Stratosphere tethered photovoltaic power platform

Abstract

The present invention is realized by apparatus and methods for placing a large utility scale photovoltaic array in the low stratosphere of earth's atmosphere at an altitude of about 20 km, above clouds, moisture, dust, and wind. This is accomplished using a large light-weight, rigid, buoyant structure to support the large photovoltaic array. Long, strong and light tethers connect the buoyant structure to the ground and hold it in position against wind forces. The electricity output from the photovoltaic array is then coupled to high voltage transmission lines which connect from the platform to the earth's surface. The electricity is then transmitted through the high voltage transmission lines to the earth's surface where it is connected to the electrical supply grid and provides lower cost, more reliable electricity.

What is claimed is: 
     
         1 . A method of providing an airborne platform for efficiently generating electricity from solar energy comprising:
 a. providing an array of photovoltaic panels,   b. providing a lightweight, rigid, buoyant structure floating in the low stratosphere, the structure supporting said photovoltaic panels,   c. providing electrical connections and apparatus combining the electrical output of said photovoltaic panels and converting it to a high voltage output,   d. providing a tether or tethers physically connecting said structure in the low stratosphere to the ground,   e. providing a high voltage cable or cables transmitting said converted high voltage electrical output to the ground,
 whereby reliable electricity can be provided. 
   
     
     
         2 . The method of  claim 1 , wherein:
 the lightweight rigid buoyant structure supporting said photovoltaic panels floating in the low stratosphere is a rigid truss structure containing gas bags filled with a buoyancy gas.   
     
     
         3 . The method of  claim 2 , comprising:
 a. providing photovoltaic platform modules ( 23 ),   b. mechanically and electrically connecting said modules to construct small photovoltaic platforms on the ground,
 whereby small platforms are conveniently assembled at ground level. 
   
     
     
         4 . The method of  claim 3 , further comprising:
 a. constructing the mechanically connected platform modules ( 23 ) folded flat on the ground with hinges joining the struts at the platform module vertices,   b. unfolding the flat platform modules to their final three dimensional form using said hinges,   c. mechanically fastening platform module vertices making the modules rigid,   d. inflating gas bags within the protected rigid structure,   whereby small platforms are conveniently assembled at ground level and then deployed to the stratosphere.   
     
     
         5 . The method of  claim 1 , comprising:
 a. providing photovoltaic platform modules ( 23 ),   b. mechanically and electrically connecting said modules to construct small photovoltaic platforms on the ground,   c. providing tethers and high voltage cables attached to each small photovoltaic platform,   d. deploying said small photovoltaic platforms from the ground to the low stratosphere using tethers,   e. mechanically connecting said small photovoltaic platforms in the low stratosphere to construct a large platform,   f. transmitting electricity down said high voltage cables to the ground,
 whereby large photovoltaic platforms generating reliable utility scale electricity can be provided. 
   
     
     
         6 . The method of  claim 5 , further comprising:
 a. providing rails or guides to transport small photovoltaic platforms horizontally through the array of tethers of deployed small photovoltaic platforms to the desired location for vertical deployment,   b. deploying or attaching booms connecting the small photovoltaic platform to the adjacent tethers with sliding or rolling connectors,   c. attaching the tether and high voltage cable to the small photovoltaic platform,   d. deploying the small photovoltaic platform vertically using the tether while the sliding connections to the adjacent tethers position the small photovoltaic platform in a fixed horizontal position,   e. mechanically connecting the small photovoltaic platform to adjacent small photovoltaic platforms on arrival at the large platform in the low stratosphere,
 whereby large photovoltaic platforms can be assembled in the low stratosphere. 
   
     
     
         7 . The method of  claim 1 , wherein:
 the photovoltaic panels are light weight, designed for operation at −65 degrees Celsius and are resistant to ozone and intense ultra violet light.   
     
     
         8 . The method of  claim 1 , wherein:
 said tether or tethers and high voltage cable or cables are combined into unified tether/high voltage cable or cables that provide both physical strength and high voltage power transmission.   
     
     
         9 . The method of  claim 1 , wherein:
 The high voltage cables are transmitting high voltage direct current.   
     
     
         10 . The method of  claim 1 , wherein:
 said rigid buoyant structure exterior vertical surface sections are formed from pressurized inflated elements.   
     
     
         11 . A floating platform, photovoltaic solar power plant apparatus operating in the low stratosphere comprising:
 a. an array of photovoltaic panels,   b. a lightweight, rigid, buoyant structure supporting said photovoltaic panels floating in the low stratosphere,   c. electrical connections and apparatus combining the electrical output of said photovoltaic panels and converting it to a high voltage output,   d. a tether or tethers physically connecting said structure in the low stratosphere to the ground,   e. a high voltage cable or cables transmitting the high voltage electrical output of said photovoltaic panels to the ground,
 whereby reliable electricity can be provided. 
   
     
     
         12 . The apparatus of  claim 11 , wherein:
 the lightweight rigid buoyant structure supporting said photovoltaic panels floating in the low stratosphere is a rigid truss structure containing gas bags filled with a buoyancy gas.   
     
     
         13 . A photovoltaic solar power plant apparatus operating in the low stratosphere comprising:
 a. a large platform floating in the low stratosphere constructed from a mechanically connected collection of small photovoltaic platforms, said small photovoltaic platforms constructed from a mechanically and electrically connected collection of photovoltaic platform modules ( 23 )   b. a tether mechanically connecting each small photovoltaic platform to the ground,   c. a high voltage cable electrically connecting each small photovoltaic platform high voltage output to a ground electricity connection,
 whereby utility scale reliable electricity can be provided. 
   
     
     
         14 . The apparatus of  claim 13 , wherein:
 a. the mechanically connected photovoltaic platform modules ( 23 ) are constructed folded flat on the ground with hinges joining the struts at the photovoltaic platform modules vertices,   b. the flat photovoltaic platform modules are unfolded to their final three dimensional form using said hinges and mechanically fastened making the modules rigid,
 whereby small photovoltaic platforms are conveniently assembled at ground level. 
   
     
     
         15 . The apparatus of  claim 13 , further comprising:
 a. rails or guides to transport said small photovoltaic platforms horizontally through the array of tethers of deployed said small photovoltaic platforms to the desired location for vertical deployment,   b. booms attached to said small photovoltaic platforms which mechanically connect the small photovoltaic platform to the adjacent tethers with sliding or rolling connectors,   c. the tether and high voltage cable attached to the small photovoltaic platform,   d. the booms connected to adjacent tethers restrict horizontal motion and the sliding or rolling connectors permit vertical motion while the small photovoltaic platform is deployed vertically using the tether,   e. the small photovoltaic platform is connected to adjacent small photovoltaic platforms on arrival at the large platform in the low stratosphere,
 whereby large photovoltaic platforms can be assembled in the low stratosphere. 
   
     
     
         16 . The apparatus of  claim 11 , wherein:
 the photovoltaic panels are light weight, designed for operation at −65 degrees Celsius and are resistant to ozone and intense ultra violet light.   
     
     
         17 . The apparatus of  claim 11 , wherein:
 said tether or tethers and high voltage cable or cables are combined into unified tether/high voltage cable or cables that provide both physical strength and high voltage power transmission.   
     
     
         18 . The apparatus of  claim 11 , wherein:
 the high voltage cables are transmitting high voltage direct current.   
     
     
         19 . The apparatus of  claim 11 , wherein:
 said rigid buoyant structure exterior vertical surface sections are formed from pressurized inflated elements.   
     
     
         20 . The apparatus of  claim 11 , wherein:
 the tether is constructed from light and strong material such as aramid fiber or UHMWPE fiber.