Kites could bring wind power to new heights
Kite-like turbines flying 30,000 feet into the air could generate electricity from high-altitude winds.
Wed, Jun 17, 2009 at 01:10 PM
The lights in Times Square may one day be powered by high-flying, energy-harnessing kites. Scientists at the Carnegie Institution and California State University have conducted a study that identified New York as an ideal location to harness the power of high-altitude winds using kite-like turbines that would fly between 20,000 and 50,000 feet into the air.
"There is a huge amount of energy available in high altitude winds," said Ken Caldeira, co-author of the study. "These winds blow much more strongly and steadily than near-surface winds, but you need to go get up miles to get a big advantage. Ideally, you would like to be up near the jet streams, around 30,000 feet."
Jet stream winds are typically steadier and 10 times faster than winds near the ground, and scientists say they contain enough energy to meet global demand for power 100 times over. Kite-like wind turbines tethered to the ground could prove to be the best way to harvest this incredible, untapped source of energy.
In addition to New York City, other places deemed to have the highest wind power densities in the world include Tokyo, Sao Paolo, Seoul and Mexico City.
The lead author of the study, Cristina Archer, says New York benefits from polar jet streams which give the city an average wind power density of up to 16 kilowatts per square meter.
Since the winds don’t blow all the time, backup power would still be necessary. Caldeira says the wind can be expected to fail about 5 percent of the time.
"This means that you either need back-up power, massive amounts of energy storage, or a continental or even global-scale electricity grid to assure power availability. So, while high-altitude wind may ultimately prove to be a major energy source, it requires substantial infrastructure."