StatoilHydro to Develop World's First Floating Wind Turbine

Oil and gas company StatoilHydro ASA (Stavanger, Norway) has announced plans to build the world's first floating wind turbine, known as Hywind, to be anchored about 10 kilometers off of Norway's coast.

Industrial Info Resources (Sugar Land, TX) reports that the project will be assembled in Amoyfjorden near Stavanger, and then towed to its location offshore, where it will be connected to three anchor points on the sea floor at a depth of about 200 meters. The flotation component of the turbine complex has a draft of 100 meters below the surface, and the assembly is designed to operate in water depths of 120-700 meters. The complete floating assembly will have a total weight of 5,300 tons.

The decision to build a floating turbine assembly was based on the knowledge that wind speeds are higher and more consistent further offshore. For instance, it is estimated that winds at a distance of 5-50 miles off the U.S. coast have the potential to generate more than 900 gigawatts of electricity, which is equivalent to the total installed power generation capacity in the U.S. Placing the project so far offshore also removes any visual environmental problems. However, it also raises technological issues pertaining to the function and stability of the turbines when exposed to large sea waves.

Statoil intends to use a spar buoy as the basis for the flotation component, provided by Technip SA (Paris). The steel and concrete buoy will extend about 100 meters below the surface and contain ballast tanks, which will enable the center of gravity to be located well below the surface, thereby eliminating unnecessary movement.

Technip has extensive experience in oil, gas and petrochemical engineering. The substructure of the platform will be constructed in the Technip yard in Pori, Finland, and towed to Amoyfjorden for assembly. Siemens AG (Munich, Germany) will provide a 2.3-megawatt turbine with 80-meter diameter blades. The turbine will be mounted about 65 meters above the surface of the sea. Siemens will also provide the surface tower structure to support the turbine and rotor assembly. The entire assembly will be connected to a land station by marine cables supplied by Nexans SA (Paris), which specializes in the manufacture of copper and fiber optic cables for building and industrial use. Connection of the cables on land will be undertaken by electricity company Haugaland Kraft SA (Haugesund, Norway).

Statoil has invested more than $64 million in the project. Rigorous tests were conducted on a 3-meter high model in the SINTEF Marintek wave simulator test tank in Trondheim. In addition, Enova Systems Incorporated (Torrance, California) has invested $9.5 million in the project, including the supply of an electronic control system to alter the angle of the turbine blades depending on the swinging motion of the assembly. Construction of the full-scale prototype of the Hywind project is expected to commence during the third quarter of 2009. The project will be fully tested over a period of two years. The concept is ideally suited for locations like Japan and the U.S., which have low energy resources and little free land, but with consistent wind conditions over the sea.

www.statoilhydro.com