To be outfitted with a 65-metre-tall 2.3-megawatt turbine, the Hywind structure, a ballasted steel jacket called a ‘spar buoy’, will stretch 100 metres below the sea surface.

Testing of the StatoilHydro’-operated unit will start in the autumn and run for two years.

The wind turbine is built by Germany’s Siemens, with France’s Technip fabricating the floating elements and handling the offshore installation.

Another French company, Nexans, is installing the cable to shore. Norway’s Haugaland Kraft will prepare landfall.

StatoiilHydro foresees installation of the 5,300 tonnes Hywind in water depths of 120-700 metres.