Kite Applications - Traction

Traction

Kites can be used to pull people and vehicles downwind. Efficient foil-type kites such as power kites can also be used to sail upwind under the same principles as used by other sailing craft, provided that lateral forces on the ground or in the water are redirected as with the keels, center boards, wheels and ice blades of traditional sailing craft. In the last two decades several kite sailing sports have become popular, such as kiteboating, kite buggying and kite surfing.

Kite sailing opens several possibilities not available in traditional sailing:

• Wind speeds are greater at higher altitudes
• Kites may be manoeuvered dynamically which increases the force available dramatically
• There is no need for mechanical structures to withstand bending forces; vehicles or hulls can be very light or dispensed with all together

The German company SkySails has developed ship-pulling kites as a supplemental power source for cargo ships, first tested in January 2008 on the ship MS Beluga Skysails. Trials on this 55 m ship have shown that, in favorable winds, the kite reduces fuel consumption by up to 30%. This system is planned to be in full commercial production late http://www.google.com/patents?id=pmVaAAAAEBAJ&dq=3326392 2008. Kites are available as an auxiliary sail or emergency spinnaker for sailing boats. Self-launching Parafoil kites are attached to the mast.

MS Beluga Skysails is the world's first commercial container cargo ship partially powered by a giant computer-controlled kite (160 m². or 1,722 sq ft.). The kite could reduce fuel consumption by 20%. It was launched on 17 December 2007 and was set to leave the northern German port of Bremerhaven to Guanta, Venezuela on 22 January 2008. Stephan Wrage, managing director of SkySails GmbH announced: "During the next few months we will finally be able to prove that our technology works in practice and significantly reduces fuel consumption and emissions." Verena Frank, project manager at Beluga Shipping GmbH, SkySails GmbH's partner further stated that "the project's core concept was using wind energy as auxiliary propulsion power and using wind as a free of charge energy". Anne Quéméré has crossed solo the Atlantic Ocean using power kites. And on 4 November 2008, she started her bid to cross the Pacific Ocean under power kites as sailing power to pull her in her small boat called Oceankite.