Hybrid Vertical Axis Wind Turbine

Abstract

A hybrid vertical axis wind turbine using a highly aerodynamic blade-profile is disclosed. The blade-profile is simple, asymmetrical with unequal upper and lower surfaces cambers and is capable of generating high starting torque even at low wind. Wind tunnel tests demonstrated that this aerodynamic profile would generate high torque of similar magnitude when wind comes from leading or trailing edge. Other characteristics of this profile are that it is compact, lightweight, durable and economical. The target users for this patent will be 44% of the world population that live in rural areas where roof-top wind turbine will be cost effective to provide enough household required electric power. This compact turbine can also use batteries to store energy, thereby reducing and possibly eliminating the need for grid power.

What is claimed is: 
     
         1 . A hybrid vertical axis wind turbine structure comprising: a vertical rotating shaft at the center of the system; upper and lower hubs to accept upper and lower rows of horizontal beams; multiple blades each connected to a set of upper and lower horizontal beams; an upper outer shaft to protect the vertical rotating shaft that is placed between the hubs; an upper thrust bearing supported on an upper base-plate placed below the lower hub; a lower outer shaft to protect the rotating shaft placed below the lower hub; a plurality of magnets that are fixed on the outer surface of the vertical rotating shaft between the upper and lower base-plates; coils of copper wire wound helically on an insulated cylinder and connected to a power storage device at the bottom; a lower outer shaft to protect the vertical rotating shaft placed between upper base-plate and lower base-plate; a power storage means which is connected to the copper coil; and a lower thrust bearing supported on the lower base-plate, which is supported directly and indirectly on foundation. 
     
     
         2 . The hybrid wind turbine according to  claim 1 , wherein the vertical rotating shaft will be placed centrally. This vertical rotating shaft supports both the hubs that accept the blades. 
     
     
         3 . The hybrid wind turbine according to  claim 1 , wherein top and bottom hubs having plan form of a regular polygon to accept a number of horizontal beams conveniently. 
     
     
         4 . The hybrid wind turbine according to  claim 1 , wherein each blade is connected rigidly with two horizontal beams having cross section of a channel. 
     
     
         5 . The wind turbine according to  claim 1 , wherein the horizontal channel beam can have compartments to catch the wind more efficiently. 
     
     
         6 . The wind turbine according to  claim 1 , wherein the blade will have the cross-section of a highly aerodynamic profile. 
     
     
         7 . The wind turbine according to  claim 1 , wherein the angle between the blade chords line and the horizontal beam will be fixed at 25 degrees. 
     
     
         8 . The wind turbine according to  claim 1 , wherein the lower outer shaft is static and will be supported on lower base-plate, which will be supported directly or indirectly on the foundation. 
     
     
         9 . A method for producing electricity using the hybrid vertical axis wind turbine, including the steps of: mounting the vertical rotating shaft and connecting with the building frame-work; fixing the hubs with the vertical rotating shaft tightly so that both the hubs and the rotating shaft spin together; fixing the horizontal beams with the hubs at one end and to the blades at the other end; mounting the blades between upper and lower horizontal beams; placing the upper thrust bearing around the vertical rotating shaft between the lower hub and upper base-plate; fixing the plurality of magnets on the vertical rotating shaft such that the magnets will spin with the vertical rotating shaft without any slip; placing the lower thrust bearing around the vertical rotating shaft on top of lower base-plate; supporting the insulated cylinder with copper coil wound on its outer surface on the lower base-plate and placing the same around the vertical rotating shaft with magnets; placing the lower outer-shaft around the insulated cylinder and fixing the same on the lower base-plate rigidly; and connecting the ends of the copper coil with the terminals of the battery or any other power storage devices including utility grid. 
     
     
         10 . A method according to  claim 9 , wherein said step of mounting the vertical rotating shaft and connecting with the building frame-work such that the vertical rotating shaft remains stable and is free to rotate with minimum torque. 
     
     
         11 . A method according to  claim 9 , wherein said step of fixing the hubs with the vertical rotating shaft tightly so that both the hubs and the rotating shaft spin together. 
     
     
         12 . A method according to  claim 9 , wherein said step of fixing the horizontal beams with the hubs at one end so that the horizontal beams can transmit the torque to the hubs without loss. 
     
     
         13 . A method according to  claim 9 , wherein said step of mounting the blades between upper and lower horizontal beams such that the angle between the blade-chords and horizontal beams is fixed at 25°. This will result in generation of highest amount of torque. 
     
     
         14 . A method according to  claim 9 , wherein said step of placing the upper thrust bearing around the vertical rotating shaft between the lower hub and upper base-plate is to allow the vertical shaft to rotate at the same time to withstand part of its weight through axial thrust. 
     
     
         15 . A method according to  claim 9 , wherein said step of fixing the plurality of magnets on the vertical rotating shaft such that the magnets will spin with the vertical rotating shaft without any slip. As a result induction current will generate. 
     
     
         16 . A method according to  claim 9 , wherein said step of placing the lower thrust bearing around the vertical rotating shaft on top of lower base-plate is to allow the vertical shaft to rotate at the same time withstand part of its weight through axial thrust. 
     
     
         17 . A method according to  claim 9 , wherein said step of supporting the insulated cylinder wound with copper coil on its outer surface from the lower base-plate and placing around the vertical rotating shaft with magnets is to generate induction current. 
     
     
         18 . A method according to  claim 9 , wherein said step of placing the lower outer-shaft around the insulated cylinder and fixing the same on the lower base-plate rigidly so that the whole system becomes very stable. It is also possible to tie the lower outer-shaft with the building framework for more stability. 
     
     
         19 . A method according to  claim 9 , wherein said step of connecting the ends of the copper coil with the terminals of the battery or any other power storage devices is to save the electric energy generated by harnessing wind energy. 
     
     
         20 . A method according to  claim 9 , wherein said step of connecting the ends of the copper coil with the utility grid can also save the electric energy generated by harnessing wind energy.