ADVANCES IN HIGH WINDS

Flying turbines tested for new type of wind power
Jay Lindsay, June 2, 2011 (AP via MSNBC)

"The world's strongest winds race high in the sky, but that doesn't mean they're out of reach as a potentially potent energy source…Flying, swooping and floating turbines are being developed to turn high-altitude winds into electricity…The challenges are huge, but the potential is immense. Scientists estimate the energy in the jet streams is 100 times the amount of power used worldwide annually.

"Cristina Archer, an atmospheric scientist at the California State University in Chico, said there's ‘not a doubt anymore’ that high-altitude winds will be tapped for power…The question is, when? Some companies project their technology will hit the market by the middle of the decade, but Fort Felker at the National Renewable Energy Laboratory says the industry is 10 years away from making a meaningful contribution to the nation's electricity demands."

click to enlarge

"No company, for instance, has met the basic requirement of demonstrating its turbine can safely fly unsupervised for prolonged periods of time…High-altitude wind power is similar to ground wind in the 1970s — facing questions but soon to prove its viability, said PJ Shepard of Oroville, California-based Sky WindPower…

"The lure of high-altitude wind is simple: Wind speed generally increases with its height above the ground as surface friction diminishes. Each time wind speed doubles, the amount of energy it theoretically holds multiplies by eight times…The world's most powerful winds circulate in the jet streams, which are found four to 10 miles (16 kilometers) off the ground and carry winds that regularly break 100 miles per hour (160 kph)."

Schematic of the concept (click to enlarge)

"The dream is to eventually tap the jet streams, but high-altitude wind companies are focusing for now below a 2,000-foot (600-meter) ceiling, above which complex federal air-space restrictions kick in…[Altaeros Energies] calculates winds at the 2,000 foot (600-meter) level are up to 2½ times stronger than winds that can be reached by a typical 350-foot (105-meter) land turbine.

"High-altitude wind advocates say their smaller, lightweight turbines will be far cheaper to build and deploy than windmills with huge blades and towers that must be drilled into land or the sea floor…Those savings would mean inexpensive energy. With wide-scale use, advocates see a range of prices, from something comparable to land wind's current 9 or 10 cents per kilowatt hour down to an astonishingly low 2 cents per kilowatt hour…"