Patent Publication Number: US-2018053869-A1

Title: Solar cell panel and window having the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims, under 35 U.S.C. § 119, the priority of Korean Patent Application No. 10-2016-0104594 filed on Aug. 18, 2016 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The following disclosure relates to a solar cell panel and a window having the same, and in particular, to a large area solar cell panel having highly efficient transmission and no increase in thickness and a window having the same. 
     BACKGROUND 
     Recently, solar energy generation facilities capable of producing power from solar energy are being gradually propagated. 
     A solar cell using solar energy does not use fossil fuels such as petroleum and coal and uses pollution-free solar energy which is an infinite energy source. Thus, the solar cell is spotlighted as a new alternative energy source and is being used for producing power in solar energy power plants and vehicles in these days. 
     Solar energy power generation is applied in various fields, among which a building integrated photovoltaic (BIPV) technique using solar cells as an exterior finishing material of a building is spotlighted as a prominent new technology for the 21 st  century. 
     Even though an exterior of an existing structure is just used for protecting the building against external environments, in the BIPV technique, the exterior of a building is actively used as a tool for creating energy. Thus, the exterior of a building using the BIPV technique may have a key part in supplying solar cells and reduce costs required for installing an existing solar energy generation system. 
     A solar window configured by coupling solar cells to a window is an example of the above configuration in which solar cells are used as an exterior of a building. The obligation to build a zero-energy structure is in progress not only in this country but also over the world by 2020, and thus the need for a self-energy production technique of a building such as the solar window is arising. 
     In order to apply the solar window to a building, a large-sized high-efficient solar cell technology ensuring long-term stability and good aesthetic property is demanded. 
     However, in an existing solar window, a solar cell module is simply interposed between a pair of glass panels, or a solar cell module is attached to one side of a glass board, which has bad efficiency and bad appearance and is not suitable for a large-sized window. 
     Recently, a solar concentrating method has been actively studied to improve the efficiency of the solar window, and International Patent Publication WO 2015/079094 (Jun. 4, 2015) and Solar Energy Materials &amp; Solar Cells 84 (2004) 411-426 disclose a solar concentration device applicable to the solar window. 
       FIG. 1  is a diagram showing the solar concentration device disclosed in International Patent Publication WO 2015/079094, and  FIG. 2  is a diagram showing the solar concentration device disclosed in Solar Energy Materials &amp; Solar Cells 84 (2004) 411-426. 
     Referring to  FIG. 1 , the solar concentration device disclosed in International Patent Publication WO 2015/079094 includes a photonic crystal coating  2  disposed at an upper surface of a transparent or semi-transparent substrate  4 , a layer of luminescent material  3  disposed at an upper surface of the photonic crystal coating  2 , and photovoltaic cells  1 A,  1 B disposed in parallel at the substrate  4 . In addition, a sealant  5  is provided to seal a region between the substrate  4  and a top sheet  6  prepared at an upper portion of the substrate  4 . 
     In the solar concentration device disclosed in International Patent Publication WO 2015/079094 as above, a wavelength of incident light is converted by the layer of luminescent material  3 , and then the incident light is guided to the photovoltaic cells  1 A,  1 B by means of the photonic crystal coating  2 . 
     Also, referring to  FIG. 2 , the solar concentration device disclosed in Solar Energy Materials &amp; Solar Cells 84 (2004) 411-426 is configured so that luminescent solar concentrators (LSCs) having three colors are laminated. In detail, luminescent solar concentrators (LSCs) doped with violet, green and pink pigments are laminated. 
     In the solar concentration device disclosed in Solar Energy Materials &amp; Solar Cells 84 (2004) 411-426, a wavelength of incident light is converted using three kinds of luminescent solar concentrators (LSCs) which allow wavelength conversion from short wavelength to long wavelength, and the incident light is transmitted to a side, where photovoltaic cells are located, through an end mirror, a reflector and a light guide. 
     In the above existing techniques, incident light is converted into a specific wavelength and then guided or transmitted toward a solar cell, which has low solar energy generation efficiency and low light transmission and also increases thickness of a window. 
     RELATED LITERATURES 
     Patent Literature 
     International Patent Publication WO 2015/079094 
     Non-patent Literature 
     Optimisation of a three-colour luminescent solar concentrator daylighting system, Solar Energy Materials &amp; Solar Cells 84 (2004) 411-426 
     SUMMARY 
     An embodiment of the present disclosure is directed to providing a large area solar cell panel having highly efficient transmission and no increase in thickness, and a window having the same. 
     In one general aspect of the present disclosure, there is provided a solar cell panel, comprising: a light diffusion layer to which light is incident and at which the light is scattered; a light concentration layer laminated at a lower portion of the light diffusion layer and having a plurality of patterns spaced apart from each other and having a cavity shape convex toward the light diffusion layer at a surface thereof opposite to the light diffusion layer so that light passing through the light diffusion layer is reflected and concentrated to a side portion thereof; and a solar cell array provided at a side surface of the light concentration layer and having a plurality of solar cells arranged along the side surface of the light concentration layer and electrically connected to each other. 
     The plurality of patterns may configure a matrix form. 
     The plurality of patterns may have a cycle of 1 to 2000 μm. 
     The pattern may have a width of 1 to 1000 μm and a height of 1 to 1000 μm. 
     The light concentration layer may be formed with a glass substrate, and the patterns having a cavity shape convex toward the light diffusion layer may be formed at a surface thereof opposite to the light diffusion layer by means of etching or laser processing. 
     The light diffusion layer and the light concentration layer may configure a single unit light concentration module, one or more unit light concentration modules may be laminated in a height direction, and the solar cell arrays may be provided respectively at sides of the unit light concentration modules according to the number of the unit light concentration modules and electrically connected to each other. 
     In another aspect of the present disclosure, there is provided a window having a solar cell panel, comprising: a solar cell panel; and a window frame coupled along an edge of the solar cell panel, wherein the solar cell panel includes: a light concentration module having a light diffusion layer to which light is incident and at which the light is scattered, and a light concentration layer laminated at a lower portion of the light diffusion layer and having a plurality of patterns spaced apart from each other and having a cavity shape convex toward the light diffusion layer at a surface thereof opposite to the light diffusion layer so that light passing through the light diffusion layer is reflected and concentrated to a side portion thereof; and a solar cell array coupled to a side surface of the light concentration module. 
     The plurality of patterns may configure a matrix form. 
     The plurality of patterns may have a cycle of 1 to 2000 μm. 
     The pattern may have a width of 1 to 1000 μm and a height of 1 to 1000 μm. 
     When a plurality of the light concentration modules is laminated in a height direction, the solar cell arrays may be provided respectively at sides of the unit light concentration modules according to the number of the unit light concentration modules and electrically connected to each other. 
     An embodiment of the present disclosure may provide a high-efficient high-transmission solar cell panel and a window having the same, in which incident light is not converted into a specific wavelength but all wavelengths are transmitted for power generation. 
     In addition, an embodiment of the present disclosure may provide a large area solar cell panel no increase in thickness and a window having the same, in which a layer of luminescent material or the like required for converting incident light into a specific wavelength is not included. 
     In addition, an embodiment of the present disclosure may simplify a manufacturing process for the solar cell panel and the window having the same. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram showing a solar concentration device disclosed in International Patent Publication WO 2015/079094. 
         FIG. 2  is a diagram showing a solar concentration device disclosed in Solar Energy Materials &amp; Solar Cells 84 (2004) 411-426. 
         FIG. 3  is a perspective view showing a window having a solar cell panel according to an embodiment of the present disclosure. 
         FIG. 4  is a cross-sectional view schematically showing a solar cell panel according to an embodiment of the present disclosure. 
         FIG. 5  is a diagram showing a light diffusion layer according to an embodiment of the present disclosure. 
         FIG. 6A  is a plane view showing a pattern formed at the light concentration layer according to an embodiment of the present disclosure. 
         FIG. 6B  is a cross-sectional view showing a pattern formed at the light concentration layer according to an embodiment of the present disclosure. 
         FIG. 7  is a plane view showing a solar cell array according to an embodiment of the present disclosure. 
         FIG. 8  is a side view showing the solar cell array according to an embodiment of the present disclosure. 
         FIG. 9  is a diagram showing a plurality of laminated light concentration modules according to an embodiment of the present disclosure. 
         FIG. 10A  is a graph showing the degree of transmittance according to the number of laminated light concentration modules according to an embodiment of the present disclosure. 
         FIG. 10B  is a table showing power generation efficiency of the solar cell panel according to an embodiment of the present disclosure. 
         FIGS. 11A and 11B  are diagrams for illustrating a method for connecting plurality of solar cell arrays in series or in parallel according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The present disclosure, advantages of operations of the present disclosure and objects accomplished by the implementation of the present disclosure can be sufficiently understood with reference to the accompanying drawings depicting embodiments of the present disclosure and explanations thereof. 
     Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals denote like elements. 
       FIG. 3  a perspective view showing a window having a solar cell panel according to an embodiment of the present disclosure,  FIG. 4  is a cross-sectional view schematically showing a solar cell panel according to an embodiment of the present disclosure,  FIG. 5  is a diagram showing a light diffusion layer according to an embodiment of the present disclosure,  FIG. 6A  is a plane view showing a pattern formed at the light concentration layer according to an embodiment of the present disclosure,  FIG. 6B  is a cross-sectional view showing a pattern formed at the light concentration layer according to an embodiment of the present disclosure,  FIG. 7  is a plane view showing a solar cell array according to an embodiment of the present disclosure, and  FIG. 8  is a side view showing the solar cell array according to an embodiment of the present disclosure. 
     Referring to  FIG. 3 , a window  100  having a solar cell panel according to an embodiment of the present disclosure includes a solar cell panel  300 , and a window frame  200  coupled along an edge of the solar cell panel  300 . 
     The solar cell panel  300  according to this embodiment is coupled to the window frame  200  and plays a role of photoelectric transformation using incident light. 
     In addition, the solar cell panel  300  includes a light concentration module  310  for scattering and reflecting incident light to be concentrated at a side portion, and a solar cell (SC) array  350  coupled to a side surface of the light concentration module  310 . 
     Referring to  FIGS. 3 to 6 , the light concentration module  310  according to this embodiment includes a light diffusion layer  320 , and a light concentration layer  330  laminated at a lower portion of the light diffusion layer  320 . 
     Referring to  FIG. 4 , the light diffusion layer (or, a diffuser)  320  plays a role of scattering and diffusing incident light. In addition, the light diffusion layer  320  is prepared at an upper portion of the light concentration layer  330 . 
     As shown in  FIG. 5 , the light diffusion layer  320  may be configured with a glass substrate  321  having metal nano particles  323  disposed at a surface thereof to be spaced apart from each other. In other words, in the light diffusion layer  320 , the metal nano particles  323  are arranged at random on the surface of the glass substrate  321  to scatter light in all directions. 
     In addition, the light concentration layer  330  plays a role of reflecting the light passing through the light diffusion layer  320  to be concentrated at the side portion thereof. 
     The light concentration layer  330  may be made using a glass substrate  331 . In addition, at a surface of the light concentration layer  330  opposite to the light diffusion layer  320 , namely at a lower surface of the light concentration layer  330 , a plurality of patterns  333  having a cavity shape convex toward the light diffusion layer  320  are formed to be spaced apart from each other. In other words, the light concentration layer  330  may be made using a glass substrate having a plurality of patterns  333  (namely, a patterned glass). 
     In addition, as shown in  FIGS. 3 and 4 , the plurality of patterns  333  may be configured in a matrix form at the lower surface of the light diffusion layer  320 . The plurality of patterns  333  are spaced apart from each other, and the plurality of patterns  333  may have a cycle (P) of 1 to 2000 μm. 
     In addition, each of the plurality of patterns  333  may be formed with a cavity shape having a width (W) of 1 to 1000 μm and a height (H) of 1 to 1000 μm. 
       FIGS. 6 a  and 6 b    show cavity-type patterns  333  formed in one direction at the lower surface of the light concentration layer  330  by means of etching or laser processing. By means of the etching or laser processing, the plurality of cavity-type patterns  333  arranged in a matrix form may be formed at the lower surface of the light concentration layer  330 . 
     As described above, the light diffusion layer  320  and the light concentration layer  330  configure a single unit light concentration module  310  to scatter and reflect incident light and concentrate the light at a side portion thereof. 
     The light concentration module  310  according to an embodiment of the present disclosure concentrate incident light as follows. 
     As shown in  FIG. 4 , the light input to the light diffusion layer  320  is scattered and diffused to all directions while passing through the light diffusion layer  320 . 
     In addition, the light diffused by the light diffusion layer  320  may be totally reflected by the plurality of cavity-type patterns  333  arranged in a matrix form at the lower surface of the light concentration layer  330  while passing through the light concentration layer  330 , so that the light may be guided and concentrated to the side portion of the light concentration layer  330 . 
     Also, the light passing through the light concentration layer  330  may be transmit through the plurality of cavity-type patterns  333  and guided and concentrated to the side portion of the light concentration layer  330 . 
     In addition, the light passing through the light concentration layer  330  may be totally reflected by the plurality of cavity-type patterns  333  and reflected at the lower surface of the light diffusion layer  320 , so as to be guided and concentrated to the side portion of the light concentration layer  330 . 
     As described above, the light concentration module  310  according to this embodiment does not convert incident light into a specific wavelength but allows all wavelengths to pass, and guides and concentrates the light to a side portion of the light concentration layer  330 , thereby obtaining high-efficient power generation effect through the solar cell array  350  provided at a side surface of the light concentration module  310 . 
     In addition, the light diffusion layer  320  and the light concentration layer  330  of the light concentration module  310  according to this embodiment are made of glass substrates, which may improve light transmission of incident light and thus further enhance power generation efficiency. 
     Moreover, since the light diffusion layer  320  and the light concentration layer  330  do not include a layer of luminescent material or the like, which is required for converting incident light into a specific wavelength, the light concentration module  310  according to this embodiment may be manufactured with a large area without increasing its thickness, and its manufacturing process may be simplified. 
     Meanwhile, the solar cell array  350  according to this embodiment plays a role of photoelectric transformation using incident the light concentrated by the light concentration module  310 . 
     Referring to  FIGS. 7 and 8 , the solar cell array  350  according to this embodiment is provided along an edge of the light concentration module  310 . In detail, if the light concentration module  310  has a rectangular planar shape, the solar cell arrays  350  may be provided along four sides of the light concentration module  310 . 
     In addition, the solar cell array  350  includes a plurality of solar cells  360  disposed along a side surface of the light concentration module  310  and electrically connected to each other, and a cell frame  370  supporting the lower surface of the solar cells  360 . 
     The solar cells  360  may be electrically connected in series or in parallel by means of wire bonding at the upper surface of the cell frame  370 . In this embodiment, the solar cells  360  may be Si-based solar cells  360  or GaAs-based solar cell  360 , but the present disclosure is not limited thereto. 
     The cell frame  370  includes an insulation layer (or, an insulator)  371  closely adhered to a partial region of the lower surface of the solar cell  360 , and a conductive layer  373  made of Al or the like and closely adhered to the lower surface of the solar cell  360  except for the region to which the insulation layer  371  is closely adhered. 
     Meanwhile, in the window  100  having a solar cell panel according to this embodiment, a plurality of light concentration modules  310  may be laminated in a height direction and coupled to the window frame  200 . 
       FIG. 9  is a diagram showing a plurality of laminated light concentration modules according to an embodiment of the present disclosure,  FIG. 10A  is a graph showing the degree of transmittance according to the number of laminated light concentration modules according to an embodiment of the present disclosure,  FIG. 10B  is a table showing power generation efficiency of the solar cell panel according to an embodiment of the present disclosure, and  FIGS. 11 a  and 11 b    are diagrams for illustrating a method for connecting plurality of solar cell arrays in series or in parallel according to an embodiment of the present disclosure. 
     As shown in  FIG. 9 , if a plurality of light concentration modules  310  is laminated in a height direction (for example, a first light concentration module  310   a , a second light concentration module  310   b  and a third light concentration module  310   c  are laminated in a height direction), solar cell arrays  350  may be provided according to the number of the light concentration modules  310  at side surfaces of the light concentration modules  310 , respectively. At this time, the solar cell arrays  350  provided at the side surfaces of the light concentration modules  310  may be electrically connected to each other in series or in parallel. Here, the pattern  333  may have a width (W) of 100 μm, a height (H) of 100 μm and a cycle (P) of 500 μm. 
       FIG. 10A  exemplarily shows transmittance of light having a visible ray wavelength, when a plurality of light concentration modules  310  (namely, a first light concentration module  310   a , a second light concentration module  310   b  and a third light concentration module  310   c  are laminated in a height direction) are laminated in  FIG. 9 . As shown in  FIG. 10A , if the number of laminated light concentration modules  310  increases, the light transmittance is lowered, and also, as shown in  FIG. 10B , the photoelectric conversion efficiency of the solar cell arrays  350  provided at the side surfaces of the light concentration modules  310  may be enhanced. 
     Meanwhile, in the case where a plurality of light concentration modules  310  (namely, a first light concentration module  310   a , a second light concentration module  310   b  and a third light concentration module  310   c  are laminated in a height direction) are laminated and solar cell arrays  350  are respectively provided at the side surfaces of the light concentration modules  310  as in  FIG. 9 ,  FIG. 11A  shows a case where the plurality of solar cells  360  in each solar cell array  350  are connected in parallel and the plurality of solar cell arrays  350  are connected in series, and  FIG. 11B  shows a case where the plurality of solar cells  360  in each solar cell array  350  are connected in parallel and the plurality of solar cell arrays  350  are connected in parallel. 
       FIGS. 11A and 11B  just show exemplarity connections of the plurality of solar cell arrays  350 , and the plurality of solar cell arrays  350  may be connected in various other ways. 
     The present disclosure is not limited to the embodiments described above, but it is obvious to those having ordinary skill in the art that the present disclosure may be changed or modified in various ways without departing from the scope thereof. Therefore, such changes or modifications should be regarded as falling into the scope of the appended claims. 
     REFERENCE SYMBOLS 
       
     
       
         
           
               
               
               
             
               
                   
                   
               
             
            
               
                   
                 100: window 
                 200: window frame 
               
               
                   
                 300: solar cell panel 
                 310: light concentration module 
               
               
                   
                 320: light diffusion layer 
                 330: light concentration layer 
               
               
                   
                 331: pattern 
                 350: solar cell array 
               
               
                   
                 360: solar cell 
                 370: cell frame