Conversion of solar energy to electrical and/or heat energy

Abstract

A parabolic primary mirror ( 10 ) has a concave specular surface ( 12 ) that is constructed and positioned to receive solar energy and focus it towards a focal point. A secondary mirror ( 14 ) having a convex specular surface ( 16 ) is constructed and positioned to receive focused solar energy from the primary mirror and focus it onto an annular receiver ( 18 ). The annular receiver ( 18 ) may include an annular array of optical elements ( 100 ) constructed to receive solar energy from the secondary specular surface ( 14 ) and focus it onto a ring of discrete areas. A ring of solar-to-electrical conversion units are positioned on the ring of discrete areas.

1 . An optical energy concentrator, comprising an annular array of optical elements, the elements each having a convex top, a convex bottom, flat inner and outer ends, and flat sides which extend radially so that the sides of the optical elements are configured to be mutually abutting to form the annular array. 
     
     
         2 . The optical energy concentrator of  claim 1 , wherein the flat inner and outer ends and the flat sides of the elements are configured to internally reflect optical energy received by the optical energy concentrator. 
     
     
         3 . The optical energy concentrator of  claim 1 , wherein the convex top and the convex bottom are spherically-convex surfaces. 
     
     
         4 . The optical energy concentrator of  claim 1 , wherein the convex top and the convex bottom of the elements are configured to focus optical energy onto focal areas spaced apart from the convex bottom of the elements. 
     
     
         5 . The optical energy concentrator of  claim 3 , wherein each of the focal areas includes a photoelectric cell. 
     
     
         6 . The optical energy concentrator of  claim 1 , wherein the optical elements further comprise elements formed from an optical glass. 
     
     
         7 . An optical element for an annular optical energy concentrator, comprising:
 first opposing optical surfaces having an optical axis and configured to converge incident optical energy;   second opposing optical surfaces having normal directions extending outwardly from respective second optical surfaces so that the normal directions are co-planar with the optical axis, wherein the second opposing optical surfaces are planar optical surfaces; and   third opposing optical surfaces parallel to the optical axis, wherein the third opposing optical surfaces are planar optical surfaces.   
     
     
         8 . The optical element of  claim 7 , wherein the first opposing optical surfaces are spherically-convex surfaces. 
     
     
         9 . The optical element of  claim 7 , wherein the second opposing optical surfaces and the third opposing optical surfaces are configured to internally reflect the optical energy. 
     
     
         10 . The optical element of  claim 7 , wherein the third opposing optical surfaces are mutually non-parallel planar surfaces and configured to abut adjoining optical elements. 
     
     
         11 . An optical energy concentrator, comprising:
 a plurality of optical elements configured to form an annular structure, wherein the optical elements are each configured to converge incident optical radiation onto a corresponding focal area positioned proximate each of the optical elements.   
     
     
         12 . The optical energy concentrator of  claim 11 , wherein each of the optical elements further comprises:
 opposing convex optical surfaces configured to receive and converge the incident optical radiation; and   at least one pair of opposing planar surfaces configured to internally reflect at least a portion of the incident optical radiation.   
     
     
         13 . The optical energy concentrator of  claim 12 , wherein at least one pair of opposing planar surfaces comprises:
 an opposing pair of planar optical surfaces; and   an opposing pair of non plane-parallel optical surfaces adjoining the pair of plane-parallel optical surfaces.   
     
     
         14 . The optical energy concentrator of  claim 11 , wherein the focal area comprises an electrically insulative area configured to receive a photovoltaic device. 
     
     
         15 . An optical energy concentration assembly, comprising:
 a plurality of optical elements configured to converge incident optical radiation; and   a support substrate having an annular recess configured to receive the plurality of optical elements, the annular recess including a plurality of focal areas proximate to and in positional correspondence with the optical elements.   
     
     
         16 . The optical energy concentration assembly of  claim 15 , further comprising photovoltaic cells positioned in the focal areas. 
     
     
         17 . The optical energy concentration assembly of  claim 15 , wherein the optical elements further comprise:
 a pair of opposing convergent optical surfaces configured to receive the incident optical radiation along an optical direction;   a pair of opposing plane-parallel optical surfaces perpendicular to the opposing convergent optical surfaces; and   a pair of opposing planar optical surfaces parallel to the optical direction.   
     
     
         18 . The optical energy concentration assembly of  claim 17 , wherein the pair of opposing convergent optical surfaces include a pair of opposing spherically-convex surfaces. 
     
     
         19 . The optical energy concentration assembly of  claim 17 , wherein the pair of opposing plane-parallel optical surfaces and the pair of opposing planar optical surfaces are configured to internally reflect the incident optical radiation. 
     
     
         20 . The optical energy concentration assembly of  claim 17 , wherein the pair of opposing planar optical surfaces are mutually non-parallel planar surfaces and configured to abut adjoining optical elements.