Some of the main issues with offshore wind farms are their environmental and esthetic impact, as well as the inconsistency of the wind. One solution to these issues is being developed by StatoilHydro. The company has developed HyWind – a floating wind turbine based on a 2.3 MW Siemens wind turbine mounted on a floating concrete constructions (Spar-buoy) familiar from North Sea oil installations or offshore loading buoys. Moving the wind turbine further away from the shore allows exploitation of the strongest and most consistent wind.

The rotor blades on the floating wind turbine will have a diameter of 80 meters, and the nacelle will tower some 65 meters above the sea surface. The floatation element will have a draft of some 100 meters below the sea surface, and will be moored to the seabed using three anchor points. The wind turbine can be located in waters with depths ranging from 120 to 700 meters.

The pilot project will be assembled in Åmøyfjorden near Stavanger and is to be located some 10 kilometers offshore Karmøy in the county of Rogaland. The wind turbine itself is to be built by Siemens. Technip will build the floatation element and have responsibility for the installation offshore. Nexans will lay cables to shore, and Haugaland Kraft will be responsible for the landfall. Enova is supporting the project with 59 million NOK.

The goal of the pilot is to reduce costs so that floating wind power can compete in the power market.

“Floating wind power is not mature technology yet, and the road to commercialization and large scale development is long. An important aspect of the project is therefore research and development. The wind turbines must work satisfactorily even when subjected to movements, and it must also be possible to carry out necessary maintenance to the highest of safety standards.” says Alexandra Bech Gjørv, head of New Energy in StatoilHydro.

The company has entered into a technology development agreement with Siemens for the project. The wind turbines must function optimally even in large waves.

A three meters high model has already been tested successfully in SINTEF Marintek’s wave simulator in Trondheim.

The goal of the pilot is to qualify the technology and reduce costs to a level that will mean that floating wind turbines can compete with other energy sources.

“If we succeed, then we will have taken a major step in moving the wind power industry offshore. Floating wind turbines can make a major contribution to providing the world with clean power, but there are major technical and commercial challenges that need to be resolved.” says Alexandra Bech Gjørv.