Systems and methods for tethered wind turbines
According to some embodiments, an airborne body extends horizontally along an axis between a first point and a second point. The body may be, for example, at least partially filled with a gas. Two or more vanes may be provided airborne with the body such that the vanes, when acted upon by a wind force perpendicular to the axis, are operable to cause rotation about the axis. Moreover, one or more tethers may be coupled to anchor the body to a third point, and one or more electrical generators may be airborne with the body to convert rotational energy produced by the rotation about the axis into electrical energy. According to some embodiments, each vane comprises a horizontal blade panel attached to and extending along the body.
1. A system, comprising:
an airborne body extending horizontally along an axis between a first point and a second point, wherein the body is at least partially filled with a gas and includes:
an inflatable envelope at least partially filled with the gas, and
a net structure substantially surrounding and constraining the inflatable envelope;
two or more vanes airborne with the body such that the vanes, when acted upon by a wind force perpendicular to the axis, are operable to cause rotation about the axis, each vane comprising a horizontal blade panel attached to and extending along the body;
one or more tethers coupled to anchor the body to a third point;
one or more electrical generators airborne with the body to convert rotational energy produced by the rotation about the axis into electrical energy; and
a structure to adjust the volume associated with the inflatable envelope, the structure including at least one of: (i) a pair of balloonets, each balloonet being located at substantially opposite sides of the axis, (ii) a center balloonet located within the inflatable envelope and substantially at a center point between the first and second points, or (iii) at least one structure to provide expandable tension for the inflatable envelope along the axis.
2. The system of claim 1 , wherein the rotation caused by the wind force comprises rotation of the body about the axis.
3. The system of claim 1 , wherein the rotation is to generate a lifting force on the airborne body.
4. The system of claim 3 , wherein the lifting force comprises a Magnus effect lifting force.
5. The system of claim 1 , wherein the net structure comprises a set of cables or straps.
6. The system of claim 1 , wherein the net structure is associated with at least one of (i) a plurality of spiral structures, (ii) a double helix, or (iii) a series of lateral structures substantially parallel to the horizontal axis.
7. The system of claim 1 , wherein the vanes are coupled to the net structure.
8. The system of claim 1 , wherein the inflatable envelope is super-pressurized with the gas.
9. The system of claim 1 , further comprising:
a surface airborne with the body to direct at least some of the wind force into an area defined by a vane.
10. The system of claim 9 , wherein the surface comprises a passive surface.
11. The system of clam 9 , wherein the surface comprises an active surface.
12. The system of claim 9 , wherein the surface is associated with at least one of: (i) a stabilizer bar, (ii) a wing, (iii) a kite, or (iv) a rudder.
13. The system of claim 9 , further comprising:
a flow divider surface airborne with the body to direct at least some of the wind force away from an area defined by a vane.
14. The system of claim 9 , wherein the surface further provides lift for the airborne body.
15. The system of claim 1 , further comprising:
a surface airborne with the body to, in response to the wind force, orient the airborne body in a position substantially normal to the wind force.
16. The system of claim 15 , wherein the surface comprises a passive rudder.
17. The system of claim 16 , wherein the passive rudder is located substantially at one side of the horizontal axis.
18. The system of claim 16 , wherein the passive rudder is substantially disk shaped and is associated with a height approximately double a height associated with a vane.
19. The system of claim 16 , wherein surface comprises a pair of passive rudders located substantially at opposite side of the horizontal axis.
20. The system of clam 15 , wherein the surface comprises an active surface.
21. The system of claim 15 , wherein the surface is coupled to at least one of: (i) a spreader bar, or (ii) a portion that provides lift for the airborne body.