The present invention relates to a solar cell module.
In response to a recent growing trend of environmental protection, photovoltaic power generating systems, which cause less environmental loads, are attracting much attention. To more spread the use of these photovoltaic power generating systems, there is a need to increase the productivity of solar cell modules, which are part of a photovoltaic power generating system.
A means for increasing the productivity of the solar cell module is to enlarge the solar cell module. When the solar cell module is enlarged, the number of manufacturing man-hours per unit area and the like can be reduced. Since a large solar cell module takes a large area, however, it receives a large wind load and a large snow load and is thereby likely to be damaged.
To solve this problem, it is proposed to place a reinforcing member, in a rectangular columnar shape, that supports the central portion of the solar cell module (see Japanese Unexamined Patent Application Publication No. 2009-57757, for example).
When a positive-pressure load due to a snow load or the like is applied to a solar cell module that is structured as described above, strong bending stress and shearing stress are applied to the solar cell module at an angular portion of the reinforcing member in a rectangular columnar shape. These stresses are repeatedly applied to the solar cell module over the design life (for example, 20 years) of the solar cell module. If stresses are repeatedly applied to a solar cell module for a long period of time, cracks may occur in a plurality of solar cell elements included in the solar cell module and in glass that covers the solar cell elements and delamination may occur between the plurality of solar cell elements and inner leads that electrically connect the solar cell elements.
To enable the use of photovoltaic power generating systems in windy areas, heavy snow areas, and the like as well in response to users' requests, there is another need to increase the load bearing performance of the solar cell module.
Accordingly, an object of the present invention is to provide a solar cell module that comprises a simple structure but is superior in load bearing performance.
A solar cell module according to an aspect of the present invention comprises: a solar cell panel that has a light-receiving surface and a non-light-receiving surface, which is equivalent to the rear surface of the light-receiving surface, and also includes a first side part and a second side part, which are disposed between the light-receiving surface and the non-light-receiving surface and are not on the same surface; a first retaining member that retains the first side part of the solar cell panel; a second retaining member that retains the second side part of the solar cell panel; and a reinforcing member disposed between the first retaining member and the second retaining member on the same side as the non-light-receiving surface, the reinforcing member being in an elongated shape. The reinforcing member comprises a support part that supports the non-light-receiving surface of the solar cell panel. The support part includes a horizontal part parallel to the non-light-receiving surface and also includes an inclined part disposed at an end of the horizontal part, the inclined part being inclined so as to be apart from the non-light-receiving surface as the inclined part is apart from the horizontal part.
When the solar cell module described above receives a positive-pressure load, the horizontal part of the reinforcing member can support the solar cell module by distributing stress in a compressed direction and the inclined part disposed at an end of the horizontal part can reduce shearing stress. Accordingly, it is possible to provide a solar cell module that comprises a simple structure but is superior in load bearing performance.
Solar cell modules according to embodiments of the present invention will be described with reference to the drawings. Members with the same name included in the solar cell modules are assigned same reference characters. The drawings are schematic drawings; the sizes, the positional relationship, and the like of constituent elements in each drawing are not necessarily accurate.
A solar cell module 101 according to a first embodiment will be described with reference to
Basically, as illustrated in
As described above, the solar cell module 101 includes: the solar cell panel 2 that has the light-receiving surface 2a and non-light-receiving surface 2b and also includes the first side part 2c1 and second side part 2c2, which are disposed between the light-receiving surface 2a and the non-light-receiving surface 2b and are not on the same surface; the first retaining part 31 that retains the first side part 2c1 of the solar cell panel 2; the second retaining part 32 that retains the second side part 2c2 of the solar cell panel 2; and the reinforcing member 4, which is disposed between the first retaining part 31 and the second retaining part 32 on the same side as the non-light-receiving surface 2b, in an elongated shape.
As illustrated in
Next, members constituting the solar cell module 101 will be described in detail.
The solar cell panel 2 includes a translucent substrate 5, a first filler 61 on the same side as the light-receiving surface 2a, a plurality of solar cell elements 8, a second filler 62 on the same side as the non-light-receiving surface 2b, a rear surface protecting film 9, and the terminal box 10 in that order, starting from the same side as the light-receiving surface 2a, as illustrated in, for example,
The translucent substrate 5, which functions as a substrate of the solar cell module 101, is made of, for example, a material having a high optical transmittance such as glass or a polycarbonate resin. The filler 6, which has a function to seal the solar cell elements 8, is made of, for example, a thermosetting resin. The plurality of solar cell elements 8, the periphery of which is protected by the filler 6, are electrically connected by inner leads 7. The rear surface protecting film 9, which has a function to protect the same side as the non-light-receiving surface 2b of the solar cell panel 2, is made of, for example, polyvinyl fluoride (PVF), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or a resin formed by laminating at least two of these components. The terminal box 10 is bonded to the rear surface protecting film 9; the terminal box 10 has a function to supply an output from the solar cell panel 2 to the outside.
The light-receiving surface 2a (one main surface of the translucent substrate 5) of the solar cell panel 2 mainly receives light. It is not true that the non-light-receiving surface 2b (one main surface of the rear surface protecting film 9), which is equivalent to the rear surface of the light-receiving surface 2a, receives no light. When, for example, the rear surface protecting film 9 and the filler 6 interposed between the solar cell elements 8 and the rear surface protecting film 9 are made of a translucent material, the non-light-receiving surface 2b may receive part of light directed from the non-light-receiving surface 2b side.
To form the solar cell element 8, a flat plate-like member made of, for example, monocrystal silicon, polycrystal silicon, or the like is used. When this type of silicon substrate is used, adjacent silicon substrates are electrically connected by the inner leads 7.
A thin-film solar cell, for example, may be used as the solar cell element 8. Alternatively, a solar cell in which a thin amorphous film is formed on a crystalline silicon substrate or the like may be used. A non-silicon solar cell may also be used as the solar cell element 8; for example, chalcopyrite-based (including CIGS (Cu (In, Ga)Se2), CISS (Cu (In, Ga)(Se, S)2, CIS (CuInS2) and the like) solar cells, CdTe solar cells, and solar cells made of other various materials may be used. In this embodiment and other embodiments described below, embodiments in which a polycrystal silicon substrate is used as the solar cell element 8 will be described.
As illustrated in
This pair of retaining members 3 each include a fitting part 3b to which the solar cell panel 2 is fitted, a wall part 3c, which is substantially perpendicular to the main surface of the solar cell panel 2, and the attaching part 3a in a plate shape, which extends from the wall part 3c toward a space enclosed by the retaining member 3 so as to partially cover the non-light-receiving surface 2b of the solar cell panel 2 and both ends of the reinforcing member 4. Although
The retaining member 3 can be manufactured by, for example, extruding aluminum, roll forming a steel sheet, or performing another method.
Although, in this embodiment, the retaining member 3 is a frame-like body that retains the sides of the entire circumference of the solar cell panel 2, this is not a limitation; if the retaining member 3 can retain the solar cell panel 2, it may be a pair of rod-like bodies that retain at least a pair of sides, which are not on the same surface, of the solar cell panel 2.
An adhesive 12 interposed between the support part 4a of the reinforcing member 4 and the non-light-receiving surface 2b of the solar cell panel 2 may be, for example, a silicon-based adhesive, a polyurethane resin-based adhesive, an epoxy resin-based adhesive, or the like can be used.
The reinforcing member 4 has a function to enhance the load bearing performance of the solar cell panel 2. The reinforcing member 4 is in an elongated shape as illustrated in
The reinforcing member 4 comprises the support part 4a in a flat plate shape, a perpendicular part 4d, and a flange part 4e as illustrated in
The support part 4a includes the horizontal part 4b parallel to the non-light-receiving surface 2b and also includes the inclined parts 4c disposed at both ends of the horizontal part 4b, the inclined part 4c being inclined so as to be apart from the non-light-receiving surface 2b as the inclined part 4c is apart from the horizontal part 4b. Specifically, the horizontal part 4b is plate-like and flat and the inclined parts 4c are disposed gently at both ends of the horizontal part 4b so as to be continuous from the horizontal part 4b, as illustrated in
This reinforcing member 4 can be manufactured by, for example, extruding aluminum, roll forming a steel sheet, or performing another method. As long as the shape of the support part 4a is as described above, the cross-sectional shape of the reinforcing member 4 can be appropriately selected according to the usage; for example, an I-shaped cross section, an H-shaped cross section, a T-shaped cross section, an L-shaped cross section, or the like can be selected.
The reinforcing member 4 is secured to the attaching part 3a of the retaining member 3 at both ends in the longitudinal direction of the reinforcing member 4 with, for example, screws 11, as illustrated in
Thus, in a case as well in which a positive load is applied to the solar cell module 101 (particularly, the solar cell panel 2), the horizontal part 4b of the reinforcing member 4 can distribute compressed stress in the positive pressure direction and the solar cell panel 2 can be preferably supported by the reinforcing member 4. Furthermore, as illustrated in
In addition, when a large positive-pressure load is applied to the solar cell panel 2, the solar cell panel 2 is convexly warped toward the non-light-receiving surface 2b between the retaining member 3 and the reinforcing member 4, as illustrated in
The reinforcing member 4 is shaped so that the inclined part 4c is gradually apart from the rear surface of the solar cell panel 2 toward its end (end in the short direction of the reinforcing member 4). Thus, as illustrated in
The short direction of the reinforcing member 4 described above refers to, for example, a direction perpendicular to the longitudinal direction of the reinforcing member 4.
As in this embodiment, the inclined part 4c is not perpendicular to the horizontal part 4b but is inclined as described above. Since, in this form, the support part 4a has a shape in which there is no angular portion in the short direction, it is possible to reduce strong bending stress and shearing stress caused by the angular portion and applied to the solar cell module.
Furthermore, in this embodiment, as illustrated in
The reinforcing member 4 may be bonded to the non-light-receiving surface 2b of the solar cell panel 2 with a member other than the adhesive 12. In this structure as well, the horizontal part 4b can distribute compressed stress in the positive pressure direction and the inclined part 4c can reduce the shearing stress, as described above. As a member, other than the adhesive 12, that is disposed between the reinforcing member 4 and the non-light-receiving surface 2b, urethane foam with a seal, ethylene propylene diene monomer (EPDM), or another foaming agent, for example, can be used.
Although, in this embodiment, the adhesive 12 is filled between the non-light-receiving surface 2b and the horizontal part 4b of the reinforcing member 4 and between the inclined part 4c and the non-light-receiving surface 2b, this is not a limitation. For example, the adhesive 12 may be disposed only between the horizontal part 4b and the non-light-receiving surface 2b. In this structure, since the inclined part 4c is positioned outside the horizontal part 4b bonded with the adhesive 12, the section modulus of the reinforcing member 4 is increased and load bearing performance can be thereby improved.
Although, in this embodiment, the inclined part 4c has a flat plate shape as an example, this is not a limitation. For example, the inclined part 4c may have a plate-like shape with a curved surface. In this structure, if an extremely large positive pressure load is applied to the solar cell panel 2 and the solar cell panel 2 is greatly curved when, for example, the solar cell module 101 is placed in a very severe environment, local load applications can be reduced.
Although, in this embodiment, the inclined part 4c is disposed at the end, which is part of the support part 4a, in the short direction of the reinforcing member 4, the support part 4a may include another plate-like part outside the inclined part 4c. This improves the section modulus.
Next, a solar cell module 102 according to a second embodiment of the present invention will be described with reference to
In the solar cell module 102 according to this embodiment, the reinforcing member 4 has a different shape than in the solar cell module 101 according to the first embodiment. Specifically, as illustrated in
In this structure, for example, the linking part between the horizontal part 4b and the inclined part 4c may be cut on the same side as the non-light-receiving surface 2 so that the reinforcing member 4 comprises a thin part (linking part 4f), as illustrated in
The structure of the reinforcing member 4 comprising the linking part 4f, which is thinned as described above, is not limited to a structure formed by making a cutout. This linking part 4f can be manufactured by, for example, applying aluminum extrusion to the reinforcing member 4 or by processing the reinforcing member 4 that has been aluminum extruded.
In this embodiment in which the linking part 4f is provided, the adhesive 12 may also be displaced between the linking part 4f and the non-light-receiving surface 2b as illustrated in
As in this embodiment, the linking part 4f is curved in a vertex form toward the non-light-receiving surface 2b and continuously links the horizontal part 4b and the inclined part 4c together. That is, as illustrated in
Next, a solar cell module 103 according to a third embodiment of the present invention will be described with reference to
Specifically, as illustrated in
In this structure as well, a warp is likely to occur at the linking part between the horizontal part 4b and inclined part 4c of the reinforcing member 4 as in the second embodiment. Thus, since the support part 4a is warped at a portion ahead of the linking part, the shearing stress can be alleviated and generation of cracks in the translucent substrate 5 and solar cell elements 8 can be suppressed, so the effect of reducing delamination between the solar cell elements 8 and the inner leads 7 can be obtained.
Furthermore, in this embodiment, in addition to the above effect, the reinforcing member 4 includes no locally thick portion in the cross sectional shape along its short direction, so it is possible to reduce reduction in strength due to stress concentrated on the reinforcing member 4 itself.
Next, a solar cell module 104 according to a fourth embodiment of the present invention will be described with reference to
Specifically, the support part 4a includes the first end part 4i1 and second end part 4i2 at both ends in the longitudinal direction of the reinforcing member 4. The first end part 4i1 and second end part 4i2 are inclined so as to be apart from the non-light-receiving surface 2b as they come close to both ends. That is, when the first end part 4i1 is taken as an example, the first end part 4i1 is inclined so as to be apart from the non-light-receiving surface 2b as the first end part 4i1 comes close to the first retaining part 31, as illustrated in
These first end part 4i1 and second end part 4i2 can be formed by elongating the horizontal part 4b in the longitudinal direction and bending the horizontal part 4b in a direction away from the non-light-receiving surface 2b.
This structure can reduce the shearing stress at both ends in the longitudinal direction of the reinforcing member 4 as well and can enhance the load bearing performance of the solar cell module 104.
In this structure, as the state in which the reinforcing member 4 and the retaining member 3 are linked, the end of the first end part 4i1 in the longitudinal direction may be disposed so as to cover part of the fitting part 3b, as illustrated in
In this embodiment, an inclination angle α of the inclined part 4c with respect to the non-light-receiving surface 2b of the solar cell panel 2 (or the horizontal surface of the horizontal part 4b) may be larger than an inclination angle β of the first end part 4i1 and second end part 4i2 with respect to the non-light-receiving surface 2b of the solar cell panel 2 (or the horizontal surface of the horizontal part 4b), as illustrated in
The inclination angle α and inclination angle β can be each an inclination angle of the various parts with respect to the horizontal surface of the horizontal part 4b, as described above. Although the inclination angle β1 of the first end part 4i1 and the inclination angle β2 of the second end part 4i2 may be the same or different, the inclination angle β1 and inclination angle β2 can be made the same from the viewpoint of the ease of manufacturing and the stiffness of the reinforcing member 4.
Next, a solar cell module 105 according to a fifth embodiment of the present invention will be described with reference to
Specifically, a fitting hole 3d is formed in the retaining member 3, as illustrated in
When the fitting protrusion 4g is fitted to the fitting hole 3d in this way, strength with which the reinforcing member 4 is attached can be increased. The distance between the support part 4a and the non-light-receiving surface 2b of the solar cell panel 2 can be restricted according to a positional relationship between the fitting protrusion 4g and the fitting hole 3d. Thus, the adhesive 12 can be managed to a desired thickness. When this type of solar cell module is assembled, the reinforcing member 4 is preferably bonded to the solar cell panel 2 before the retaining member 3 is attached to the solar cell panel 2. This can increase the load bearing performance of the solar cell module.
Next, a solar cell module 106 according to a sixth embodiment of the present invention will be described with reference to
That is, in this embodiment, the support part 4a includes the reinforcing protrusions 4h, which extend from the horizontal part 4b or inclined part 4c in a direction away from the non-light-receiving surface 2b. Since these reinforcing protrusions 4h are formed, warp of the reinforcing member 4 in its longitudinal direction can be reduced. This can further increase the load bearing performance of the solar cell module 106.
In this embodiment, the reinforcing protrusion 4h is formed in a direction perpendicular to the non-light-receiving surface 2b. The support part 4a includes four reinforcing protrusions 4h of this type. Since the reinforcing protrusion 4h extends perpendicularly to the non-light-receiving surface 2b, the effect of reducing warp of the reinforcing member 4 in its longitudinal direction can be increased. The number of reinforcing protrusions 4h may be appropriately selected according to the shape and material of the reinforcing member 4. The reinforcing protrusions 4h may be formed only on the horizontal part 4b. Alternatively, they may be formed on only the inclined part 4c.
Next, a solar cell module 107 according to a seventh embodiment of the present invention will be described with reference to
Specifically, the support part 4a has the through-holes 4j, which extend approximately perpendicular to the non-light-receiving surface 2b, as illustrated in
Since, in this embodiment, the through-holes 4j described above are formed, the adhesive 12 can be easily placed in the clearance between the reinforcing member 4 and the rear surface protecting film 9, which is equivalent to the non-light-receiving surface 2b of the solar cell panel 2. This improves working efficiency in solar cell module assembling.
This embodiment is structured so that when the adhesive 12 spreads toward the inclined part 4c as the adhesive 12 is injected from the through-holes 4j, the clearance between the inclined part 4c and the non-light-receiving surface 2b gradually expands toward the outside. Thus, the adhesive 12 is likely to stay in the clearance, reducing extrusion of the adhesive 12 from the reinforcing member 4.
Although, in this embodiment, the through-holes 4j are formed in the horizontal part 4b of the support part 4a, this is not a limitation. It suffices that the through-holes 4j are only formed so as to enable the adhesive 12 to be injected; for example, the through-holes 4j may be formed in the inclined part 4c.
Next, a solar cell module 108 according to an eighth embodiment of the present invention will be described with reference to
Specifically, in this embodiment, the support part 4a includes the arch part 4k, horizontal part 4b, and inclined part 4c sequentially in that order in the short direction of the reinforcing member 4, starting from its center, as illustrated in
In this structure, the adhesive 12 is injected from the through-holes 4j as described in the seventh embodiment. The adhesive 12 that has been injected from the through-holes 4j are viscous before curing, so the adhesive 12 is likely to flow from a narrow clearance to a wide clearance. Since, in this embodiment, the support part 4a includes the arch part 4k as described above, a wide path through which the adhesive 12 flows is formed inside the arch part 4k, that is, between the arch part 4k and the non-light-receiving surface 2b. Accordingly, the adhesive 12 that has injected from the through-holes 4j preferentially spreads first in the longitudinal direction of the reinforcing member 4. The adhesive 12 then spreads in the short direction of the reinforcing member 4. The clearance between the support part 4a and the non-light-receiving surface 2b is filled with the adhesive 12, which has spread in this way, bonding the support part 4a and the non-light-receiving surface 2b together. Thus, the adhesive 12 can be smoothly injected to places distant from the through-holes 4j. As a result, in this embodiment, the number of through-holes 4j can be reduced, so working efficiency in the injection of the adhesive 12 can be improved.
Although the adhesive 12 also spreads toward the inclined part 4c, that is, in the short direction of the reinforcing member 4 as the adhesive 12 is injected from the through-holes 4j, this embodiment is structured so that the clearance between the inclined part 4c and the non-light-receiving surface 2b gradually expands in the short direction of the reinforcing member 4 toward the outside, as in the embodiment described above. Accordingly, the adhesive 12 is likely to stay in the clearance and the effect of reducing extrusion of the adhesive 12 from the reinforcing member 4 can be obtained.
Furthermore, in this embodiment, the arch part 4k is positioned at a central portion of the support part 4a in the short direction of the reinforcing member 4, as illustrated in
The central portion, described here, of the support part 4a in the short direction may be defined as follows: if the dimension of the support part 4a in the short direction is assumed to be L4a, then the central portion may be an area with a dimension of L4a/2 centered around the midpoint of the support part 4a in the short direction.
Next, a solar cell module 109 according to a ninth embodiment of the present invention will be described with reference to
Specifically, the support part 4a includes the reinforcing protrusions 4h that extend from the inclined part 4c toward the non-light-receiving surface 2b. The reinforcing protrusion 4h in this embodiment extends in a direction substantially perpendicular to the inclined part 4c.
Since, in this embodiment, the reinforcing protrusions 4h as described above are provided, the adhesive 12 can be protected against ultraviolet rays incident on the adhesive 12 and deterioration of the adhesive 12 due to the ultraviolet rays can be thereby reduced. Accordingly, detachment of the adhesive 12 from ends can be reduced. Furthermore, in this structure, the section modulus of the reinforcing member 4 is also increased, so the reinforcing member 4 is less likely to be warped and the strength of the solar cell module 109 can also be increased.
In this structure as well, since the support part 4a includes the reinforcing protrusions 4h, the effect of reducing the warp of the reinforcing member 4 in its longitudinal direction can also be obtained as in the sixth embodiment.
So far, embodiments of the present invention have been exemplified, but the present invention is not limited to the embodiments described above. It is needless to say that the present invention can take any embodiment without departing from the object of the present invention. For example, another embodiment of the present invention may be any combination of the embodiments described above.
In the case of the reinforcing member 4, for example, horizontal end parts 4m can be formed at both ends of the inclined part 4c along the longitudinal direction of the reinforcing member 4 in the solar cell module 101 of the first embodiment and the like, as illustrated in
As illustrated in
As illustrated in
Solar cell modules to which the present invention can be applied are not limited to solar cell modules having the super straight structure described in the above embodiments. The present invention can also be applied to solar cell modules having glass package structures, substrate structures, and other various structures.
Number | Date | Country | Kind |
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2011-017451 | Jan 2011 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2012/051988 | 1/30/2012 | WO | 00 | 7/31/2013 |