Vessel and method for mounting an offshore wind turbine

Abstract

A method for erecting an offshore wind turbine at a wind turbine erection site is provided, wherein the wind turbine includes a rotor, which has, in a fully assembled condition, a predetermined number of rotor blades mounted to a rotor hub. The method comprises transporting the rotor hub to the erection site; transporting rotor blades to the erection site; and, mounting, on a vessel, rotor blades to the rotor hub so that the rotor is in the fully assembled condition. Further, a vessel having at least one flange for mounting a rotor hub is provided.

1 . A method for erecting an offshore wind turbine at a wind turbine erection site, wherein the wind turbine includes a rotor, which has, in a fully assembled condition, a predetermined number of rotor blades mounted to a rotor hub, the method comprising:
 a) transporting the rotor hub to the erection site;   b) transporting rotor blades to the erection site; and,   c) mounting, on a vessel, rotor blades to the rotor hub so that the rotor is in the fully assembled condition.   
     
     
         2 . The method of  claim 1 , further comprising:
 a) erecting a wind turbine tower at the wind turbine erection site;   b) mounting a nacelle to the top of the tower;   c) lifting the fully assembled rotor to its position at the tower; and,   d) mounting the fully assembled rotor to the nacelle.   
     
     
         3 . The method of  claim 1 , wherein the hub is mounted to the vessel during mounting of rotor blades. 
     
     
         4 . The method of  claim 3 , wherein the hub is mounted to the vessel by a flange. 
     
     
         5 . The method of  claim 1 , wherein the rotor blades are held in a horizontal position while being mounted to the hub. 
     
     
         6 . The method of  claim 1 , wherein the hub is supported by a crane during the mounting process of the rotor blades. 
     
     
         7 . The method of  claim 1 , wherein the rotor blade is supported by a crane during the mounting process. 
     
     
         8 . The method of  claim 2 , wherein the fully assembled rotor is tilted from a horizontal position to a vertical position before being mounted to the nacelle. 
     
     
         9 . The method of  claim 2 , wherein the fully assembled rotor is lifted by a first crane to its position at the tower, and is tilted during the lifting. 
     
     
         10 . The method of  claim 9 , wherein the tilting is carried out by using a second hook on the first crane. 
     
     
         11 . The method of  claim 9 , wherein the tilting is carried out by a second crane. 
     
     
         12 . The method of  claim 1 , wherein a rotor is transported to the erection site with the predetermined number of rotor blades mounted to the hub except at least one rotor blade, which is mounted after arriving at the erection site. 
     
     
         13 . The method of  claim 1 , wherein a rotor is transported to the erection site with the predetermined number of rotor blades mounted to the hub except two rotor blades. 
     
     
         14 . The method of  claim 1 , wherein a rotor is transported to the erection site without any rotor blades mounted to the hub. 
     
     
         15 . The method of  claim 1 , wherein the at least one rotor blade is supported by a support during mounting on the vessel. 
     
     
         16 . A method for erecting an offshore wind turbine at a wind turbine erection site, wherein the wind turbine includes a rotor, which has, in a fully assembled condition, a predetermined number of rotor blades mounted to a rotor hub, the method comprising:
 a) transporting the rotor to the erection site, which has a smaller number than the predetermined number of rotor blades mounted to the rotor hub;   b) transporting rotor blades to the erection site; and,   c) mounting, on a vessel, the rotor by assembling rotor blades to the rotor hub so that the rotor is in the fully assembled condition.   
     
     
         17 . The method of  claim 16 , further comprising:
 a) erecting a wind turbine tower at the wind turbine erection site;   b) mounting a nacelle to the top of the tower;   c) lifting the fully assembled rotor to its position at the tower; and,   d) mounting the rotor to the nacelle.   
     
     
         18 . The method of  claim 16 , wherein the hub is mounted to the vessel during mounting of rotor blades. 
     
     
         19 . The method of  claim 16 , wherein the hub is supported by a crane during mounting of rotor blades. 
     
     
         20 . A vessel, comprising:
 a) a vessel deck;   b) space for mounting a wind turbine rotor on the deck; and   c) at least one flange for mounting a wind turbine rotor hub to the deck.