Solar cell module

Abstract

To improve the impact resistance of solar cell modules. [Solution] The solar cell module comprises a light-transmitting resin surface protective layer, a back-side reinforcing layer, a solar cell element disposed between the surface protective layer and the back-side reinforcing layer, a light-transmitting front-side reinforcing layer disposed between the surface protective layer and the solar cell element, and a filler material that fills the space between the back-side reinforcing layer and the front-side reinforcing layer while covering the solar cell element. The Young's modulus of the front-side reinforcing layer is greater than that of the back-side reinforcing layer. The bending stiffness of the back-side reinforcing layer is higher than that of the front-side reinforcing layer.

Description

[Technical Field]

[0001] This disclosure relates to solar cell modules. [Background technology]

[0002] A solar cell module is known in which multiple solar cells are positioned between a surface member and a back member (see, for example, the description in Patent Document 1). In this solar cell module, the back member has higher rigidity than the surface member. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2015-170817 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] There is room for improvement in terms of increasing the impact resistance of solar cell modules. [Means for solving the problem]

[0005] The solar cell module is disclosed.

[0006] One embodiment of a solar cell module comprises a translucent resin surface protective layer, a back-side reinforcing layer, a solar cell element disposed between the surface protective layer and the back-side reinforcing layer, a translucent front-side reinforcing layer disposed between the surface protective layer and the solar cell element, and a filler material that fills the space between the back-side reinforcing layer and the front-side reinforcing layer while covering the solar cell element. The Young's modulus of the front-side reinforcing layer is greater than that of the back-side reinforcing layer. The bending stiffness of the back-side reinforcing layer is higher than that of the front-side reinforcing layer. [Effects of the Invention]

[0007] This can improve the impact resistance of solar cell modules. [Brief explanation of the drawing]

[0008] [Figure 1] This is a plan view showing an example of the appearance of a solar cell module according to the first embodiment when viewed from above. [Figure 2] This figure shows an example of a hypothetical cross-section along the Ib-Ib line of the solar cell module shown in Figure 1. [Figure 3] This figure shows an example of the structure of a solar cell element when viewed from above, specifically the first element surface. [Figure 4] This figure shows an example of the structure of a solar cell element when viewed from above, specifically the second element surface. [Figure 5] This figure illustrates the state of a cross-section during the manufacturing process of a solar cell module according to the first embodiment. [Figure 6] This figure illustrates the state of a cross-section during the manufacturing process of a solar cell module according to the first embodiment. [Figure 7] This figure illustrates the state of a cross-section during the manufacturing process of a solar cell module according to the first embodiment. [Figure 8] Figure 2 is a cross-sectional view showing an example of the stacked configuration of region RA. [Figure 9] This figure shows an example of how to calculate the neutral axis in the Z direction. [Figure 10] This is a cross-sectional view showing an example of a laminated structure according to the second embodiment. [Figure 11] This is a cross-sectional view showing an example of a laminated configuration according to the third embodiment. [Modes for carrying out the invention]

[0009] A solar cell module is known in which multiple solar cell elements are positioned between a front member and a back member. In this solar cell module, the back member has higher rigidity than the front member.

[0010] By the way, in a solar cell module that employs a resin surface protection layer for the purpose of weight reduction, if the impact resistance is insufficient, for example, the surface protection layer may be deformed by hail and cracks may occur in the solar cell element.

[0011] Therefore, the inventor of the present disclosure has created a technology capable of enhancing the impact resistance of a solar cell module. This will be described below with reference to the drawings from the first embodiment to the third embodiment.

[0012] In the drawings, parts having the same or similar configurations and functions are denoted by the same reference numerals, and duplicate descriptions are omitted in the following description. The drawings are schematically shown. In FIGS. 1 to 11, a right-handed XYZ coordinate system is attached. In this XYZ coordinate system, the short-side direction of the front surface 10f of the solar cell panel 10 is taken as the +X direction, the long-side direction of the front surface 10f is taken as the +Y direction, and the normal direction of the front surface 10f perpendicular to both the +X direction and the +Y direction is taken as the +Z direction.

[0013] Also, in the present disclosure, even when ordinal numbers such as "first" or "second" are used, these terms are used for convenience in order to facilitate understanding of the content of the embodiment, and the content of the embodiment is not limited to the order or the like that may be caused by these ordinal numbers.

[0014] Also, in the present disclosure, when described as "A or B", this description includes, as long as there is no contradiction, the case of indicating only one of A and B and the case of indicating both A and B.

[0015] <First Embodiment> Hereinafter, the solar cell module according to the present embodiment will be described.

[0016] <Solar Cell Module> Figure 1 is a plan view showing an example of the appearance of a solar cell module according to the first embodiment when viewed from above. Here, a plan view corresponds to viewing the solar cell module toward its main surface. Figure 2 is a diagram showing an example of a hypothetical cross-section along the Ib-Ib line of the solar cell module in Figure 1. The region RA shown in Figure 2 will be described later.

[0017] As shown in Figures 1 and 2, the solar cell module 100 includes, for example, a solar cell panel 10. The solar cell panel 10 has, for example, a light-receiving surface (also called the front surface 10f) to which light is mainly incident, and a back surface 10b located on the opposite side of the front surface 10f. In the first embodiment, the front surface 10f is facing in the +Z direction, and the back surface 10b is facing in the -Z direction. The +Z direction is set, for example, to face the sun at its highest point in the sky. In the example of Figure 1, the front surface 10f has a rectangular shape as an example of a square shape. The corners of the rectangular solar cell panel 10 may be chamfered as appropriate.

[0018] The solar cell module 100 may further include a terminal box (not shown) for extracting the power generated by the solar cell panel 10 to the outside.

[0019] As shown in Figures 1 and 2, the solar cell panel 10 comprises, for example, a surface protective layer 1, an adhesive layer 13, a front-side reinforcing layer 12, a solar cell portion 3, a filler material 4, a back-side reinforcing layer 9, and an adhesive layer 7. The solar cell panel 10 may also include a back-side protective layer 2.

[0020] <Surface protective layer> The surface protection layer 1 has, for example, a first surface 1f and a second surface 1s (see Figure 2). In the first embodiment, the first surface 1f constitutes, for example, the front surface 10f of the solar cell panel 10. That is, the surface protection layer 1 has a rectangular shape as an example of a square shape. The corners of the rectangular surface protection layer 1 may be chamfered as appropriate. In the examples of Figures 1 and 2, the first surface 1f is exposed to the space outside the solar cell module 100 (also referred to as the external space 200). The second surface 1s is the surface opposite to the first surface 1f.

[0021] The surface protective layer 1 has, for example, light transmittance. Specifically, the surface protective layer 1 has, for example, light transmittance to light within a specific range of wavelengths. The specific range of wavelengths includes, for example, the wavelengths of light that the solar cell unit 3 can photoelectrically convert. If the specific range of wavelengths includes wavelengths of light with high irradiation intensity from sunlight, the photoelectric conversion efficiency of the solar cell module 100 can be improved.

[0022] The material of the surface protection layer 1 is, for example, a weather-resistant resin. In other words, the surface protection layer 1 is a layer made of, for example, a weather-resistant resin. Here, weather resistance means the property of being resistant to deterioration such as deformation, discoloration, and degradation when used outdoors. By applying resin to the material of the surface protection layer 1, the surface protection layer 1 reduces the intrusion of water, such as water droplets, from the external space 200 of the solar cell module 100 toward the solar cell section 3, and also has the property of allowing moisture to pass easily from the filler material 4 toward the external space 200 (also called moisture permeability and waterproofing). Here, the weather-resistant resin includes, for example, polyethylene terephthalate (PET) or a fluorine-based resin. Fluorine-based resins include, for example, fluorinated ethylene propylene copolymer (FEP), ethylene tetrafluoroethylene copolymer (ETFE), and ethylene chlorotrifluoroethylene copolymer (ECTFE). Here, for example, the surface protective layer 1 may be composed of two or more weather-resistant resins. In this case, the resin applied to the surface protective layer 1 may be, for example, two or more types of resins. For this reason, for example, an embodiment in which the resin applied to the surface protective layer 1 includes at least one resin from among PET, FEP, ETFE, and ECTFE is conceivable.

[0023] The thickness of the surface protection layer 1 is, for example, about 0.1 millimeters (mm) to 0.5 mm. Thus, the surface protection layer 1 is made of a relatively low-density resin with water-repellent properties, and because it is thin, the surface protection layer 1 is lightweight. For this reason, compared to a structure in which a high-density glass with a thickness of about 1 mm or more is used instead of the surface protection layer 1, the solar cell module 100 can be made lighter and the solar cell module 100 can be made thinner.

[0024] In addition, the material of the surface protection layer 1 may be acrylic resin and polycarbonate, or other resins, instead of the resin mentioned above, or in combination with the resin mentioned above. When acrylic resin and polycarbonate are used, the thickness of the resin is, for example, about 0.03 mm to 0.6 mm. The surface protection layer 1 may be composed of multiple types of resins laminated together.

[0025] <Adhesive layer> The adhesive layer 13 is a layer that adheres the surface reinforcing layer 12 and the surface protective layer 1. The adhesive layer 13 has, for example, a first surface 13f and a second surface 13s located on the opposite side from the first surface 13f. The first surface 13f of the adhesive layer 13 is, for example, adhered to the second surface 1s of the surface protective layer 1. The second surface 13s of the adhesive layer 13 is, for example, adhered to the first surface 12f of the surface reinforcing layer 12.

[0026] The thickness of the adhesive layer 13 is, for example, about 0.05 mm to 0.5 mm. The materials used to make up the adhesive layer 13 include, for example, ionomer (IO), ethylene vinyl acetate copolymer (EVA), or polyolefin elastomer (POE). The adhesive layer 13 may also be made of the same material as the filler 4.

[0027] Furthermore, if either the material of the surface protective layer 1 or the material of the front reinforcing layer 12 is a material that can be fused to adjacent layers by heating during the lamination process, then the adhesive layer 13 may not be provided.

[0028] <Top side reinforcement layer> The surface reinforcing layer 12 is a layer formed, for example, by impregnating at least a portion of the gaps in the fiber material with an impregnating material. The surface reinforcing layer 12 is translucent. The surface reinforcing layer 12 has, for example, a first surface 12f and a second surface 12s located on the opposite side of the first surface 12f. The surface reinforcing layer 12 has a rectangular shape, as an example of a square shape. The corners of the surface reinforcing layer 12, which is square in plan view, may be chamfered as appropriate. The first surface 12f of the surface reinforcing layer 12 is facing the surface protection layer 1 via the adhesive layer 13. The second surface 12s of the surface reinforcing layer 12 is facing the filler material 4. In other words, the second surface 12s of the surface reinforcing layer 12 is covered by the filler material 4. Furthermore, the second surface 12s of the surface reinforcing layer 12 is facing the first element surface 31f of the solar cell element 31 via the filler material 4. The surface reinforcing layer 12 is, for example, in a stage before forming a laminated structure by lamination, in which the fibrous material is sufficiently impregnated with an impregnating material such as resin.

[0029] The thickness of the surface reinforcing layer 12 is approximately 0.01 mm to 0.2 mm. For example, glass fiber is used as the fibrous material included in the surface reinforcing layer 12. For example, IO, epoxy resin, EVA, POE, or polymethyl methacrylate resin can be used as the impregnating material for the fibrous material. For example, when glass fiber is impregnated with epoxy resin, the Young's modulus of the surface reinforcing layer 12 is approximately 4.549 GPa, and the bending stiffness is b × 3.8 × 10 for a thickness in the range of 0.01 mm to 0.2 mm. -7 From b × 3.0 × 10 ―3 [Pa·m 4 It is approximately ]. Here, b is the length of the solar cell module 100 in the X direction, in other words, the length of the shorter side in Figure 1. Also, the Young's modulus of the epoxy resin assumed to be the impregnating material for the front reinforcing layer 12 is approximately 2.8 GPa. The impregnating material impregnating the fibrous material in the front reinforcing layer 12 prevents the movement of air from the back protective layer 2 side to the front protective layer 1 side.

[0030] <Solar cell department> The solar cell section 3 is located, for example, between the surface protection layer 1 and the back protection layer 2. In other words, the solar cell section 3 is facing the surface protection layer 1 in the Z direction and also facing the back protection layer 2 in the Z direction. The solar cell section 3 is also located, for example, between the surface protection layer 1 and the back reinforcement layer 9. In other words, the solar cell section 3 is facing the surface protection layer 1 in the Z direction and also facing the back reinforcement layer 9 in the Z direction. The solar cell section 3 has at least one solar cell element 31. In the example shown in Figures 1 and 2, the solar cell section 3 has a plurality of solar cell elements 31. The plurality of solar cell elements 31 are located between the second surface 1s of the surface protection layer 1 and the back protection layer 2. In the first embodiment, the plurality of solar cell elements 31 are arranged in a two-dimensional manner. In the example shown in Figures 1 and 2, the plurality of solar cell elements 31 are arranged in a planar manner so as to be located along the second surface 1s of the surface protection layer 1. The plurality of solar cell elements 31 may also be arranged in a one-dimensional manner.

[0031] The solar cell unit 3 further includes, for example, a plurality of first wiring materials 32, a second wiring material 33, and a third wiring material 34. The solar cell unit 3 includes, for example, a plurality (here, two) solar cell strings 30. The plurality of solar cell strings 30 are arranged, for example, in the X direction. Each of the plurality of solar cell strings 30 includes, for example, a plurality (here, five) solar cell elements 31 and a plurality of first wiring materials 32. In each solar cell string 30, the plurality of solar cell elements 31 are arranged, for example, in the Y direction. The plurality of first wiring materials 32 are in a state where, for example, two adjacent solar cell elements 31 among the plurality of solar cell elements 31 are electrically connected. The second wiring material 33 is in a state where two adjacent solar cell strings 30 among the plurality of solar cell strings 30 are electrically connected. In the example of Figures 1 and 2, the two third wiring materials 34 are each connected to the two solar cell strings 30. The third wiring material 34 connected to the solar cell string 30 located at the furthest -X direction end, and the third wiring material 34 connected to the solar cell string 30 located at the furthest +X direction end, are both extended to the outside of the solar cell panel 10.

[0032] Each of the multiple solar cell elements 31 can convert light energy into electrical energy. Each of the multiple solar cell elements 31 has a surface located on the front side (also called the first element surface 31f) and a surface on the opposite side of the first element surface 31f (also called the second element surface 31s). In the example in Figure 2, the first element surface 31f is facing in the +Z direction, and the second element surface 31s is facing in the -Z direction. In this case, for example, the first element surface 31f mainly acts as the surface to which light is incident (also called the light-receiving surface), and the second element surface 31s mainly acts as the surface to which light is not incident (also called the non-light-receiving surface).

[0033] In the first embodiment, as shown in Figures 3 and 4, each of the plurality of solar cell elements 31 includes a semiconductor substrate 310, a first output electrode 311, a first current collector electrode 312, a second output electrode 313, and a second current collector electrode 314. Here, Figure 3 is a diagram showing an example of the structure when the first element surface of the solar cell element is viewed from above. Figure 4 is a diagram showing an example of the structure when the second element surface of the solar cell element is viewed from above.

[0034] The semiconductor substrate 310 can be made of, for example, a crystalline semiconductor such as crystalline silicon, an amorphous semiconductor such as amorphous silicon, or a compound semiconductor using four elements such as copper, indium, gallium, and selenium, or two elements such as cadmium and tellurium. Here, we assume that crystalline silicon is used for the semiconductor substrate 310. In this case, the semiconductor substrate 310 mainly has a region having a first conductivity type (also called the first conductivity type region) and a region having a second conductivity type opposite to the first conductivity type (also called the second conductivity type region). The first conductivity type region is located, for example, on the second element surface 31s side in the -Z direction of the semiconductor substrate 310. The second conductivity type region is located, for example, on the surface layer on the first element surface 31f side in the +Z direction of the semiconductor substrate 310. Here, for example, if the first conductivity type is p-type, the second conductivity type will be n-type. Also, for example, if the first conductivity type is n-type, the second conductivity type will be p-type. As a result, the semiconductor substrate 310 has a pn junction located at the interface between the first conductivity type region and the second conductivity type region. The thickness of the semiconductor substrate 310 is, for example, about 0.15 mm to 0.5 mm.

[0035] The first output electrodes 311 and the first current collector electrodes 312 are located, for example, on the surface of the semiconductor substrate 310 on the first element surface 31f side. For example, a busbar electrode is applied to the first output electrodes 311. For example, a finger electrode is applied to the first current collector electrodes 312. In the example of Figure 3, five substantially parallel first output electrodes 311 are located on the first element surface 31f side of the semiconductor substrate 310, and a number of substantially parallel first current collector electrodes 312 are located substantially perpendicular to the five first output electrodes 311. In the example of Figure 3, each of the first output electrodes 311 has an elongated shape that is long in the Y direction, and each of the first current collector electrodes 312 has a linear shape that is long in the X direction. Furthermore, in the region of the semiconductor substrate 310 where the first output electrode 311 and the first current collector electrode 312 are not formed, an insulating film as an anti-reflective film 315, for example, made of silicon nitride, may be located. Here, for example, if the main component of the first output electrode 311 is silver, the first output electrode 311 can be formed by applying silver paste to a desired shape using screen printing or the like, and then firing it. The main component refers to the component that has the largest (highest) proportion (also called the content rate) among the contained components. For example, the silver paste can be a metal paste containing silver as the main component, an organic vehicle, and glass frit. For example, if the main component of the first current collector electrode 312 is silver, the first current collector electrode 312 can be formed by applying silver paste to a desired shape using screen printing or the like, and then firing it. The first output electrode 311 and the first current collector electrode 312 may be formed in separate processes or in the same process.

[0036] The second output electrode 313 and the second current collector electrode 314 are located, for example, on the second element surface 31s side of the semiconductor substrate 310. For example, a busbar electrode is applied to the second output electrode 313. In the example of Figure 4, five rows of second output electrodes 313 are located on the second element surface 31s side of the semiconductor substrate 310, substantially parallel to each other along the +Y direction. The second current collector electrode 314 is located on the second element surface 31s side of the semiconductor substrate 310, covering substantially the entire area where the second output electrodes 313 are not formed, except for the portion where the second output electrodes 313 and the second current collector electrode 314 are connected by overlapping. Each of the five rows of second output electrodes 313 includes, for example, four electrodes arranged in a row. Furthermore, for example, a thin film of an oxide or nitride such as aluminum oxide may exist as a passivation film in a desired pattern between the first conductivity type region of the semiconductor substrate 310 and the second output electrode 313 and the second current collector electrode 314. Here, for example, if the main component of the second output electrode 313 is silver, the second output electrode 313 can be formed by applying silver paste in a desired shape by screen printing or the like and then firing it. For example, if the main component of the second current collector electrode 314 is aluminum, the second current collector electrode 314 can be formed by applying aluminum paste in a desired shape by screen printing or the like and then firing it. For example, the aluminum paste may be a metal paste containing metal powder with aluminum as the main component, an organic vehicle and glass frit.

[0037] The first wiring material 32 is electrically connected, for example, to the first output electrode 311 of one solar cell element 31 and to the second output electrode 313 of another solar cell element 31 adjacent to this first solar cell element 31. In the examples of Figures 3 and 4, the outer edges of the multiple first wiring materials 32 attached to each of the solar cell elements 31 are virtually depicted by dashed lines. In the examples of Figures 1 to 4, the first wiring material 32 has an elongated shape that is long in the Y direction. Here, the first wiring material 32 is joined to, for example, the first output electrode 311 and the second output electrode 313. Specifically, for example, there is a portion (also called the first joining portion 321) located between the first wiring material 32 and the first output electrode 311 that joins the first wiring material 32 and the first output electrode 311. Therefore, for example, the first wiring material 32 is joined to the first output electrode 311 of one solar cell element 31 via the first junction portion 321. Also, for example, there is a portion (also called the second junction portion 322) located between the first wiring material 32 and the second output electrode 313 that joins the first wiring material 32 and the second output electrode 313. Therefore, for example, the first wiring material 32 is joined to the second output electrode 313 of another solar cell element 31 adjacent to one solar cell element 31 via the second junction portion 322. For example, a linear or strip-shaped conductive metal body is applied to the first wiring material 32. For example, the material of the first junction portion 321 and the second junction portion 322 is an alloy with a low melting point such as solder or a single metal with a low melting point. More specifically, for example, a copper foil having a thickness of about 0.1 mm to 0.2 mm and a width of about 1 mm to 2 mm is applied to the first wiring material 32, and the entire surface of the first wiring material 32 is covered with solder. The first wiring material 32 is electrically connected to the first output electrode 311 and the second output electrode 313, for example, by soldering. In this case, for example, the solder located between the first wiring material 32 and the first output electrode 311 constitutes the first joint portion 321. Also, for example, the solder located between the first wiring material 32 and the second output electrode 313 constitutes the second joint portion 322.

[0038] <Filling material> The filler material 4 covers the solar cell portion 3 between the surface protective layer 1 and the back protective layer 2. More specifically, it covers multiple solar cell elements 31 between the front reinforcing layer 12 and the back reinforcing layer 9.

[0039] The filler material 4 has a first surface 4f located on the front side and a second surface 4s located on the opposite side from the first surface 4f. The first surface 4f of the filler material 4 is in contact with the second surface 12s of the front reinforcing layer 12, and the second surface 4s of the filler material 4 is in contact with the back reinforcing layer 9.

[0040] In the first embodiment, the filler 4 includes, for example, a filler located on the front surface 10f side (also referred to as the first filler 41) and a filler located on the back surface 10b side (also referred to as the second filler 42). The first filler 41 is, for example, in a state that constitutes the first surface 4f and covers the entire surface of the solar cell section 3 on the surface protection layer 1 side. In other words, the first filler 41 is, for example, in a state that covers the multiple solar cell elements 31 between the surface protection layer 1 and the multiple solar cell elements 31. The second filler 42 is, for example, in a state that constitutes the second surface 4s and covers the entire back surface of the solar cell section 3 on the back protection layer 2 side. In other words, the second filler 42 is, for example, in a state that covers the multiple solar cell elements 31 between the back protection layer 2 and the multiple solar cell elements 31. Therefore, in the first embodiment, the solar cell section 3 is, for example, surrounded by being sandwiched between the first filler 41 and the second filler 42. This allows the orientation of the solar cell section 3 to be maintained by the filler material 4, for example. The thickness of the first filler material 41 can be, for example, 0.6 mm, and the thickness of the second filler material 42 can be, for example, 0.6 mm.

[0041] Furthermore, the filler 4 has, for example, light-transmitting properties. Here, the filler 4 has, for example, light-transmitting properties to light of a specific range of wavelengths as described above. Here, for example, if at least the first filler 41 of the first filler 41 and second filler 42 constituting the filler 4 has light-transmitting properties, incident light from the front surface 10f can reach the solar cell section 3.

[0042] The material for the first filler 41 can be, for example, polyvinyl acetal such as IO, EVA, POE, and polyvinyl butyral (PVB), and acid-modified resins. Here, IO is a thermoplastic resin obtained by introducing a small amount of ionic groups into the backbone of low-density polyethylene as a host polymer, thereby crosslinking some of the molecules. As ionic groups, metal ions such as sodium ions, zinc ions, potassium ions, and magnesium ions can be used. The ionic groups form ionic aggregates and act as pseudocrosslinking points, thereby imparting various physical properties to the host polymer. Such IO has, for example, high melt tension, melt viscosity, and transparency. When the material is IO, the Young's modulus of the filler 4 is about 0.285 GPa.

[0043] Furthermore, if, for example, relatively inexpensive EVA is used as the material for the first filler 41, the ability to protect multiple solar cell elements 31 can be easily achieved. For example, the acid-modified resin can be a modified polyolefin resin that can be formed by graft modification with an acid on a resin such as polyolefin. Acids that can be used for graft modification of the acid-modified resin can be, for example, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, hymic anhydride, itaconic anhydride, and citraconic anhydride. For example, the material for the second filler 42 can be polyvinyl acetal such as EVA and PVB, and an acid-modified resin. The first filler 41 and the second filler 42 may be composed of, for example, two or more types of materials.

[0044] The second filler 42 may contain, for example, a pigment. If, for example, a white pigment is included, the light transmitted through the solar cell section 3 can be reflected by the second filler 42 and re-entered into the solar cell section 3. This can improve the power generation efficiency of the solar cell module 100.

[0045] <Reinforced layer on the back> The back reinforcing layer 9 is, for example, a layer made of resin. The back reinforcing layer 9 has, for example, a first surface 9f and a second surface 9s located on the opposite side of the first surface 9f. The first surface 9f of the back reinforcing layer 9 faces the filler material 4. The second surface 9s of the back reinforcing layer 9 faces the back protective layer 2 via the adhesive layer 7. The first surface 9f of the back reinforcing layer 9 is covered with the filler material 4. The direction connecting the front reinforcing layer 12 and the back reinforcing layer 9 corresponds to the Z direction, and the front reinforcing layer 12 and the back reinforcing layer 9 are laminated in the Z direction with other layers in between.

[0046] The thickness of the back reinforcement layer 9 is approximately 0.3 mm to 2 mm. The materials constituting the back reinforcement layer 9 may include, for example, PET, polyvinyl fluoride (PVF), or polyethylene naphthalate (PEN). The back reinforcement layer 9 may also be a laminated structure of multiple materials. For example, the back reinforcement layer 9 may be a laminated structure of PET and POE. For example, in the case of a laminated structure of PET and POE, the Young's modulus of the back reinforcement layer 9 is approximately 2.0 GPa, and the bending stiffness is b × 4.5 × 10 for thicknesses ranging from 0.3 mm to 2 mm. -3 from b × 1.3 [Pa·m 4 It is approximately [this value]. The Young's modulus of the back-side reinforcing layer 9 is higher than that of the filler material 4. Furthermore, the bending rigidity of the back-side reinforcing layer 9 is the highest among the configurations of the solar cell panel 10 that are located on the back-side protective layer 2 side of the solar cell elements 31.

[0047] <Adhesive layer> The adhesive layer 7 is, for example, a layer that adheres the back-side reinforcing layer 9 and the back-side protective layer 2. The adhesive layer 7 has, for example, a first surface 7f and a second surface 7s located on the opposite side of the first surface 7f (see Figure 2). The first surface 7f of the adhesive layer 7 is, for example, adhered to the second surface 9s of the back-side reinforcing layer 9.

[0048] The thickness of the adhesive layer 7 is, for example, about 0.1 mm to 0.5 mm. The material constituting the adhesive layer 7 may be, for example, IO, EVA, or POE. The adhesive layer 7 may also be made of the same material as the filler 4.

[0049] <Back protective layer> The back protective layer 2 is, for example, in a state where it constitutes the back surface 10b of the solar cell panel 10. The back protective layer 2 is bonded to the back reinforcing layer 9 via the adhesive layer 7. The back protective layer 2 has, for example, a first surface 2f and a second surface 2s located on the opposite side of the first surface 2f (see Figure 2).

[0050] The back protective layer 2 can, for example, protect the solar cell section 3 from the back surface 10b side. For example, a backsheet that constitutes the back surface 10b is applied to the back protective layer 2. The thickness of the backsheet is approximately 0.15 mm to 0.5 mm.

[0051] For example, resin can be used as the material for the backsheet. The resin can be, for example, the same material as the surface protective layer 1. When viewed from the back surface 10b side, the back protective layer 2 has the same or a similar shape as the surface protective layer 1. For example, when viewed from the back surface 10b side, both the surface protective layer 1 and the back protective layer 2 are assumed to have a rectangular outer shape. The corners of the rectangular back protective layer 2 may be chamfered as appropriate.

[0052] Furthermore, if either the material of the back protective layer 2 or the material of the back reinforcing layer 9 is a material that can be fused to an adjacent layer by heating during the lamination process, then the adhesive layer 7 may not be provided.

[0053] <Manufacturing method for solar cell modules> Next, an example of a method for manufacturing the solar cell module 100 will be described based on Figures 5 to 7. Here, Figures 5 to 7 are diagrams illustrating the cross-sectional state during the manufacturing process of the solar cell module according to the first embodiment. Note that the thickness of each layer in Figures 5 to 7 is illustrative and may not be the same as that of the actual layers, including their relative sizes.

[0054] First, a surface protection layer 1 is prepared. Here, for example, a rectangular surface protection layer 1 is prepared, which is a resin film with weather resistance on both sides. As the weather-resistant resin, for example, a fluoropolymer resin is used. As a fluoropolymer resin, for example, FEP, ETFE, or ECTFE is used. Here, for example, a surface activation treatment such as corona treatment or plasma treatment is applied to the second surface 1s, which is one side of the surface protection layer 1. This can improve the adhesion between the surface protection layer 1 and the filler 4 in the lamination process described later.

[0055] Next, as shown in Figures 7 and 8, for example, a laminate 10s is formed by stacking a surface protective layer 1, a sheet 131, a front-side reinforcing layer 12, a sheet 41s, a solar cell section 3, a sheet 42s, a back-side reinforcing layer 9, a sheet 71, and a back-side protective layer 2.

[0056] In the laminate 10s, the multiple solar cell elements 31 of the solar cell section 3 are positioned with spacing between them in the X direction. At this time, wiring is appropriately arranged to be drawn out from the solar cell section 3 to the outside of the solar cell panel 10 and connected to a terminal box or the like. For example, the multiple solar cell elements 31 of the solar cell section 3 are interconnected by a first wiring material 32 and a second wiring material 33. In addition, a third wiring material 34 is connected to the solar cell section 3.

[0057] Sheet 131 is a sheet made of resin (such as IO or EVA). Sheet 131 may be made of the same material as sheets 41s or 42s. Sheet 131 is located between the surface protective layer 1 and the surface reinforcing layer 12.

[0058] The sheet 41s is a sheet made of resin (such as IO or EVA) that forms the basis of the first filler 41. The sheet 41s is located between the front reinforcing layer 12 and the solar cell section 3. In other words, the sheet 41s is located on top of the front reinforcing layer 12, and the solar cell section 3 is located on top of the sheet 41s. In a plan view, the sheet 41s has a rectangular shape, which is an example of a square shape.

[0059] Sheet 42s is a sheet made of resin (such as IO or EVA) that forms the basis of the second filler 42. Sheet 42s may contain a pigment.

[0060] Sheet 42s is located between the back reinforcement layer 9 and the solar cell section 3. In a plan view, sheet 42s has a rectangular shape, which is an example of a square shape.

[0061] The back reinforcing layer 9 is, for example, a layer made up of multiple laminated resins. The back reinforcing layer 9 is located between sheet 71 and sheet 42s.

[0062] Sheet 71 is a sheet made of resin (such as IO or EVA). Sheet 71 may be made of the same material as sheet 131, sheet 41s, or sheet 42s. Sheet 71 is located between the back protective layer 2 and the back reinforcing layer 9. The back protective layer 2 is located on top of sheet 71.

[0063] Next, for example, a lamination process is performed on the laminate 10s. Here, for example, a laminating device (laminator) is used to integrate the laminate 10s. For example, in a laminator, the laminate 10s is placed on a heater plate in the chamber, and the chamber is depressurized from 50 Pascals (Pa) to about 150 Pa while the laminate 10s is heated from 100 degrees Celsius (100°C) to about 200 degrees Celsius (200°C). At this time, the sheets 131, 41s, 42s and 71 become somewhat fluid due to the heating. In this state, the laminate 10s is integrated by pressing it in the Z direction with a pressing body such as a diaphragm sheet inside the chamber.

[0064] After lamination, terminal boxes and other components may be attached to the solar panel 10 as appropriate. At this time, for example, the wiring that has been brought out from the solar cell section 3 to the outside of the solar panel 10 is connected to the terminals inside the terminal box as appropriate. This completes the assembly of the solar module 100.

[0065] <Layered structure> Figure 8 is a cross-sectional view showing an example of the laminated structure of region RA in Figure 2. The filler material 4, which is filled between the front reinforcing layer 12 and the back reinforcing layer 9, is filled in a state where it is integrated within the region. In Figure 8, however, the dotted line indicates a hypothetical boundary line between the sheets 41s and 42s before lamination, which will become the filler material 4 after lamination.

[0066] The stacked configuration shown in Figure 8 can improve the impact resistance of the solar cell module 100. Specifically, this is as follows:

[0067] The types of damage that occur in the solar cell module 100 when an incoming object collides with it mainly include Hertz fracture, which is caused by the propagation of shock waves from the impact, and bending fracture, which is caused by tensile and compressive stress resulting from the bending of the solar cell module 100 due to the impact.

[0068] Of the above, if we assume that hail is the object that flies onto the solar cell module 100, it is presumed that the damage caused by the hailstorm is likely to be bending fracture.

[0069] When hailstones with a diameter of approximately 50 mm fall, their free-fall velocity is limited by air resistance, and is thought to be limited to, for example, around 100 km / h to 120 km / h. Also, because hailstones have relatively low hardness, they shatter upon impact with the solar cell module 100, and their kinetic energy is consumed. From these considerations, it is thought that the shock wave propagated to the solar cell module 100 when the hailstones collide with it is small, and therefore, as mentioned above, it is presumed that the fracture caused by the hailstorm is likely to be flexural fracture.

[0070] In the stacked configuration shown in Figure 8, the Young's modulus of the front-side reinforcing layer 12, located on the +Z side of the solar cell element 31, is greater than that of the back-side reinforcing layer 9. This makes it less likely for the front-side reinforcing layer 12 to undergo instantaneous expansion and contraction when falling objects such as hailstones fall. As a result, irregularities are less likely to occur on the contact surface with the falling object (specifically, the first surface 1f of the surface protection layer 1 supported by the front-side reinforcing layer 12). In other words, bending fracture is less likely to occur on the side of the solar cell module 100 that collides with the falling object, and Hertz fracture is relatively more likely to occur. To put it another way, bending fracture is less likely to occur on the +Z side of the solar cell element 31, and Hertz fracture is relatively more likely to occur.

[0071] As mentioned above, damage caused by falling objects such as hail is unlikely to be Hertz fracture in the first place, but if the resulting damage is Hertz fracture, the area over which cracks may occur can be narrowed and limited compared to when bending fracture occurs. Cracks caused by bending fracture have a large contact area with the falling object, and because the falling object decelerates while the solar cell module 100 is bending, radial cracks tend to extend over a wide area.

[0072] Furthermore, in the laminated configuration shown in Figure 8, the Young's modulus of the front reinforcing layer 12 is large, which allows for a reduction in the thickness of the front reinforcing layer 12 necessary to achieve the above effects. Therefore, the transmittance of the layer configuration in the +Z direction of the solar cell element 31 can be increased, thereby improving the power generation efficiency of the solar cell element 31.

[0073] On the other hand, on the side of the solar cell module 100 opposite to the side that collides with the falling object, static bending deformation may predominantly occur. In other words, on the -Z direction side of the solar cell element 31, static bending deformation may predominantly occur.

[0074] In contrast, in the stacked configuration shown in Figure 8, the back-side reinforcing layer 9 is provided on the -Z side of the solar cell element 31. The bending rigidity of the back-side reinforcing layer 9 is higher than that of the front-side reinforcing layer 12. As a result, the high bending rigidity of the back-side reinforcing layer 9 keeps the area flat against static bending deformation that may occur in the -Z side of the solar cell element 31, thereby suppressing bending deformation in the solar cell element 31 cells.

[0075] Here, the bending fracture that can occur when falling objects such as hailstones fall is thought to occur with respect to the neutral axis in the Z direction of the laminated structure shown in Figure 8. Compressive stress is generated in the range in the +Z direction from the neutral axis, and tensile stress is generated in the range in the -Z direction from the neutral axis. The neutral axis is, for example, any axis along the XY plane in Figure 8, or an axis extending in a direction perpendicular to the Z direction.

[0076] In contrast, solar cell elements 31, which are mainly made of silicon, are more prone to cracking under tensile stress than under compressive stress.

[0077] Therefore, in the stacked configuration shown in Figure 8, the solar cell elements 31 are positioned in the +Z direction range from the neutral axis (in other words, closer to the surface protective layer 1 than the neutral axis). This makes it possible to suppress the occurrence of cracks in the solar cell elements 31.

[0078] Figure 9 shows an example of calculating the neutral axis in the Z direction. Here, the solar cell module 100 is treated as a combined beam, and the neutral axis 300 in the Z direction is calculated.

[0079] When subjected to a bending moment, if the radius of curvature at the neutral axis 300 is ρ, the axial normal stress (axial stress) is given by Hooke's Law as shown in equation (1) below. Here, the axial direction refers to the direction along the XY plane.

[0080]

number

[0081] Here, σ represents the axial stress, E represents Young's modulus, and y represents the distance from an arbitrary position to the neutral plane (with the -Z direction being the positive direction).

[0082] Furthermore, considering each layer in the laminated structure, it can be expressed as shown in equation (2) below.

[0083]

number

[0084] Here, the subscripts σ, E, and y correspond to each layer constituting the laminated structure (surface protective layer 1, adhesive layer 13, front side reinforcing layer 12, filler 4, solar cell element 31, back side reinforcing layer 9, adhesive layer 7, and back side protective layer 2).

[0085] Since the sum of axial stresses when subjected to a bending moment is zero, it can be expressed as shown in equation (3) below.

[0086]

number

[0087] Here, S is as shown in equation (4) below. i When defining S iIt corresponds to the first moment of inertia of each layer with respect to the neutral axis 300. In addition, Ai in equations (3) and (4) indicates the integration region and represents integration over the range of each layer constituting the laminated structure.

[0088]

Number

[0089] Therefore, the following equation (5) is derived.

[0090]

Number

[0091] Here, if (S i ) Z is taken as the first moment of inertia of each layer in the Z direction, equation (4) becomes as follows.

[0092]

Number

[0093] Here, y z in equation (6) represents the distance from the first surface 1f of the surface protection layer 1 to an arbitrary position when the -Z direction is taken as the positive direction. Furthermore, substituting equation (6) into equation (4), equation (7) is obtained.

[0094]

Number

[0095] From equation (7), the distance from the first surface 1f of the surface protection layer 1 to the neutral plane (neutral axis 300) is expressed as the following equation (8).

[0096]

Number

[0097] Here, in equation (8)

[0098]

number

[0099] This indicates the distance from the first surface 1f of the surface protective layer 1 to the neutral plane (neutral axis 300).

[0100] <Second Embodiment> A solar cell module according to this embodiment will now be described. In the following description, components that are the same as or similar to those described in the embodiments described above will be denoted by the same reference numerals, and their detailed descriptions will be omitted as appropriate.

[0101] <Layered structure> Figure 10 is a cross-sectional view showing an example of a laminated configuration according to the second embodiment. Figure 10 corresponds to another example of the laminated configuration of region RA in Figure 2.

[0102] In the configuration shown in Figure 10, a fiber layer 8 is provided in addition to the configuration shown in Figure 8. The filler material 4, which is filled between the front reinforcing layer 12 and the back reinforcing layer 9, is filled in a state where it is integrated within that region. In Figure 10, however, a dotted line indicates a virtual boundary between the sheets 41s and 42sa before lamination, which will become the filler material 4 after lamination. Here, sheets 42sa and 42sb are stacked in the order of sheet 42sa, fiber layer 8, and sheet 42sb before lamination, and are formed by lamination with the fiber layer 8 sandwiched in between.

[0103] <Fiber layer> The fiber layer 8 is a layer formed, for example, by impregnating at least a portion of the gaps between the fiber material with an impregnating material. The fiber material and impregnating material of the fiber layer 8 may be the same as or different from the fiber material and impregnating material of the front reinforcing layer 12. The fiber layer 8 has, for example, a first surface 8f and a second surface 8s located on the opposite side of the first surface 8f. The first surface 8f of the fiber layer 8 is facing the solar cell element 31. The second surface 8s of the fiber layer 8 is facing the back reinforcing layer 9. The first surface 8f and the second surface 8s of the fiber layer 8 are covered with a filler material 4. The fiber layer 8 is formed, for example, by impregnating the fiber material with a fluid resin during a lamination process. In the fiber layer 8 formed after the lamination process, voids (spaces) where the resin is not impregnated may be partially formed in the gaps between the fiber material.

[0104] The thickness of the fiber layer 8 is approximately 0.01 mm to 0.1 mm. The fiber material included in the fiber layer 8 may be, for example, glass fiber or carbon fiber. The impregnating material used to impregnate the fiber material may be, for example, IO, epoxy resin, EVA, POE, or polymethyl methacrylate resin. The impregnating material impregnating the fiber material in the fiber layer 8 prevents the movement of air from the back protective layer 2 side to the front protective layer 1 side.

[0105] The stacked configuration shown in Figure 10 can improve the impact resistance of the solar cell module.

[0106] Specifically, because the fiber layer 8 is positioned between the solar cell element 31 and the back-side reinforcing layer 9, the fiber layer 8 has higher bending rigidity than the filler material 4, allowing the fiber layer 8 to support the solar cell element 31 flatly from the -Z direction. Therefore, the total bending rigidity on the -Z direction side of the solar cell element 31 can be increased, which can suppress deflection in the solar cell module when a localized load is applied to the solar cell module, such as by hailstorms. This ensures that bending failure in the solar cell element 31 is reliably suppressed.

[0107] <Third Embodiment> A solar cell module according to this embodiment will now be described. In the following description, components that are the same as or similar to those described in the embodiments described above will be denoted by the same reference numerals, and their detailed descriptions will be omitted as appropriate.

[0108] <Layered structure> Figure 11 is a cross-sectional view showing an example of a laminated configuration according to the third embodiment. Figure 11 corresponds to another example of the laminated configuration of region RA in Figure 2.

[0109] In the configuration shown in Figure 11, a support member 5 is provided in addition to the configuration shown in Figure 8. The filler material 4 filled between the front reinforcing layer 12 and the back reinforcing layer 9 is filled in a state where it is integrated in that region, but in Figure 11, the imaginary boundary line between the sheets 41s and 42s before lamination, which will become the filler material 4 after lamination, is shown by a dotted line.

[0110] <Support member> The support member 5 is a component for improving the rigidity of the solar cell panel 10, and has higher rigidity than, for example, the surface protective layer 1, the back protective layer 2, and the filler material 4. The material of the support member 5 can be, for example, metal, and more specifically, aluminum or stainless steel can be used. The support member 5 has, for example, a first surface 5f and a second surface 5s located on the opposite side of the first surface 5f.

[0111] In a plan view, the support member 5 is positioned adjacent to the solar cell section 3 with a gap between them. In other words, in a plan view, the support member 5 is positioned so as not to overlap with the solar cell element 31. The support member 5 is positioned between the front reinforcing layer 12 and the back protective layer 2, covered by the filler material 4. In other words, the support member 5 is facing the front reinforcing layer 12 in the Z direction, and is also facing the back protective layer 2 in the Z direction, and is covered by the filler material 4.

[0112] In the example shown in Figure 11, the support member 5 has a plate-like shape and a rectangular shape in plan view. In the example shown in Figure 11, the ZX cross-section of the support member 5 also has a rectangular shape. The corners of the support member 5 may be chamfered as appropriate. The longitudinal direction of the support member 5 (here, the Y direction) is, for example, along one side of the surface protection layer 1 or one side of the front reinforcing layer 12. The longitudinal direction of the support member 5 is also, for example, along the arrangement direction (here, the Y direction) of the multiple solar cell elements 31 included in one solar cell string 30. In other words, the longitudinal direction of the support member 5 is, for example, along the longitudinal direction (here, the Y direction) of the first wiring material 32.

[0113] In the example shown in Figure 11, the solar cell panel 10 is provided with one support member 5 along each of two opposing sides of the front reinforcing layer 12 in a plan view. In other words, the solar cell panel 10 is provided with one support member 5 along each of two opposing sides of the surface protective layer 1 in a plan view. That is, a support member 5 is also provided at the opposite end (one side) of the front reinforcing layer 12, which is not shown. The two support members 5 are each positioned along both sides of the surface protective layer 1 located on both sides in the X direction. The sides located on both sides in the X direction here include one side (first side) extending along the Y direction at the -X direction end of the surface protective layer 1, and one side (second side) extending along the Y direction at the +X direction end. In other words, the first support member of the support member 5 located on the -X direction side is located at the -X direction end of the surface protection layer 1 and has a rectangular shape with its longitudinal direction being the Y direction, and the second support member of the support member 5 located on the +X direction side is located at the +X direction end of the surface protection layer 1 and has a rectangular shape with its longitudinal direction being the Y direction. The length of the support member 5 in the longitudinal direction (here, the Y direction) is approximately equal to, for example, the length of the surface protection layer 1 or the length of the front reinforcement layer 12. However, the support member 5 may extend along the entire side of the front reinforcement layer 12, or it may be located partially (for example, intermittently) along one side of the front reinforcement layer 12. The width of the support member 5 in the short direction (here, the X direction) is set to, for example, several tens of mm or more. The thickness of the support member 5 is greater than the thickness of the solar cell part 3, for example, set to about 1 mm to 5 mm. Also, if the support member 5 is made of aluminum alloy, the Young's modulus of the support member 5 is, for example, about 70 GPa.

[0114] The distance between the surface protective layer 1 and the back protective layer 2 increases in the area where the support member 5 is placed. More specifically, the back protective layer 2 is positioned such that the distance from the surface protective layer 1 increases as it approaches the support member 5.

[0115] The stacked configuration shown in Figure 11 can improve the impact resistance of the solar cell module.

[0116] By arranging a pair of support members 5 along two opposing sides of the front reinforcing layer 12, the deformation of the solar cell element 31 tends to become monoconvex. A monoconvex surface here refers to a curved surface (prismatic surface) such as a part of the curved surface of a cylinder, and in the case of Figure 11, it is a curved surface between the pair of support members 5 where the displacement in the -Z direction increases as the distance from the support members 5 increases.

[0117] For example, in the case of hailstorms, when hailstones collide with a solar cell module, a complex curved surface may be formed that bends in a hemispherical shape around the point of impact. Here, a complex curved surface is a surface that is not a linear surface, and is not a surface that can be represented as the trajectory of a straight line (called a generatrix) that moves smoothly with a single degree of freedom parameter.

[0118] When the solar cell elements 31 within the solar cell module deform to conform to a curved surface, the solar cell elements 31, being made of, for example, silicon, have extremely low elasticity and are prone to cracking.

[0119] In contrast, according to the laminated configuration shown in Figure 11, a pair of support members 5 are arranged along two opposing sides. In other words, a pair of support members 5 are arranged along each side extending in the Y direction, located on both sides of the X direction of the front reinforcing layer 12. Therefore, when hail or other debris collides with the solar cell module, the resulting deflection tends to form a simple curved surface, with the longitudinal direction of the highly rigid support member 5 being the prismatic direction of the cylinder.

[0120] The solar cell element 31 is less prone to cracking when deformed to conform to a single curved surface than when deformed to conform to multiple curved surfaces. Therefore, it is possible to suppress the occurrence of cracks in the solar cell element 31 when it is struck by hail or other debris.

[0121] In addition, in Figure 11, the fiber layer 8 shown in Figure 10 may be further provided.

[0122] This disclosure includes the following:

[0123] (1) In one embodiment, the solar cell module comprises a light-transmitting resin surface protective layer, a back-side reinforcing layer, a solar cell element disposed between the surface protective layer and the back-side reinforcing layer, a light-transmitting front-side reinforcing layer disposed between the surface protective layer and the solar cell element, and a filler material that covers the solar cell element and is filled between the back-side reinforcing layer and the front-side reinforcing layer, wherein the Young's modulus of the front-side reinforcing layer is greater than the Young's modulus of the back-side reinforcing layer, and the bending rigidity of the back-side reinforcing layer is higher than the bending rigidity of the front-side reinforcing layer.

[0124] (2) In the solar cell module described in (1) above, the solar cell elements may be positioned closer to the surface protective layer than the neutral axis in the direction connecting the surface protective layer and the back side reinforcing layer.

[0125] (3) In the solar cell module described in (1) or (2) above, the front reinforcing layer is a first fiber layer in which the first impregnating material is impregnated into the first fiber material, and the Young's modulus of the first impregnating material may be greater than the Young's modulus of the filler material.

[0126] (4) The solar cell module described in any one of (1) to (3) above may further include a second fiber layer disposed between the solar cell element and the back side reinforcing layer, wherein the second fiber material is impregnated with the second impregnation material.

[0127] (5) The solar cell module described in any one of (1) to (4) above has a first side and a second side which are two opposing sides of the surface protective layer, and further comprises a first support member arranged along the first side and a second support member arranged along the second side, wherein the surface protective layer is rectangular in shape in plan view, and the Young's modulus of both the first support member and the second support member may be greater than the Young's modulus of the front side reinforcing layer and the Young's modulus of the back side reinforcing layer. [Explanation of Symbols]

[0128] 1 Surface protective layer 4 Filling material 5. Support Member 8 fiber layers 9. Reinforcement layer on the back 12 Front reinforcement layer 31 Solar cell elements 100 solar modules 300 Neutral axis

Claims

1. A translucent resin surface protective layer, Reinforcement layer on the back, A solar cell element is disposed between the surface protective layer and the back reinforcement layer, Displaced between the surface protective layer and the solar cell element, and having light-transmitting surface reinforcement layer, The solar cell element is covered by a filler material which is filled between the back-side reinforcing layer and the front-side reinforcing layer. The Young's modulus of the front reinforcing layer is greater than that of the back reinforcing layer. The bending rigidity of the back-side reinforcing layer is higher than that of the front-side reinforcing layer. Solar cell module.

2. The solar cell module according to claim 1, The solar cell element is positioned closer to the surface protective layer than the neutral axis in the direction connecting the surface protective layer and the back side reinforcing layer. Solar cell module.

3. A solar cell module according to claim 1 or 2, The aforementioned surface reinforcing layer is a first fiber layer in which the first fiber material is impregnated with the first impregnation material. The Young's modulus of the first impregnating material is greater than the Young's modulus of the filler. Solar cell module.

4. A solar cell module according to claim 1 or 2, The second fiber material is impregnated with the second impregnation material, and the second fiber layer is further disposed between the solar cell element and the back side reinforcing layer. Solar cell module.

5. A solar cell module according to claim 1 or 2, The surface protective layer has a first side and a second side which are two opposing sides, The system further comprises a first support member positioned along the first side and a second support member positioned along the second side. The aforementioned surface protective layer has a rectangular shape in plan view. The Young's modulus of both the first support member and the second support member is greater than the Young's modulus of the front reinforcing layer and the Young's modulus of the back reinforcing layer. Solar cell module.

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