Vessel for transporting wind turbines, methods of moving a wind turbine, and a wind turbine for an off-shore wind farm

Abstract

A wind turbine ( 1 ) has a base ( 5 ) divided into at least three ballast tanks ( 12 ). A vessel ( 7 ) has means for displacing the wind turbine between a loading space ( 25 ) and an unloading position ( 26 ). At its unloading position the vessel has winches ( 11 ) with at least three flexible lines ( 10 ) that can be connected with horizontally distanced lifting points ( 23 ) on the wind turbine base.

1 - 18 . (canceled)  
   
   
       19 . A method of moving a wind turbine, wherein the wind turbine has a wind turbine base with tower, nacelle and rotor blades, wherein at least one wind turbine is positioned on a vessel and is supplied with ballast in the wind turbine base before being sailed out to the wind farm, and wherein in connection with transfer of the wind turbine from the vessel to a place of installation on the wind farm, a ballast condition of the wind turbine base is changed at said unloading position by supplying ballast is supplied to the wind turbine base while the wind turbine base is held suspended in at least three horizontally distanced flexible lines from the vessel with at least most of the upper surface of the wind turbine base located above the sea surface.  
   
   
       20 . A method according to  claim 19 , wherein the at least one wind turbine is in an upright position corresponding to the upright operating position of the wind turbine during sailing out to the place of installation on the offshore wind farm.  
   
   
       21 . A method according to  claim 19 , wherein the wind turbine is self-floating and is moved in a floating, upright position to a position above a loading space on the vessel before the ballast is supplied in connection with placing on the vessel.  
   
   
       22 . A method according to  claim 19 , wherein the wind turbine is in a floating, up-right position at the offshore wind farm before the wind turbine is lowered down to its place of installation.  
   
   
       23 . A method according to  claim 19 , wherein the wind turbine floats in an upright position from the loading space to an unloading position on the vessel.  
   
   
       24 . A method according to claims  19 , wherein the vessel is loaded with at least three, such as four or five, ready-assembled and function-tested wind turbines.  
   
   
       25 . A method of moving a wind turbine from a place of installation on a seabed on an offshore wind farm by means of a vessel, wherein a wind turbine base is connected to at least three horizontally distanced flexible lines from the vessel, wherein ballast means on the vessel are connected to the wind turbine base, wherein lifting by the flexible lines is performed while the wind turbine is standing on the seabed, and wherein ballast is removed from the wind turbine base, the lift in the flexible lines being maintained until at least most of the upper surface of the wind turbine base is located above the sea surface.  
   
   
       26 . A method according to  claim 25 , wherein liquid is pumped down below the wind turbine base in connection with lifting the base off from the seabed.  
   
   
       27 . A wind turbine having a wind turbine base and a tower with nacelle and rotor blades mounted on said wind turbine base, wherein the wind turbine base is divided into at least three chambers, at least three of which act as ballast tanks, and wherein the wind turbine base has at least three lifting points with fittings for mounting fastening means.  
   
   
       28 . A wind turbine according to  claim 27 , wherein the wind turbine base has four chambers.  
   
   
       29 . A wind turbine according to  claim 27 , wherein the wind turbine base has a central chamber and four chambers distributed around the central chamber.  
   
   
       30 . A wind turbine according to  claim 29 , wherein the wall of the central chamber ex-tends upwards into a cylindrical pipe connected with the tower of the wind turbine.  
   
   
       31 . A wind turbine according to  claim 27 , wherein the base has a square shape at its lower part and a lifting fitting at each corner.  
   
   
       32 . A wind turbine according to claims  27 , wherein each ballast tank of the base has a filling pipe and an emptying pipe, the emptying pipe extending down near the bottom of the ballast tank.  
   
   
       33 . A wind turbine according to  claim 32 , wherein each ballast tank has a sounding pipe extending down near the bottom of the ballast tank.  
   
   
       34 . A wind turbine according to  claim 32 , wherein the emptying pipe is provided with an ejector for suction of fluid from the ballast tank when the ejector is supplied with pressurized liquid.  
   
   
       35 . A wind turbine according to claims  27 , wherein the base has a pipe opening out at the lower side of the base.  
   
   
       36 . A wind turbine according to  claim 27 , wherein pipes for use at filling and emptying of ballast are permanent pipes extending up above a waterline of the base in a self-floating condition of the turbine.  
   
   
       37 . A wind turbine according to  claim 36 , wherein the pipes extend up above the waterline of the wind turbine when the wind turbine is placed on the seabed, and terminate in connecting parts for hose connections.  
   
   
       38 . A method of building an off-shore wind power farm having an electric grid with cables placed on the sea bottom and a plurality of wind turbines connected to the electric grid for delivering power thereto, wherein the cables in the electric grid are installed on the sea bottom before all wind turbines have been installed, and wherein some of the wind turbines are placed on the farm and connected to the electric grid before all the wind turbines have been placed on the farm.  
   
   
       39 . A method according to  claim 38 , wherein said electric grid is placed on the sea bottom prior to the placement of the first wind turbine on the farm.  
   
   
       40 . A method according to  claim 38 , wherein a transformer station is connected to the electric grid before all wind turbines have been placed on the farm.  
   
   
       41 . A method according to  claim 38 , wherein one or more of the wind turbines are connected to the electric grid and begin to produce electricity before all wind turbines have been placed on the farm.