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Kite power

Massimo Ippolito, a keen kite surfer and hang glider, spells it out: "Two ribbons of wind completely encircle the Earth; the one in the southern hemisphere is at the latitude of Tierra del Fuego, and the other passes through Europe and the Northern United States."

"The altitude of this ribbon goes from 500m to 10 000m, and its breadth from 4000km to 5000km. The power of this wind averages 2 kW per square metre, from which you can deduce that the wind passing over Europe has the force of 100 000 nuclear plants. This enormous renewable energy source prompted us to consider how a series of kites could entrap and exploit it."

Enter the Kite Wind Generator (KiteGen) — likened by Wired writer Nicole Martinelli to a "backyard drying rack on steroids". Sequoia prefer to compare their concept to a giant carousel. Anchored solidly to the ground, it's activated by the wind itself, which drags the light and ultra-tough kites out of funnels within the arms and propels them 1000m or more into the sky. The rotating central structure contains automatic winches that release pairs of cables to guide the kites.

As they circle in the air, the vertical rotating axis of the structure activates very large alternators that are geared down to handle the extraordinary force exerted on them.

Sequoia estimate that their Kite Wind Generator, working night and day, could produce up to 1 gigawatt of power at a cost of just €1.5 per megawatt hour, or just a fraction of the cost of conventional power in Europe. But it doesn't stop there.

A scaled-up version of the KiteGen design, spanning all of 2000m, could theoretically generate 5 gigawatts of energy.

A sophisticated control system would adjust the kites' flight pattern to optimise its wind-catching efficiency, and radar would be used to detect incoming objects stray aircraft and flocks of birds come readily to mind and quickly redirect the carousel. Naturally, this also raises the question of aircraft flight paths. However, Sequoia insist this is hardly a deal-breaker, pointing out that their arrays would be hoisted only after negotiation with civil aviation authorities over the use of airspace. Ippolito expects a fully functional carousel to be ready within two years. To achieve that goal, he's assembled a team of 20 experts in various fields who appear to be as passionate as he is about the project. They genuinely believe that KiteGen will help reduce the world's reliance on fossil fuels and together with solar and other sustainable power resources make a significant contribution to clean energy initiatives. But will it work? Okay, so what are their chances? On the face of it, not bad. A few months ago, the company built and launched a small-scale prototype from the back of a truck. The single kite generated a small amount of energy, but it was enough to get the team very excited. Earlier this year, Sequoia won a 2006 World Renewable Energy Award for its KiteGen project. There's even some start-up money: the Turin utility company, AEM, signed on as a technical partner and agreed to cover 40 percent of the development expenses. Ippolito estimates that a 1 gigawatt version of their unique energy plant can be built for as little as €360 000 . While conceding that the KiteGen concept will attract its fair share of sceptics, Ippolito believes the rest of the world badly underestimates the potential of wind energy, citing the proven efficacy of windmills and the experience of many generations of sailors. "We hope... that a project with such high potential will not be considered 'too good to be true' to receive the attention and financing that it deserves." | features Kite power

kite, wind, energy