Wind energy at sea (Offshore)

"Offshore wind energy" is the name used to describe electricity generated from wind power on the sea. Offshore wind farms already exist in the North Sea and the Baltic Sea, in the waters off the coasts of Denmark, Great Britain, Sweden and the Netherlands. They are connected to the power grid by subsea cables.

The high average wind speeds at sea enable large energy potential. If future, offshore wind turbines are to make an important contribution to the power supply in Germany too. The Federal Government considers 20,000 to 25,000 megawatt capacity to be possible by 2030. The possible annual electricity yield they can achieve is estimated to be 85 TWh. 

Germany's first wind farm at sea alpha ventus has been completed and connected to the grid in November 2009, after 7 months of construction works. For now alpha ventus is the first offshore wind farm, in which a dozen of wind turbines of the 5 megawatt type are supplying with current.