摘要 |
A method and a system for installing an offshore wind power station (1) at sea and/or transporting one from sea e.g. for maintenance, said wind power station comprising a base (2) to be set on the sea bottom, and a tower (3) attached to the base, which wind power station is transported to a place of installation at sea by means of a transport vessel (4) and lowered to the sea bottom and/or lifted off the sea bottom and transported to land/ashore by means of a transport vessel. The wind power station is lowered by adding ballast water into a ballast water tank (6, 7) provided in the wind power station, and raised by reducing the amount of ballast water in the ballast water tank. The wind power station comprises a ballast water tank (6, 7). |