World’s biggest wind turbine to take a spin in Norway
The world’s biggest wind turbine will be constructed in Norway. The prototype turbine will stand 162 meters (533 feet) tall and feature a rotor diameter of 145 meters (475 feet). It is expected to be capable of generating 10-megawatts – enough to power 2,000 homes. The turbine will be tested on land in Øygarden in Hordaland County, Norway, for two years but is intended for offshore placement, where the winds are stronger and more consistent, and the concerns of ruined views and vibrations are removed.
Like the HyWind turbines, the turbines to be built by Sway AS are floating turbines. The Sway system is based on a floating tower which extends far below the water surface. The tower consists of a floating pole with ballast in the lower end, similar to a floating bottle. The tower, which is filled with ballast, has its center of gravity located far below the center of buoyancy of the tower. This gives the tower sufficient stability to resist the large loads produced by the wind turbine mounted on top of it.
The floating structure is anchored to the seabed with a single pipe and a suction anchor. When the wind hits the rotor the tower is capable of tilting 5-8 degrees and when the wind changes direction, the entire tower turns around a subsea swivel. This, in turn, makes it possible to reinforce the tower with a tension rod system similar to wire stays on a sailboat mast. Due to the resulting reduction of stresses in the tower, the tower is capable of carrying a much larger turbine.
Sway AS developed the concept in cooperation with Norwegian technology firm Smartmotor AS with a view towards reducing turbine weight ad the number of moving parts, as well as the use of a gearless generator system. Now Enova SF, a public enterprise owned by the Royal Norwegian Ministry of Petroleum and Energy, has provided NOK 137 million (US$24 million at time of publication) of funding towards the NOK 395 million (US$67.5 million) it will cost to construct and demonstrate the wind turbine prototype.
It is hoped the new turbine prototype will be installed in 2011.