Method and apparatus for concentrating optical radiation using light trapping elements

Abstract

A holographic planar concentrator for collecting and concentrating solar radiation with light trapping elements. A holographic planar concentrator (HPC) comprises a transparent planar plate with at least one holographic film mounted on the face of the planar plate and a solar energy collecting device attached to at least one edge of the planar plate with a reflective surface or coating mounted along the remaining edges of the planar plate. A holographic planar concentrator with light trapping elements reduces potential light losses, and the amount solar energy collecting material required while enabling a more uniform visual appearance and lower manufacturing and installation costs.

1 . A holographic planar concentrator for collecting and concentrating optical radiation for solar energy applications comprising:
 a transparent planar plate;   a holographic film mounted on at least one face of said transparent planar plate;   a solar energy collecting device attached to at least one edge of said transparent planar plate; and,   a reflective surface or coating attached to at least one edge of said planar transparent plate.   
     
     
         2 . The holographic planar concentrator of  claim 1  wherein said transparent planar plate is glass or an optically transparent polymer. 
     
     
         3 . The holographic planar concentrator of  claim 1  wherein said reflective surface or coating is attached to all edges of said planar transparent plate except said edge with said solar energy collecting device. 
     
     
         4 . The holographic planar concentrator of  claim 1  wherein said holographic film contains at least one repeated diffractive grating structure. 
     
     
         5 . The holographic planar concentrator of  claim 1  wherein said solar energy collecting device is selected from the group consisting of photovoltaic cells, thermally absorbing surfaces and fiber optic cables. 
     
     
         6 . The holographic planar concentrator of  claim 1  wherein said solar energy collecting device is attached to only part of one edge of said transparent planar plate. 
     
     
         7 . The holographic planar concentrator of  claim 6  wherein remaining portions of said one edge is covered by a reflective surface or coating. 
     
     
         8 . The holographic planar concentrator of  claim 1  wherein said solar energy collecting device is attached to two opposing edges of said transparent planar plate. 
     
     
         9 . The holographic planar concentrator of  claim 1  wherein said reflective surface is a metal foil. 
     
     
         10 . The holographic planar concentrator of  claim 1  wherein said reflective surface is a paint. 
     
     
         11 . The holographic planar concentrator of  claim 1  further comprising attaching a second solar energy collecting device to a face of said transparent planar plate opposed to said one face with said holographic film. 
     
     
         12 . A holographic planar concentrator for collecting and concentrating optical radiation for solar energy applications comprising:
 a transparent planar plate;   a holographic film mounted on one face of said transparent planar plate;   a solar energy collecting device mounted on an opposing face of said transparent planar plate;   a reflective surface attached to at least on edge of said transparent planar plate.   
     
     
         13 . The holographic planar concentrator of  claim 12  wherein said reflective surface is attached to all edges of said transparent planar plate. 
     
     
         14 . The holographic planar concentrator of  claim 12  further comprising a second solar energy collecting device mounted on an edge of said transparent planar plate. 
     
     
         15 . The holographic planar concentrator of  claim 12  wherein said solar energy collecting device is selected from the group consisting of photovoltaic cells, thermally absorbing surfaces and fiber optic cables. 
     
     
         16 . The holographic planar concentrator of  claim 12  wherein said holographic film contains at least one repeated diffractive grating structure. 
     
     
         17 . A method for concentrating solar energy with a transparent planar plate comprising the steps of:
 attaching a holographic film to one face of said transparent planar plate;   attaching a reflective surface to at least one edge of said transparent planar plate;   attaching a solar energy collection device to at least one edge of said transparent planar plate.   
     
     
         18 . The method of  claim 17  further comprising the step of attaching a solar energy collection device to a face of said transparent planar plate opposed to said one face with said holographic film. 
     
     
         19 . The method of  claim 17  wherein said solar energy collecting device is selected from the group consisting of photovoltaic cells, thermally absorbing surfaces and fiber optic cables. 
     
     
         20 . The method of  claim 17  wherein said transparent planar plate is glass or an optically transparent polymer.