Enercon is one of Europe’s biggest wind turbine manufacturers, and these days, with turbine demand vastly outstripping supply (wind developers must line up two years in advance to order their turbines) Enercon is extremely busy. So the company is building its own turbine-delivery ship which cut fuel use about 30 percent. Enercon’s E-Ship 1 currently being assembled in Germany will have four giant 27-meter-high, 4-meter-in-diameter cylindrical towers positioned two fore and two aft. These towers, called Flettner rotors, were named after a German inventor, Anton Flettner, who developed marine propulsion systems back in the ’20s.
A spinning cylinder in a moving airstream creates a lateral force perpendicular to the direction of the airstream which, when used on ships, propels the ship to move forward.
During wind flow, the rotors spin to create lift force (10-14 times that of a trapezoid-shaped sail) through what is called the Magnus Effect. Enercon said it expected with the addition of the four rotors to achieve fuel savings of 30%–40% compared to a conventional diesel powered vessel of the same size. Enercon says the Flettner rotors were well tested back in the 1920s but never gained wide use because of the cheap price of fuel. The E-Ship 1 is scheduled to launch by the end of 2009.
– from www.treehugger.com, marinebuzz