Full spin aheadOLD technologies can return with a twist, just as airships keep threatening to and windmills and electric cars have already. Fitting ships with sails to assist with propulsion, thus saving fuel and reducing emissions, is an idea that has been around for decades. It has now gained renewed interest with a search by the Energy Technologies Institute (ETI), a British public–private partnership that promotes low-carbon uses, for suppliers and a shipowner prepared to undertake a trial of wind-driven rotors on a large cargo vessel. The plan is to gather operating data on whether rotor sails are a worthwhile investment. Depending on the routes, suitably equipped vessels could reduce fuel consumption by 5-12%. As some 90% of the world’s trade travels by sea, such savings would soon add up.
The type of sail the ETI is interested in is the Flettner rotor. These were demonstrated by Anton Flettner, a German aerospace engineer, in the 1920s. When placed on a ship the giant rotating cylinders extract energy from the wind using the Magnus effect, a force acting on a spinning body in an airstream to create a pressure...Continue reading
Source: Science and technology http://ift.tt/25NeKnJ
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