Solar concentrator with square mirrors

Abstract

The present invention is a solar concentrator system incorporating a square primary mirror, a square secondary mirror, and an optical receiver. The square secondary mirror provides highly efficient throughput of light in combination with the square primary mirror, with minimal shading. Manufacturing features may be incorporated into the square secondary mirror to assist in simplifying fabrication issues and assembly steps related to its non-circular shape. An optional heat shield around the optical receiver may be included, further enhancing performance of the solar concentrator system.

1 . A solar concentrator system, comprising:
 a substantially planar surface;   a curved primary mirror for reflecting solar radiation, said curved primary mirror having a first perimeter which is substantially square, and wherein at least a portion of said first perimeter is in contact with said substantially planar surface;   a curved secondary mirror positioned to reflect said solar radiation from said primary mirror, said curved secondary mirror having a second perimeter which is substantially square, and wherein at least a portion of said second perimeter is in contact with said substantially planar surface; and   an optical receiver positioned to receive said solar radiation from said curved secondary mirror.   
     
     
         2 . The solar concentrator system of  claim 1 , wherein said curved secondary mirror comprises molded glass. 
     
     
         3 . The solar concentrator system of  claim 1 , wherein said curved secondary mirror is convex. 
     
     
         4 . The solar concentrator system of  claim 1 , wherein said curved secondary mirror further comprises a datum feature for orienting said second perimeter of said curved secondary mirror with respect to said first perimeter of said curved primary mirror. 
     
     
         5 . The solar concentrator system of  claim 4 , wherein said curved secondary mirror further comprises a side face, wherein said datum feature is located on said side face. 
     
     
         6 . The solar energy system of  claim 1 , further comprising a heat shield around said optical receiver. 
     
     
         7 . The solar energy system of  claim 6 , wherein said a heat shield has an upper edge with a contour, wherein said contour of said upper edge is derived from a zone shaded by said curved secondary mirror. 
     
     
         8 . The solar concentrator system of  claim 1 , wherein said optical receiver comprises a photovoltaic cell. 
     
     
         9 . The solar concentrator system of  claim 8 , wherein said optical receiver further comprises a non-imaging concentrator. 
     
     
         10 . The solar concentrator system of  claim 9 , wherein said non-imaging concentrator is a truncated pyramid. 
     
     
         11 . The solar concentrator system of  claim 1 , further comprising a space between said curved primary mirror and said curved secondary mirror, wherein said space is filled with a dielectric material. 
     
     
         12 . The solar concentrator system of  claim 11 , further comprising a heat shield around said optical receiver. 
     
     
         13 . A method of concentrating solar radiation with a curved primary mirror having a first perimeter which is substantially square, a curved secondary mirror having a second perimeter which is substantially square and an optical receiver, comprising the steps of:
 attaching at least a portion of said first substantially square perimeter of said curved primary mirror to a substantially planar surface;   attaching at least a portion of said second substantially square perimeter of said curved secondary mirror to said substantially planar surface;   positioning said optical receiver to receive solar radiation that passes through said substantially planar surface, is reflected from said curved primary mirror, and is reflected from curved secondary mirror.   
     
     
         14 . The method of concentrating solar radiation of  claim 13 , wherein said optical receiver comprises a photovoltaic cell. 
     
     
         15 . The method of concentrating solar radiation of  claim 14 , wherein said optical receiver further comprises a non-imaging concentrator. 
     
     
         16 . The method of concentrating solar radiation of  claim 15 , wherein said non-imaging concentrator is a truncated pyramid. 
     
     
         17 . The method of concentrating solar radiation of  claim 13 , further comprising the step of positioning a heat shield around said optical receiver. 
     
     
         18 . The method of concentrating solar radiation of  claim 17 , wherein a portion of said solar radiation is reflected off of said heat shield. 
     
     
         19 . The method of concentrating solar radiation of  claim 15 , wherein said curved secondary mirror comprises molded glass. 
     
     
         20 . The method of concentrating solar radiation of  claim 15 , wherein a dielectric material is located between said curved primary mirror and said curved secondary mirror.