Apparatus for extracting energy from winds at high altitudes

• US 4,572,962 A
• Filed: 04/28/1982
• Issued: 02/25/1986
• Est. Priority Date: 04/28/1982
• Status: Expired due to Fees

• Current Assignee: Cognitronics Corp. (ThinkEngine Networks, Inc.)
• Original Assignee: Cognitronics Corp. (ThinkEngine Networks, Inc.)
• Inventors: Shepard, David H.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): Duncanson, Jr., W. E.
• Application Number:
  US06/372,632
• Time in Patent Office: 1,399 Days
• Field of Search: 290/44, 290/55, 416/7, 416/8, 416/84-86, 415/5, 415/7, 244/153 A, 244/20
• US Class Current: 290/55
• CPC Class Codes: F03D 13/20 Arrangements for mounting or supporting wind motors; Masts or towers for wind motors
• CPC Class Codes: F03D 5/00 Other wind motors controlling thereof F03D7/00
• CPC Class Codes: F03D 9/25 the apparatus being an electrical generator F03D9/22 takes precedence
• CPC Class Codes: F05B 2240/124 Cascades, i.e. assemblies of similar profiles acting in parallel
• CPC Class Codes: F05B 2240/921 kept aloft due to aerodynamic effects
• CPC Class Codes: Y02E 10/70 Wind energy
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02E 10/728 Onshore wind turbines

Abstract

A wind-operated power-generating module for operation at high altitudes such as 1000 meters comprising a frame structure mounting a pair of vertically-separated parallel shafts around which pass endless belts supporting a series of parallel, elongate wing-like elements for movement around a closed path including the parallel shafts. Wind flow drives these elements around the closed path, to enable electrical power to be generated, and also provides lift to hold the module up at the appropriate high altitude. A number of such modules are tethered in fixed positions in the sky, and are controllable as is appropriate to accommodate changing wind conditions.

Claims

1. Apparatus for extracting energy from air currents at high altitude, comprising:

frame means at said high altitude;

endless belt means supported by said frame means and arranged for movement around a closed path having an ascending leg and a descending leg;

a plurality of air-foil elements secured to said endless belt means for movement around said closed path;

flexible tether means securing said frame means to the surface of the earth;

said air-foil elements being oriented with respect to said endless belt means so as to apply forces from said air currents to said endless belt means effecting (1) motion of said endless belt means around said path, and (2) a lifting force on said frame means tending to move the frame means up and to apply tension to said tether means; and

means responsive to the movement of said endless belt means around said path for transmitting power to the surface of the earth.

2. Apparatus as claimed in claim 1, wherein said air-foil elements comprise wing-like elements;

said wing-like elements being oriented so that those in said ascending leg apply an upward force to said endless belt means, producing movement thereof around said path.

3. Apparatus as claimed in claim 2, wherein said wing-like elements in the descending leg are disposed so as to offer minimum drag resistance.

4. Apparatus as claimed in claim 1, wherein the endless belt movement responsive means comprises an electric generator.

5. Apparatus as claimed in claim 1, wherein aerodynamic surfaces of said apparatus are arranged to produce rotational forces about the vertical tending to align the structure of said apparatus with said wing-like elements extending in a direction perpendicular to the air currents.

6. The method of developing power from the wind at relatively high altitudes comprising

lofting an apparatus to said high altitude by means of lift from the wind;

tethering said apparatus at a fixed position in the sky;

supporting with said apparatus a plurality of airfoil elements positioned side-by-side and arranged for movement in a closed path;

said elements being perpendicular to said closed path and effectively defining a cylindrical region around said path having its axis parallel to the earth'"'"'s surface;

moving said elements by wind interaction at said high altitude; and

developing an electrical output from the movement of said elements.

7. The method of claim 6, including the step of lowering said apparatus substantially in a direction straight back to earth during periods of low wind velocity;

and

producing a relatively slow descent through interaction between the airfoil elements and the air.

8. Apparatus for converting wind energy at high altitude into power usable at the surface of the earth, comprising:

lift means at said high altitude responsive to air currents for developing lifting force;

said lift means comprising a plurality of wing-like airfoil elements arranged for movement about a closed path having an ascending leg and a descending leg;

said elements being driven about said path by said air currents;

power means supported by said lift means for converting energy from air currents at said altitude into power;

flexible tether means comprising a plurality of lines secured to the surface of the earth at spaced locations generally beneath said lift means with said lines extending up from said spaced locations to a common region at or close to said lift means;

means at said common region securing said lines together at a common junction;

means connecting said lift means to said common junction so that said lifting force develops tension in said lines and to provide that said lift means is held in a relatively fixed position both laterally and vertically; and

means to transfer energy from said power means to the surface of the earth.

9. Apparatus as claimed in claim 8, wherein said airfoil elements are supported in a horizontal position.

10. Apparatus as claimed in claim 8, wherein said airfoil elements in said ascending leg are disposed so as to deflect the air passing by in a direction which is at least substantially aligned with the airfoil elements in said descending leg.

11. Apparatus as claimed in claim 8, wherein the force of the air currents striking the airfoil elements in said ascending leg provides said lift tending to maintain said apparatus at the desired altitude.

12. Apparatus as claimed in claim 8, wherein said power means comprises means coupled to said airfoil elements to derive power from the movement thereof about said closed path.

13. Apparatus for converting wind energy at high altitude into energy on the surface of the earth, comprising:

a structure at said high altitude;

air-foil means responsive to air currents for establishing a lifting-force holding said structure at said altitude;

means supported by said structure for developing power from air currents to provide for transmission thereof to the ground;

flexible tether means secured to the ground and extending to said structure to hold it in a fixed position with respect to lateral movement; and

means operable to reel in said tether means to accommodate downward movement of said structure while maintaining it fixed laterally;

said airfoil means including means arranged to interact with the air during such descent to produce relatively high drag forces in the absence of lateral wind currents, whereby to assure relatively slow descent.

14. Apparatus for converting the movement of air currents at high altitudes into useful energy at the surface of the earth, comprising:

an array of devices at high altitudes with each including airfoil means responsive to wind currents both for developing lifting forces for holding the devices up at such altitudes and for extracting energy therefrom for transmission to ground;

said devices being disposed in a pattern providing lateral separation of all of said devices from one another sufficient to avoid interference therebetween;

tether means arranged to establish for each of said devices an operating zone which is substantially fixed in space laterally to maintain said separation between said devices;

means operable with said airfoil means for developing power from the movement thereof responsive to wind currents; and

means for transmitting such power to the surface of the earth.

15. Apparatus as claimed in claim 14, wherein said tether means consists of a plurality of tethers for said devices respectively and arranged to establish for each of said devices a corresponding tether point which is substantially fixed in space with respect to lateral movement;

and

a flexible line connecting each tether point to the corresponding device;

said connecting means further comprising means to accommodate swiveling movement of said line about its tether point to provide that each device can swing to a down wind position from its tether point in accordance with the wind direction at the altitude of that device.

16. In a system wherein a wind-supported power-producing module is normally fixed in position at a relatively high altitude to extract power from the wind, and wherein the wind is variable such that for certain periods there will be insufficient wind velocity to maintain the module at the required altitude;

the improved method for returning the module to earth at such a period comprising;

operating airfoil elements on the module to interact with the air encountered during descent to produce reactive upward forces tending to hold the module up during descent; and

guiding the module during descent along an essentially straight line from said fixed position to the point of retrieval.

17. Apparatus for converting wind energy at high altitude into power usable at the surface of the earth, comprising:

lift means at said high altitude responsive to air currents for developing lifting force;

power means supported by said lift means for converting energy from air currents at said altitude into power;

said power means comprising an electric generator supported by said lift means;

airfoil means comprising a plurality of wing-like elements responsive to air currents and serving to actuate said generator;

endless belt means mounting said wing-like elements in horizontal orientation for movement about a closed path having ascending and descending legs;

said generator being coupled to said endless belt means;

means for transmitting electrical power from said generator to the ground;

flexible tether means comprising a plurality of lines secured to the surface of the earth at spaced locations generally beneath said lift means with said lines extending up from said spaced locations to a common region at or close to said lift means;

means at said common region securing said lines together at a common junction;

means connecting said lift means to said common junction so that said lifting force develops tension in said lines and to provide that aaid lift means is held in a relatively fixed position both laterally and vertically; and

means to transfer energy from said power means to the surface of the earth.

18. Apparatus for converting wind energy at high altitude into energy on the surface of the earth, comprising:

a structure at said high altitude;

air-foil means responsive to air currents for establishing a lifting force holding said structure at said altitude;

said air-foil means comprising a plurality of wing-like elements;

endless belt means mounted on said structure for movement about at least one closed path having ascending and descending legs;

said wing-like elements being secured to said endless belt means in parallel, horizontal orientation to develop forces causing motion of said endless belt means about said closed path;

means supported by said structure for developing power from air currents to provide for transmission thereof to the ground;

said means for developing power comprising means driven by movement of said wing-like elements;

flexible tether means secured to the ground and extending to said structure to hold it in a fixed position with respect to lateral movement; and

means operable to reel in said tether means to accommodate downward movement of said structure while maintaining it fixed laterally;

said air-foil means interacting with the air during such descent to produce relatively high drag forces in the absence of lateral wind currents, whereby to assure relatively slow descent.

19. Apparatus as claimed in claim 18, wherein said ascending and descending legs of said endless belt means extend between two horizontal axes which are displaced vertically.

20. The method of developing power from the wind at relatively high altitudes comprising:

lofting an apparatus to said high altitude by means of lift from the wind;

tethering said apparatus at a fixed position in the sky;

supporting with said apparatus a plurality of elongate and parallel elements positioned side-by-side around a closed loop extending perpendicularly to the longitudinal axes of said elements and arranged for movement together around said loop;

moving said elements around said closed loop by wind interaction at said high altitude; and

developing an electrical output from the movement of said elements.

21. Apparatus for converting wind energy at high altitude into power usable at the surface of the earth, comprising:

lift means at said high altitude responsive to air currents for developing lifting force;

said lift means comprising a module with a plurality of movable airfoil elements;

said airfoil elements being arranged to develop forces to self-align said module in a direction facing the direction of the air currents;

power means supported by said lift means for converting energy from air currents at high altitude into power;

flexible tether means comprising a plurality of flexible lines secured to the surface of the earth at spaced locations generally beneath said lift means with said lines extending up from said spaced locations to a common region at or close to said lift means;

means at said common region securing said lines together at a common junction;

means connecting said lift means to said common junction comprising a single flexible tether line;

said lifting force being transmitted through said single tether line to said common junction to develop tension in said plurality of lines;

said lift means being held in a relatively fixed position both laterally and vertically by all of said flexible lines;

said single flexible line extending from said common junction to said module in a direction having both a lateral and a vertical component with reference to the surface of the earth;

said connecting means further comprising means affording relative rotational movement of said single flexible tether line about a vertical axis through said common junction to provide for shifting movement of said module to effect alignment thereof with the direction of air currents; and

means to transfer energy from said power means to the surface of the earth.