A sea-change for wind power

, England (CNN) -- Whenever there is a hike in oil prices, the idea of a return to wind-powered shipping catches favor, but sail ship designs have often fallen short on a number of points, not least that they have to rely on unpredictable weather.

However, the future of shipping could feature wind power, but with kites, not sails.

Flying a kite to propel a ship might sound like something from Kevin Costner's cinematic damp swib, "Waterworld", but that is exactly what a number of nautical engineering firms propose.

Sails, no matter how sophisticated their design or use of lightweight modern materials have a fundamental flaw: they take up valuable deck space and storage room that is better used for cargo.

Kites have the advantage of not needing masts, do not need a large area to store them and can be retrofitted to existing ships.

"Kites hold the potential to change the way we move goods across oceans. They are eco-friendly and sufficiently cost effective to herald a return to sail that the Earth's finite petroleum supplies mandate," says Dave Culp, President of California based company KiteShip.

Another company that is throwing itself into towing kite technology is SkySails, based in Hamburg, Germany. The company was founded by Stefan Wrage, who has developed his idea in the face of much scepticism in the past.

Neither company is proposing that engines will be made redundant with the use of a kite, rather that the added propulsion will save a considerable amount in fuel costs.

Earlier this year SkySails trailed a kite on an 800-ton former buoy tender in the Baltic Sea. Using a towing kite of only 80-square-meters the Beufort reached five knots in low winds.

While this doesn't sound very impressive, add to it engine propulsion and Wrage and his team believe that a saving of between ten and 35 percent could be made on fuel costs and in better wind conditions, perhaps even 50 percent.

Read the rest of this CNN article.