The first 5 Mw wind turbine has been erected in the North sea to power an off shore platform. Its dimensions are impressive : the Rotor is composed of 3 blades, Diameter 126 m weight 120 tons supported by a mast of 90 m high. It has been developed by Multibrid Entwicklungs Gmbh using new manufacturing technologies like carbon fibers, glass fibers and plastic and also a new electricity generation system which is not an extension of that used for smaller units. It will also serve as a prototype for further developments of future projects. It is thought that this kind of wind turbines could be largely used for off shore wind farms ( up to 1 Gw ) where environmental impacts are less important than those created on the ground.