Offshore vertical-axis wind turbine and associated systems and methods

Abstract

An offshore wind turbine has a vertical-axis wind turbine (VAWT) mounted on a platform. The VAWT has a vertical rotor and curved blades coupled to a gearbox and an electric generator. The VAWT can fixedly extend from the platform or may be capable of reclining on the platform either manually or automatically. The platform can be composed of modular elements coupled together. Offshore, the platform can be semi-submersible with the VAWT extending out of the water and with a counterbalance extending below the platform. Alternatively, the platform can float on the water's surface and can have several arms that extend outwardly from the VAWT to increase the platform's footprint. To anchor the turbine offshore, anchoring systems can anchor the platform to the seabed while allowing the floating wind turbine to adjust passively or actively to changes in sea level due to tidal variations or storm swells.

1 . A method for deploying a wind turbine, comprising:
 floating an offshore wind turbine to a desired position offshore, the offshore wind turbine comprising—
 a vertical axis wind turbine comprising a vertically-extending rotor, a plurality of blades coupled to the rotor, and a generator for producing power from rotation of the rotor, 
 a floating platform upon which the vertical axis wind turbine is mounted, wherein the floating platform floats in water to support the vertical axis wind turbine above the water surface, and 
 an anchoring system coupleable to the floating platform, the anchoring system having an anchor and a weight connected by a cable; 
   anchoring the floating platform to the seabed with the anchoring system by resting the anchor on the seabed; and   supporting the weight between the floating platform and the anchor by passing the cable through at least one pulley on the floating platform.   
     
     
         2 . The method of  claim 1 , wherein anchoring the floating platform to the seabed comprises resting the anchor on the seabed without directly affixing the anchor to the seabed. 
     
     
         3 . The method of  claim 1 , wherein anchoring the floating platform to the seabed comprises flooding the anchor. 
     
     
         4 . The method of  claim 1 , wherein the anchoring system allows the floating platform to be passively or actively adjusted to maintain a proper position relative to the water surface. 
     
     
         5 . The method of  claim 1 , wherein floating the offshore wind turbine to a desired position offshore comprises floating both the floating platform and the anchoring system as separate pieces or as a stack. 
     
     
         6 . The method of  claim 1 , further comprising floating the offshore wind turbine from the desired position offshore to a position on shore. 
     
     
         7 . The method of  claim 6 , wherein floating the offshore wind turbine from the desired position offshore to a position on shore comprises floating the anchoring system. 
     
     
         8 . The method of  claim 1 , wherein a plurality of the cables connect the weight to the anchor, and wherein supporting the weight comprises passing the cables through a plurality of the at least one pulley disposed on the floating platform. 
     
     
         9 . The method of  claim 1 , wherein the floating platform comprises a plurality of legs spreading horizontally from the vertical axis wind turbine. 
     
     
         10 . The method of  claim 1 , wherein the vertical axis wind turbine is tiltable with respect to the floating platform. 
     
     
         11 . A method for deploying a wind turbine, comprising:
 floating an offshore wind turbine to a desired position offshore, the offshore wind turbine comprising—
 a vertical axis wind turbine comprising a vertically-extending rotor, a plurality of blades coupled to the rotor, and a generator for producing power from rotation of the rotor, and 
 a submersible platform upon which the vertical axis wind turbine is mounted; and 
   sinking the submersible platform to come to rest on the seabed, wherein the submersible platform is not directly affixed to the seabed, and wherein at least a portion of the vertical axis wind turbine remains above the water surface.   
     
     
         12 . The method of  claim 11 , wherein the submersible platform comprises a plurality of legs spreading horizontally from the vertical axis wind turbine. 
     
     
         13 . The method of  claim 11 , wherein the submersible platform comprises hollows, and wherein sinking the submersible platform comprises filling the hollows with water. 
     
     
         14 . The method of  claim 11 , further comprising adjusting an axis of the vertically-extending rotor relative to the sunk submersible platform, wherein the adjusted axis is generally vertical. 
     
     
         15 . The method of  claim 11 , further comprising adjusting an angle of the submersible platform relative to the seabed so that the submersible platform is generally horizontal. 
     
     
         16 . The method of  claim 11 , further comprising floating the submersible platform to move the offshore wind turbine from the desired position offshore to a position on shore. 
     
     
         17 . The method of  claim 11 , wherein sinking the submersible platform to come to rest on the seabed comprises:
 sinking a rigid body of the submersible platform on which the vertically-extending rotor is perpendicularly mounted, and   resting a preconfigured angle defined by the rigid body on the seabed such that the vertically-extending rotor extends generally vertical from the water surface.   
     
     
         18 . The method of  claim 11 , further comprising:
 supporting a proximal end of the vertically-extending rotor on the submersible platform; and   securing a distal end of the vertically-extending rotor by cables directly to the seabed or to the submersible platform.   
     
     
         19 . A method for retrieving a movable wind turbine, comprising:
 raising an offshore wind turbine from the seabed to float in the water, the offshore wind turbine comprising—
 a vertical axis wind turbine comprising a vertically-extending rotor, a plurality of blades coupled to the rotor, and a generator for producing power from rotation of the rotor, and 
 a submersible platform upon which the vertical axis wind turbine is mounted; and 
   towing the floating offshore wind turbine to shore.   
     
     
         20 . A method for deploying a wind turbine, comprising:
 assembling an offshore wind turbine on shore, the offshore wind turbine having a vertical axis wind turbine mounted on a submersible platform;   floating the assembled offshore wind turbine to a desired position offshore;   submerging the submersible platform to the seabed while the vertical axis wind turbine extends above the surface of the water; and   connecting the vertical axis wind turbine to a power cable.   
     
     
         21 . A method for retrieving a movable wind turbine, comprising:
 disconnecting an offshore wind turbine from a power sink, the offshore wind turbine having a vertical axis wind turbine extending above the surface of the water and having a submersible platform submerged to the seabed;   raising the submersible platform from the seabed to float in the water; and   towing the floating offshore wind turbine to shore.