The loop of kiteplanes can ultimately go up to 30.000 feet, which would generate approximately 100MW.
Which would be enough to power 100,000 homes. Students have already tested a tiny version that successfully generated 10 kW, and are about to test a 50 kW model.
Here's a video where the Laddermill's prime backer, Dr. Wubbel Oeckels--perhaps not so coincidentally the first Dutchman in space--explains the idea's potential and appeal:
5. KiteGen--Airborne Nuclear Power Plant?
Not exactly--but Italian tech company KiteGen has made quite a claim: that its complex high altitude kite system can create as much energy as a nuclear power plant. Its Kite Wind Generator (KWG) is designed with a vertical spin axis that sends a kite up to 800 meters in the air to capitalize on high energy winds.
All the equipment that generates power remains on the ground, and only the 'airfoils' are held aloft by the wind. Each kite would be able to create 3 MW--and an entire installation occupying the same are of a nuclear power plant (a square mile or so) could feasibly create just as much energy. Another bonus: the land would still be able to be used for agriculture or development, as the KWG's spacing would be intermittent.
Here's a video of KiteGen's plans in simulated action:
With many stunning projects like these well into the development stages, imagining the day when the planet is powered by the jet stream is getting easier and easier. Which is not to say we're there quite yet--there are a slew of hurdles to yet overcome: transmission issues, a lack of serious investment in most cases, and the obvious airspace complications. That said, it looks like it might not be long before we start zoning the skies.