Solar cell modules

Abstract

To improve the durability of solar cell modules against various installation environments. [Solution] The solar cell module comprises a surface protective layer, a fiber-reinforced plastic layer in which a first impregnating material is impregnated into a first fiber material, a solar cell element disposed between the surface protective layer and the fiber-reinforced plastic layer with its light-receiving surface facing the surface protective layer, a translucent glass fiber layer disposed between the surface protective layer and the solar cell element in which a second impregnating material is impregnated into the glass fibers, and a filler. The glass fibers contain 1 wt% or less of alkali metals or do not contain alkali metals.

Description

Technical Field

[0001] This disclosure relates to a solar cell module.

Background Art

[0002] A solar cell module in which a plurality of solar cells are positioned between a front surface member and a back surface member is known (see, for example, the description of Patent Document 1). In this solar cell module, the structural rigidity is increased to suppress a decrease in power generation ability.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is room for improvement from the viewpoint of enhancing the durability of the solar cell module against the installation environment.

Means for Solving the Problems

[0005] A solar cell module is disclosed.

[0006] One aspect of the solar cell module includes a resin-made surface protection layer having translucency, a fiber reinforced plastic layer in a state where a first impregnating material is impregnated in a first fiber material, a solar cell element disposed between the surface protection layer and the fiber reinforced plastic layer and having a light receiving surface facing the surface protection layer, a translucent glass fiber layer disposed between the surface protection layer and the solar cell element in a state where a second impregnating material is impregnated in glass fibers, and a filler filled between the fiber reinforced plastic layer and the glass fiber layer while covering the solar cell element. The glass fibers contain 1 wt% or less of an alkali metal or do not contain an alkali metal.

Advantages of the Invention

[0007] This can improve the durability of solar cell modules against various installation environments. [Brief explanation of the drawing]

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

[0009] As a phenomenon that reduces the durability of a solar cell module, for example, a crystalline silicon-based solar cell module, voltage-induced degradation (PID) is known.

[0010] PID is considered to occur when a high voltage is generated between the outer frame or protective layer of the solar cell module and the solar cell element for some reason, and when the voltage of the solar cell element is negative, sodium or the like contained in the protective layer or the like moves into the solar cell element. Also, it is said that conditions such as temperature, humidity or voltage affect it.

[0011] Therefore, the inventors of the present disclosure have created a technology that can suppress the occurrence of PID and improve the durability against the installation environment for solar cell modules. Regarding this, the first to fourth embodiments will be described below based on the drawings.

[0012] In the drawings, parts having the same or similar configurations and functions are denoted by the same reference numerals, and duplicate explanations 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 the +X direction, the long side direction of the front surface 10f is the +Y direction, and the normal direction of the front surface 10f perpendicular to both the +X direction and the +Y direction is 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 easily understand 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 both the case where only one of A and B is shown and the case where both A and B are shown as long as there is no contradiction.

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

[0016] <Solar Cell Module> FIG. 1 is a plan view showing an example of the appearance of a solar cell module according to the first embodiment in a plan view. Here, the plan view corresponds to the case where the solar cell module is viewed toward its main surface. Further, FIG. 2 is a view showing an example of a virtual cut surface along the Ib-Ib line of the solar cell module of FIG. 1. The region RA shown in FIG. 2 will be described later.

[0017] As shown in FIGS. 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 referred to as the front surface 10f) mainly for light incidence and a back surface 10b located on the opposite side of the front surface 10f. In the first embodiment, the front surface 10f is in a state facing the +Z direction, and the back surface 10b is in a state facing the -Z direction. The +Z direction is set, for example, in the direction facing the sun in the south. In the example of FIG. 1, the front surface 10f has a rectangular shape as an example of a quadrilateral shape. Note that the corners of the rectangular solar cell panel 10 may have a rounded shape.

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

[0019] As shown in FIGS. 1 and 2, the solar cell panel 10 includes, for example, a surface protection layer 1, an adhesive layer 13, a glass fiber layer 12, a solar cell portion 3, a filler 4, a fiber-reinforced plastic layer 6, and an adhesive layer 7. Further, the solar cell panel 10 may include a back surface protection layer 2.

[0020] <Surface Protection 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 have a rounded shape. 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 glass fiber layer 12 and the surface protection layer 1. The adhesive layer 13 has, for example, a first surface 13f and a second surface 13s located on the opposite side of 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 protection layer 1. The second surface 13s of the adhesive layer 13 is, for example, adhered to the first surface 12f of the glass fiber 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 protection layer 1 or the material of the glass fiber layer 12 is a material that can be fused to an adjacent layer by heating during the lamination process, then the adhesive layer 13 may not be provided.

[0028] <Glass fiber layer> The glass fiber layer 12 is a layer formed by impregnating at least a portion of the gaps between glass fibers, which are a fibrous material, with an impregnating material. Here, the glass fibers contain 1 wt% or less of alkali metals, or do not contain alkali metals. Alkali metals include, for example, sodium and potassium. Here, wt% is weight percentage, indicating the proportion (percentage) of a substance based on its mass contained in the composition, mixture, or solution. The glass fiber layer 12 is translucent. The glass fiber 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 glass fiber layer 12 has a rectangular shape as an example of a square shape. The corners of the glass fiber layer 12, which is square in plan view, may have a rounded shape. The first surface 12f of the glass fiber layer 12 is facing the surface protection layer 1 via the adhesive layer 13. The second surface 12s of the glass fiber layer 12 is facing the filler material 4. In other words, the second surface 12s of the glass fiber layer 12 is covered by the filler material 4. Also, the second surface 12s of the glass fiber layer 12 is facing the first element surface 31f of the solar cell element 31 via the filler material 4. The glass fiber layer 12 is, for example, sufficiently impregnated with an impregnating material such as resin in advance at a stage before forming a laminated structure by lamination.

[0029] The thickness of the glass fiber layer 12 is approximately 0.01 mm to 0.2 mm. Examples of impregnating materials used to fill the glass fibers include IO, epoxy resin, EVA, POE, or polymethyl methacrylate resin. The impregnating material in the glass fiber layer 12 prevents air from moving from the back protective layer 2 to the front protective layer 1.

[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. Alternatively, the solar cell section 3 is located, for example, between the surface protection layer 1 and the fiber-reinforced plastic layer 6. In other words, the solar cell section 3 is facing the surface protection layer 1 in the Z direction and also facing the fiber-reinforced plastic layer 6 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 planarly 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 the +Z direction, and the second element surface 31s is facing the -Z direction. The first element surface 31f faces the surface protective layer 1, and the second element surface 31s faces the fiber-reinforced plastic layer 6. 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). Each solar cell element 31 converts the light energy of light incident on the light-receiving surface into electrical energy.

[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 glass fiber layer 12 and the fiber-reinforced plastic layer 6.

[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 glass fiber layer 12, and the second surface 4s of the filler material 4 is in contact with the fiber-reinforced plastic layer 6.

[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 within the specific range of wavelengths 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, the main incident light from the front surface 10f can reach the solar cell section 3.

[0042] The material of the first filler 41 can be, for example, IO, EVA, POE, polyvinyl acetal such as polyvinyl butyral (PVB), and acid-modified resins. Here, the volume resistivity of IO is 1 × 10⁻⁶. 16 [Ω·m] or greater, and 1 × 10⁻⁶ 18 It is less than or equal to [Ω·m]. Also, the volume resistivity of EVA or POE is 1 × 10⁻⁶ 13 [Ω·m] or greater, and 1 × 10⁻⁶ 16 The density is less than or equal to [Ω·m]. Furthermore, IO is a thermoplastic resin formed by introducing a small amount of ionic groups into the backbone of a low-density polyethylene (as a host polymer) and crosslinking some of the molecules. 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.

[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 the acid-modified resin, for example, a modified polyolefin resin that can be formed by graft modification with an acid on a resin such as polyolefin can be used. Acids that can be used for graft modification of the acid-modified resin include, for example, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, hymic anhydride, itaconic anhydride, and citraconic anhydride. For the material of the second filler 42, for example, polyvinyl acetal such as IO, EVA, PVB, and acid-modified resin can be used. For example, the same material as the first filler may be used for the second filler 42. 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] <Fiber-reinforced plastic layer> The fiber-reinforced plastic layer 6 is a layer formed, for example, by impregnating at least a portion of the gaps between the fibers with an impregnating material. The fiber-reinforced plastic layer 6 has, for example, a first surface 6f and a second surface 6s located on the opposite side of the first surface 6f (see Figure 2). The first surface 6f of the fiber-reinforced plastic layer 6 is, for example, facing the second surface 1s of the surface protection layer 1. The fiber-reinforced plastic layer 6 is in contact with the filler 4 on the side opposite to the surface protection layer 1. The fiber-reinforced plastic layer 6 is positioned facing the solar cell portion 3 in the Z direction.

[0046] The fiber-reinforced plastic layer 6 shown in Figure 2 is positioned to overlap the entire solar cell element 31 in a plan view. However, the fiber-reinforced plastic layer 6 may overlap only a portion of the solar cell element 31.

[0047] The thickness of the fiber-reinforced plastic layer 6 is, for example, about 0.01 mm to 0.5 mm. The fiber material contained in the fiber-reinforced plastic layer 6 may be a non-combustible or flame-retardant material such as glass fiber, poly(p-phenylene terephthalamide) (Kevlar, registered trademark), ultra-high molecular weight polyethylene (Dyneema, registered trademark), or metal fiber. Here, the fiber material of the fiber-reinforced plastic layer 6 contains more than 1 wt% alkali metal. The impregnating material used to impregnate the fiber material may be, for example, IO, epoxy resin, EVA, POE, or polymethyl methacrylate resin.

[0048] <Adhesive layer> The adhesive layer 7 is, for example, a layer that adheres the fiber-reinforced plastic layer 6 and the back 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 6s of the fiber-reinforced plastic layer 6.

[0049] 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.

[0050] <Back protective layer> The back protective layer 2 is, for example, constituting the back surface 10b of the solar cell panel 10. The back protective layer 2 is bonded to the fiber-reinforced plastic layer 6 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).

[0051] 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.

[0052] 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.

[0053] Furthermore, if either the material of the back protective layer 2 or the material of the fiber-reinforced plastic layer 6 is a material that can be fused to adjacent layers by heating during the lamination process, then the adhesive layer 7 may not be provided.

[0054] <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.

[0055] 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.

[0056] Next, as shown in Figures 6 and 7, for example, a laminate 10s is formed by laminating a surface protective layer 1, a sheet 131, a glass fiber layer 12, a sheet 41s, a solar cell section 3, a sheet 42s, a fiber material 61, a sheet 71, and a back surface protective layer 2.

[0057] 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.

[0058] Sheet 131 is a sheet made of resin (such as IO or EVA). Sheet 131 may be made of the same material as sheet 41s or sheet 42s. Sheet 131 is located between the surface protective layer 1 and the glass fiber layer 12.

[0059] 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 glass fiber layer 12 and the solar cell section 3. In other words, the sheet 41s is located on top of the glass fiber 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.

[0060] 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.

[0061] The sheet 42s is located between the fiber material 61 and the solar cell section 3. In a plan view, the sheet 42s has a rectangular shape, which is an example of a square shape.

[0062] The fiber material 61 is a fiber material that constitutes the fiber-reinforced plastic layer 6. The fiber material 61 becomes the fiber-reinforced plastic layer 6 when the sheet 42s or sheet 71 facing the fiber material 61 is impregnated during the lamination process described later. The fiber material 61 is located between sheet 71 and sheet 42s.

[0063] 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 fiber material 61. The back protective layer 2 is located on top of sheet 71.

[0064] 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.

[0065] In the fiber-reinforced plastic layer 6 formed after lamination, voids (spaces) that are not impregnated by the sheet 42s or sheet 71 may be partially formed in the gaps between the fiber material 61. These voids (spaces) may be completely contained within the fiber-reinforced plastic layer 6, or they may open to the outside on the surface of the fiber-reinforced plastic layer 6.

[0066] As shown in Figures 6 and 7, if the fiber material 61 is not impregnated with an impregnating agent (e.g., resin) before lamination, and only the adjacent resin sheet (e.g., sheet 42t or sheet 71) is impregnated into the fiber material 61 during lamination, then voids (spaces) that are not impregnated with the impregnating agent (e.g., resin) are likely to form in the fiber-reinforced plastic layer 6 after lamination. On the other hand, if the fiber material 61 is pre-impregnated with an impregnating agent (e.g., resin) before lamination, and then incorporated into the lamination configuration for lamination, and then the fiber-reinforced plastic layer 6 is formed by lamination, then voids (spaces) that are not impregnated with the impregnating agent (e.g., resin) are less likely to form. Furthermore, the amount (or proportion) of voids (spaces) formed in the fiber-reinforced plastic layer 6 can be adjusted by adjusting the amount of impregnating agent pre-impregnated into the fiber material 61 before lamination.

[0067] 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.

[0068] <Layered structure> Figure 8 is a cross-sectional view showing an example of the laminated structure of region RA in Figure 2. The filler 4, which is filled between the glass fiber layer 12 and the fiber-reinforced plastic layer 6, is filled in an integrated state within the region. In Figure 8, however, the dotted line indicates a hypothetical boundary between the sheets 41s and 42s before lamination, which will become the filler 4 after lamination.

[0069] According to the stacked configuration shown in Figure 8, in the glass fiber layer 12 positioned opposite the light-receiving surface of the solar cell element 31, the alkali metal content in the glass fibers is suppressed to 1 wt% or less (including cases where no alkali metal is present). Therefore, the movement of alkali metal (ions) from the glass fiber layer 12 to the light-receiving surface where the main photoelectric conversion element of the solar cell element 31 is provided is suppressed, and as a result, the occurrence of PID, which is said to be caused by the movement of alkali metal to the solar cell element 31, can be suppressed.

[0070] Furthermore, according to the lamination configuration shown in Figure 8, the fiber-reinforced plastic layer 6, which is positioned opposite the light-receiving surface of the solar cell element 31, may contain more than 1 wt% alkali metal in the fiber material. Therefore, the range of selectable fiber materials can be increased.

[0071] Furthermore, when spaces are formed in the gaps of the fiber material 61, the movement of alkali metal ions contained in the fiber-reinforced plastic layer 6 toward the solar cell element 31 is suppressed by the spaces. As a result, the occurrence of PID, which is thought to be caused by the movement of alkali metals toward the solar cell element 31, can be suppressed.

[0072] Furthermore, when IO is used for the filler 4, the resistance of the filler 4 is higher than when EVA or other materials are used. As a result, alkali metal ions released from the fibers of the fiber-reinforced plastic layer 6 are prevented from moving by the filler 4, which has high deposition and fixing resistance. Consequently, the occurrence of PID, which is believed to be caused by the migration of alkali metals to the solar cell element 31, can be suppressed.

[0073] <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.

[0074] <Layered structure> Figure 9 is a cross-sectional view showing an example of a laminated configuration according to the second embodiment. Figure 9 corresponds to another example of the laminated configuration of region RA in Figure 2.

[0075] In the configuration shown in Figure 9, a resin layer 9 is provided in addition to the configuration shown in Figure 8. The filler material 4, which is filled between the glass fiber layer 12 and the resin layer 9, is filled in a state where it is integrated within that region. In Figure 9, the dotted line indicates a virtual boundary between the sheets 41s and 42s before lamination, which will become the filler material 4 after lamination.

[0076] <Resin layer> The resin layer 9 is a layer made of resin. The resin 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 resin layer 9 faces the second element surface 31s of the solar cell element 31 via the filler material 4. The second surface 9s of the resin layer 9 faces the first surface 6f of the fiber-reinforced plastic layer 6.

[0077] The direction connecting the glass fiber layer 12 and the resin layer 9 corresponds to the Z direction, and the glass fiber layer 12 and the resin layer 9 are laminated in the Z direction with other layers in between.

[0078] The thickness of the resin layer 9 is approximately 0.3 mm to 2 mm. Examples of materials that make up the resin layer 9 include PET, polyvinyl fluoride (PVF), or polyethylene naphthalate (PEN). The resin layer 9 may also be a laminate of multiple materials. For example, the resin layer 9 may be a laminated structure made of PET and POE.

[0079] According to the lamination configuration shown in Figure 9, a resin layer 9, which is a laminated structure, is placed between the fiber-reinforced plastic layer 6 and the solar cell element 31. Therefore, when alkali metal ions contained in the fiber-reinforced plastic layer 6 move toward the solar cell element 31, the movement of alkali metal ions is suppressed by the interfaces of each layer in the laminated resin layer 9. As a result, the occurrence of PID, which is said to be caused by the movement of alkali metals toward the solar cell element 31, can be suppressed.

[0080] <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.

[0081] <Layered structure> Figure 10 is a cross-sectional view showing an example of a laminated configuration according to the third embodiment. Figure 10 corresponds to another example of the laminated configuration of region RA in Figure 2.

[0082] In the configuration shown in Figure 10, a back fiber layer 8 is provided in addition to the configuration shown in Figure 8. The filler material 4, which is filled between the glass fiber layer 12 and the fiber-reinforced plastic layer 6, is filled in a state where it is integrated in 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, back fiber layer 8, and sheet 42sb before lamination, and are formed by lamination with the back fiber layer 8 sandwiched in between.

[0083] <Backside fiber layer> The back 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 back fiber layer 8 may be the same as or different from the fiber material and impregnating material of the glass fiber layer 12. The back 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 back fiber layer 8 is facing the solar cell element 31. The second surface 8s of the back fiber layer 8 is facing the fiber-reinforced plastic layer 6. The first surface 8f and the second surface 8s of the back fiber layer 8 are covered with filler material 4. The back fiber layer 8 is formed, for example, by impregnating the fiber material with a fluid resin during lamination. In the back fiber layer 8 formed after lamination, voids (spaces) where the impregnating material such as resin is not impregnated may be partially formed in the gaps between the fiber material.

[0084] The thickness of the back fiber layer 8 is approximately 0.01 mm to 0.2 mm. The fiber material included in the back fiber layer 8 may be, for example, glass fiber, poly(p-phenylene terephthalamide) (Kevlar, registered trademark), ultra-high molecular weight polyethylene (Dyneema, registered trademark), or carbon fiber. Here, the fiber material of the back fiber layer 8 may contain 1 wt% or less of alkali metals, or may not contain alkali metals. 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 back fiber layer 8 prevents the movement of air from the back protective layer 2 to the front protective layer 1.

[0085] According to the layered configuration shown in Figure 10, the alkali metal content in the fiber layer 8 located near the solar cell element 31 is suppressed to 1 wt% or less (including cases where no alkali metal is present). Therefore, the movement of alkali metal (ions) from the fiber layer 8 to the solar cell element 31 is suppressed, and as a result, the occurrence of PID, which is said to be caused by the movement of alkali metal to the solar cell element 31, can be suppressed. In addition, the strength of the solar cell module 100 can be increased by providing the fiber layer 8. Furthermore, if a space is formed in the gap between the fibers of the fiber layer 8, the movement of alkali metal ions contained in the fiber-reinforced plastic layer 6 toward the solar cell element 31 is suppressed by the space. As a result, the occurrence of PID, which is said to be caused by the movement of alkali metal to the solar cell element 31, can be suppressed.

[0086] In addition, in Figure 10, the resin layer 9 shown in Figure 9 may be further provided.

[0087] <Fourth 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.

[0088] <Layered structure> Figure 11 is a cross-sectional view showing an example of a laminated configuration according to the fourth embodiment. Figure 11 corresponds to another example of the laminated configuration of region RA in Figure 2.

[0089] In the configuration shown in Figure 11, a support member 5 is provided in addition to the configuration shown in Figure 8. The filler 4, which is filled between the glass fiber layer 12 and the fiber-reinforced plastic layer 6, is filled in a state where it is integrated in that region. In Figure 11, the dotted line indicates a virtual boundary between the sheets 41s and 42s before lamination, which will become the filler 4 after lamination.

[0090] <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.

[0091] 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 glass fiber layer 12 and the back protective layer 2, covered by the filler material 4. In other words, the support member 5 is facing the glass fiber 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.

[0092] 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 glass fiber 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.

[0093] 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 glass fiber 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 protection layer 1 in a plan view. That is, a support member 5 is also provided at the opposite end (one side) of the glass fiber layer 12, which is not shown. The two support members 5 are each positioned along both sides of the surface protection 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 protection 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 glass fiber layer 12. However, the support member 5 may extend along the entire side of the glass fiber layer 12, or it may be located partially (for example, intermittently) along one side of the glass fiber 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.

[0094] 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.

[0095] The stacked configuration shown in Figure 11 can improve the impact resistance of the solar cell module.

[0096] In addition, in Figure 11, the resin layer 9 shown in Figure 9 or the back fiber layer 8 shown in Figure 10 may be further provided.

[0097] This disclosure includes the following:

[0098] (1) In one embodiment, the solar cell module comprises a light-transmitting resin surface protective layer, a fiber-reinforced plastic layer in which a first fibrous material is impregnated with a first impregnating material, a solar cell element disposed between the surface protective layer and the fiber-reinforced plastic layer and having a light-receiving surface facing the surface protective layer, a light-transmitting glass fiber layer disposed between the surface protective layer and the solar cell element in which glass fibers are impregnated with a second impregnating material, and a filler that covers the solar cell element and is filled between the fiber-reinforced plastic layer and the glass fiber layer. The glass fibers contain 1 wt% or less of alkali metals or do not contain alkali metals.

[0099] (2) The solar cell module described in (1) may further include a resin layer disposed between the solar cell element and the fiber-reinforced plastic layer. The filler is filled in such a way that it covers the resin layer, and the resin layer may be formed by stacking multiple layers in the direction connecting the solar cell element and the fiber-reinforced plastic layer.

[0100] (3) In the solar cell module described in (1) or (2), a first space may be formed in the gap between the first fiber material in a state in which the first impregnating material is not impregnated.

[0101] (4) A solar cell module according to any one of (1) to (3) may further include a back fiber layer disposed between the solar cell element and the fiber-reinforced plastic layer, wherein the second fiber material is impregnated with the third impregnating material. In this case, the filler is filled in such a way that it covers the back fiber layer, and the second fiber material contains 1 wt% or less of alkali metal or does not contain alkali metal.

[0102] (5) In the solar cell module described in (4), a second space may be formed in the gap between the second fiber material in which the third impregnating material is not impregnated.

[0103] (6) In the solar cell module described in any one of (1) to (5), the filler material may include an ionomer.

[0104] (7) In the solar cell module described in any one of (1) to (6), the first fiber material may contain more than 1 wt% of alkali metal. [Explanation of symbols]

[0105] 1 Surface protective layer 4 Filling material 6. Fiber-reinforced plastic layer 8. Backside fiber layer 9. Resin layer 12 Glass fiber layer 31 Solar cell elements 61 Fiber materials 100 solar modules

Claims

1. A translucent resin surface protective layer, A fiber-reinforced plastic layer in which a first fibrous material is impregnated with a first impregnation material, A solar cell element is disposed between the surface protective layer and the fiber-reinforced plastic layer, and its light-receiving surface faces the surface protective layer. With the glass fibers impregnated with the second impregnation material, a translucent glass fiber layer is placed between the surface protective layer and the solar cell element, The solar cell element is covered by a filler material which is filled between the fiber-reinforced plastic layer and the glass fiber layer. The glass fiber contains 1 wt% or less of an alkali metal or does not contain an alkali metal. Solar cell module.

2. The solar cell module according to claim 1, The solar cell element further comprises a resin layer disposed between the fiber-reinforced plastic layer, The filler is filled in such a way that it covers the resin layer. The resin layer is formed by stacking multiple layers in the direction connecting the solar cell element and the fiber-reinforced plastic layer. Solar cell module.

3. A solar cell module according to claim 1 or 2, A first space is formed in the gap between the first fibrous material, where the first impregnating material is not impregnated. Solar cell module.

4. A solar cell module according to claim 1 or 2, The second fibrous material is impregnated with a third impregnating material, and the back fibrous layer is further disposed between the solar cell element and the fiber-reinforced plastic layer. The filler is filled in such a way that it covers the back fiber layer. The second fiber material contains 1 wt% or less of alkali metals or does not contain alkali metals. Solar cell module.

5. The solar cell module according to claim 4, A second space is formed in the gap between the second fibrous material, where the third impregnating material is not impregnated. Solar cell module.

6. A solar cell module according to claim 1 or 2, The aforementioned filler includes an ionomer, Solar cell module.

7. A solar cell module according to claim 1 or 2, The first fiber material contains more than 1 wt% of alkali metals. Solar cell module.

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