APPARATUS AND METHOD FOR MAKING OPTIMAL USE OF A PHOTOVOLTAIC ARRAY ON AN AIRBORNE POWER SYSTEM

• US 20090230237A1
• Filed: 10/14/2008
• Published: 09/17/2009
• Est. Priority Date: 03/14/2008
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Tillotson, Brian J.
• Granted Patent: US 7,938,364 B2
• Time in Patent Office: Days
• US Class Current: 244/30
• CPC Class Codes: F24S 20/80 Airborne solar heat collector modules, e.g. inflatable structures
• CPC Class Codes: F24S 50/20 for tracking
• CPC Class Codes: H02S 20/00 Supporting structures for PV modules
• CPC Class Codes: H02S 20/30 Supporting structures being movable or adjustable, e.g. for angle adjustment
• CPC Class Codes: Y02E 10/47 Mountings or tracking
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

A system for generating power from sunlight collected substantially above the earth'"'"'s surface comprises an airborne platform which supports solar power generation system to collect sunlight, convert the sunlight to electricity, and to transmit the electricity to a selected location on the earth'"'"'s surface. The solar power generation system is coupled to the airborne platform by a support which can be manipulated by a control system to move the solar power generation system away from a shadow that might be cast by the airborne platform.

Claims

1. A system for converting sunlight to electricity comprising:

an airborne platform deploying the system above the surface of the earth;

a solar power generation system coupled to the airborne platform by a support; and

a control system coupled to the support to manipulate the support such that the solar power generation system may be moved away from a shadow that might be cast by the airborne platform.

2. The system of claim 1, wherein the support comprises an axle or pivot coupled to the airborne platform, and a beam or truss that is capable of rotating in a horizontal plane coupled to the vertical axle.

3. The system of claim 2, further comprising an axle coupled to the beam or truss, wherein said solar power generation system is coupled to the axle such that the solar power generation system may be pivoted about both the horizontal and vertical axles.

4. The system of claim 2, wherein the beam or truss and the axle are comprised of a single moveable system.

5. The system of claim 2, wherein the solar power generation system is supported adjacent one end of the beam or truss, and further comprising a counterbalance coupled to the beam or truss at an end opposite the solar power generation system.

6. The system of claim 5, wherein the counterbalance also provides aerodynamic lift to substantially counter torque produced by aerodynamic lift of the solar power generation system.

7. The system of claim 5, wherein the counterbalance has a flat side, and the solar power generation system has a sun-facing side, and the counterbalance is mounted such that the flat side is substantially parallel to the sun-facing side of the solar power generation system.

8. The system of claim 2, further comprising a converter for connecting power from the solar energy power generation to microwave energy, and a microwave power transmitter for transmitting microwave energy to a remote collector, supported by the beam or truss.

9. The system of claim 1, wherein the solar power generation system includes a plurality of steerable solar energy collection panels.

10. The system of claim 1, wherein the control system comprises actuators coupled to a command system to manipulate the support.

11. The system of claim 2, wherein the support is a tether for maintaining the solar power generation system in a desired location above the Earth.

12. The system of claim 1, comprising two or more solar energy power generation systems coupled to the airborne platform.

13. The system of claim 12, wherein the two or more solar energy power generation systems are supported on a common axle.

14. The systems of claim 12, wherein the two or more solar energy power generation systems are supported on separate axles.

15. A method of preventing a solar power generation system on an airborne platform from contacting a tether coupled to the airborne platform comprising the steps of:

monitoring the position of the horizontal beam;

determining when the horizontal beam is close to the tether; and

engaging the control system to hold the horizontal beam away from the tether.

16. The method of claim 15, further comprising the steps of:

measuring if a cosine loss of holding the horizontal beam away from the tether is greater than a predetermined level; and

if the cosine loss is less than the predetermined level, holding the horizontal beam in place away from the tether; and

if the cosine loss is greater than the predetermined level, initiating a process comprising the acts of swiveling the horizontal beam nearly 180 degrees about the vertical axis so the horizontal beam is now on the other side of the tether and flipping the solar power generation system to point at the sun from its new position.

17. A method of increasing efficiency of the solar power generation system on an airborne platform, comprising the acts of:

monitoring position and angle of absorption with regard to sunlight of the solar power generation system;

engaging a control system to keep the solar power generation system out of the shadow of the airborne platform; and

engaging a control system to orient the solar power generation system such that solar power generation system is substantially perpendicular to sunlight.

18. The method of claim 17, including the step of providing a counterbalance for the solar power generation system.

19. The method of claim 18, including the step of adjusting the counterbalance to counter an aerodynamic lift produced by the solar power generation system.

20. The method of claim 18, including the step of adjusting the counterbalance to counter a torque produced by the solar power generation system.