Abstract:
A roof cover type solar cell module includes a roof cover base member and a power generating unit. The roof cover base member has a mounting surface to which the power generating unit is mounted, and an underlap that can mate with an adjacent roof cover. The power generating unit is mounted to the mounting surface, leaving a part of the mounting surface uncovered. Thus, a roof cover type solar cell module for which a variety of materials can be used for the roof cover base member, which can be produced at low cost, and which is excellent in stability when placed on the roof surface, and also excellent in workability, weather resistance and design property, is provided.

Description:
[0001]     This nonprovisional application is based on Japanese Patent Application No. 2003-353615 filed with the Japan Patent Office on Oct. 14, 2003, the entire contents of which are hereby incorporated by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a solar cell module. More particularly, the present invention relates to a solar cell module having an outer structure allowing mating with an adjacent roof cover.  
         [0004]     2. Description of the Background Art  
         [0005]     To secure a solar cell module to a roof surface, in many cases, a stand is placed on a roof cover at the roof surface, and the solar cell module is secured to the stand. With recent diversification of the users&#39; needs, however, a large number of solar cell modules having a solar cell integrated with a roof cover and excellent in design property have been proposed (see, e.g., Japanese Patent Laying-Open Nos. 11-324234, and 2002-070271).  
         [0006]     In many of the proposed solar cell modules with the solar cell integrated with the roof cover, however, a power generating unit is housed in a concave portion or a bent portion that is provided in a roof cover base member to be mated with an adjacent roof cover. In such a case, a large area of the roof cover base member would externally be exposed after installation of the solar cell module on the roof surface. Thus, in order not to impair its design, weatherproof coating should be applied to or a weatherproof color steel plate should be used for the roof cover base member, which leads to an increased material cost.  
       SUMMARY OF THE INVENTION  
       [0007]     An object of the present invention is to provide a roof cover type solar cell module for which a variety of materials can be used for its roof cover base member, and which can be formed at low cost, can be placed stably on the roof surface, and is excellent in workability, weather resistance and design property.  
         [0008]     To achieve the object, the inventors prepared by way of trial roof cover type solar cell modules having various structures and studied their properties. As a result, the inventors have found that the roof cover type solar cell module of a certain structure exhibits excellent properties, and have completed the present invention.  
         [0009]     Specifically, the roof cover type solar cell module according to the present invention includes: a roof cover base member having a mounting surface and a structure allowing mating with an adjacent roof cover; and a power generating unit mounted to the mounting surface, with a part of the mounting surface exposed.  
         [0010]     In the roof cover type solar cell module of the present invention, the power generating unit covers the mounting surface of the roof cover base member. This can hide the base material of the roof cover base member, and eliminates the need to use a color steel plate or the like for, or apply weatherproof coating on, the roof cover base member, so that considerable cost reduction becomes possible.  
         [0011]     As such, the roof cover type solar cell module of the present invention is one for which a variety of materials can be used for the roof cover base member, which can be produced at low cost and can be installed stably on the roof surface, and which is excellent in workability, weather resistance and design property.  
         [0012]     Here, the power generating unit may be mounted to the mounting surface, with a part of the mounting surface exposed in the vicinity of at least one vertex of a polygon constituting a contour of the mounting surface.  
         [0013]     The mounting surface may have a contour of n-gon (n is a natural number) and the power generating unit may have a contour of (n+1)-gon or (n+2)-gon (n is a natural number). Further, the mounting surface may have a contour of tetragon and the power generating unit may have a contour of pentagon or hexagon with one or two vertices of the tetragon congruent with the mounting surface truncated.  
         [0014]     The exposed part of the mounting surface may be provided with a hole for driving a nail or a screw in so as to secure the roof cover base member to the adjacent roof In this case, the hole for driving a nail or a screw in may be provided on a projection that is formed at the exposed part of the mounting surface. The projection is configured to have a height greater than a thickness of the power generating unit.  
         [0015]     Further, an intermodule fixing tool may be attached to the exposed part of the mounting surface. In this case, the intermodule fixing tool is configured such that, when a plurality of such roof cover type solar cell modules are placed on a roof surface, the roof cover type solar cell modules located at the eaves side and the ridge side are secured to each other.  
         [0016]     Here, the roof cover type solar cell module located at the ridge side may be provided with a rib on the eaves side of the roof cover base member. The rib is configured to be hooked on the intermodule fixing tool of the roof cover type solar cell module located at the eaves side.  
         [0017]     Further, the roof cover base member may be provided with a notch that is open to the ridge side. The notch is configured to make a terminal box provided at the power generating unit exposed to the roof surface side.  
         [0018]     The roof cover base member and the power generating unit may be secured by adhesion. Further, the roof cover base member may be provided with a concave portion configured to receive an adhesive therein.  
         [0019]     Still further, the roof cover base member may have a facing cover attached on the eaves side. The facing cover is configured to cover the eaves side end portion of the roof cover base member when the roof cover type solar cell module is placed on the roof surface.  
         [0020]     The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]      FIG. 1  is a perspective view of an example of a roof cover type solar cell module according to the present invention, shown in the state where a roof cover base member and a power generating unit are separated from each other.  
         [0022]      FIGS. 2A and 2B  are perspective views of an example of the roof cover type solar cell module of the present invention, seen from the back and the front, respectively.  
         [0023]      FIGS. 3A and 3B  are perspective views of the roof cover base member  1  of the roof cover type solar cell module shown in  FIGS. 2A and 2B , seen from the back and the front, respectively.  
         [0024]      FIG. 4  is a cross sectional view showing by way of example roof cover type solar cell modules of the present invention in the installed state.  
         [0025]      FIG. 5  is a perspective view of an example of the roof cover type solar cell module of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]     Hereinafter, embodiments of the present invention will be described.  
         [0027]      FIG. 1  shows an example of the roof cover type solar cell module of the present invention, with the roof cover base member and the power generating unit separated from each other.  
         [0028]     In the present embodiment, description will be made based on a solar cell module having an outer structure that allows mating with a plain roof tile of which working region (i.e., part exposed on the roof surface after installation) has a working width of 305 mm and a working length of 280 mm. The roof cover type solar cell module shown in  FIG. 1  is placed on the roof surface so that the direction indicated by an arrow A 1  corresponds to the ridge side and the direction indicated by an arrow A 2  corresponds to the eaves side.  
         [0029]     In  FIG. 1 , a roof cover base member  1  is provided with a mounting surface  3  for mounting a power generating unit  2  thereto, and an underlap  6  for mating with an adjacent roof cover such as a roof tile. Roof cover base member  1  may be made of an aluminum plate, stainless steel plate, galvalium steel plate, zinc-aluminum-magnesium alloy plated steel plate or the like, which may be used with or without coating. Roof cover base member  1  preferably has a thickness of greater than 0.6 mm for the purpose of ensuring strength.  
         [0030]     Power generating unit  2  preferably has a superstrate structure where solar cells  7 , each including a semiconductor member of monocrystalline sheet type, polycrystalline sheet type or amorphous type structure, are sandwiched between a glass and a weatherproof film and sealed with a resin. Alternatively, power generating unit  2  may have a substrate structure where a transparent film is used instead of the glass described above. Power generating unit  2  is provided, e.g., with a terminal box  11  (see  FIG. 2A  as will be explained later) and a cable  8  for drawing out power therefrom.  
         [0031]     Preferably, the power generating unit of the present invention is mounted to the mounting surface of the roof cover base member, with a part of the mounting surface left uncovered. More preferably, the power generating unit is mounted to the mounting surface in such a manner that the power generating unit does not cover the mounting surface in the vicinity of at least one vertex of a polygon constituting the contour of the mounting surface. Still more preferably, the contour of the mounting surface is an n-gon (n is a natural number), and the contour of the power generating unit is an (n+1)-gon or an (n+2)-gon (n is a natural number). It is particularly preferable that the contour of the mounting surface is a tetragon, and the contour of the power generating unit is a pentagon or a hexagon with one or two vertices of the tetragon congruent with the mounting surface truncated.  FIG. 1  shows the case where mounting surface  3  of roof cover base member  1  has a contour of tetragon, and power generating unit  2  has a contour of pentagon with a truncation  17  formed at one vertex of the tetragon congruent with mounting surface  3 .  
         [0032]     In the roof cover type solar cell module of the present invention, at least one hole for driving a nail or a screw in is preferably provided in the part of the mounting surface uncovered by the power generating unit, to secure the roof cover base member to an adjacent roof.  FIG. 1  shows the case where a screw hole  4  for securing roof cover base member  1  to the roof surface is provided in the vicinity of one vertex of roof cover base member  1 . This screw hole  4  is provided on a projection  5  for the purposes of preventing water from entering and facilitating the work of screwing. Projection  5  has a height greater than the thickness of power generating unit  2 . Power generating unit  2  shown in  FIG. 1  has a contour of pentagon with truncation  17  formed at one vertex of the tetragon. Truncation  17  is formed with a particular size at a particular position so that projection  5  is uncovered by power generating unit  2  when power generating unit  2  is mounted to mounting surface  3  of roof cover base member  1 . Screw hole  4  is preferably placed at the ridge side A 1  of roof cover base member  1 , since it needs to be approximately aligned with a screw hole of the adjacent roof cover.  
         [0033]     Upon securing roof cover base member  1  to the roof surface with a screw, insufficient strength of roof cover base member  1  will lead to deformation of the part around screw hole  4  due to screwing. To avoid this, a U-shaped, reinforcing angle may be inserted at the back of screw hole  4  of roof cover base member  1 . In this case, the height of the U-shaped reinforcing angle is preferably made adjustable, which can make the heights of roof cover base member  1  and the adjacent roof cover adjustable as well. Further, in the case where the neighboring roof covers are of the type hooked and secured on tile battens, the U-shaped reinforcing angle may be processed to have a bent portion so that it can be hooked on the tile batten as well.  
         [0034]     When the roof cover type solar cell module of the present invention is installed on the roof surface, power generating unit  2  is exposed as the working region. Since a transparent glass or a transparent film is provided at the outermost surface of power generating unit  2 , the externally visible color of power generating unit  2  largely depends on solar cells  7  and the weatherproof film. In the present invention, the colors of solar cells  7  and the weatherproof film may be matched with the color of the neighboring roof covers, so as to provide a roof cover type solar cell module having sense of unity with the neighboring roof covers in terms of design. Alternatively, the colors of solar cells  7  and the weatherproof film may be differentiated from that of the neighboring roof covers so as to make the solar cell portion distinctive.  
         [0035]      FIGS. 2A and 2B  are perspective views of an example of the roof cover type solar cell module of the present invention, seen from the back and the front, respectively.  FIGS. 3A and 3B  are perspective views of roof cover base member  1  of the roof cover type solar cell module shown in  FIGS. 2A and 2B , seen from the back and the front, respectively.  
         [0036]     In the present embodiment, in the case where terminal box  11  for drawing out power is placed on the back side of power generating unit  2 , a notch  13  is provided at roof cover base member  1  to expose terminal box  11  to the roof surface side. Notch  13  is made open to the ridge side A 1 . Notch  13  may be provided with a bent portion  14  for alignment of terminal box  11  with roof cover base member  1 .  
         [0037]     The roof cover type solar cell module of the present invention preferably has an intermodule fixing tool  10  provided at the part of mounting surface  3  of roof cover base member  1  uncovered by power generating unit  2 , as shown in  FIGS. 2A, 2B ,  3 A and  3 B, so that when a plurality of such roof cover type solar cell modules are to be installed on the roof surface, the neighboring roof cover type solar cell modules placed at the eaves side A 2  and the ridge side A 1  are secured to each other by means of intermodule fixing tool  10 . Specifically, as shown in  FIGS. 2A, 2B ,  3 A and  3 B, a bent portion  15  for intermodule fixing tool is provided at the ridge side A 1  of roof cover base member  1  and, with a burring hole provided at bent portion  15 , intermodule fixing tool  10  is attached thereto. Intermodule fixing tool  10  preferably has a metal as its material for the purposes of ensuring strength and others. Intermodule fixing tool  10  may be fixed to roof cover base member  1  in any manner. For example, they may be secured using a bolt and a nut, or may be secured by adhesion or riveting. The shape of intermodule fixing tool  10  is preferably designed to guarantee a spacing of 2 mm to 3 mm between intermodule fixing tool  10  and power generating unit  2 .  
         [0038]     Preferably, intermodule fixing tool  10  is formed by bending a metal plate to have a flat face in contact with bent portion  15  for intermodule fixing tool for attachment of intermodule fixing tool  10 , a flat face in contact with mounting surface  3  of roof cover base member  1 , and a flat face erected therefrom and extending in parallel with mounting surface  3 . Intermodule fixing tool  10  is preferably made of an aluminum plate, stainless steel plate, galvalium steel plate, zinc-aluminum-magnesium alloy plated steel plate or the like.  
         [0039]     The roof cover type solar cell module of the present invention preferably includes roof cover base member  1  and power generating unit  2  fixed to each other by adhesion. In this case, as shown in  FIGS. 3A and 3B , the roof cover base member is preferably provided with a concave portion  16  that can receive an adhesive therein. Applying the adhesive in concave portion  16  enables adhesion of roof cover base member  1  and power generating unit  2  while preventing the adhesive from externally running off.  
         [0040]     Although power generating unit  2  rested on mounting surface  3  of roof cover base member  1  can prevent external exposure of the color of the base material of roof cover base member  1 , the edge of roof cover base member  1  at the eaves side A 2  may still be exposed. To avoid this, roof cover base member  1  may be coated, or a facing cover  9  may be attached to hide the edge. Facing cover  9  is preferably made of a color galvalium steel plate, aluminum plate, colorless steel plate or the like. Facing cover  9  may be fixed to roof cover base member  1  by adhesion, caulking by bending, or screwing.  
         [0041]      FIG. 4  is a cross sectional view showing, by way of example, roof cover type solar cell modules of the present invention in the installed state. Preferably, the roof cover type solar cell module of the present invention is provided with a rib  12  at the eaves side A 2  of roof cover base member  1 . When a plurality of such roof cover type solar cell modules are to be installed on the roof surface, rib  12  of one module is hooked on intermodule fixing tool  10  of the adjacent module on the eaves side A 2 . In the example shown in  FIG. 4 , rib  12  is provided at the eaves side A 2  of roof cover base member  1 , and the rib is inserted into the spacing provided between intermodule fixing tool  10  and power generating unit  2  so as to be hooked, and thus, the module at the ridge side A 1  and the module at the eaves side A 2  are secured to each other. Facing cover  9  is provided at the eaves side end portion of roof cover base member  1  to cover rib  12 , and thus, power generating unit  2  of the module on the ridge side A 2  is secured as it is sandwiched between roof cover base member  1  of its own and facing cover  9  of the adjacent module on the eaves side A 1 .  
         [0042]     If rib  12  is insufficient in strength, an angle as a reinforcing member may be attached thereto. In this case, the reinforcing member is preferably made of an aluminum plate, stainless steel plate, galvalium steel plate, zinc-aluminum-magnesium alloy plated steel plate, or the like.  
         [0043]      FIG. 5  is a perspective view of an example of the roof cover type solar cell module of the present invention.  
         [0044]     As shown in  FIG. 5 , when mounting surface  3  of roof cover base member  1  is a tetragon, power generating unit  2  is preferably a hexagon having truncations  17  formed at two vertices thereof, since such a shape is advantageous in the case where two screw holes  4  are required to ensure strength of attachment to the roof surface.  
         [0045]     Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.