Tethered airfoil wind energy conversion system

1. A tethered airfoil wind energy conversion system, comprising:

a positive-lift, lighter-than-air, flexible gas bag-type airfoil provided with a lined vent which extends completely generally axially therethrough;

a wind turbine having a power output-providing device;

frame means supported by said airfoil and mounting said wind turbine for rotation relative to said airfoil in axial alignment with said vent;

a plurality of motorized, individually operable winches, being at least three in number, and being for disposition at spaced sites generally in an imaginary ring on the ground;

each such winch having a tether line wound thereon and having a respective outer end;

means connecting each tether line outer end to said airfoil radially distally of said vent, so that said airfoil is tethered to said winches from a plurality of widely distributed sites;

a means for supplying inflating lighter-than-air gas to the airfoil, this means including a gas inlet control valve;

a means for releasing inflating lighter-than-air gas from within the airfoil, this means including a gas release control valve;

means for sensing wind direction incident upon said airfoil and for providing an output signal in relation thereto;

a tether control system incorporating means for determining for each of a plurality of various different wind direction-related output signals received from said sensing means, respective control signals equating to the amounts by which each of the respective tether lines must be reeled in or played out in order to tilt the airfoil into the wind at an optimum angle of attack to maximize power output of said power output-providing device of said wind turbine;

means operatively connecting said sensing means to said tether control system for furnishing said output signal to said tether control system; and

means operatively connecting said tether control system to each of said motorized, independently operable winches for furnishing said respective control signals to the respective said winches.

2. The tethered airfoil wind energy conversion system of claim 1, wherein:

the airfoil is of generally hemispherical shape, base generally downwards, with said wind turbine being mounted generally at the lower end of said vent.

3. The tethered airfoil wind energy conversion system of claim 2, further including flap means skirting said airfoil at the base thereof.

4. The tethered airfoil wind energy conversion system of claim 2, wherein:

said airfoil being internally divided into a plurality of individual compartments by internal wall means, in order to prevent one puncture from causing catastrophic loss of inflating gas from said airfoil.

5. The tethered airfoil wind energy conversion system of claim 4, wherein:

said internal wall means comprise a plurality of internal walls of flexible sheet extending perpendicularly to said base and radially of said vent at about 30.degree. intervals.

6. The tethered airfoil wind energy conversion system of claim 5, wherein:

said base and said internal walls are relatively dark-colored and, and wherein the remainder of said airfoil is relatively transparent for enhancing warming by solar radiation of inflating gas contained in said airfoil.

7. The tethered airfoil wind energy conversion system of claim 1, wherein:

said tether control system operates in use to tilt said airfoil at an angle .alpha. of up to about 30.degree. from horizontal, headed into the wind.

8. The tethered airfoil wind energy conversion system of claim 1, wherein:

said lined vent is superficially provided with ridge means spiraling thereabout along the length thereof for creating a vortex of the wind passing therethrough.

9. The tethered airfoil wind energy conversion system of claim 1, wherein:

said means for supplying inflating lighter-than-air gas to the airfoil includes a gas generator.

10. The tethered airfoil wind energy conversion system of claim 9, wherein said gas generator is a hydrogen generator.

11. The tethered airfoil wind energy conversion system of claim 10, wherein:

said hydrogen generator is borne aloft by said airfoil.

12. The tethered airfoil wind energy conversion system of claim 10, wherein:

said hydrogen generator constitutes at least part of said power output-providing device by having a capacity, when in use, to provide substantially more hydrogen, as an output product, than is required for providing inflating gas for said airfoil; and means for taking-off excess hydrogen from said hydrogen generator as an output product.

13. The tethered airfoil wind energy conversion system of claim 1, further including:

means communicated to said tether lines, said tether control system, and said control valves, for sensing the tension on said tether lines and for admitting inflating gas to said airfoil and for releasing inflating gas from said airfoil for maintaining said tension within a preselected range.

14. The tethered airfoil wind energy conversion system of claim 1, wherein:

said power output-providing device comprises rotary-driven electrical generator operatively coupled to said wind turbine.

15. The tethered airfoil wind energy conversion system of claim 14, wherein:

said electrical generator is supported aloft by said airfoil.

16. The tethered airfoil wind energy conversion system of claim 15, further comprising:

a service line connected with said electrical generator and extending therefrom for taking-off electrical power generated by operation of said electrical generator.

17. The tethered airfoil wind energy conversion system of claim 16, wherein:

said service line extends to the ground along one of said tether lines.

18. The tethered airfoil wind energy conversion system of claim 12, further comprising:

means for transmitting electrical power generated by opertion of said electrical generator to remotely of said electrical generator.

19. The tethered airfoil wind energy conversion system of claim 18, wherein:

said transmitting means is constituted by a microwave transmitter supported by said airfoil and a microwave receiver located on the ground.

20. The tethered airfoil wind energy conversion system of claim 1, wherein:

said power output-providing device comprises a rotary shaft.

21. The tethered airfoil wind energy conversion system of claim 20, wherein:

said rotary shaft is flexible.

22. The tethered airfoil wind energy conversion system of claim 1, wherein:

said frame means comprises three arms and a ring, of which the three arms extend from the wind turbine generally radially outwards to said ring and said ring extends about the outer periphery of the airfoil.

23. The tethered airfoil wind energy conversion system of claim 1, wherein:

said frame means comprises three arms extending from said wind turbine to the base of said lined vent, a ring having said three arms joined thereto at the base of said lined vent; an outer ring extending around the outer periphery of the airfoil; and a plurality of tensioned mechanical tie means interconnecting the inner and outer rings at a plurality of angularly spaced points.

24. The tethered airfoil wind energy conversion system of claim 1, further comprising:

a cradle disposed on the ground beneath said airfoil; and

means for guidingly lowering said airfoil down onto said cradle to a non-use position thereon.

25. A tethered airfoil wind energy conversion system, comprising:

a wind turbine having a power output-providing device for providing a power output as the wind turbine is rotated by the wind;

a generally toric, lighter-than-air gas-filled airfoil having a generally hemispherical outer, upper side and a generally flat inner, lower side, with a generally central, lined vent passageway communicating generally axially between said sides so as to have an entrance through said lower side and an exit through said upper side;

means coaxially mounting said wind turbine relative to said vent adjacent said vent entrance;

a plurality comprising at least three angularly widely distributed tether lines each attached to said airfoil distally of the longitudinal axis thereof;

a plurality of ground-based tether line payout/takeup devices, each having a respective said tether line connected therewith, so that the individual said devices may be operated to increase and decrease the lengths of the individual tether lines effectively in use, for directing the tethered airfoil and the wind turbine supported thereby into the wind both azimuthally and vertically without need for rotating the airfoil.

26. A tethered airfoil wind energy conversion system comprising:

a wind turbine having a power output shaft means;

frame means mounting the wind turbine for rotation about a generally vertical, but tiltable axis;

a buoyant-in-air gas bag means havig said frame means mounted thereto for deploying the resulting wind turbine, frame means, gas bag means assembly above a datum surface;

a plurality comprising at least three angularly widely distributed tether lines each having an upper end secured to said assembly and a lower end extended down to adjacency with said datum surface;

a separate means anchoring each said tether line lower end relative to said datum surface and including means for acting upon the respective tether line for effectively lengthening and shortening the distance between each respective tether line upper end and said datum surface;

control means connected to all of said effectively lengthening and shortening means and being operable to coordinately modify said distances by shortening at least one and/or lengthening at least another for selectively tilting said axis and thus both azimuthally and vertically directing the wind turbine into the wind.

27. A method for deploying a wind turbine into the wind, comprising:

suspending the wind turbine in mid-air above a datum surface by buoying the wind turbine with a lighter-than-air gas bag so that the wind turbine longitudinal axis is generally vertically oriented;

tethering the wind turbine down to the datum surface using a plurality of perimetrically widely distributed tether lines; and

coordinately relatively lengthening and shortening said tether lines in order to incline the wind turbine longitudinal axis in the azimuthal direction and to the degree which maximizes wind energy conversion by said wind turbine to rotary output power.

28. A wind energy conversion device tethered airfoil wind energy conversion system, comprising:

a positive-lift, lighter-than-air, flexible gas bag-type airfoil provided with a lined vent which extends completely therethrough;

a wind energy conversion device comprising a means for accepting a wind energy mechanical input and providing a converted power output;

means mounting said wind energy conversion device on said airfoil for movement of portions thereof with respect thereto incident to accepting said input and providing said converted output, said wind energy conversion device being disposed athwart said vent, so that at least some wind in order to transit said vent must impact said wind energy conversion device;

a plurality of tether lines, being at least three in number, each having a first end effectively secured to the airfoil and a depending second end;

a respective anchor means associated with said second end of each tether line;

each tether line and respective anchor means associated there with including means for effectively adjusting the length in use of the respective tether line for correspondingly adjusting the vector of tilting of said airfoil and thus adjusting the aiming of said vent, for regulating the acceptance of wind energy by said wind energy conversion device.

29. The wind energy conversion device tethered airfoil wind energy conversion system of claim 28 wherein:

said wind energy conversion device comprises a wind turbine and frame means mounting that wind turbine on the airfoil.

30. The wind energy conversion device tethered airfoil wind energy conversion system of claim 28 wherein:

said wind energy conversion device comprises an electrical generator for converting mechanical motion to electrical power.

31. The wind energy conversion device tethered airfoil wind energy conversion system of claim 28 wherein:

said system further includes means for communicating said converted power output to a ground site off-board said airfoil.

32. Apparatus for supporting aloft a wind-operated means, comprising:

a positive-lift, lighter-than-air, flexible, gas bag-type airfoil provided with a lined vent which extends completely therethrough;

a wind-operated means comprising means for accepting a wind input and causing an effect of said wind input to be manifested by said wind-operated means;

means mounting said wind-operated means on said airfoil effectively athwart said vent so that at least some wind in order to transit said vent must effectively encounter said wind-operated means, and experience said effect caused thereby;

a plurality of tether lines, being at least three in number, each having a first end effectively secured to the airfoil and a depending second end;

a respective anchor means associated with said second end of each tether line;

each tether line and respective anchor means associated there with including means for effectively adjusting the length in use of the respective tether line for correspondingly adjusting the vector of tilting of said airfoil and thus adjusting the aiming of said vent, for regulating the acceptance of wind energy by said wind energy conversion device.

33. A method for deploying a wind-operated means into the wind, comprising:

suspending the wind-operated means in mid-air above a datum surface by buoying the wind-operated means above a datum surface with a lighter-than-air gas bag so that the wind-operated means is accessible along a generally vertical path;

tethering the wind-operated means down to the datum surface using a plurality of perimetrically widely distributed tether lines; and

coordinately relatively lengthening and shortening said tether lines in order to incline said path of accessibility in the azimuthal direction and to the degree which maximizes per unit time operating effect of the wind on said wind-operated means.