Receiver for concentrating photovoltaic-thermal system

Abstract

Systems, methods, and apparatus by which solar energy may be collected to provide electricity or a combination of heat and electricity are disclosed herein. Examples of solar energy receivers are disclosed that may be used to collect concentrated solar radiation.

1 . A solar energy collector comprising:
 first and second linearly extending receivers each comprising one or more coolant channels extending along its long axis, the first and second receivers mechanically coupled to each other to form a V-shape with a long axis of the first receiver parallel to a long axis of the second receiver, each receiver comprising a surface facing outward from the V-shape and an opposite surface facing into the V-shape; and   a linearly extending cover substantially parallel to the long axes of the first and second receivers and arranged above or between the first and second receivers to at least substantially close the opening at the upper end of the V-shape.   
     
     
         2 . The solar energy collector of  claim 1 , wherein the cover is not substantially transparent to solar radiation. 
     
     
         3 . The solar energy collector of  claim 2 , comprising a first plurality of solar cells disposed on the outward facing surface of the first receiver, and a second plurality of solar cells disposed on the outward facing surface of the second receiver. 
     
     
         4 . The solar energy collector of  claim 3 , comprising thermal insulation disposed on the inward facing surfaces of the first and second receivers. 
     
     
         5 . The solar energy collector of  claim 4 , wherein the cover seals the top of the V-shape. 
     
     
         6 . The solar energy collector of  claim 4 , wherein a portion of the outward facing surfaces of the first receiver and the second receiver do not comprise solar cells, and at least some of that portion is coated, painted, or otherwise treated to increase absorption of solar radiation. 
     
     
         7 . The solar energy collector of  claim 4 , comprising a layer of material substantially transparent to solar radiation disposed adjacent to the solar cells on the first receiver, and another layer of material substantially transparent to solar radiation disposed adjacent to the solar cells on the second receiver, wherein the transparent layers are spaced apart from the solar cells to form insulating air gaps between the solar cells and the transparent layers. 
     
     
         8 . The solar energy collector of  claim 2 , wherein a surface of the cover facing outward from the V-shape is coated, painted, or otherwise treated to increase absorption of solar radiation. 
     
     
         9 . The solar energy collector of  claim 1 , wherein the cover is substantially transparent to solar radiation. 
     
     
         10 . The solar energy collector of  claim 9 , comprising a first plurality of solar cells disposed on the outward facing surface of the first receiver, and a second plurality of solar cells disposed on the outward facing surface of the second receiver. 
     
     
         11 . The solar energy collector of  claim 10 , wherein a portion of the outward facing surfaces of the first receiver and the second receiver do not comprise solar cells, and at least some of that portion is coated, painted, or otherwise treated to increase absorption of solar radiation. 
     
     
         12 . The solar energy collector of  claim 10 , comprising a third plurality of solar cells disposed on the inward facing surface of at least one of the receivers. 
     
     
         13 . The solar energy collector of  claim 10 , comprising a layer of material substantially transparent to solar radiation disposed adjacent to the solar cells on the first receiver, and another layer of material substantially transparent to solar radiation disposed adjacent to the solar cells on the second receiver, wherein the transparent layers are spaced apart from the solar cells to form insulating air gaps between the solar cells and the transparent layers. 
     
     
         14 . The solar energy collector of  claim 9 , wherein the inward facing surfaces of the first and second receivers are coated, painted, or otherwise treated to increase absorption of solar radiation. 
     
     
         15 . The solar energy collector of  claim 9 , comprising a layer of material substantially transparent to solar radiation disposed on or adjacent to the inward facing surface of the first receiver, and a layer of material substantially transparent to solar radiation disposed on or adjacent to the inward facing surface of the second receiver. 
     
     
         16 . The solar energy receiver of  claim 15 , wherein the layers of substantially transparent material are spaced apart from the inward facing surfaces of the receivers to form insulating air gaps between the transparent layers and the inward facing surfaces. 
     
     
         17 . The solar energy collector of  claim 9 , wherein the cover seals the top of the V-shape. 
     
     
         18 . A solar energy collector comprising:
 first and second linearly extending receivers each comprising one or more coolant channels extending along its long axis, the first and second receivers mechanically coupled to each other to form a V-shape with a long axis of the first receiver parallel to a long axis of the second receiver, each receiver comprising a surface facing outward from the V-shape and an opposite surface facing into the V-shape; and   a third linearly extending receiver extending substantially parallel to the long axes of the first and second receivers and arranged above or between the first and second receivers to at least substantially close the opening at the upper end of the V-shape.   
     
     
         19 . The solar energy collector of  claim 18 , wherein the third receiver comprises one or more coolant channels extending along its long axis. 
     
     
         20 . The solar energy collector of  claim 18 , comprising a first plurality of solar cells disposed on the outward facing surface of the first receiver, and a second plurality of solar cells disposed on the outward facing surface of the second receiver. 
     
     
         21 . The solar energy collector of  claim 20 , comprising a third plurality of solar cells disposed on a surface of the third receiver facing outward from the V-shape. 
     
     
         22 . The solar energy collector of  claim 20 , wherein the third receiver comprises one or more coolant channels extending along its long axis. 
     
     
         23 . The solar energy collector of  claim 18 , comprising thermal insulation disposed on the inward facing surfaces of the first and second receivers. 
     
     
         24 . The solar energy collector of  claim 18 , wherein the third receiver seals the top of the V-shape. 
     
     
         25 . The solar energy collector of  claim 20 , wherein a portion of the outward facing surfaces of the first receiver and the second receiver do not comprise solar cells, and at least some of that portion is coated, painted, or otherwise treated to increase absorption of solar radiation. 
     
     
         26 . The solar energy collector of  claim 20 , comprising a layer of material substantially transparent to solar radiation disposed adjacent to the solar cells on the first receiver, and another layer of material substantially transparent to solar radiation disposed adjacent to the solar cells on the second receiver, wherein the transparent layers are spaced apart from the solar cells to form insulating air gaps between the solar cells and the transparent layers. 
     
     
         27 . A solar energy collector comprising:
 first and second linearly extending receivers each comprising one or more coolant channels extending along its long axis, the first and second receivers mechanically coupled to each other to form a V-shape with a long axis of the first receiver parallel to a long axis of the second receiver, each receiver comprising a surface facing outward from the V-shape and an opposite surface facing into the V-shape;   wherein the outward facing surface of the first receiver comprises a plurality of solar cells, and the outward facing surface of the second receiver does not comprise solar cells.   
     
     
         28 . The solar energy collector of  claim 27  wherein the one or more coolant channels of the first receiver are fluidly coupled to the one or more coolant channels of the second receiver. 
     
     
         29 . A solar energy collector comprising:
 first and second linearly extending receivers each comprising one or more coolant channels extending along its long axis, the first and second receivers mechanically coupled to each other to form a V-shape with a long axis of the first receiver parallel to a long axis of the second receiver, each receiver comprising a surface facing outward from the V-shape and an opposite surface facing into the V-shape;   wherein the majority of the outward facing surface of the first receiver and the majority of the outward facing surface of the second receiver do not comprise solar cells.   
     
     
         30 . The solar energy collector of  claim 29 , wherein neither the outward facing surface of the first receiver nor the outward facing surface of the second receiver comprise solar cells. 
     
     
         31 . The solar energy collector of  claim 29 , comprising a linearly extending cover substantially parallel to the long axes of the first and second receivers and arranged above or between the first and second receivers to at least substantially close the opening at the upper end of the V-shape. 
     
     
         32 . The solar energy collector of  claim 29 , comprising a third linearly extending receiver extending substantially parallel to the long axes of the first and second receivers and arranged above or between the first and second receivers to at least substantially close the opening at the upper end of the V-shape, the third receiver comprising one or more coolant channels extending along its long axis. 
     
     
         33 . A solar energy receiver comprising:
 a linearly extending substrate having first and second surfaces on opposite sides of the substrate;   one or more coolant channels extending through the substrate along its long axis;   a plurality of solar cells disposed on the first surface of the substrate; and   thermal insulation disposed on the second surface of the substrate.   
     
     
         34 . The solar energy receiver of  claim 33 , comprising a layer of material substantially transparent to solar radiation disposed on or adjacent to the first surface. 
     
     
         35 . The solar energy receiver of  claim 34 , wherein the layer of substantially transparent material is spaced apart from the first surface to form an insulating air gap. 
     
     
         36 . The solar energy receiver of  claim 33 , wherein a portion of the first surface does not comprise solar cells, and at least some of that portion is coated, painted, or otherwise treated to increase absorption of solar radiation. 
     
     
         37 . A solar energy receiver comprising:
 a linearly extending substrate having first and second surfaces on opposite sides of the substrate;   one or more coolant channels extending through the substrate along its long axis;   a plurality of solar cells disposed on the first surface of the substrate; and   a layer of material substantially transparent to solar radiation disposed on the second surface of the substrate.   
     
     
         38 . The solar energy receiver of  claim 37 , wherein the layer of substantially transparent material is spaced apart from the second surface to form an insulating air gap between the layer and the second surface. 
     
     
         39 . The solar energy receiver of  claim 37 , wherein the second surface is coated, painted, or otherwise treated to increase absorption of solar radiation. 
     
     
         40 . The solar energy receiver of  claim 37 , comprising a layer of material substantially transparent to solar radiation disposed on or adjacent to the first surface. 
     
     
         41 . The solar energy receiver of  claim 40 , wherein the layer of substantially transparent material is spaced apart from the first surface to form an insulating air gap. 
     
     
         42 . The solar energy receiver of  claim 37 , wherein a portion of the first surface does not comprise solar cells, and at least some of that portion is coated, painted, or otherwise treated to increase absorption of solar radiation. 
     
     
         43 . A solar energy receiver comprising:
 a linearly extending substrate having first and second surfaces on opposite sides of the substrate;   one or more coolant channels extending through the substrate along its long axis; and   a plurality of solar cells disposed on the first surface of the substrate;   wherein the second surface is coated, painted, or otherwise treated to increase absorption of solar radiation.   
     
     
         44 . The solar energy receiver of  claim 43 , comprising a layer of material substantially transparent to solar radiation disposed on or adjacent to the first surface. 
     
     
         45 . The solar energy receiver of  claim 44 , wherein the layer of substantially transparent material is spaced apart from the first surface to form an insulating air gap. 
     
     
         46 . The solar energy receiver of  claim 43 , wherein a portion of the first surface does not comprise solar cells, and at least some of that portion is coated, painted, or otherwise treated to increase absorption of solar radiation. 
     
     
         47 . A solar energy receiver comprising:
 a linearly extending substrate having first and second surfaces on opposite sides of the substrate;   one or more coolant channels extending through the substrate along its long axis;   a plurality of solar cells disposed on the first surface of the substrate; and   a second plurality of solar cells disposed on the second surface of the substrate.   
     
     
         48 . The solar energy receiver of  claim 47 , wherein a portion of the second surface does not comprise solar cells, and at least some of that portion is coated, painted, or otherwise treated to increase absorption of solar radiation. 
     
     
         49 . The solar energy receiver of  claim 47 , comprising a layer of material substantially transparent to solar radiation disposed on or adjacent to the first surface. 
     
     
         50 . The solar energy receiver of  claim 49 , wherein the layer of substantially transparent material is spaced apart from the first surface to form an insulating air gap. 
     
     
         51 . The solar energy receiver of  claim 47 , wherein a portion of the first surface does not comprise solar cells, and at least some of that portion is coated, painted, or otherwise treated to increase absorption of solar radiation. 
     
     
         52 . A solar energy receiver comprising:
 a linearly extending substrate;   one or more coolant channels extending through the substrate along its long axis;   a plurality of solar cells disposed on a surface of the substrate; and   a layer of material substantially transparent to solar radiation disposed on or adjacent to the surface.   
     
     
         53 . The solar energy receiver of  claim 52 , wherein the layer of substantially transparent material is spaced apart from the surface to form an insulating air gap. 
     
     
         54 . The solar energy receiver of  claim 52 , wherein a portion of the surface does not comprise solar cells, and at least some of that portion is coated, painted, or otherwise treated to increase absorption of solar radiation. 
     
     
         55 . A solar energy receiver comprising:
 a linearly extending substrate;   one or more coolant channels extending through the substrate along its long axis; and   a plurality of solar cells disposed on a surface of the substrate;   wherein a portion of the surface does not comprise solar cells, and at least some of that portion is coated, painted, or otherwise treated to increase absorption of solar radiation.   
     
     
         56 . The solar energy receiver of  claim 55 , wherein the plurality of solar cells comprises a first string of solar cells and a second string of solar cells disposed on the surface with a gap between the first string and the second string, and at least a portion of the surface in the gap is coated, painted, or otherwise treated to increase absorption of solar radiation. 
     
     
         57 . A solar energy collector comprising:
 a first linearly extending reflector having a linear focus oriented in a substantially North-South direction;   a first linearly extending receiver arranged parallel to the first reflector and located approximately at the focus of the first reflector, the first receiver comprising one or more coolant channels extending along its axis and a plurality of solar cells arranged to be illuminated by solar radiation focused by the first reflector;   a second linearly extending reflector having a linear focus approximately parallel to and in line with the linear focus of the first reflector; the second reflector spaced apart from the first reflector;   a second linearly extending receiver arranged parallel to the second reflector and located approximately at the focus of the second reflector, the second receiver comprising one or more coolant channels extending along its axis and a plurality of solar cells arranged to be illuminated by solar radiation focused by the second reflector; and   a straight conduit extending from the first receiver to the second receiver to fluidly couple the one or more coolant channels in the first receiver to the one or more coolant channels in the second receiver;   wherein during operation the conduit is illuminated by solar radiation concentrated by the first reflector, the second reflector, or both.   
     
     
         58 . The solar energy collector of  claim 57 , wherein a greater length of the conduit is illuminated by concentrated solar radiation during the winter than during the summer. 
     
     
         59 . The solar energy collector of  claim 57 , wherein the first reflector is located closer than the second reflector to the earth's equator, and wherein during operation, as the angle of the sun above the earth's horizon decreases, solar radiation concentrated by the first reflector walks partially off of the first receiver and at least partially onto the conduit. 
     
     
         60 . The solar energy collector of  claim 57 , wherein the first reflector is located closer than the second reflector to the earth's equator and wherein, during operation, as the angle of the sun above the earth's horizon decreases, solar radiation concentrated by the first reflector, the second reflector, or both reflectors walks partially off of the conduit and onto the second receiver. 
     
     
         61 . A method of operating a linearly extending concentrating solar energy receiver, the method comprising:
 flowing a coolant in a first direction along a first channel extending through the receiver substantially parallel to the receiver's long axis;   flowing the coolant in a second direction substantially counter-parallel to the first direction in a second channel extending through the receiver substantially parallel to the receiver's long axis; and   illuminating with concentrated solar radiation a surface of the receiver comprising solar cells in thermal contact with the coolant.   
     
     
         62 . The method of  claim 61 , wherein the concentrated solar radiation has an intensity greater on portions of the surface of the receiver near the first channel than on portions of the receiver near the second channel. 
     
     
         63 . The method of  claim 62 , wherein the coolant flows through the first channel prior to flowing through the second channel. 
     
     
         64 . The method of  claim 62 , wherein the coolant flow through the second channel prior to flowing through the first channel. 
     
     
         65 . A method of operating a linearly extending concentrating solar energy receiver, the method comprising:
 flowing a coolant in a first direction along a first channel extending through the receiver substantially parallel to the receiver's long axis;   flowing the coolant in a direction substantially parallel to the first direction in a second channel extending through the receiver substantially parallel to the receiver's long axis;   flowing the coolant through a plurality of channels extending transverse to the receiver's long axis between the first channel and the second channel; and   illuminating with concentrated solar radiation a surface of the receiver comprising solar cells in thermal contact with the coolant.   
     
     
         66 . A solar energy receiver comprising:
 a linearly extending substrate;   a plurality of solar cells disposed on a surface of the substrate and arranged in two or more rows each substantially parallel to a long axis of the substrate;   wherein solar cells within each row are electrically connected in series and cells in different rows are not electrically connected in series.   
     
     
         67 . A solar energy receiver comprising:
 a plurality of solar cells arranged in at least one row substantially parallel to a long axis of the receiver; and   a plurality of bypass diodes each electrically coupled to a different solar cell or group of solar cells to bypass such solar cell or group of solar cells if a threshold current through such solar cell or group of solar cells is not exceeded;   wherein the length of the receiver along its long axis bypassed per diode is smaller near an end of the receiver than near a central portion of the receiver.   
     
     
         68 . The solar energy receiver of  claim 67 , wherein at least some of the bypass diodes are coupled in parallel to a same conductor. 
     
     
         69 . The solar energy receiver of  claim 68 , wherein at least some of the bypass diodes are coupled to each other in series. 
     
     
         70 . A solar energy receiver, comprising:
 a linearly extending substrate comprising one or more coolant channels; and   a plurality of solar cells disposed on a surface of the substrate, the solar cells comprising electrical contacts on a front surface that is illuminated during use;   wherein some or all of the electrical contacts are coated, painted, or otherwise treated to increase absorption of solar radiation, or formed from a material chosen to increase absorption of solar radiation.   
     
     
         71 . A method of operating a solar energy collector comprising a linear array of solar cells, the method comprising:
 concentrating solar radiation to an approximately linear focus on the linear array of solar cells, with the linear focus approximately parallel to a long axis of the linear array of solar cell and approximately centered in the linear array of solar cells;   wherein at least about 95% of the solar energy incident on the solar cells is concentrated on a central portion of the linear array of solar cells having a width, perpendicular to the long axis of the array of solar cells, of less than about 80% of the corresponding width of the linear array of solar cells.   
     
     
         72 . The method of  claim 71 , wherein the solar radiation is concentrated on a front surface of the solar cells, and the solar cells comprise a bus bar located near an edge of the front surface outside of the central portion. 
     
     
         73 . A method of operating a solar energy collector comprising a linear array of solar cells, the method comprising:
 concentrating solar radiation to an approximately linear focus on a front surface of the linear array of solar cells, with the linear focus approximately parallel to a long axis of the linear array of solar cell and approximately centered in the linear array of solar cells;   wherein the solar cells comprise at least one bus bar located near an edge of the front surface and oriented approximately parallel to the long axis of the linear array, and the intensity of concentrated solar radiation incident on the bus bar is less than about 5% of a peak intensity incident on the linear array of solar cells.   
     
     
         74 . A solar energy collection system comprising:
 first and second linearly extending receivers each comprising one or more coolant channels extending along its long axis, the first and second receivers mechanically coupled to each other to form a V-shape with a long axis of the first receiver parallel to a long axis of the second receiver, each receiver comprising a surface facing outward from the V-shape and an opposite surface facing into the V-shape;   a first plurality of solar cells disposed on the outward facing surface of the first receiver,   a second plurality of solar cells disposed on the outward facing surface of the second receiver;   a first inverter electrically coupled to the first plurality of solar cells but not to the second plurality of solar cells; and   a second inverter electrically coupled to the second plurality of solar cells but not to the first plurality of solar cells.   
     
     
         75 . The solar energy collection system of  claim 74 , wherein the first and second inverters are central inverters.