Solar cell panel

Abstract

In a four-terminal tandem solar cell panel, provided is a solar cell panel in which the number of terminal boxes can be reduced to one. A solar cell panel 100 comprises: a four-terminal tandem solar cell module 110 having a bottom-side solar cell sub-module 10 and a top-side solar cell sub-module 20 which are stacked in a stacking direction; and a four-terminal terminal box 120 having a pair of bottom-side terminal bases 61 for the solar cell sub-module 10 and a pair of top-side terminal bases 62 for the solar cell sub-module 20. The solar cell module 110 has an insulating layer 8 disposed between the bottom-side solar cell sub-module 10 and the top-side solar cell sub-module 20. The terminal box 120 has an insulating isolation wall 50 disposed between the pair of bottom-side terminal bases 61 and the pair of top-side terminal bases 62.

Description

Solar panels

[0001] This invention relates to a solar cell panel.

[0002] Solar cell modules are known in which a solar cell submodule containing multiple solar cells is sealed with a protective material such as glass or transparent resin and a sealing material. Known solar cell types include crystalline silicon solar cells using a crystalline silicon substrate as the photoelectric conversion layer, and thin-film solar cells using inorganic thin films such as amorphous silicon thin films or organic thin films such as perovskite thin films (specifically, organic / inorganic hybrid thin films) as the photoelectric conversion layer.

[0003] Furthermore, in recent years, multi-junction (tandem) solar cell modules have been developed that stack photoelectric conversion layers with different band gaps, with the aim of effectively utilizing light across a wide wavelength range to improve the conversion efficiency of solar cells. For example, Patent Documents 1 and 2 disclose multi-junction solar cell modules that stack two types of solar cells, each containing a different photoelectric conversion layer. In this solar cell module, for example, a crystalline silicon-based solar cell submodule, which consists of a bottom cell containing a crystalline silicon substrate as the photoelectric conversion layer, and a perovskite-based solar cell submodule, which consists of a top cell containing a perovskite thin film as the photoelectric conversion layer, are stacked as two types of solar cell submodules.

[0004] Japanese Patent Publication No. 2018-157175 Japanese Patent Publication No. 2018-157176

[0005] In a multi-junction (tandem) solar cell module where different types of solar cell submodules are stacked, the output power (voltage and current) of the bottom cell and the top cell differs, resulting in a four-terminal module with two terminals for the bottom cell and two terminals for the top cell. In such a four-terminal module, separate terminal boxes are provided for the bottom cell and the top cell.

[0006] In such four-terminal multi-junction (tandem) solar cell modules, there is a demand to consolidate the terminal boxes of the bottom cell and the top cell for purposes such as improving manufacturability, reducing costs, enhancing design, reducing weight, and miniaturizing the module.

[0007] The present invention aims to provide a solar cell panel in which the terminal boxes of the bottom cell and the top cell can be combined, in a tandem solar cell panel with four terminals.

[0008] The solar cell panel according to the present invention comprises a four-terminal type and a tandem type solar cell module having a bottom-side solar cell submodule and a top-side solar cell submodule stacked in the stacking direction, and a four-terminal type terminal box having a pair of bottom-side terminal blocks for the bottom-side solar cell submodule and a pair of top-side terminal blocks for the top-side solar cell submodule. The solar cell module further has an insulating layer disposed between the bottom-side solar cell submodule and the top-side solar cell submodule, and the terminal box further has an insulating isolation wall disposed between the pair of bottom-side terminal blocks and the pair of top-side terminal blocks.

[0009] According to the present invention, in a four-terminal tandem solar cell panel, the terminal boxes of the bottom cell and the top cell can be combined while ensuring insulation.

[0010] This is a schematic cross-sectional view of a solar cell panel according to this embodiment. This is a schematic plan view of the terminal box and the vicinity of the terminal box of the solar cell module in the solar cell panel shown in Figure 1, viewed from the light-receiving surface side. This is a schematic plan view of the terminal box and the vicinity of the terminal box of the solar cell module in the solar cell panel shown in Figure 1, viewed from the back side. This is a schematic cross-sectional view of a perovskite-type solar cell submodule shown in Figure 1. This is a schematic plan view of the terminal box and the vicinity of the terminal box of the solar cell module in a modified solar cell panel according to this embodiment, viewed from the light-receiving surface side. This is a schematic plan view of the terminal box and the vicinity of the terminal box of the solar cell module in a modified solar cell panel according to this embodiment, viewed from the back side. This is a schematic cross-sectional view of a solar cell panel according to a modified example of this embodiment.

[0011] An example of an embodiment of the present invention will be described below with reference to the attached drawings. The same or corresponding parts will be denoted by the same reference numerals in each drawing. For convenience, hatching and component reference numerals may be omitted; in such cases, refer to other drawings.

[0012] (Solar Panel) Figure 1 is a schematic cross-sectional view of a solar panel according to this embodiment. Figure 2 is a schematic plan view of the terminal box and the vicinity of the terminal box of the solar cell module in the solar panel shown in Figure 1, as seen from the light-receiving surface side. Figure 3 is a schematic plan view of the terminal box and the vicinity of the terminal box of the solar cell module in the solar panel shown in Figure 1, as seen from the back side. As shown in Figures 1 to 3, the solar panel 100 comprises a solar cell module 110 and a terminal box 120.

[0013] (Solar Cell Module) As shown in Figures 1 to 3, the solar cell module 110 is a four-terminal tandem solar cell module. The solar cell module 110 comprises a top solar cell submodule 20 and a bottom solar cell submodule 10 stacked in the Z direction (stack direction) from the light-receiving surface side. An insulating layer 8 is interposed between the top solar cell submodule 20 and the bottom solar cell submodule 10.

[0014] The top solar cell submodule 20 includes a plurality of solar cells 21 connected in series or parallel, and the bottom solar cell submodule 10 includes a plurality of solar cells 11 connected in series or parallel.

[0015] The solar cell submodules 10 and 20 are sandwiched between a light-receiving protective member 3 and a back-side protective member 4. A liquid or solid sealing material 5 is filled between the light-receiving protective member 3 and the back-side protective member 4, thereby sealing the solar cell submodules 10 and 20.

[0016] The sealing material 5 seals and protects the solar cell submodules 10 and 20, and is interposed between the light-receiving surface of the top solar cell submodule 20 and the light-receiving protective member 3, between the back surface of the top solar cell submodule 20 and the insulating layer 8, between the light-receiving surface of the bottom solar cell submodule 10 and the insulating layer 8, and between the back surface of the bottom solar cell submodule 10 and the back protective member 4. Note that if the top solar cell submodule 20 is a thin-film solar cell submodule, the substrate 30b shown in Figure 4 (described later) may also serve as the light-receiving protective member 3. In this case, the sealing material 5 is not interposed between the light-receiving surface of the top solar cell submodule 20 and the light-receiving protective member 3. The shape of the sealing material 5 is not particularly limited; for example, it can be in the form of a sheet. This is because a sheet shape makes it easy to cover the front and back surfaces of the planar solar cell submodules 10 and 20.

[0017] The material of the encapsulant 5 is not particularly limited, but it is preferable that it has the property of transmitting light (light transmission). Furthermore, it is preferable that the material of the encapsulant 5 has adhesive properties for bonding the solar cell submodule 20 to the light-receiving protective member 3, adhesive properties for bonding the solar cell submodule 10 to the back protective member 4, and adhesive properties for bonding the solar cell submodules 10 and 20 to the insulating layer 8. Examples of such materials include light-transmitting resins such as ethylene / vinyl acetate copolymer (EVA), ethylene / α-olefin copolymer, ethylene / vinyl acetate / triallyl isocyanurate (EVAT), polyvinyl butyrate (PVB), acrylic resin, urethane resin, or silicone resin.

[0018] The light-receiving protective member 3 protects the solar cell submodules 10 and 20 by covering their surfaces (light-receiving surfaces) via the sealing material 5. The shape of the light-receiving protective member 3 is not particularly limited, but a plate-like, sheet-like, or film-like shape is preferred in order to indirectly cover the planar light-receiving surface.

[0019] The material of the light-receiving protective member 3 is not particularly limited, but like the sealing material 5, a material that is light-transmitting yet resistant to ultraviolet light is preferred. Examples include glass, or transparent resins such as acrylic resin or polycarbonate resin. The surface of the light-receiving protective member 3 may be processed to have an uneven surface, or it may be covered with an anti-reflective coating layer. This is because the light-receiving protective member 3 makes it difficult for the received light to be reflected, allowing more light to be guided to the solar cell submodules 10 and 20. Furthermore, if the material of the light-receiving protective member 3 is resin, a barrier film that prevents the passage of water vapor may be provided on the back or front surface of the light-receiving protective member 3. This protects the solar cell submodules 10 and 20 from water vapor.

[0020] The back-side protective member 4 protects the solar cell submodules 10 and 20 by covering their back surfaces via the sealing material 5. The shape of the back-side protective member 4 is not particularly limited, but like the light-receiving side protective member 3, a plate or sheet shape is preferred as it indirectly covers the planar back surface.

[0021] The material of the back protective member 4 is not particularly limited, but a material that prevents the intrusion of water, etc. (high water-resistant material) is preferred. Examples include resin films such as polyethylene terephthalate (PET), polyethylene (PE), olefin resin, fluororesin, or silicone resin, or laminates of a translucent plate-shaped resin member such as glass, polycarbonate, or acrylic and a metal foil such as aluminum foil. If the material of the back protective member 4 is resin, a barrier film that prevents the passage of water vapor may be provided on the surface or back of the back protective member 4. This protects the solar cell submodules 10 and 20 from water vapor.

[0022] <Bottom-side solar cell submodule: crystalline silicon solar cell submodule> The bottom-side solar cell submodule 10 is a crystalline silicon solar cell submodule containing multiple crystalline silicon solar cells 11 (hereinafter, the bottom-side solar cell submodule will also be referred to as the crystalline silicon solar cell submodule). For example, the multiple crystalline silicon solar cells 11 are connected in series or in parallel, thereby forming a two-terminal module for the bottom-side solar cell submodule 10.

[0023] <<Crystalline Silicon Solar Cell>> The crystalline silicon solar cell 11 includes a semiconductor substrate as a photoelectric conversion layer. The semiconductor substrate absorbs light and generates photocarriers. The semiconductor substrate is a crystalline silicon substrate such as single-crystal silicon or polycrystalline silicon.

[0024] The semiconductor substrate may have a pyramidal, finely uneven structure called a textured structure on the light-receiving surface. This reduces the reflection of incident light on the light-receiving surface, improving the light confinement effect of the semiconductor substrate.

[0025] Furthermore, the semiconductor substrate may have a pyramidal, finely uneven structure called a textured structure on its back side. This increases the efficiency of recovering light that has passed through the semiconductor substrate without being absorbed.

[0026] Examples of crystalline silicon solar cells 11 include a diffusion cell in which a second conductivity type diffusion layer is provided on the light-receiving surface side of a first conductivity type single crystal silicon substrate, and a heterojunction cell in which silicon-based thin films are provided on both sides of a first conductivity type single crystal silicon substrate.

[0027] In the case of a heterojunction cell having silicon-based thin films on both sides of a single-crystal silicon substrate, the crystalline silicon solar cell 11 has a conductive silicon-based thin film formed on the light-receiving side of the photoelectric conversion layer and a conductive silicon-based thin film formed on the back side of the photoelectric conversion layer.

[0028] The single-crystal silicon substrate can be either p-type or n-type. When comparing holes and electrons, electrons have higher mobility, so using an n-type single-crystal silicon substrate results in particularly excellent conversion characteristics. Conductive silicon-based thin films are either p-type or n-type silicon-based thin films.

[0029] It is preferable to provide an intrinsic silicon thin film between the single-crystal silicon substrate, which serves as the photoelectric conversion layer, and the conductive silicon thin film. By providing an intrinsic silicon thin film on the surface of the single-crystal silicon substrate, surface passivation can be effectively performed while suppressing the diffusion of impurities into the single-crystal silicon substrate. By providing an intrinsic amorphous silicon thin film as the intrinsic silicon thin film on the surface of the single-crystal silicon substrate, a high passivation effect on the surface of the single-crystal silicon substrate can be obtained.

[0030] The crystalline silicon solar cell 11 may be a double-electrode type (also called a double-junction type) cell, or a back-electrode type (also called a back-junction type or back-contact type) cell. In the case of a back-electrode type cell, the output of the solar cell module can be improved compared to a double-electrode type cell, and the design of the solar cell module can also be improved.

[0031] The crystalline silicon solar cell 11 may be a large semiconductor substrate (wafer) of a specified size (for example, a 6-inch semi-square shape), or it may be a half-cut cell obtained by cutting a large semiconductor substrate (wafer) in half.

[0032] <Top-side solar cell submodule: Thin-film solar cell submodule> The top-side solar cell submodule 20 is a thin-film solar cell submodule containing multiple thin-film solar cells 21 (hereinafter, the top-side solar cell submodule will also be referred to as the thin-film solar cell submodule).

[0033] <<Thin-film solar cell>> The thin-film solar cell 21 includes a thin-film semiconductor layer as a photoelectric conversion layer. The semiconductor layer absorbs light and generates photo carriers. The semiconductor layer has a band gap different from that of the semiconductor substrate of the crystalline silicon-based solar cell described above. Therefore, the semiconductor substrate and the semiconductor layer described above have spectral sensitivity characteristics in different wavelength ranges. Therefore, in the tandem solar cell module in which the crystalline silicon-based solar cell sub-module 10 and the thin-film solar cell sub-module 20 described above are stacked, light with a wider wavelength can contribute to photoelectric conversion.

[0034] Specifically, examples of the thin film constituting the semiconductor layer include inorganic semiconductor thin films, organic semiconductor thin films, or organic-inorganic hybrid semiconductor thin films, such as amorphous silicon-based or perovskite-based thin films. Hereinafter, a perovskite-based solar cell will be exemplified as the thin-film solar cell 21.

[0035] The compound constituting the perovskite-type crystal material is not particularly limited. For example, the general formula R １ NH ３ M １ X ３ or HC(NH ２ ) ２ M １ X ３ is represented. In the formula, R １ is an alkyl group, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group is particularly preferable. M １ is a divalent metal ion, and Pb or Sn is preferable. X is a halogen, and examples include F, Cl, Br, and I. Note that the three Xs may all be the same halogen element, or a plurality of halogens may be mixed.

[0036] A preferred example of the compound constituting the perovskite-type crystal material is the formula CH ３ NH ３ Pb(I １－ｘ Br ｘ ) ３Compounds represented by (where 0 ≤ x ≤ 1) are included. The perovskite material can change its spectral sensitivity characteristics by changing the type and ratio of halogen. The perovskite semiconductor thin film can be formed by various dry processes or solution film formation such as spin coating.

[0037] FIG. 4 is a schematic cross-sectional view of the thin-film solar cell 21 in the thin-film solar cell submodule 20 shown in FIG. 1. Since FIG. 4 is a schematic view, the position of the base material 30b is not limited to the back side and includes the case where it is on the light-receiving side. When the position of the base material 30b is on the light-receiving side, as described above, the base material 30b may also serve as the light-receiving side protection member 3.

[0038] The thin-film solar cell 21 is divided in the X direction (integration direction: first direction) on one base material 30b, extends in the Y direction (second direction) intersecting the X direction, and is composed of a plurality of unit cells 30 connected in series and integrated. As a result, the conductive distance in the X direction can be shortened, and the current amount per unit cell 30 can be reduced. Consequently, the resistance loss due to the electrodes 34, 35, particularly the electrodes 34, 35 composed of the transparent electrode (ITO), can be reduced.

[0039] The unit cell 30 is formed on a film-like or plate-like base material 30b. Examples of the material of the base material 30b include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), glass, and the like.

[0040] The unit cell 30 has a perovskite layer 31 as a photoelectric conversion layer and charge transport layers 32, 33. One of the charge transport layers 32, 33 is a hole transport layer, and the other is an electron transport layer.

[0041] Examples of materials for the hole transport layer include polythiophene derivatives such as poly-3-hexylthiophene (P3HT) and poly(3,4-ethylenedioxythiophene) (PEDOT), fluorene derivatives such as 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (Spiro-OMeTAD), carbazole derivatives such as polyvinylcarbazole, triphenylamine derivatives, diphenylamine derivatives, polysilane derivatives, and polyaniline derivatives.

[0042] Examples of materials for the electron transport layer include metal oxides such as titanium oxide, zinc oxide, niobium oxide, zirconium oxide, and aluminum oxide.

[0043] An electrode 34 for extracting photogenerated carriers is formed on the charge transport layer 32 side of the unit cell 30. An electrode 35 for extracting photogenerated carriers is formed on the charge transport layer 33 side of the unit cell 30.

[0044] Electrode 34 may include a transparent electrode and a metal electrode, or it may include only a transparent electrode, or it may include only a metal electrode. Similarly, electrode 35 may include a transparent electrode and a metal electrode, or it may include only a transparent electrode, or it may include only a metal electrode. Preferably, metal oxides such as ITO, zinc oxide, and tin oxide are used as the material for the transparent electrode. Preferably, silver, copper, and aluminum are used as the material for the metal electrode.

[0045] This allows the top-side solar cell submodule 20 to be connected in series or parallel, thereby configuring a two-terminal type top-side solar cell submodule 20.

[0046] In this way, the two-terminal top solar cell submodule 20 and the two-terminal bottom solar cell submodule 10 constitute a four-terminal solar cell module.

[0047] A pair of top-side lead wires 7 are connected to the two-terminal top-side solar cell submodule 20. The pair of top-side lead wires 7 extend from the top-side solar cell submodule 20 and are connected to a pair of top-side terminal blocks 62, 62 of the terminal box 120, which will be described later.

[0048] A pair of bottom-side lead wires 6 are connected to the two-terminal bottom-side solar cell submodule 10. The pair of bottom-side lead wires 6 extend from the bottom-side solar cell submodule 10 and are connected to a pair of bottom-side terminal blocks 61, 61 of the terminal box 120, which will be described later.

[0049] As described above, an insulating layer 8 is placed between the bottom solar cell submodule 10 and the top solar cell submodule 20. Examples of materials for the insulating layer 8 include insulating resin films such as PET (polyethylene terephthalate), PEN (polyethylene naphthalate), nylon, polypropylene, and fluororesin, or films laminated with VA or olefin resin to improve adhesion to the sealing material, or films laminated with SiOx to improve barrier properties.

[0050] (Terminal Box) As shown in Figures 1 to 3, the terminal box 120 is a four-terminal type terminal box. The terminal box 120 also comprises a housing 121, an isolation wall 50 and two pairs of terminal blocks 61 and 62 located inside the housing 121, two reverse current prevention diodes 65 and 65, and two pairs of cables 71 and 72 and connectors 81 and 82 extending from inside to outside the housing 121.

[0051] The housing 121 covers the outer edge of the terminal box 120, except for the areas where the pair of bottom-side lead wires 6 and the pair of top-side lead wires 7, as well as the insulating layer 8, are inserted, and where the two pairs of cables 71 and 72 are pulled out.

[0052] The two pairs of terminal blocks 61, 62, namely the pair of top-side terminal blocks 62, 62 and the pair of bottom-side terminal blocks 61, 61, are stacked in the Z direction (stack direction). The pair of top-side terminal blocks 62, 62 are terminal blocks for the top-side solar cell submodule 20. A pair of top-side lead wires 7, 7 are connected to the pair of top-side terminal blocks 62, 62, and one end of a pair of cables 72 is also connected to each of them. A pair of connectors 82 are connected to the other ends of the pair of cables 72, respectively.

[0053] The pair of bottom terminal blocks 61, 61 are terminal blocks for the bottom solar cell submodule 10. A pair of bottom lead wires 6, 6 are connected to each of the bottom terminal blocks 61, 61, and one end of a pair of cables 71 is also connected to each of them. A pair of connectors 81 are connected to the other ends of the pair of cables 71.

[0054] One reverse current blocking diode 65 is connected between a pair of top-side terminal blocks 62, 62 to prevent reverse current flow between the two terminals of the top-side solar cell submodule 20. The other reverse current blocking diode 65 is connected between a pair of bottom-side terminal blocks 61, 61 to prevent reverse current flow between the two terminals of the bottom-side solar cell submodule 10.

[0055] The isolation wall 50 is positioned between the pair of top terminal blocks 62, 62 and the pair of bottom terminal blocks 61, 61, and between the two reverse current prevention diodes 65, and provides insulation. From a manufacturing standpoint, it is preferable that the isolation wall 50 be made of the same material as the terminal box, such as PPE (polyphenylene ether). This allows the isolation wall 50 to insulate and isolate the pair of top terminal blocks 62, 62 and the pair of bottom terminal blocks 61, 61.

[0056] (Details of the insulating layer and isolation wall) As shown in Figures 1 to 3, as described above, an insulating layer 8 is placed between the bottom solar cell submodule 10 and the top solar cell submodule 20 in the solar cell module 110. In addition, an insulating isolation wall 50 is placed between the pair of bottom terminal blocks 61, 61 and the pair of top terminal blocks 62, 62 in the terminal box 120.

[0057] At least a portion of the end of the insulating layer 8 may extend toward the terminal box 120 and overlap with and be in contact with at least a portion of the end of the isolation wall 50. As a result, at least a portion of the end of the insulating layer 8 will be interposed between the pair of bottom-side lead wires 6, 6 and the pair of top-side lead wires 7, 7. This ensures creepage distance between the insulating layer 8 and the isolation wall 50, and between the bottom-side solar cell submodule 10 and the top-side solar cell submodule 20, between the pair of bottom-side lead wires 6, 6 and the pair of top-side lead wires 7, 7, and between the pair of bottom-side terminal blocks 61, 61 and the pair of top-side terminal blocks 62, 62, thereby ensuring insulation.

[0058] In this case, each of the pair of bottom-side lead wires 6 and the pair of top-side lead wires 7 may be in a form that is not covered by an insulating covering member.

[0059] As described above, according to the solar cell panel 100 of this embodiment, the solar cell module 110 has an insulating layer 8 disposed between the bottom solar cell submodule 10 and the top solar cell submodule 20, and the terminal box 120 has an insulating isolation wall 50 disposed between a pair of bottom terminal blocks 61 and a pair of top terminal blocks 62. This makes it possible to ensure insulation and consolidate the terminal boxes of the bottom solar cell submodule 10 and the top solar cell submodule 20 in a 4-terminal multi-junction (tandem) type solar cell panel 100. In other words, the bottom-side lead wiring 6 and the top-side lead wiring 7 can be consolidated into the terminal box 120. This reduces the number of terminal boxes. In this embodiment, only one terminal box is needed.

[0060] Furthermore, at least a portion of the end of the insulating layer 8 in the solar cell module 110 extends toward the terminal box 120, overlapping and in contact with at least a portion of the end of the isolation wall 50 of the terminal box 120, and is positioned between the pair of bottom-side lead wires 6, 6 and the pair of top-side lead wires 7, 7. This ensures creepage distance in the insulating layer 8 and the isolation wall 50, further ensuring insulation, and allows the terminal boxes of the bottom-side solar cell submodule 10 and the top-side solar cell submodule 20 to be combined in the 4-terminal multi-junction (tandem) solar cell panel 100. For example, even if each of the pair of bottom-side lead wires 6, 6 and the pair of top-side lead wires 7, 7 is not covered by an insulating covering member, insulation can be ensured, and the terminal boxes of the bottom-side solar cell submodule 10 and the top-side solar cell submodule 20 can be combined.

[0061] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications and variations are possible. For example, in the embodiments described above, as shown in Figures 2 and 3, a part of the end of the insulating layer 8 in the solar cell module 110 extends toward the terminal box 120 from one bottom-side lead wire 6 to the other bottom-side lead wire 6, and from one top-side lead wire 7 to the other top-side lead wire 7. However, this embodiment is not limited to this, and various modifications are possible.

[0062] Figure 5 is a schematic plan view showing the terminal box and the vicinity of the terminal box of the solar cell module in a modified solar cell panel according to this embodiment, as seen from the light-receiving surface side, and Figure 6 is a schematic plan view showing the terminal box and the vicinity of the terminal box of the solar cell module in a modified solar cell panel according to this embodiment, as seen from the back side. As shown in Figures 5 and 6, a portion of the end of the insulating layer 8 in the solar cell module 110 extends toward the terminal box 120 in the vicinity of one bottom-side lead wiring 6 and the other bottom-side lead wiring 6, and in the vicinity of one top-side lead wiring 7 and the other top-side lead wiring 7, but does not extend toward the terminal box 120 between the vicinity of one bottom-side lead wiring 6 and the other bottom-side lead wiring 6, and between the vicinity of one top-side lead wiring 7 and the other top-side lead wiring 7.

[0063] Furthermore, in the above-described embodiment, as shown in Figure 1, an example was given in which the terminal box 120 is arranged on the side of the solar cell module 110. However, this embodiment is not limited to this, and various modifications are possible. For example, as shown in Figure 7, the terminal box 120 may be arranged on the back surface of the solar cell module 110.

[0064] In this case, for example as shown in Figure 7, the pair of top-side lead wires 7 extend from the top-side solar cell submodule 20, are folded back at the end of the solar cell module 110, pass through the insulating layer 8 to the back side of the bottom-side solar cell submodule 10, and are connected to the pair of top-side terminal blocks 62 of the terminal box 120 through through holes in the back-side protective member 4. The pair of bottom-side lead wires 6 extend from the bottom-side solar cell submodule 10, are folded back at the end of the solar cell module 110, pass through the insulating layer 8A to the back side of the bottom-side solar cell submodule 10, and are connected to the pair of bottom-side terminal blocks 61 of the terminal box 120 through through holes in the back-side protective member 4. The insulating layer 8 is folded back at the end of the solar cell module 110, passes through the back side of the bottom-side solar cell submodule 10, extends toward the terminal box 120 through through holes in the back-side protective member 4, is positioned between the pair of bottom-side lead wires and the pair of top-side lead wires, and overlaps with at least a portion of the end of the isolation wall 50.

[0065] Furthermore, in this embodiment, an example is shown in which the terminal box of the bottom solar cell submodule 10 and the terminal box of the top solar cell submodule 20 are combined into a single terminal box. However, this embodiment is not limited to this, and the terminal boxes of the bottom solar cell submodule 10 and the top solar cell submodule 20 may be divided and combined into multiple terminal boxes. For example, a portion of the bottom-side lead wiring 6 and a portion of the top-side lead wiring 7 may be combined into one terminal box, and another portion of the bottom-side lead wiring 6 and another portion of the top-side lead wiring 7 may be combined into another terminal box. In this case, multiple terminal boxes constitute a four-terminal type terminal box.

[0066] 3 Light-receiving side protective member 4 Back side protective member 5 Sealing material 6 Bottom side lead wiring 7 Top side lead wiring 8 Insulating layer 8A Insulating layer 10 Bottom side solar cell submodule 11 Bottom side solar cell 20 Top side solar cell submodule 21 Top side solar cell 30 Unit cell 30b Substrate 31 Perovskite layer (photoelectric conversion layer) 32, 33 Charge transport layer 34, 35 Electrode 50 Isolation wall 61 Bottom side terminal block 62 Top side terminal block 65 Reverse current prevention diode 71, 72 Cable 81, 82 Connector 100 Solar panel 110 Solar cell module 120 Terminal box 121 Enclosure

Claims

1. A solar panel comprising: a four-terminal and tandem type solar module having a bottom solar cell submodule and a top solar cell submodule stacked in a stacking direction; a four-terminal terminal box having a pair of bottom terminal blocks for the bottom solar cell submodule and a pair of top terminal blocks for the top solar cell submodule, wherein the solar cell module further has an insulating layer disposed between the bottom solar cell submodule and the top solar cell submodule; and the terminal box further has an insulating isolation wall disposed between the pair of bottom terminal blocks and the pair of top terminal blocks.

2. The solar cell module further comprises: a pair of bottom-side lead wires extending from the bottom-side solar cell submodule and connected to the pair of bottom-side terminal blocks; and a pair of top-side lead wires extending from the top-side solar cell submodule and connected to the pair of top-side terminal blocks, wherein at least a portion of the end of the insulating layer extends toward the terminal box and overlaps with at least a portion of the end of the isolation wall, and is positioned between the pair of bottom-side lead wires and the pair of top-side lead wires, according to claim 1.

3. The solar cell panel according to claim 2, wherein each of the pair of bottom-side lead wires and the pair of top-side lead wires is not covered by an insulating covering member.

4. The solar panel according to any one of claims 1 to 3, wherein the bottom solar cell submodule includes a plurality of electrically connected crystalline silicon solar cells, and the top solar cell submodule includes a plurality of electrically connected thin-film solar cells.

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