Abstract:
According to one aspect, there is provided a solar energy converter, including: a lens; a base plate having a first surface that faces the lens and a second surface that is opposite to the first surface; and a solar cell sandwiched between the lens and the base plate, wherein both the lens and the base plate are each provided with at least one channel for fluid for cooling the solar cell. Also contemplated is provision of at least one fin on both the lens and the base plate for cooling the solar cell. According to a second aspect, there is provided a method for cooling a solar energy converter having a lens, a base, and at least one solar cell sandwiched between said lens and said base plate, the method comprising the step of: cooling the at least one solar cell on two opposing sides.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage of International Application No. PCT/SG2012/000036, filed Feb. 8, 2012. 
     FIELD OF THE INVENTION 
     The invention relates to a solar energy converter. 
     BACKGROUND 
     Solar energy can be converted into other forms of energy, such as thermal or electrical energy, through the use of a solar energy converter. 
     A solar energy converter may have a lens, a heat exchanger and a solar cell. The lens focuses sunlight onto the solar cell which converts solar energy into electrical energy. The heat exchanger converts the solar energy into thermal energy. 
     There are several drawbacks to such a solar energy converter. 
     The temperature of the solar cells, during normal operating conditions, rises higher than the optimum operating temperature, which is typically 25° C. The temperature rise of the solar cells is due to the heat from the sun being transmitted directly on to the solar cells through a lens, typically fabricated from glass. Since the efficiency of a solar cell reduces when its temperature increases, the solar cell becomes less efficient during such normal operating conditions. 
     The lens is typically fabricated using tempered glass. Such a lens is heavy, expensive and can break. 
     Further, the solar energy converter is typically designed as a rigid flat panel because of the use of silicon solar cells. Such a rigid flat panel is not readily usable on uneven surfaces. 
     One or more of the above drawbacks is addressed in a solar energy converter according to various embodiments mentioned below. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the invention, there is provided a solar energy converter, including: a lens; a base plate having a first surface that faces the lens and a second surface that is opposite to the first surface, wherein the second surface is exposed to form an outer surface of the solar energy converter; and a solar cell sandwiched between the lens and the base plate, wherein both the lens and the base plate are each provided with at least one channel system for fluid for cooling the solar cell. For example, it may be provided that the fluid absorbs heat from the sun before it heats up the at least one solar cell, where in one embodiment it is the fluid in the at least one channel system of the lens that absorbs the heat. Further, it may be provided that the fluid absorbs heat generated from the at least one solar cell when the at least one solar cell converts light energy into electrical energy. 
     Each of the lens, the at least one solar cell, and the base plate may define a plane, wherein the plane defined by the at least one solar cell is arranged between the plane defined by the lens and the plane defined by the base plate. These three planes may be arranged in parallel. The direction perpendicular to these planes is defined as first direction. 
     The term “channel system” (as used in the present application) of the lens or provided in the lens, respectively, (in short: channels system of the lens) may comprise or consist of one or more channels. These one or more channels may be channels according to the classical sense of the term “channel” and/or one or more chambers or any hollow space or spaces, or a combination thereof. The at least one channel according to the classical sense of the term “channel” may extend straight, or bent, or curved, or meander-shaped, or in any other suitable manner, or in according to a combination thereof. The channel system may consist of a plurality of channels and/or chambers and/or hollow spaces. The channel system of the lens may be closed and/or sealed to the outside of the lens, or one or more openings provided in the outer surface of the lens may be in fluid connection with the channel system, so that the channel system is open to the outside of the lens, wherein said at least one opening may serve for providing fluid into the channel system of the lens and/or discharging fluid out of the channel system of the lens. For example, the lens may have two or more openings to the outside of the lens, wherein one of these openings is or may be connected to a supply channel through which fluid may be continuously supplied into the lens, and wherein the other of these openings is or may be connected to a discharge channel through which fluid may be continuously discharged out of the lens. Effectively, with such a design, heat from the sun is absorbed by the cooling fluid before it heats up the at least one solar cell, which reduces the temperature of the at least one solar cell and improves the heat transfer out of the solar energy converter. 
     According to another embodiment of the invention, the channel system of the lens may have one or more openings to the outside of the lens, wherein these one or more openings are closed and/or sealed by means of detachable closure members. 
     The channel system of the lens may be filled with a fluid for heat absorption and cooling the at least one solar cell. 
     The channel system of the lens may have one or more branching. 
     All channels or chambers or hollow spaces belonging to the same channel system of the lens may be in fluid connection with each other, and in particular may be in fluid connection with each other within the lens. 
     The lens may comprise exactly one channel system for receiving or guiding fluid, respectively, for cooling the at least one solar cell. In another embodiment the lens may comprise more than one channel system, wherein all channels or chambers or hollow spaces belonging to the same channel system of the lens may be, for example within the lens, in fluid connection with each other, and wherein the different channel systems of the lens are not in fluid connection with each other. 
     At least one channel of the channel system of the lens may be designed as or delimited by a recess within or on the surface of the lens such that the at least one channel is open to the outside of the lens along its longitudinal direction. The at least one channel that is open to the outside of the lens along its longitudinal direction may be designed as recess provided in that outer surface of the lens, which outer surface is directed towards the at least one solar cells, for example. Such a design may be such, that the at least one channel is open in the direction towards the at least one solar cell or the first direction, respectively. The outer surface of the lens, which surface is directed to the solar cell may be corrugated, thereby forming channels of the channel system of the lens. However, the open side of such channels may be closed by a cover. For example, the at least one solar cell may serve as cover, or a member interposed between the at least one solar cell and the lens. 
     One, more, or all of the channels of the channel systems may be delimited by material such, that all cross-sections perpendicular to the longitudinal axis of the respective channel are completely surrounded by material. Said material may be material of the lens. In some alternative embodiments said material may be partly material of the lens and partly material of a member positioned adjacent to the lens and serving as cover. 
     The channel system of the lens may have a plurality of channels. 
     The channel system of the lens may have a plurality of channels arranged in parallel to each other. 
     Channels or all of channels of the channel system of the lens may be arranged in one plane or in different planes, for example. However, other configurations may be provided as well. 
     The cross-sectional shape of the channel or the channels of the channels system of the lens may be, for example, circular, or polygonal, or hemispherical, or ellipsoid, or convex, or concave, or triangular, or trapezoidal, or square, or rectangular, or octagonal, or pentagonal, or any other shape, or combination thereof. The channel system of the lens may have a plurality of channels having identical or various cross-sectional shapes. In particular, different channels may be different than the afore-mentioned cross-sectional shapes. 
     The distance or shortest distance, respectively, between the channel system of the lens and the solar cell may be less than 30% of the thickness of the solar energy converter, for example less than 25% of the thickness of the solar energy converter, or less than 20% of the thickness of the solar energy converter, or less than 15% of the thickness of the solar energy converter, or less than 10% of the thickness of the solar energy converter, or less than 8% of the thickness of the solar energy converter, or less than 5% of the thickness of the solar energy converter. 
     Fluid or cooling fluid, respectively, provided in or flowing through the channel system of the lens may be any fluid suitable for cooling and heat absorption. For example, the fluid may be a liquid, gas or air. 
     Fluid may be provided in the channel system of the lens, so as to absorb heat from the sun and cool the solar cell due to its position with regard to the solar cell. Thus, the lens performs the functions of absorbing heat from the sun before it heats up the solar cell, cooling of the solar cell and focusing and/or transmitting light onto the solar cell. 
     The lens may be, for example, an entirely solid object. The term lens as used in the present application may comprise a lens in the classical sense of the term “lens” or may comprise members that cause at least one optical refraction of with regard to a light beam beaming there through. For example, the lens may have one curved surface or two opposing curved surfaces. One surface of the lens may be convex and opposing surface of the lens may be concave. In alternative embodiments both of opposing surfaces of the lens may be concave. In yet other embodiments of the lens both of opposing surfaces of the lens may be convex. The lens may be designed so as to focus light, for example so as to focus light on the at least on solar cell. However, as an example for a lens that causes at least one optical refraction, the lens may designed as a plate having flat or molded surfaces. 
     The walls delimiting channels of the channel system of the lens or being allocated between adjacent channels of the channel system of the lens may have a cross-section or shape that is, for example, polygonal or hemispherical or ellipsoid or convex or concave or trapezoidal or triangular or rectangular or octagonal or pentagonal, or of any other shape. By providing such shapes or cross-sections, respectively, the light path of the light toward the at least one solar cell can be influenced. 
     The lens may be provided with a shock absorbing device. For example, such a shock absorbing device may be designed such that recesses or hollow spaces are located adjacent to the ends of walls delimiting adjacent channels of the channels system of the lens, which ends are directed to at least one the solar cell, so that the respective wall can slightly move into said recess or hollow space, respectively, upon a shock impacting the outer surface of the lens, which outer surface is opposite the surface (of the lens) facing the at least one solar cell. Accordingly, in one embodiment, the lens may have a surface that faces the at least one solar cell. The surface has at least one recess, wherein the lens has at least one wall located between two channels of the channel system, and wherein the at least one wall is located opposite to the at least one recess. 
     The term “channel system” (as used in the present application) of the base plate or provided in the base plate, respectively, (in short: channels system of the base plate) may comprise or consist of one or more channels. These one or more channels may be channels according to the classical sense of the term “channel” and/or one or more chambers or any hollow space or spaces, or a combination thereof. The at least one channel according to the classical sense of the term “channel” may extend straight, or bent, or curved, or meander-shaped, or in any other suitable manner, or in according to a combination thereof. The channel system may consist of a plurality of channels and/or chambers and/or hollow spaces. The channel system of the base plate may be closed and/or sealed to the outside of the base plate, or one or more openings provided in the outer surface of the base plate may be in fluid connection with the channel system, so that the channel system is open to the outside of the base plate, wherein said at least one opening may serve for providing fluid into the channel system of the base plate and/or discharging fluid out of the channel system of the base plate. For example, the base plate may have two or more openings to the outside of the base plate, wherein one of these openings is or may be connected to a supply channel through which fluid may be continuously supplied into the base plate, and wherein the other of these openings is or may be connected to a discharge channel through which fluid may be continuously discharged out of the base plate. Such a design will improve the heat transfer out of the solar energy converter. 
     According to another embodiment of the invention, the channel system of the base plate may have one or more openings to the outside of the base plate, wherein these one or more openings are closed and/or sealed by means of detachable closure members. 
     The channel system of the base plate may be filled with a fluid for cooling the at least one solar cell. 
     The channel system of the base plate may have one or more branching. 
     All channels or chambers or hollow spaces belonging to the same channel system of the base plate may be in fluid connection with each other, and in particular may be in fluid connection with each other within the base plate. 
     The base plate may comprise exactly one channel system for receiving or guiding fluid, respectively, for cooling the at least one solar cell. In another embodiment the base plate may comprise more than one channel system, wherein all channels or chambers or hollow spaces belonging to the same channel system of the base plate may be, for example within the base plate, in fluid connection with each other, and wherein the different channel systems of the base plate are not in fluid connection with each other. 
     At least one channel of the channel system of the base plate may be designed as or delimited by a recess within or on the surface of the base plate such that the at least one channel is open to the outside of the base plate along its longitudinal direction. The at least one channel that is open to the outside of the base plate along its longitudinal direction may be designed as recess provided in that outer surface of the base plate, which outer surface is directed towards the at least one solar cells, for example. Such a design may be such, that the at least one channel is open in the direction towards the at least one solar cell or the first direction, respectively. The outer surface of the base plate, which surface is directed to the solar cell may be corrugated, thereby forming channels of the channel system of the base plate. However, the open side of such channels may be closed by a cover. 
     One, more, or all of the channels of the channel systems may be delimited by material such, that all cross-sections perpendicular to the longitudinal axis of the respective channel are completely surrounded by material. Said material may be material of the base plate. In some alternative embodiments said material may be partly material of the base plate and partly material of a member positioned adjacent to the base and serving as cover. 
     The channel system of the base plate may have a plurality of channels. 
     The channel system of the base plate may have a plurality of channels arranged in parallel to each other. 
     Channels or all of channels of the channel system of the base plate may be arranged in one plane or in different planes, for example. However, other configurations may be provided as well. 
     The cross-sectional shape of the channel or the channels of the channels system of the base plate may be, for example, circular, or polygonal, or hemispherical, or ellipsoid, or convex, or concave, or triangular, or trapezoidal, or square, or rectangular, or octagonal, or pentagonal, or any other shape, or combination thereof. The channel system of the base plate may have a plurality of channels having identical or various cross-sectional shapes. In particular, different channels may be different than the afore-mentioned cross-sectional shapes. 
     The distance or shortest distance, respectively, between the channel system of the base plate and the solar cell may be less than 40% of the thickness of the solar energy converter, for example less than 35% of the solar energy converter, or less than 30% of the thickness of the solar energy converter, or less than 25% of the thickness of the solar energy converter, or less than 20% of the thickness of the solar energy converter, or less than 15% of the thickness of the solar energy converter, or less than 10% of the thickness of the solar energy converter, or less than 8% of the thickness of the solar energy converter, or less than 5% of the thickness of the solar energy converter. 
     Fluid or cooling fluid, respectively, provided in or flowing through the channel system of the base plate may be any fluid suitable for cooling For example, the fluid may be a liquid, gas or air. 
     Fluid may be provided in the channel system of the base plate, so as to cool the solar cell due to its position with regard to the solar cell. Thus, the base plate performs the functions of both cooling of the solar cell and providing a base. 
     The base plate may be, for example, an entirely solid object. 
     The material of the lens may comprise or consist of, for example, glass and/or polymer, for example poly(methyl methacrylate) (PMMA) and/or polycarbonate and/or acrylic and/or plastics and/or thermoplastics and/or thermosetting plastics, or any combination thereof, or any other suitable material. For example, the lens may comprise or consist of thermoplastics or thermosetting plastics. The lens may be transparent. 
     The lens may consist of only one material. Alternatively, the lens may consist of various materials. 
     The lens may comprise impact absorption material or consist of impact absorption material. 
     The material of the base plate comprise or consist of, for example, metal, for example aluminum or aluminum heatsink, and/or plastic and/or polymer, for example poly(methyl methacrylate) (PMMA) and/or polycarbonate and/or acrylic, and/or thermoplastics and/or thermosetting plastics, or any combination thereof. The base plate may consist of one material. Alternatively, the base plate may consist of various materials. In particular, the base plate may consist of plastic or polymer material, wherein the base plate is provided with fins made from metal, e.g. aluminum or aluminum heatsink. 
     The channel system of the lens may comprise a plurality of parallel channels, or channels of different channels systems of the lens may be in parallel. 
     The channel system of the base plate may comprise a plurality of parallel channels, or channels of different channels systems of the base plate may be in parallel. 
     The lens may comprise a plurality of parallel channels and the base plate may comprise a plurality of parallel channels, wherein these parallel channels of the base plate are non-parallel, for example perpendicular, to these parallel channels of the lens. 
     The lens may have a constant or a varying thickness. The base plate may have a constant or a varying thickness. It must be noted that the thickness of the lens or base plate, respectively, may be measured in the first direction. 
     A first adhesive layer may be provided between the lens and the solar cell, wherein a first or the upper surface of the adhesive layer is in contact with the lens, and wherein a second or lower surface of the first adhesive layer is in contact with the solar cell. 
     A second adhesive layer may be provided between the solar cell and the base plate, wherein a first or upper surface of the second adhesive layer is in contact with the solar cell and a second of lower surface of the second adhesive layer is in contact with the first surface of the base plate. 
     The first and/or second adhesive layers may be fabricated from ethylene vinyl acetate. 
     According to a further aspect of the invention a method for cooling a solar energy converter is provided, the solar energy converter having a lens, a base, and at least one solar cell sandwiched between said lens and said base plate, wherein said method comprises the step of: cooling the at least one solar cell on two opposing sides, wherein the lens is arranged on the one of these opposing sides, and wherein the base is arranged on the other of these opposing sides. 
     Cooling of the at least one solar cell may be performed, for example, by means of a fluid provided in or flowing through at least one first channel system provided in the base plate, and by means of a fluid provided in or flowing through at least on second channel system provided in the lens. For example, it may be provided that the fluid absorbs heat from the sun before it heats up the at least one solar cell, where in one embodiment it is the fluid in the second channel system provided in the lens that absorbs the heat. Further, it may be provided that the fluid absorbs heat generated from the at least one solar cell when the at least one solar cell converts light energy into electrical energy. 
     In the cases of flowing fluid, the fluid may pressurized or non-pressurized. The fluid may be a gas, for example air, or a liquid. 
     The method according to the invention may be, for example, performed by means of the solar energy converter according to the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of various embodiments. In the following description, various embodiments are described with reference to the following drawings, in which: 
         FIG. 1  shows a schematic of a solar energy converter in accordance with an embodiment. 
         FIG. 2  shows an exploded view of a solar energy converter in accordance with an embodiment. 
         FIG. 3  shows a cross section view of a solar energy converter in accordance with an embodiment. 
         FIGS. 4A to 4E  show various views of a solar energy converter in accordance with an embodiment. 
         FIG. 5  shows a cross section view of a lens built in accordance with an embodiment. 
         FIG. 6  shows a flow chart of an exemplary fabrication process to manufacture a solar energy converter in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     While embodiments have been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of various embodiments as defined by the appended claims. The scope of various embodiments is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced. It will be appreciated that common numerals, used in the relevant drawings, refer to components that serve a similar or the same purpose. 
       FIG. 1  shows a schematic of a solar energy converter  100  in accordance with an embodiment. 
     The solar energy converter  100  has a solar cell  102  located or sandwiched, respectively, between a base plate  104  and a lens  106 . 
     The base plate  104  has a first surface  104   f  that faces the solar cell  102  and a second surface  104   s  that is opposite to the first surface  104   f , wherein the second surface  104   s  is exposed to form an outer surface  100   b  of the solar energy converter  100 . 
     The lens  106  has a first surface  106   f  that faces the solar cell  102  and a second surface  106   s  that is opposite to the first surface  106   f , wherein the second surface  106   s  is exposed to form an outer surface  100   t  of the solar energy converter  100 . 
     The solar cell  102  is sandwiched between the lens  106  and the base plate  104 , wherein both the lens  106  and the base plate  104  are each provided with at least one channel system (denoted  110   s  for the base plate  104  and  108   s  for the lens  106 ) having at least one channel (denoted  110  for the base plate  104  and  108  for the lens  106 ) for receiving or guiding fluid for cooling the solar cell  102 . For example, it may be provided that the fluid absorbs heat from the sun before it heats up the solar cell  102 , where in one embodiment it is the fluid in the at least one channel system  108   s  of the lens  106  that absorbs the heat. Further, it may be provided that the fluid absorbs heat generated from the solar cell  102  when the solar cell  102  converts light energy into electrical energy. 
     In  FIG. 1 , the distance  130  between the lens  106  and the solar cell  102 , and the distance  132  between the solar cell  102  and the base plate  104  is such that the solar cell  102  is in sufficient proximity to both the base plate  104  or the channel system  110   s  of the base plate  104 , respectively, and the lens  106  or the channel system  108   s  of the lens  106 , respectively, so that fluid in the respective channel system  110   s  and  108   s  can absorb heat from the sun before it heats up the solar cell  102  and cool the solar cell  102 . In use, the solar cell  102  heats up due to exposure to incident light. At high temperatures, the solar cell  102  converts solar energy into electrical energy less efficiently. Thus, heat absorption and cooling by the fluid ensures optimal operating conditions for the solar cell  102 . 
     Expressing the distance  130  between the lens  106  and the solar cell  102  and the distance  132  between the lens  106  and the base plate  104  in terms of the thickness  104   t  of the base plate  104 , the distance  130  between facing surfaces of the lens  106  and the solar cell  102  may be between 0 to 20%, for example between 0 to 10%, for example between 0 to 5% of the base plate thickness  104   t . The distance  132  between facing surfaces of the solar cell  102  and the base plate  104  may be between 0 to 20%, for example between 0 to 10%, for example between 0 to 5% of the base plate thickness  104   t . However, any other values may be used as well. 
     The outer surfaces  100   t  and  100   b  respectively form the top and bottom surfaces of the solar energy converter  100 . In use, the solar energy converter  100  is arranged such that the top surface  100   t  is exposed to light or sun light, respectively. 
     The lens  106  has at least one wall  112  located between two channels  108  of the at least one channel system  108   s  of the lens  106 . The wall  112  allows for a means to control fluid flow in the lens  106 , especially when the wall  112  does not extend along the entire width (denoted  206   w  in  FIG. 2 ) of the lens  106 . Each wall  112  may have a gap (not shown) that allows fluid flow between two adjacent channels  108  of the channel system  108   s . In this manner, fluid introduced into the lens  106  at a leftmost channel may continuously flow through the respective gap of each wall  112  to the rightmost channel, where the heated fluid may then be extracted. 
     In addition to providing a means to control fluid flow in the lens  106 , each wall  112  acts as a light modulating structure that can further refract light that passes through the top section  116  of the lens  106 . By adjusting the location of each channel  108  within the lens  106  (thereby shifting the location of the walls  112 ), the manner in which light transmits through the lens  106  can be controlled so that light can be directed to focus on specific areas of the solar cell  102 . Thus the walls  112  also function as an array of internal lenses. 
     The cross-section of the wall  112  is rectangular. However, in other embodiments, the wall  112  may have a cross-section (not shown) that is hemispherical, ellipsoid, convex, concave or trapezoidal. Polygonal cross-sections such as square, octagonal or pentagonal are also possible. Nevertheless, the shapes of cross-sections of such walls shall not be delimited to the afore-mentioned shapes. The use of different cross-sections affect how light, transmitting through the lens  106 , is refracted and eventually passes out from the bottom or base section  114 , respectively, of the lens  106 . Accordingly, the walls  112  may have different cross-sections to each other. 
     The lens  106  has a base section  114  having a surface (i.e. the first surface  1060  that faces the solar cell  102  and a top section  116  that is opposite to the base section  114 . The surface  106   f  of the base section  114  that faces the solar cell  102  may have at least one recess (denoted  416  in  FIGS. 4D and 4E ), wherein the at least one wall  112  is located opposite to the at least one recess. 
     Referring to  FIGS. 4D and 4E , the arrangement of the recess  416  and the wall  112  provides the lens  106  with a shock absorbing mechanism. When an object impacts on the portion  402  of the lens  106  adjacent to the wall  112  that protrudes from the portion of the lens  106  where the recess  416  is located, the wall  112  moves to occupy the space provided by the recess  416 . A plurality of such shock absorbing mechanisms may be disposed at intervals across the lens  106 , so that the lens  106  is provided with several impact points. Without this shock absorbing mechanism, there is a tendency for the at least one solar cell  102  to crack when impacted by objects. 
     In the embodiment shown in  FIGS. 4D and 4E , the wall  112  located opposite to the at least one recess  416  extends from an inner surface  404  of the base section  114  of the lens  106  to an inner surface  406  of the top section  116  of the lens  106 . In another embodiment (not shown), the wall  112  only extends from an inner surface  404  of the base section  114 , but does not contact with the inner surface  406  of the top section  116  of the lens  106 . 
     Returning to  FIG. 1 , the lens  106  has an opening  118  in communication with the at least one channel system  108   s  of the lens  106 . The opening  118  is provided on an outer surface of the lens  106 . The opening  118  allows for fluid to be extracted or introduced into the lens  106 . Extraction may be performed when the fluid has reached above a predetermined temperature and the heated fluid is replaced with cool water. The extracted heated fluid can be piped for other uses. In another embodiment (not shown) where the lens  106  is air-cooled, the at least one channel system  108   s  of the lens  106  is sealed within the lens  106 , wherein the fluid for cooling the solar cell  102  is within the at least one channel system  108   s.    
     As shown in  FIG. 1 , the lens  106  has a channel system  108   s  comprising a plurality of channels  108 . The plurality of channels  108  are arranged in parallel to each other. 
     The base plate  104  has at least one wall  120  located between two channels  110  of the at least one channel system  110   s  of the base plate  104 . The wall  120  allows for a means to control fluid flow in the base plate  104 , especially when the wall  120  does not extend along the entire width (denoted  204   w  in  FIG. 2 ) of the base plate  104 . Each wall  120  may have a gap (not shown) that allows fluid flow between two adjacent channels  110 . In this manner, fluid introduced into the base plate  104  at a leftmost channel may continuously flow through the respective gap of each wall  120  to the rightmost channel, where the heated fluid may then be extracted. 
     The cross-section of the wall  120  is rectangular. However, in other embodiments, the wall  120  may have a cross-section (not shown) that is hemispherical, ellipsoid, convex, concave or trapezoidal. Polygonal cross-sections such as square, octagonal or pentagonal are also possible. 
     The base plate  104  includes an opening  122  in communication with the at least one channel system  110   s  of the base plate  104 . The opening  122  is provided on an outer surface of the base plate  104 . The opening  122  allows for fluid to be extracted or introduced into the base plate  104 . Extraction may be performed when the fluid has reached above a predetermined temperature and the heated fluid is replaced with cool water. The extracted heated fluid can be piped for other uses. In another embodiment (not shown) where the base plate  104  is air-cooled, the at least one channel system  110   s  of the base plate  104  is sealed within the base plate  104 , wherein the fluid for cooling the solar cell  102  is within the at least one channel system  110   s.    
     As shown in  FIG. 1 , the base plate  104  has a channel system  110   s  comprising a plurality of channels  110 . The plurality of channels  110  are arranged in parallel to each other. 
     Comparing the channels  108  in the lens  106  with the channels  110  in the base plate  104 , one or more of the channels  108  of the lens  106  is arranged in parallel to one or more of the channels  110  of the base plate  104 . By having these channels  108  and  110  run parallel to each other, the solar energy converter  100  has a degree of flexibility in that the base  100   b  and the top  100   t  of the solar energy converter  100  can follow the contour of the surface upon which the solar energy converter  100  is placed. Thus, a flat planar surface is not required. Such a design may be advantageous for use with thin film solar cells for the solar cell  102 , to manufacture a solar energy converter  100  that can be contoured. 
     The embodiment of  FIG. 1  shows the solar energy converter  100  as a disconnected structure (i.e. the lens  106  is separated from the solar cell  102 , and the base plate  104  is separated from the solar cell  102 ). However, in another embodiment (not shown), the first surface  106   f  of the lens  106  is secured directly to the solar cell  102  and therefore rests on the solar cell  102 , while the solar cell  102  is secured directly to the base plate  104 , so that the solar cell  102  rests on the first surface  104   f  of the base plate  104 . In yet another embodiment (not shown), only the solar cell  102  is secured directly to the base plate  104 , so that the solar cell  102  rests on the first surface  104   f  of the base plate  104 , while the lens  106  is proximate to the solar cell  102  but does not rest directly on the solar cell  102 . 
       FIG. 2  shows an exploded view of a solar energy converter  200  in accordance with an embodiment. 
     Similar to  FIG. 1 , the solar energy converter  200  has a solar cell  102  located between a base plate  104  and a lens  106 . 
     The base plate  104  has a first surface  104   f  that faces the solar cell  102  and a second surface (hidden from view) that is opposite to the first surface  104   f , wherein the second surface is exposed to form an outer surface of the solar energy converter  100 . The first surface  104   f  of the base plate  104  and the second surface of the base plate  104  have identical shapes. In addition, the first surface  104   f  of the base plate  104  has a boundary and the second surface of the base plate  104  has a boundary, wherein the boundary of the first surface  104   f  of the base plate  104  is identical to the boundary of the second surface of the base plate  104 . 
     The lens  106  has a first surface (hidden from view) that faces the solar cell  102  and a second surface  106   s  that is opposite to the first surface, wherein the second surface  106   s  is exposed to form an outer surface  100   t  of the solar energy converter  100 . The first surface of the lens  106  and the second surface  106   s  of the lens  106  have identical shapes. In addition, the first surface of the lens  106  has a boundary and the second surface  106   s  of the lens  106  has a boundary, wherein the boundary of the first surface of the lens  106  is identical to the boundary of the second surface  106   s  of the lens  106 . 
     The solar cell  102  is sandwiched between the lens  106  and the base plate  104 , wherein both the lens  106  and the base plate  104  are each provided with a channel system (denoted  110   s  for the base plate  104  and  108   s  for the lens  106 ) having at least one channel (denoted  110  for the base plate  104  and  108  for the lens  106 ) for fluid for cooling the solar cell  102 . As shown in  FIG. 2 , each of the lens  106  and the base plate  104  has a plurality of channels  108  and  110 . 
     The solar cell  102  is provided with wire connections  240  and  242  to tap the electricity converted by the solar cell  102  from solar energy or ambient light. 
     The differences between the solar energy converter  200  and the solar energy converter  100  are described below. 
     In the embodiment of  FIG. 2 , one or more or all of the at least one channel  108  of the lens  106  is arranged perpendicular to one or more or all of the at least one channel  110  of the base plate  104  (in  FIG. 1 , the solar energy converter  100  has the channels  108  of its lens  106  arranged parallel to the channels  110  of the base plate  104 ). 
     By having the channels  108  and channels  106  arranged perpendicular to each other, the solar energy converter  200  has a strong and rigid structure. 
     An adhesive layer  244  is provided between the lens  106  and the solar cell  102 . An upper surface  244   u  of the adhesive layer  244  is in contact with the lens  106  (or more specifically the first surface of the lens  106 ) and a lower surface (hidden from view) of the adhesive layer  244  is in contact with the solar cell  102 . 
     In one embodiment, the upper surface  244   u  may have the same surface area as the first surface of the lens  106  to ensure maximum adhesion of the lens  106  to the solar cell  102 . 
     Another adhesive layer  246  is provided between the solar cell  102  and the base plate  104 . An upper surface  246   u  of the adhesive layer  246  is in contact with the solar cell  102  and a lower surface (hidden from view) of the adhesive layer  246  is in contact with the first surface  104   f  of the base plate  104 . 
     In one embodiment, the upper surface  246   u  may have the same surface area as the facing surface of the solar cell  102  to ensure maximum adhesion of the solar cell  102  to the base plate  104 . 
     The thickness of the adhesive layers  244  and  246  is chosen so that heat conduction between the cooling fluid in the channels  108  and  110  and the solar cell  102  is not adversely affected. The adhesive layers  244  and  246  may be fabricated from ethylene vinyl acetate. During manufacture, the adhesive layers  244  and  246  are vacuum pressed together with the solar cell  102 , the base plate  104  and the lens  106 . 
       FIG. 3  shows a cross section view of the solar energy converter  200  of  FIG. 2  taken along the line X-X in  FIG. 2 . While  FIG. 2  shows an exploded view,  FIG. 3  shows the solar energy converter  200  in its assembled form where the adhesive layer  244  secures the lens  106  to the solar cell  102 , and the adhesive layer  246  secures the solar cell  102  to the base plate  104 . 
     The at least one channel system  110   s  of the base plate  104  is positioned between the plane  302  on which the boundary of the first surface  104   f  of the base plate  104  lies and the plane  304  on which the boundary of the second surface  104   s  of the base plate  104  lies. 
       FIG. 4A  shows a top view of the solar energy converter  200  of  FIG. 2 . The lens  106  is shown as a transparent object, but for the sake of simplicity, the other components of the solar energy converter  200  that can be seen through the lens  106  are omitted so that only the second surface  106   s  of the lens  106  is shown in  FIG. 4A . 
       FIG. 4B  shows a cross section view of the solar energy converter  200  of  FIG. 4A  taken along the line Y-Y in  FIG. 4A . 
       FIG. 4C  shows a cross section view of the solar energy converter  200  of  FIG. 4A  taken along the line X-X in  FIG. 4A . 
     Similar to  FIG. 3 ,  FIGS. 4B and 4C  show the solar energy converter  200  in its assembled form. 
       FIG. 4D  shows an enlarged view of section  408  of  FIG. 4B , while  FIG. 4E  shows an enlarged view of section  412  of  FIG. 4C . 
     For  FIGS. 4D and 4E , it was mentioned above that the arrangement of the recess  416  and the wall  112  provides the lens  106  with a shock absorbing mechanism. In  FIGS. 4D and 4E , the recess  416  is formed on the first surface  106   f  of the lens  106 . However, in another embodiment (not shown), the recess  416  may be formed in the adhesive layer  244  that is between the lens  106  and the solar cell  102 . In such an embodiment, the adhesive layer  244  will not be a unitary piece, but provided as an array of separate sections. 
     To further assist the shock absorbing nature of the mechanical arrangement of the recess  416  and the wall  412 , the lens  106  may be made of impact absorption material. For example, the lens may be made of a material the hardness of which is less than the hardness of the base plate. 
     Any of the components used in the solar energy converter  100  and  200  (such as the base plate  104  or the lens  106 ) may be manufactured separately and therefore individually used in existing solar energy converter systems. 
     It is also possible to have a base plate or a lens which has only selected features of the base plate  104  and the lens  106  as respectively mentioned above. 
     For instance,  FIG. 5  shows a cross section view of a lens  506  built in accordance with an embodiment. 
     In the embodiment shown in  FIG. 5 , the lens  506  has the shock absorbing mechanism described in  FIGS. 4D and 4E . 
     The lens  506  has a base section  514  and a top section  516  that is opposite to the base  514 . The outer surface  506   f  of the base  514  has at least one recess  550 . 
     The lens  506  has at least one channel system  508   s  comprising one or more channels  508  being a chamber or cavity formed in the lens  506 . The channels  508  are separated by a wall  512  formed within the lens  506  and located opposite to the at least one recess  550 . The wall  512  protrudes from an inner surface  514   i  of the base  514  of the lens  106  opposite to where the recess  550  is located. 
     The arrangement of the recess  550  and the wall  512  provides the lens  506  with a shock absorbing mechanism  570 . When an object impacts on the portion  580  of the top section  516  of the lens  506  (i.e. the portion of the lens  506  opposite to the inner surface  514   i  of the lens  106 ), the wall  512  moves to occupy the space provided by the recess  416 , thereby dissipating the concussion of the impact. 
     A plurality of such shock absorbing mechanisms  570  may be disposed across the lens  506  at regular or irregular intervals, so that the lens  106  is provided with several impact points. 
     In the embodiment shown in  FIG. 5 , the wall  512  extends across the space defined between the inner surface  514   i  and the inner surface  516   i  of the lens  106 . In another embodiment (not shown), the wall  512  only extends from the inner surface  514   i  of the base section  514 , but does not contact with the inner surface  516   i  of the top section  516  of the lens  506 . 
     Referring to  FIGS. 1 to 4 , each of the base plate  104 , the lens  106  and the solar cell  102  may have a respective thickness  104   t ,  106   t  and  102   t  that is constant. The lens  106 , the solar cell  102  and the base plate  104  are parallel to each other. The lens  106  may be fabricated from materials such as glass or polymer or any other suitable material. The base plate  104  may be fabricated from materials such as polymer or any suitable material. 
     Polymer that may be used to fabricate the lens  106  and/or the base plate  104  include poly(methyl methacrylate) (PMMA), polycarbonate, acrylic, thermoplastics and thermosetting plastics. By using polymer to fabricate the lens  106  and the base plate  104 , the solar energy converter  100 / 200  can follow the contour of the surface upon which the solar panel  100 / 200  is placed, especially when the channels  108  of the lens  106  and the channels  110  of the base plate  104  run parallel to each other (see  FIG. 1 ). In addition, using the same material to fabricate the lens  106  and the base plate  104  simplifies production reduces production costs. The lens  106  and the base plate  104  may be fabricated using an extrusion and injection molding process. 
     With reference to  FIGS. 2 and 3 , the solar energy converter  200  may have a width  206   w  of around 70 cm and a length  206   l  of around 1.0 m, and the thickness  200   t  may be less than both the width and the length. It will be appreciated that other dimensions are possible. 
     The fluid for heat absorption and cooling the solar cell  102  may be a liquid (such as water) or a gas (such as air). The solar cell  102  may also belong to an array of solar cells sandwiched between the base plate  104  and the lens  106 . 
     It is also possible for the base plate  104  to be fabricated from metal such as aluminum. 
     In one embodiment (not shown) where metal is used to fabricate the base plate  104 , the base plate  104  may be a heatsink with a cooling fin. In this embodiment, the channel of the base plate  104  may be formed on the first surface  104   f  or the second surface  104   s  of the base plate  104 . A fin structure is formed on the first surface  104   f  or the second surface  104   s  of the base plate  104 , wherein the at least one channel of the base plate  104  is defined by the space between two adjacent fins of the fin structure. 
     According to various embodiments, the lens  106  is fabricated with internal passages (the channel  108 ) of various shapes and sizes having various heat absorbing mediums. The heat absorbing mediums first absorb heat from the sun before it heats up the solar cell  102  and also absorb heat from the solar cell  102 . The various heat absorbing mediums may freely flow through these internal passages, where the various heat absorbing mediums are sealed within the lens  106  or allowed to exit from the lens  106 . A back support plate (the base plate  104 ) is fabricated with corrugated cooling channels  110  of various shapes and sizes having various heat absorbing mediums. The various heat absorbing mediums may freely flow through these corrugated cooling channels  110 , where the various heat absorbing mediums are sealed within the back support plate or allowed to exit from the back support plate. The absorption of heat via the various heat absorbing mediums in the lens  106  and the back support plate improves the efficiency of the solar energy converter  100 / 200 . 
     The lens  106  is placed in contact with a substrate (such as the adhesive layer  244 ) which is in contact with the solar cell  102 . Heat from the sun is first absorbed by the heat absorbing medium in the lens  106 , and heat from the solar cell  110  is absorbed by the heat absorbing medium sealed in the passages of the lens  106  (or in the case where the heat absorbing medium is allowed to exit from the lens  106 , as the heat absorbing medium flows through the passages) thereby reducing the temperature of the solar cell  102 . The lens  106  may be fabricated from plastic using an extrusion and injection moulding process. However, other lighter density materials with sufficient clarity and other fabrication processes may also be used. 
     The back support plate may be fabricated using various fire-retardant materials with corrugated cooling channels in various shapes and sizes using an extrusion and injection moulding process to allow additional heat transfer thereby further reducing the temperature of the solar cell  102 . However, other materials and other fabrication processes may be used. The lens  106  and the back support plate can be contoured such that solar energy converter  100 / 200  can be flexed into various shapes and forms. 
       FIG. 6  shows a flow chart  600  of a fabrication process to manufacture a solar panel in accordance with an embodiment. 
     The fabrication process begins at  602  where a lens is provided. At  604 , a base plate having a first surface and a second surface that is opposite to the first surface is provided. At  606 , a solar cell is sandwiched between the lens and the base plate to form the solar energy converter. The first surface of the base plate faces the lens and the second surface of the base plate is exposed to form an outer surface of the solar energy converter. Both the lens and the base plate are each provided with at least one channel for fluid for heat absorption and cooling the solar cell.