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03/07/2009 05:12 am ET | Updated May 25, 2011

Pulling Cargo Ships With Parasails To Save Energy

DÜSSELDORF, Germany, Feb 4 (Tierramérica) - They say that faith can move mountains. Now, faith in the wind has led to a new way to move ships. The technique, developed in Germany, is powerful enough to move today's deep-draught cargo vessels and can reduce fuel consumption by 50 percent.

An adapted parasail is attached to the ship by cables that can be adjusted according to the direction and intensity of the winds. It is activated automatically, guided by an on-board computer.

A 160-square-metre parasail can use the wind to create a traction force of up to eight tonnes, nearly the same push produced by an engine of an Airbus A318 aircraft.

With the parasail system, ships can cut their annual fuel use by 10 to 30 percent, reaching 50 percent under optimal wind conditions.

In a way it is a return to navigation's origins, prior to the development of steam or diesel powered engines, when sails dominated the seascape.

But now, instead of a tall mast with a mainsail attached to it, the large parasail - like a giant parachute - can move in all directions. Its function does not replace, but rather complements the power produced by the engines.

The mind behind this return to the wind is Stephan Wrage, born in the northern German port city of Hamburg. He is an engineer and an aficionado of sailing and paragliding.

"The idea came to me 15 years ago. I was paragliding on the beach and I wondered if this enormous drag force couldn't be used also to move boats," Wrage told Tierramérica.

In 2001, the SkySails company opened its doors, and began manufacturing this new parasail for ships. In 2007 it began its pilot testing on international routes aboard two cargo ships.

The use of wind as a driving force for navigation has met modern technology, notes Peter Schenzle, an advisor for the HSVA, a maritime industries research and development group in Hamburg.

Perhaps the most encouraging aspect of the project is that the parasails are pollution free: wind is a clean energy source - and abundant on the high seas.

There would be great advantages to its widespread use, given that 90 percent of the goods traded in the world is transported by boat along at least one portion of its path from producer to consumer.

Currently, there are more than 100,000 ships on the world's seas. The global fleet is predicted to increase 75 percent by 2020. Average fuel consumption of a 100,000-horsepower ship is 12 to 15 tonnes per hour.

According to industry estimates, global maritime traffic is thus responsible for some 800 million tonnes of carbon dioxide emissions per year.

Although maritime transport is comparatively less polluting than other modes of transport, new regulations are being considered in order to monitor and limit greenhouse gas emissions from ships.

In fact, the International Maritime Organisation, an agency of the United Nations, is drafting standards for reducing carbon dioxide emissions from ship traffic, after doing the same in 2008 for sulphur dioxide emissions.

Furthermore, one of the most enticing questions about the parasail technology is how it can reduce a ship's operating costs, 90 percent of which is fuel.

"We decided to use the SkySails system to preserve the environment, to save resources and, in the long term with gas and oil prices, to continue being competitive," said Gerd Wessels, director of the Wessels shipping company and owner of one of the ships already using the parasail.

Depending on the size, the price of the system varies from 500,000 to 3.5 million dollars. According to SkySails, the investment is recovered in three to five years.

In the second half of 2009, the company will begin assembly-line manufacture of the product. With orders already in place from Germany, Norway and other European countries, it has already surpassed production capacity for the first year.

(*This story was originally published by Latin American newspapers that are part of the Tierramérica network. Tierramérica is a specialised news service produced by IPS with the backing of the United Nations Development Programme, United Nations Environment Programme and the World Bank.)

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