Abstract:
There is provided a solar cell module capable of discharging water retained on the upper surface of a solar cell panel therefrom while maintaining the mechanical strength of a frame body. This solar cell module includes a gasket including a groove to discharge the water retained on the upper surface of the solar cell panel, arranged between the solar cell panel and the frame body.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The priority application number JP2010-016445, Solar Cell Module, Jan. 28, 2010, Yusaku Tago and Yasuo Kadonaga, upon which this patent application is based is hereby incorporated by reference. This application is a continuation of PCT/JP2011/050748, Solar Cell Module, Jan. 18, 2011, Yusaku Tago and Yasuo Kadonaga. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a solar cell module, and more particularly, it relates to a solar cell module including a gasket. 
         [0004]    2. Description of the Background Art 
         [0005]    A solar cell module including a gasket is known in general, as disclosed in Japanese Patent Laying-Open No. 2000-243998, for example. 
         [0006]    The aforementioned Japanese Patent Laying-Open No. 2000-243998 discloses a solar cell module including a solar cell panel, an outer frame fixing the solar cell panel by holding end portions of the solar cell panel by an upper portion, a lower portion, and side surface portions thereof, and a sealant (gasket) made of silicon resin arranged between the solar cell panel and the outer frame. 
         [0007]    However, in the solar cell module described in the aforementioned Japanese Patent Laying-Open No. 2000-243998, water retained on the upper surface of the solar cell panel is held back by the upper portion of the outer frame located on the upper surface side of the solar cell panel, whereby it is difficult to discharge the water. 
         [0008]    In this regard, there is proposed a technique to solve the aforementioned problem in Japanese Utility Model Laying-Open No. 6-017257 (1994), for example. The aforementioned Japanese Utility Model Laying-Open No. 6-017257 discloses a solar cell module including a solar cell panel, a frame (frame body) fixing the solar cell panel by holding the solar cell panel by an upper portion, a lower portion, and side surface portions thereof, and a butyl rubber (gasket) arranged between the solar cell panel and the frame, in which a notch to discharge water is formed in a side of the frame located on the lower side when the solar cell module is obliquely placed. The notch is formed by partially notching the upper portion of the frame, and in this notch, the upper surface of the solar cell panel, the butyl rubber, and the frame (upper surfaces of the side surface portions) are coplanar with each other. Consequently, water retained on the upper surface of the solar cell panel is discharged through the notch. 
         [0009]    However, in the solar cell module disclosed in the aforementioned Japanese Utility Model Laying-Open No. 6-017257, the upper portion of the frame is notched in the side of the frame located on the lower side when the solar cell module is obliquely placed, and hence the mechanical strength of the side of the frame (frame body) located on the lower side when the solar cell module is obliquely placed may become insufficient. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention has been proposed in order to solve the aforementioned problems, and an object of the present invention is to provide a solar cell module capable of discharging water retained on the upper surface of a solar cell panel while maintaining the mechanical strength of a frame body. 
         [0011]    In order to attain the aforementioned object, a solar cell module according to an aspect of the present invention includes a solar cell panel including a solar cell, a frame body to support an end portion of the solar cell panel, and a gasket including a groove to discharge water retained on the upper surface of the solar cell panel, arranged between the solar cell panel and the frame body. 
         [0012]    In the solar cell module according to the aspect of the present invention, as hereinabove described, the groove to discharge the water retained on the upper surface of the solar cell panel is formed in the gasket, whereby the water retained on the upper surface of the solar cell panel can be discharged through the groove. Furthermore, it is not necessary to form a flow channel by notching an upper portion of the frame body in order to discharge the water retained on the upper surface of the solar cell panel, and hence the mechanical strength of the frame body can be maintained. Therefore, the water retained on the upper surface of the solar cell panel can be discharged while the mechanical strength of the frame body is maintained. 
         [0013]    In the aforementioned solar cell module according to the aspect, the solar cell panel preferably has a substantially rectangular shape in plan view, and the groove of the gasket preferably extends from an end portion of the gasket closer to the upper surface of the solar cell panel to intersect with the extensional direction of a side surface of the solar cell panel on which the gasket is arranged. According to this structure, the groove can extend from the end portion of the gasket closer to the upper surface of the solar cell panel to the outside along a separating direction, dissimilarly to a case where the groove of the gasket extends parallel to the extensional direction of the side surface of the solar cell panel, and hence the water retained on the upper surface of the solar cell panel can be discharged through the groove. 
         [0014]    In this case, the groove of the gasket preferably extends from the end portion of the gasket closer to the upper surface of the solar cell panel to be substantially orthogonal to the extensional direction of the side surface of the solar cell panel on which the gasket is arranged. According to this structure, the overall length of the groove in which water flows can be reduced as compared with a case where the groove obliquely intersect with the extensional direction of the side surface of the solar cell panel, and hence the water retained on the upper surface of the solar cell panel can be more reliably discharged through the groove. 
         [0015]    In the aforementioned solar cell module according to the aspect, the groove of the gasket is preferably formed in a surface coming into contact with the solar cell panel. According to this structure, the water retained on the upper surface of the solar cell panel can be reliably discharged as compared with a case where the groove is formed in a portion (region) different from the surface coming into contact with the solar cell panel. 
         [0016]    In the aforementioned solar cell module according to the aspect, the groove of the gasket is preferably formed in an end portion of the gasket closer to the upper surface of the solar cell panel and at least a region of the gasket corresponding to the upper surface of the solar cell panel. According to this structure, the water retained on the upper surface of the solar cell panel can be discharged to at least the vicinity of the side surface of the solar cell panel through the groove. 
         [0017]    In the aforementioned solar cell module according to the aspect, the solar cell panel preferably has a substantially rectangular shape in plan view, and the groove of the gasket is preferably formed at least in the vicinity of the four corners of the solar cell panel. According to this structure, when one of the four corners of the solar cell panel is arranged below the other corners, the water retained on the upper surface of the corner of the solar cell panel arranged on the lower side can be discharged through the groove formed in the vicinity of the corner of the gasket corresponding to the corner of the solar cell panel. 
         [0018]    In the aforementioned solar cell module according to the aspect, the solar cell panel preferably has a substantially rectangular shape in plan view, and the groove of the gasket is preferably formed in a region corresponding to at least a partial region of each of the four sides of the solar cell panel. According to this structure, when one of the four sides of the solar cell panel is arranged below the other sides, the water retained on the upper surface of the side of the solar cell panel arranged on the lower side can be discharged through the groove formed in the region corresponding to at least the partial region of the side of the solar cell panel. 
         [0019]    In this case, a plurality of grooves of the gasket are preferably formed in a region corresponding to a substantially entire region of the four sides of the solar cell panel. According to this structure, when one of the four sides of the solar cell panel is arranged below the other sides, the water retained on the upper surface of the side of the solar cell panel arranged on the lower side can be reliably discharged through the plurality of grooves formed in a substantially entire region of the side of the gasket corresponding to the side of the solar cell panel arranged on the lower side. 
         [0020]    In the aforementioned solar cell module according to the aspect, the gasket preferably further includes a flat portion formed between a plurality of grooves, coming into surface contact with the solar cell panel. According to this structure, flow channels each having a closed periphery can be configured by a surface of the solar cell panel and the grooves of the gasket supporting the solar cell panel in a state where the flat portion is in close contact with the solar cell panel. Thus, water can be inhibited from leaking from portions other than the grooves during discharge. 
         [0021]    In the aforementioned solar cell module according to the aspect, the groove of the gasket preferably extends from an end portion of the gasket closer to the upper surface of the solar cell panel to an end portion of the gasket closer to the lower surface of the solar cell panel. According to this structure, the water retained on the upper surface of the solar cell panel can be discharged through the groove of the gasket extending from the end portion of the gasket closer to the upper surface of the solar cell panel to the end portion of the gasket closer to the lower surface of the solar cell panel. 
         [0022]    In the aforementioned solar cell module according to the aspect, a hole is preferably formed as a discharge portion in a region of the gasket corresponding to a side surface of the solar cell panel. According to this structure, the water retained on the upper surface of the solar cell panel can be discharged through not only the groove of the gasket but also the hole formed as a discharge portion. 
         [0023]    In this case, the groove of the gasket is preferably formed to be connected to the hole. According to this structure, the water retained on the upper surface of the solar cell panel can be easily discharged through the groove of the gasket and the hole connected to the groove. 
         [0024]    In the aforementioned solar cell module in which the groove of the gasket is connected to the hole, the solar cell panel preferably further includes an upper surface cover portion made of a water-resistant material, arranged on the upper surface of the solar cell panel and a lower surface cover portion arranged on the lower surface of the solar cell panel, the groove of the gasket is preferably formed in a surface coming into contact with the solar cell panel, and extends from an end portion of the gasket closer to the upper surface of the solar cell panel to the hole, and the hole of the gasket is preferably formed in a region corresponding to a vicinity of a boundary between the upper surface cover portion and the lower surface cover portion of the side surface of the solar cell panel or a region corresponding to a position closer to the upper surface of the solar cell panel beyond the vicinity of the boundary. According to this structure, the water retained on the upper surface of the solar cell panel is allowed to flow employing a portion between the water-resistant upper surface cover portion and the groove of the gasket as a flow channel, and the water can be discharged through the hole formed in the region corresponding to the vicinity of the boundary between the upper surface cover portion and the lower surface cover portion of the side surface of the solar cell panel or the region corresponding to the position closer to the upper surface of the solar cell panel beyond the vicinity of the boundary. Thus, the water can be inhibited from flowing employing a portion between the lower surface cover portion having relatively low water resistance as compared with the upper surface cover portion and the gasket as a flow channel. 
         [0025]    In the aforementioned solar cell module in which the groove of the gasket is connected to the hole, a plurality of adjacent grooves of the gasket are preferably formed to be connected to the common hole. According to this structure, even if the plurality of grooves are close to each other and it is difficult to provide a hole with respect to each of the plurality of grooves, the common hole is formed with respect to the plurality of grooves so that the hole serving as a discharge portion can be reliably formed in the gasket. 
         [0026]    In the aforementioned solar cell module in which the hole is formed in the gasket, the frame body preferably includes an upper portion located in a region corresponding to the upper surface of the solar cell panel, a lower portion located in a region corresponding to the lower surface of the solar cell panel, and a side surface portion located in a region corresponding to the side surface of the solar cell panel, a discharge hole to discharge water is preferably provided in the side surface portion of the frame body, and the water retained on the upper surface of the solar cell panel is preferably discharged through the groove and the hole of the gasket and the discharge hole of the side surface portion of the frame body. According to this structure, the water discharged to the side of the gasket closer to the frame body through the groove of the gasket and the hole provided in a region of the gasket corresponding to the side surface of the solar cell panel can be discharged to an external portion of the frame body through the discharge hole provided in the side surface portion of the frame body. Furthermore, the discharge hole to discharge the water to the external portion is provided in the side surface portion of the frame body, whereby the mechanical strength of the frame body can be further maintained as compared with a case where the upper portion of the frame body is notched. 
         [0027]    In the aforementioned solar cell module in which the discharge hole is provided in the side surface portion of the frame body, the hole of the gasket is preferably formed to be connected to the discharge hole of the frame body. According to this structure, the water discharged to the hole through the groove can be reliably discharged to the external portion through the hole and the discharge hole connected to the hole. 
         [0028]    In the aforementioned solar cell module according to the aspect, a notch is preferably provided as a discharge portion in a region of the gasket corresponding to the lower surface of the solar cell panel. According to this structure, the water retained on the upper surface of the solar cell panel can be discharged through not only the groove of the gasket but also the notch formed as a discharge portion. 
         [0029]    In this case, the groove of the gasket is preferably formed to be connected to the notch. According to this structure, the water retained on the upper surface of the solar cell panel can be easily discharged through the groove of the gasket and the notch connected to the groove. 
         [0030]    In the aforementioned solar cell module in which the groove of the gasket is connected to the notch, a plurality of adjacent grooves of the gasket are preferably formed to be connected to the common notch. According to this structure, even if the plurality of grooves are close to each other and it is difficult to provide a notch with respect to each of the plurality of grooves, the common notch is formed with respect to the plurality of grooves so that the notch serving as a discharge portion can be reliably formed in the gasket. 
         [0031]    In the aforementioned solar cell module in which the notch is provided in the gasket, the frame body preferably includes an upper portion located in a region corresponding to the upper surface of the solar cell panel, a lower portion located in a region corresponding to the lower surface of the solar cell panel, and a side surface portion located in a region corresponding to a side surface of the solar cell panel, a discharge hole to discharge water is preferably provided in the side surface portion or the lower portion of the frame body, and the water retained on the upper surface of the solar cell panel is preferably discharged through the groove and the notch of the gasket and the discharge hole of the frame body. According to this structure, the water discharged to the side of the gasket closer to the frame body through the groove of the gasket and the notch provided in a region of the gasket corresponding to the lower surface of the solar cell panel can be discharged to the external portion of the frame body through the discharge hole provided in the side surface portion or the lower portion of the frame body. Furthermore, the discharge hole to discharge the water to the external portion is provided in the side surface portion or the lower portion of the frame body, whereby the mechanical strength of the frame body can be further maintained as compared with a case where the upper portion of the frame body is notched. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]      FIG. 1  is a perspective view of a solar cell module according to a first embodiment of the present invention; 
           [0033]      FIG. 2  is a plan view of the solar cell module according to the first embodiment of the present invention; 
           [0034]      FIG. 3  is a sectional view corresponding to a flat portion of a gasket of the solar cell module taken along the line  1000 - 1000  in  FIG. 2 ; 
           [0035]      FIG. 4  is a plan view of the gasket according to the first embodiment of the present invention; 
           [0036]      FIG. 5  is a perspective view of a part of the gasket according to the first embodiment of the present invention; 
           [0037]      FIG. 6  is a side elevational view of the gasket as viewed in a direction A in  FIG. 4 ; 
           [0038]      FIG. 7  is a developed view of the gasket according to the first embodiment of the present invention; 
           [0039]      FIG. 8  is a sectional view of the gasket taken along the line  3000 - 3000  in  FIG. 7 ; 
           [0040]      FIG. 9  is a sectional view corresponding to a groove of the gasket of the solar cell module taken along the line  2000 - 2000  in  FIG. 2 ; 
           [0041]      FIG. 10  is a perspective view of a solar cell module according to a second embodiment of the present invention; 
           [0042]      FIG. 11  is a sectional view of a gasket and a frame body of the solar cell module taken along the line  4000 - 4000  in  FIG. 10 ; 
           [0043]      FIG. 12  is a perspective view of a part of the gasket according to the second embodiment of the present invention; 
           [0044]      FIG. 13  is a side elevational view of the gasket as viewed in a direction B in  FIG. 11 ; 
           [0045]      FIG. 14  is a developed view of the gasket according to the second embodiment of the present invention; 
           [0046]      FIG. 15  is a sectional view of the gasket taken along the line  7000 - 7000  in  FIG. 14 ; 
           [0047]      FIG. 16  is a sectional view corresponding to a groove and a hole of the gasket of the solar cell module taken along the line  6000 - 6000  in  FIG. 11 ; 
           [0048]      FIG. 17  is a perspective view of a part of a gasket according to a modification of the second embodiment of the present invention; 
           [0049]      FIG. 18  is a side elevational view of the gasket according to the modification of the second embodiment of the present invention; 
           [0050]      FIG. 19  is a sectional view corresponding to a contact portion of the gasket taken along the line  8000 - 8000  in  FIG. 18 ; 
           [0051]      FIG. 20  is a sectional view corresponding to a groove and a hole of the gasket taken along the line  9000 - 9000  in  FIG. 18 ; 
           [0052]      FIG. 21  is a perspective view of a part of a gasket according to a third embodiment of the present invention; 
           [0053]      FIG. 22  is a side elevational view of the gasket according to the third embodiment of the present invention; 
           [0054]      FIG. 23  is a developed view of the gasket according to the third embodiment of the present invention; 
           [0055]      FIG. 24  is a sectional view corresponding to a groove and a notch of the gasket taken along the line  11000 - 11000  in  FIG. 22 ; 
           [0056]      FIG. 25  is a sectional view corresponding to a groove and a notch of a gasket of a solar cell module according to a modification of the third embodiment of the present invention; 
           [0057]      FIG. 26  is a perspective view of a part of a gasket according to a first modification of each of the first to third embodiments of the present invention; 
           [0058]      FIG. 27  is a developed view of the gasket according to the first modification of each of the first to third embodiments of the present invention; 
           [0059]      FIG. 28  is a perspective view of a part of a gasket according to a second modification of each of the first to third embodiments of the present invention; and 
           [0060]      FIG. 29  is a side elevational view of the gasket according to the second modification of each of the first to third embodiments of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0061]    Embodiments of the present invention are now described with reference to the drawings. 
       First Embodiment 
       [0062]    As shown in  FIGS. 1 and 2 , a solar cell module  100  according to a first embodiment is constituted by a solar cell panel  1 , a frame body  2  made of metal such as aluminum to support the solar cell panel  1 , and a gasket  3  (see  FIG. 1 ) made of rubber or the like arranged between the solar cell panel  1  and the frame body  2 . In plan view, the solar cell panel  1  has a substantially rectangular shape. 
         [0063]    As shown in  FIG. 3 , the solar cell panel  1  is constituted by a water-resistant upper surface-side cover  11  made of glass, a weather-resistant lower surface-side cover  12  made of a resin film of polyethylene terephthalate (PET) or the like, a plurality of solar cells  13  arranged between the upper surface-side cover  11  and the lower surface-side cover  12 , and a filler  14  provided between the upper surface-side cover  11  (lower surface-side cover  12 ) and the plurality of solar cells  13 . The upper surface-side cover  11  is an example of the “upper surface cover portion” in the present invention, and the lower surface-side cover  12  is an example of the “lower surface cover portion” in the present invention. 
         [0064]    The upper surface  1   a  and the upper side surfaces  1   b  of the solar cell panel  1  on which the upper surface-side cover  11  is located are substantially flat. The lower surface  1   c  of the solar cell panel  1  on which the lower surface-side cover  12  is located is substantially flat, while the lower side surfaces  1   d  of the solar cell panel  1  on which the lower surface-side cover  12  is located are substantially arcuate. The upper side surfaces  1   b  are examples of the “side surface of the solar cell panel” in the present invention. 
         [0065]    As shown in  FIG. 2 , each of the plurality of solar cells  13  is formed with a finger electrode  13   a  extending along a direction X. The plurality of solar cells  13  are connected in series with each other by wiring members  15   a,  and the plurality of solar cells  13  connected in series with each other are connected in series with each other by connecting members  15   b.    
         [0066]    As shown in  FIGS. 1 and 2 , the frame body  2  is provided in the form of a substantially rectangular frame to surround the upper surface  1   a  and the lower surface  1   c  in the vicinity of end portions of the solar cell panel  1 , the upper side surfaces  1   b,  and the lower side surfaces  1   d  in plan view. The frame body  2  includes an upper portion  2   a  opposed to the upper surface  1   a  of the solar cell panel  1 , a lower portion  2   b  opposed to the lower surface  1   c  of the solar cell panel  1 , and a side surface portion  2   c  opposed to the upper side surfaces  1   b  and the lower side surfaces  1   d  of the solar cell panel  1 , and these upper portion  2   a,  lower portion  2   b,  and side surface portion  2   c  form a recess portion  20  in which the solar cell panel  1  and the gasket  3  are arranged, as shown in  FIG. 3 . Outer peripheral grooves  2   d  and hollow portions  2   e  allowing water to be discharged are provided in both end portions of the frame body  2  in the direction X and both end portions of the frame body  2  in a direction Y (see  FIG. 1 ). These hollow portions  2   e  are connected with the outer peripheral grooves  2   d  through unshown holes. 
         [0067]    As shown in  FIG. 4 , the gasket  3  is provided in the form of a substantially rectangular frame in plan view. The gasket  3  has a substantially U-shaped section, as shown in  FIG. 5 . The inner surface  30  of the gasket  3  includes an upper inner surface  30   a  supporting the upper surface  1   a  in the vicinity of the end portions of the solar cell panel  1 , a lower inner surface  30   b  supporting the lower surface  1   c  in the vicinity of the end portions of the solar cell panel  1 , and a side inner surface  30   c  supporting the upper side surfaces  1   b  and the lower side surfaces  1   d  of the solar cell panel  1 . The inner surface  30  is an example of the “surface coming into contact with the solar cell panel” in the present invention. 
         [0068]    According to the first embodiment, a plurality of grooves  31  to discharge water are formed in a substantially entire region of the inner surface  30  of the gasket  3 , that is the surface coming into contact with the solar cell panel  1 , on the four sides at constant intervals, as shown in  FIG. 4 . These grooves  31  are formed also in the vicinity of the corners of the gasket  3  corresponding to the four corners (see  FIG. 2 ) of the solar cell panel  1 . As shown in  FIG. 8 , the grooves  31  each have a substantially triangular section. Substantially flat portions  32  are formed between the respective adjacent grooves  31 . 
         [0069]    According to the first embodiment, the grooves  31  are formed to extend from a first end portion  30   d  of the upper inner surface  30   a  of the inner surface  30  to a second end portion  30   e  of the lower inner surface  30   b  through the upper inner surface  30   a,  the side inner surface  30   c,  and the lower inner surface  30   b,  as shown in  FIGS. 5 and 7 . As shown in  FIG. 4 , in a portion of the gasket  3  along arrow Y 1  (Y 2 ), the grooves  31  formed in the upper inner surface  30   a  and the lower inner surface  30   b  are formed to extend in the direction Y substantially orthogonal to the direction X that is the extensional direction of the corresponding upper side surface  1   b  and lower side surface  1   d  of the solar cell panel  1 . The grooves  31  formed in the side inner surface  30   c  are formed to extend in a direction Z substantially orthogonal to the direction X. The first end portion  30   d  is an example of the “end portion of the gasket closer to the upper surface of the solar cell panel” in the present invention, and the second end portion  30   e  is an example of the “end portion of the gasket closer to a lower surface of the solar cell panel” in the present invention. 
         [0070]    Furthermore, as shown in  FIG. 4 , in a portion of the gasket  3  along arrow X 1  (X 2 ), the grooves  31  formed in the upper inner surface  30   a  and the lower inner surface  30   b  are formed to extend in the direction X substantially orthogonal to the direction Y that is the extensional direction of the corresponding upper side surface  1   b  and lower side surface  1   d  of the solar cell panel  1 . The grooves  31  formed in the side inner surface  30   c  are formed to extend in the direction Z substantially orthogonal to the direction Y. 
         [0071]    As shown in  FIG. 3 , the flat portions  32  of the gasket  3  are configured to come into surface contact with the upper surface  1   a  in the vicinity of the end portions of the solar cell panel  1  and the upper side surfaces  1   b  and come into surface contact with the lower surface  1   c  in the vicinity of the second end portion  30   e.  Thus, the solar cell panel  1  is configured to be supported by the flat portions  32  of the gasket  3 . 
         [0072]    On the other hand, the grooves  31  of the gasket  3  are configured not to be in contact with any of the upper surface  1   a,  the upper side surfaces  1   b,  the lower surface  1   c,  and the lower side surfaces  1   d  of the solar cell panel  1 , as shown in  FIG. 9 . Thus, water retained on the upper surface  1   a  of the solar cell panel  1  is discharged from the side of the lower surface  1   c  (along arrow Z 2 ) of the solar cell panel  1  through flow channels formed by the grooves  31  of the gasket  3  and the upper surface  1   a,  the upper side surfaces  1   b,  the lower side surfaces  1   d,  and the lower surface  1   c  of the solar cell panel  1 . 
         [0073]    According to the first embodiment, as hereinabove described, the grooves  31  are formed in the inner surface  30  of the gasket  3 , and formed to extend from the first end portion  30   d  to the second end portion  30   e  through the upper inner surface  30   a,  the side inner surface  30   c,  and the lower inner surface  30   b,  whereby the water retained on the upper surface  1   a  of the solar cell panel  1  can be discharged from the side of the lower surface  1   c  of the solar cell panel  1  through the grooves  31  of the gasket  3  extending from the first end portion  30   d  to the second end portion  30   e.  Furthermore, it is not necessary to form a flow channel by notching the upper portion  2   a  of the frame body  2  in order to discharge the water retained on the upper surface  1   a  of the solar cell panel  1 , and hence the mechanical strength of the frame body  2  can be maintained. Therefore, the water retained on the upper surface  1   a  of the solar cell panel  1  can be discharged while the mechanical strength of the frame body  2  is maintained. In addition, the water retained on the upper surface  1   a  of the solar cell panel  1  can be reliably discharged as compared with a case where the grooves  31  are formed in the surface (outer surface of the gasket  3 ) opposite to the surface (inner surface  30 ) coming into contact with the solar cell panel  1 . 
         [0074]    According to the first embodiment, as hereinabove described, the grooves  31  are formed to extend in the directions substantially orthogonal to the extensional directions of the corresponding upper side surfaces  1   b  and lower side surfaces  1   d  of the solar cell panel  1  on the four sides of the gasket  3 . Thus, the grooves  31  can extend from the end portion of the gasket  3  closer to the upper surface  1   a  of the solar cell panel  1  to the outside along a separating direction while the overall length of each of the grooves  31  in which water flows is reduced as compared with a case where the grooves  31  obliquely intersect with the extensional directions of the corresponding upper side surfaces  1   b  and lower side surfaces  1   d  of the solar cell panel  1 , and hence the water retained on the upper surface  1   a  of the solar cell panel  1  can be more reliably discharged through the grooves  31 . 
         [0075]    According to the first embodiment, as hereinabove described, the grooves  31  are formed in the vicinity of the corners of the gasket  3  corresponding to the four corners of the solar cell panel  1 , and the plurality of grooves  31  are formed in the substantially entire region of the four sides of the gasket  3  corresponding to the four sides of the solar cell panel  1 , whereby the water retained on the upper surface  1   a  of the corner of the solar cell panel  1  arranged on the lower side can be discharged through the grooves  31  formed in the vicinity of the corner of the gasket  3  corresponding to the corner of the solar cell panel  1  when one of the four corners of the solar cell panel  1  is arranged below the other corners. Furthermore, when one of the four sides of the solar cell panel  1  is arranged below the other sides, the water retained on the upper surface  1   a  of the side of the solar cell panel  1  arranged on the lower side can be discharged through the plurality of grooves  31  formed in the substantially entire region of the side of the gasket  3  corresponding to the side of the solar cell panel  1  arranged on the lower side. 
         [0076]    According to the first embodiment, as hereinabove described, the flat portions  32  formed between the respective adjacent grooves  31  are configured to come into surface contact with the upper surface  1   a  in the vicinity of the end portions of the solar cell panel  1  and the upper side surfaces  1   b  and come into surface contact with the lower surface  1   c  in the vicinity of the second end portion  30   e,  whereby the flow channels each having a closed periphery can be configured by the surface (the upper surface  1   a,  the upper side surfaces  1   b,  and the lower surface  1   c ) of the solar cell panel  1  and the grooves  31  of the gasket  3  supporting the solar cell panel  1  in a state where the flat portions  32  are in close contact with the solar cell panel  1 . Thus, water can be inhibited from leaking from portions other than the grooves  31  during discharge. 
       Second Embodiment 
       [0077]    Next, a solar cell module  200  according to a second embodiment of the present invention is described with reference to  FIGS. 3 and 10  to  16 . In this second embodiment, a plurality of discharge holes  202   f  are formed in a frame body  202  while holes  233  are formed in a gasket  203 , dissimilarly to the aforementioned first embodiment. 
         [0078]    As shown in  FIG. 10 , the plurality of discharge holes  202   f  are formed at prescribed intervals on the four sides of the frame body  202  of the solar cell module  200  according to the second embodiment. As shown in  FIG. 16 , these discharge holes  202   f  are formed in side surface portions  2   c  of the frame body  202  opposed to upper side surfaces  1   b  of a solar cell panel  1 , and formed to pass through the side surface portions  2   c  in a direction Y. 
         [0079]    As shown in  FIG. 12 , pairs of grooves  231  are formed in an inner surface  30  of the gasket  203  on a side from which the solar cell panel  1  of the solar cell module  200  according to the second embodiment is inserted. These pairs of grooves  231  are formed at constant intervals as shown in  FIGS. 13 and 14 , and each have a substantially rectangular section as shown in  FIG. 15 . Regions of the inner surface  30  other than the grooves  231  are flat portions  232  each having a flat surface. As shown in  FIG. 3 , these flat portions  232  are configured to come into surface contact with an upper surface  1   a  in the vicinity of end portions of the solar cell panel  1  and the upper side surfaces  1   b  and come into surface contact with a lower surface is in the vicinity of a second end portion  30   e.    
         [0080]    According to the second embodiment, the holes  233  are formed in a side inner surface  30   c  of the inner surface  30  of the gasket  203 , as shown in  FIG. 12 . These holes  233  are formed in regions of the side inner surface  30   c  corresponding to the upper side surfaces  1   b  of the solar cell panel  1 , as shown in  FIG. 16 . The pairs of grooves  231  are formed to extend from a first end portion  30   d  to the common holes  233  formed in the side inner surface  30   c  through an upper inner surface  30   a.  In other words, the pairs of grooves  231  are connected to the common holes  233 . 
         [0081]    As shown in  FIG. 11 , the holes  233  of the gasket  203  are formed to be connected with the discharge holes  202   f  formed in the side surface portions  2   c  of the frame body  202 . Thus, water flowing into the holes  233  of the gasket  203  can be discharged through the discharge holes  202   f.    
         [0082]    As shown in  FIG. 16 , the grooves  231  of the gasket  203  are configured not to be in contact with any of the upper surface  1   a  and the upper side surfaces  1   b  of the solar cell panel  1 . Thus, water retained on the upper surface  1   a  of the solar cell panel  1  reaches the holes  233  of the gasket  203  through flow channels formed by the grooves  231  formed to extend from the first end portion  30   d  of the gasket  203  to an upper portion of the side inner surface  30   c  through the upper inner surface  30   a  and the upper surface  1   a  and parts of the upper side surfaces  1   b  of the solar cell panel  1 . At this time, the water does not come into contact with the lower surface  1   c  and the lower side surfaces  1   d  of the solar cell panel  1 . 
         [0083]    The water reaching the holes  233  of the gasket  203  is discharged from the outer side (side opposite to a side on which the solar cell panel  1  is supported) of the solar cell panel  1  to external portions (outer peripheral grooves  2   d ) through the holes  233  of the gasket  203  and the discharge holes  202   f  of the frame body  202 . The remaining structure of the second embodiment is similar to that of the aforementioned first embodiment. 
         [0084]    According to the second embodiment, as hereinabove described, the grooves  231  are formed to extend from the first end portion  30   d  to the holes  233  formed in the side inner surface  30   c  through the upper inner surface  30   a  while the holes  233  are formed in the side inner surface  30   c  corresponding to the upper side surfaces  1   b  of the solar cell panel  1 . Thus, the water retained on the upper surface  1   a  of the solar cell panel  1  is allowed to flow employing portions between a water-resistant upper surface-side cover  11  made of glass and the grooves  231  of the gasket  203  as flow channels, and the water can be easily discharged through the holes  233  formed in the regions of the side inner surface  30   c  corresponding to the upper side surfaces  1   b  of the solar cell panel  1 . Thus, the water can be inhibited from flowing employing a portion between a lower surface-side cover  12  having relatively low water resistance as compared with the upper surface-side cover  11  and the gasket  203  as a flow channel. Consequently, the water can be inhibited from coming into contact with an interface between the upper surface-side cover  11  and the lower surface-side cover  12  and an interface between the upper surface-side cover  11  and a filler  14 , and hence the water can be further inhibited from entering the inside of the solar cell panel  1 . Furthermore, even if the filler  14  is exposed from the lower side surfaces  1   d  of the solar cell panel  1 , the water does not come into contact with the lower side surfaces  1   d  so that the water can be further inhibited from entering the inside of the solar cell panel  1  through the filler  14 . 
         [0085]    According to the second embodiment, as hereinabove described, the pairs of grooves  231  are formed to extend to the common holes  233 . Thus, even if a plurality of grooves  231  are close to each other and it is difficult to provide a hole  233  with respect to each of the plurality of grooves  231 , a common hole  233  is formed with respect to each of the pairs of grooves  231  so that the holes  233  serving as discharge portions can be reliably formed in the gasket  203 . 
         [0086]    According to the second embodiment, as hereinabove described, the water retained on the upper surface  1   a  of the solar cell panel  1  is discharged through the grooves  231  and the holes  233  of the gasket  203  and the discharge holes  202   f  provided in the side surface portions  2   c  of the frame body  202 , whereby the water discharged to the side of the gasket  202  closer to the frame body  202  through the grooves  231  and the holes  233  of the gasket  203  can be discharged to the external portions (outer peripheral grooves  2   d ) of the frame body  202  through the discharge holes  202   f  provided in the side surface portions  2   c  of the frame body  202 . Furthermore, the discharge holes  202   f  to discharge the water to the external portions are provided in the side surface portions  2   c  of the frame body  202 , whereby the mechanical strength of the frame body  202  can be further maintained as compared with a case where an upper portion  2   a  of the frame body  202  is notched. 
         [0087]    According to the second embodiment, as hereinabove described, the holes  233  of the gasket  203  are formed to be connected with the discharge holes  202   f  formed in the side surface portions  2   c  of the frame body  202 , whereby the water discharged to the holes  233  through the grooves  231  can be reliably discharged to the external portions through the holes  233  and the discharge holes  202   f  connected to the holes  233 . 
         [0088]    The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment. 
       Modification of Second Embodiment 
       [0089]    Next, a solar cell module  300  according to a modification of the second embodiment of the present invention is described with reference to  FIGS. 17 to 20 . In this modification of the second embodiment, a gasket  303  is constituted by an upper gasket  340  and a lower gasket  350 , dissimilarly to the aforementioned second embodiment in which the gasket  203  is integrally formed. 
         [0090]    As shown in  FIGS. 17 and 18 , the gasket  303  of the solar cell module  300  according to the modification of the second embodiment is constituted by the upper gasket  340  and the lower gasket  350 . This upper gasket  340  is formed with an upper surface portion  341 , protrusion portions  342  formed at constant intervals to protrude downward (along arrow Z 2 ) from the upper surface portion  341 , and contact portions  343  formed on a side opposite to a side from which a solar cell panel  1  is inserted (see  FIGS. 19 and 20 ), extending downward from the protrusion portions  342 . These protrusion portions  342  have flat portions  342   a  coming into surface contact with an upper surface  1   a  in the vicinity of end portions of the solar cell panel  1 . The contact portions  343  are configured to come into surface contact with the upper side surfaces  1   b  of the solar cell panel  1 . 
         [0091]    The lower gasket  350  is formed with a lower surface portion  351  and a contact portion  352  formed on the side opposite to the side from which the solar cell panel  1  is inserted, protruding upward (along arrow Z 1 ) from the lower surface portion  351 . This lower surface portion  351  is configured to come into surface contact with a lower surface  1   c  in the vicinity of an end portion  350   a  of the lower gasket  350  on the side from which the solar cell panel  1  is inserted, as shown in  FIGS. 19 and 20 . The contact portion  352  is configured to come into surface contact with parts of the upper side surfaces  1   b  of the solar cell panel  1 . Furthermore, the upper surface  352   a  of the contact portion  352  comes into contact with the lower surfaces  343   a  of the contact portions  343  of the upper gasket  340  on the side opposite to the side from which the solar cell panel  1  is inserted. 
         [0092]    Thus, in regions of the gasket  303  where no protrusion portion  342  of the upper gasket  340  is formed, grooves  331  extending from an end portion  340   a  on the side from which the solar cell panel  1  is inserted to the side opposite the side from which the solar cell panel  1  is inserted are formed by the upper surface portion  341  of the upper gasket  340  and the protrusion portions  342 , as shown in  FIG. 20 . Furthermore, in regions of the gasket  303  other than the protrusion portions  342  of the upper gasket  340  and the contact portion  352 , holes  333  are formed by the upper surface portion  341  of the upper gasket  340  and the contact portion  352  of the lower gasket  350 , as shown in  FIG. 18 . The solar cell module  300  is so configured that water is discharged therefrom through these holes  333  and discharge holes  202   f  formed in side surface portions  2   c  of a frame body  202 . At this time, the water does not come into contact with the lower surface  1   c  and the lower side surfaces  1   d  of the solar cell panel  1 . Consequently, the water can be inhibited from coming into contact with an interface between an upper surface-side cover  11  and a lower surface-side cover  12  and an interface between the upper surface-side cover  11  and a filler  14 , and hence the water can be further inhibited from entering the inside of the solar cell panel  1 . Furthermore, even if the filler  14  is exposed from the lower side surfaces  1   d  of the solar cell panel  1 , the water does not come into contact with the lower side surfaces  1   d  so that the water can be further inhibited from entering the inside of the solar cell panel  1  through the filler  14 . 
         [0093]    The remaining structure and the remaining effects of the modification of the second embodiment are similar to those of the aforementioned second embodiment. 
       Third Embodiment 
       [0094]    Next, a solar cell module  400  according to a third embodiment of the present invention is described with reference to  FIGS. 3 and 21  to  24 . In this third embodiment, notches  434  are formed in a gasket  403 , dissimilarly to the aforementioned second embodiment in which the holes  233  are provided in the gasket  203 . 
         [0095]    As shown in  FIGS. 21 and 22 , sets of three grooves  431  are formed at constant intervals in the inner surface  30  of the gasket  403  of the solar cell module  400  according to the third embodiment. Regions of the inner surface  30  other than the grooves  431  are flat portions  432  each having a substantially flat surface. As shown in  FIG. 3 , these flat portions  432  are configured to come into surface contact with an upper surface  1   a  in the vicinity of end portions of a solar cell panel  1  and upper side surfaces  1   b  and come into surface contact with a lower surface  1   c  in the vicinity of a second end portion  30   e.    
         [0096]    According to the third embodiment, the notches  434  are formed from the end portion  30   e  of the lower inner surface  30   b  of the inner surface  30  of the gasket  403  to parts of a side inner surface  30   c  on the side of the lower inner surface  30   b,  as shown in  FIGS. 21 to 23 . The sets of three grooves  431  are formed to extend from a first end portion  30   d  to the common notches  434  formed in the side inner surface  30   c  through an upper inner surface  30   a.  In other words, the sets of three grooves  431  are connected to the common notches  434 . 
         [0097]    As shown in  FIG. 24 , the notches  434  of the gasket  403  are formed to be connected with discharge holes  202   f  provided in side surface portions  2   c  of a frame body  202 . Thus, water flowing into the notches  434  of the gasket  403  can be discharged to external portions (outer peripheral grooves  2   d ) through the discharge holes  202   f.  Furthermore, the notches  434  of the gasket  403  are formed also in the lower inner surface  30   b  of the inner surface  30 , whereby the water flowing into the notches  434  of the gasket  403  can be discharged from the side of the lower surface  1   c  (along arrow Z 2 ) of the solar cell panel  1  through a flow channel formed by the lower surface (surface along arrow Z 2 ) of a recess portion  20  of the frame body  202  and the lower surface is of the solar cell panel  1 . The remaining structure of the third embodiment is similar to that of the aforementioned second embodiment. 
         [0098]    According to the third embodiment, as hereinabove described, the notches  434  are formed in the lower inner surface  30   b  and regions of the parts of the side inner surface  30   c  on the side of the lower inner surface  30   b  of the inner surface  30  of the gasket  403 . Thus, water retained on the upper surface  1   a  of the solar cell panel  1  can be discharged through the grooves  431  and the notches  434  of the gasket  403  and the discharge holes  202   f.    
         [0099]    According to the third embodiment, as hereinabove described, the sets of three grooves  431  are formed to extend from the first end portion  30   d  to the common notches  434  formed in the side inner surface  30   c  through the upper inner surface  30   a,  whereby the water retained on the upper surface  1   a  of the solar cell panel  1  can be reliably discharged through the grooves  431  of the gasket  403  and the notches  434  connected to the grooves  431 . Furthermore, even if a plurality of grooves  431  are close to each other and it is difficult to provide a notch  434  with respect to each of the plurality of grooves  431 , a common notch  434  is formed with respect to each of the sets of three grooves  431  so that the notches  434  serving as discharge portions can be reliably formed in the gasket  403 . 
         [0100]    According to the third embodiment, as hereinabove described, the water retained on the upper surface  1   a  of the solar cell panel  1  is discharged through the grooves  431  and the notches  434  of the gasket  403  and the discharge holes  202   f  provided in the side surface portions  2   c  of the frame body  202 , whereby water discharged to the side of the gasket  403  closer to the frame body  202  through the grooves  431  and the notches  434  of the gasket  403  can be discharged to the external portions (outer peripheral grooves  2   d ) of the frame body  202  through the discharge holes  202   f  provided in the side surface portions  2   c  of the frame body  202 . 
         [0101]    The remaining effects of the third embodiment are similar to those of the aforementioned first embodiment. 
       Modification of Third Embodiment 
       [0102]    Next, a solar cell module  500  according to a modification of the third embodiment of the present invention is described with reference to  FIG. 25 . In this modification of the third embodiment, discharge holes  502   g  are provided in a lower portion  2   b  of a frame body  502 , dissimilarly to the aforementioned third embodiment in which the discharge holes  202   f  are formed in the side surface portions  2   c  of the frame body  202 . 
         [0103]    As shown in  FIG. 25 , the discharge holes  502   g  are formed in the lower portion  2   b  of the frame body  502  of the solar cell module  500  according to the modification of the third embodiment. The discharge holes  502   g  are formed to pass through the lower portion  2   b  of the frame body  502  in a direction Z. Thus, water reaching the discharge holes  502   g  through grooves  431  and notches  434  of a gasket  403  passes through the discharge holes  502   g  and hollow portions  2   e,  and thereafter is discharged to external portions (outer peripheral grooves  2   d ) through unshown holes connected with the outer peripheral grooves  2   d.    
         [0104]    The remaining structure of the modification of the third embodiment is similar to that of the aforementioned third embodiment. 
         [0105]    According to the modification of the third embodiment, as hereinabove described, water retained on the upper surface  1   a  of a solar cell panel  1  is discharged through the grooves  431  and the notches  434  of the gasket  403  and the discharge holes  502   g  provided in the lower portion  2   b  of the frame body  502 , whereby water discharged to the side of the gasket  403  closer to the frame body  502  through the grooves  431  and the notches  434  of the gasket  403  can be discharged to the external portions (outer peripheral grooves  2   d ) of the frame body  502  through the discharge holes  502   g  provided in the lower portion  2   b  of the frame body  502 . Furthermore, the discharge holes  502   g  are provided in the lower portion  2   b  of the frame body  502 , whereby water discharged to the lower portion  2   b  of the frame body  502  can be reliably discharged. 
         [0106]    The remaining effects of the modification of the third embodiment are similar to those of the aforementioned first embodiment. 
         [0107]    The embodiments disclosed this time must be considered as illustrative in all points and not restrictive. The range of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and all modifications within the meaning and range equivalent to the scope of claims for patent are included. 
         [0108]    For example, while the grooves  31 ,  231 ,  331 , or  431  of the gasket  3 ,  203 ,  303 , or  403  are formed to extend in the directions substantially orthogonal to the extensional directions of the corresponding upper side surfaces  1   b  and lower side surfaces  1   d  of the solar cell panel  1  in each of the aforementioned first to third embodiments, the present invention is not restricted to this. For example, as in a first modification of each of the first to third embodiments shown in  FIGS. 26 and 27 , grooves  631  of a gasket  603  may be formed to obliquely extend in directions intersecting with extensional directions of the corresponding upper side surfaces and lower side surfaces of a solar cell panel. Furthermore, the grooves may be formed to extend to the holes according to the second embodiment or the notches according to the third embodiment formed in the gasket while being oblique in the directions intersecting with the extensional directions of the corresponding upper side surfaces and lower side surfaces of the solar cell panel. 
         [0109]    While the grooves  31  extending from the first end portion  30   d  to the second end portion  30   e  are formed in the gasket  3  in the aforementioned first embodiment, the holes  233  and the grooves  231  extending to the holes  233  are formed in the gasket  203  in the aforementioned second embodiment, and the notches  434  and the grooves  431  extending to the notches  434  are formed in the gasket  403  in the aforementioned third embodiment, the present invention is not restricted to this. For example, a gasket having all of the structure of the first embodiment, the structure of the second embodiment, and the structure of the third embodiment may be prepared by separately providing regions where the grooves extending from the first end portion to the second end portion are formed, where the holes and the grooves extending to the holes are formed, and where the notches and the grooves extending to the notches in the gasket. Alternatively, a gasket having two of the structure of the first embodiment, the structure of the second embodiment, and the structure of the third embodiment may be prepared. 
         [0110]    While the grooves  31 ,  231 ,  331 , or  431  are formed in the substantially entire region of the four sides of the gasket  3 ,  203 ,  303 , or  403  in each of the aforementioned first to third embodiments, the present invention is not restricted to this. According to the present invention, the grooves of the gasket may simply be formed at least in the vicinity of the corners of the gasket corresponding to the four corners of the solar cell panel. 
         [0111]    While the grooves  31 ,  231 ,  331 , or  431  are formed in the substantially entire region of the four sides of the gasket  3 ,  203 ,  303 , or  403  in each of the aforementioned first to third embodiments, the present invention is not restricted to this. According to the present invention, the grooves of the gasket may be formed in a region corresponding to a partial region of the four sides of the solar cell panel. 
         [0112]    While the holes  233  are formed in the regions of the side inner surface  30   c  corresponding to the upper side surfaces  1   b  of the solar cell panel  1  in the aforementioned second embodiment, the present invention is not restricted to this. According to the present invention, the holes may be formed in regions of the side inner surface corresponding to vicinities of boundaries between the upper side surfaces and the lower side surfaces. Alternatively, the holes may be formed in regions of the side inner surface corresponding to the lower side surfaces of the solar cell panel. 
         [0113]    While the flat portions  32 ,  232 ,  342   a,  or  432  come into surface contact with the solar cell panel  1  in each of the aforementioned first to third embodiments, the present invention is not restricted to this. For example, as in a second modification of each of the first to third embodiments shown in  FIGS. 28 and 29 , apexes  732  of substantially triangular portions formed between a plurality of grooves  731  of a gasket  703  may come into contact with a solar cell panel. 
         [0114]    While the grooves  31 ,  231 ,  331 , or  431  are formed in the surface (inner surface  30 ) coming into contact with the solar cell panel  1  in each of the aforementioned first to third embodiments, the present invention is not restricted to this. According to the present invention, the grooves of the gasket may not be formed in the surface coming into contact with the solar cell panel but may be formed in a surface coming into contact with the frame body. 
         [0115]    The present invention is also applicable to a solar cell module employing thin-film solar cells.