Abstract: A method for installing a wind turbine comprises establishing a substructure, the substructure comprising at least one pile extending upwards and the at least one pile being part of a primary structure of the substructure, establishing a support of a secondary structure on the at least one pile, mounting of fittings to the secondary structure, the mounting of the fittings to the secondary structure preferably being established by welding or bolting, and not mounting fittings to at least one of the at least one pile being part of the primary structure. A method may alternatively comprise mounting a wind turbine tower to the at least one pile being part of the primary structure, and the secondary structure constituting an intermediate structure between the at least one pile and the wind turbine tower.

Abstract: The invention relates to methods for installing a wind turbine. A method may comprise the steps of establishing a substructure, said substructure comprising at least one pipe (1) extending upwards and said at least one pipe (1) being part of a primary structure of the substructure, establishing a support of a secondary structure (5) on the at least one pile (1), mounting of fittings to the secondary structure (5), said mounting of the fittings to the secondary structure (5) preferably being established by welding or bolting, and not mounting fittings to at least one of the at least one pile (1) being part of the primary structure. A method may alternatively comprise the steps of mounting a wind turbine tower to the at least one pile (1) being part of the primary structure, and the secondary structure (5) constituting an intermediate structure (5, 11) between the at least one pile (1) and the wind turbine tower (7).

Abstract: An offshore wind turbine is disclosed wherein the power transmission in the nacelle is cooled by means of a liquid conducted to the nacelle from the tower on which the nacelle is pivotally arranged around a vertical yawing axis. The liquid transfers heat to the seawater near the turbine which is used as a heat sink of low temperature and enormous heat capacity as compared to traditional air cooling. The liquid is conducted in a closed circuit and the cooling system may comprise more than one cooling circuit. The flow of cooling-liquid may be conducted between the tower and the nacelle through a heat transfer unit having a first part that is stationary with respect to the tower and a second part that is stationary with respect to the nacelle. The parts have at least one annular passageway for a liquid flow defined between abutting surfaces of the parts.