Nov 12 2009

Kite Power at Sea

Posted by: Jonathan Marshall

While kitepower is still only an exciting concept as a source of renewable energy on land, it has already become a viable commercial product over water.

A kite flown over the ocean is just a sail by another name. SkySails, a company based in Hamburg, Germany, has reinvented the sailing ship by designing towing kites that dramatically cut the reliance of cargo vessels on polluting fuels.

Ocean-going ships are an enormous source of air pollution. They contribute nearly 3 percent of all the world's CO2 emissions. In addition, they emit about 9 percent of global sulphur oxides and at least a fifth of all nitrogen oxide pollution.

U.S. researchers estimated in 2007 that high-sulfur marine fuels caused the premature death of 60,000 people in 2002. The U.S. EPA has proposed tough new engine and fuel standards that could prevent 13,000 to 33,000 premature deaths by 2030 and produce health benefits of $110 billion to $280 billion annually.

One way to cut down on pollution is kitepower. Like a giant spinnaker, the 160-square-meter SkySail can tug ships forward with the equivalent force of a thousand horespower engine, reducing fuel consumption 10-to-30 percent, the company claims. That can save big money as well as reducing pollution.

Flying at an altitude of more than 100 meters, the sail picks up high-velocity winds, giving it several times more propulsion power than traditional sails. It doesn't require extensive rigging, and because it causes little or no heeling of the vessel, it is said to be far better suited to modern shipping than other sailing rigs.

When not in use, the kite can be folded into a space the size of a telephone booth.

Last year, Beluga Skysails became the first commercial cargo ship to cross the Atlantic--from Venezuela to Norway--with assistance from a towing kite, which provided 20 percent of the vessel's power.

Wessels Shipping Company is now equipping some of its new cargo ships with SkySails, and plans to retrofit the Beluga SkySails with a monster new 300 sq. meter towing kite. It should be fun to watch, but don't try hooking one of these babies up to your kiteboard unless you want to become an astronaut.

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