Solar cell module

Abstract

This disclosure provides a solar cell module with improved sealability compared to conventional ones.　A solar cell (20) is disposed between a light-receiving-side substrate (10) and a rear-surface-side substrate (16), and a rear-surface-side sealing material (14) is disposed between the solar cell (20) and the rear-surface-side substrate (16). In plan view, the solar cell (20) and the rear-surface-side sealing material (14) are surrounded by a surrounding sealing material (15) that bonds the light-receiving-side substrate (10) and the rear-surface-side substrate (16). When viewed in a cross-sectional view, a portion of the rear-surface-side sealing material (14) is between the surrounding sealing material (15) and the rear-surface-side substrate (16).

Description

solar cell module

[0001] The present invention relates to a solar cell module.

[0002] Conventionally, when sealing a solar cell, the solar cell is sandwiched between a light-receiving-side substrate that covers the light-receiving side of the solar cell and a back-side substrate that covers the back side of the solar cell, and the gap between the solar cell and the light-receiving-side substrate is sealed with a light-receiving-side sealing material, and the gap between the solar cell and the back-side substrate is sealed with a back-side sealing material (for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2021-145399

[0004] However, in conventional solar cell sealing structures, the solar cell is sandwiched between a light-receiving-side sealing material and a back-side sealing material, so the interface between the light-receiving-side sealing material and the back-side sealing material is exposed to the outside, and there is a risk that water or the like may enter the solar cell side from the interface between the light-receiving-side sealing material and the back-side sealing material, leaving room for further improvement.

[0005] Therefore, an object of the present invention is to provide a solar cell module that has superior sealing properties compared to conventional solar cell modules.

[0006] One aspect of the present invention for solving the above-described problems is a solar cell module in which a solar cell is arranged between a light-receiving-side substrate and a back-side substrate, and a back-side sealing material is arranged between the solar cell and the back-side substrate, and when viewed in a plane, the solar cell module has an surrounding sealing material that surrounds the solar cell and the back-side sealing material and bonds the light-receiving-side substrate and the back-side substrate, and when viewed in cross-section, a portion of the back-side sealing material has penetrated between the surrounding sealing material and the back-side substrate.

[0007] According to this aspect, the back side of the solar cell is sealed by the back-side sealing material, and the solar cell and the back-side sealing material are further surrounded and sealed by the surrounding sealing material, thereby improving sealing performance compared to conventional methods. Furthermore, according to this aspect, the back-side sealing material penetrates between the surrounding sealing material and the back-side substrate on the back side of the solar cell, preventing water and the like from entering through the interface between the surrounding sealing material and the back-side substrate, thereby improving sealing performance compared to conventional methods.

[0008] In a preferred aspect, the back surface-side sealing material has a first sealing material and a second sealing material, the first sealing material having elasticity, being provided on the solar cell, having a housing portion on the surface facing the light-receiving side substrate for housing a portion of the solar cell, and having a smooth surface on the back surface-side substrate side, and the second sealing material being provided on the first sealing material, having a smooth surface on both the light-receiving side substrate side and the back surface-side substrate side.

[0009] According to this aspect, the thickness of the solar cell is absorbed by the first sealing material, and the second sealing material can adhere and seal the first sealing material and the back side substrate in a flat manner, thereby preventing water and other contaminants from reaching the solar cell inside the first sealing material.

[0010] In a preferred aspect, the second sealing material in the rear surface side sealing material is partly inserted between the surrounding sealing material and the rear surface side substrate.

[0011] According to this aspect, the second sealing material, which is different from the first sealing material that seals the solar cells, can prevent water and the like from entering through the interface between the surrounding sealing material and the back surface substrate, thereby providing higher sealing performance.

[0012] In a preferred aspect, the second sealing material and the surrounding sealing material are substantially the same color.

[0013] According to this aspect, when viewed from the light-receiving substrate side, the second sealing material and the surrounding sealing material can be made to look like a single continuous member, resulting in a unified appearance.

[0014] In a preferred aspect, the surrounding sealing material covers the interface between the first sealing material and the second sealing material.

[0015] According to this aspect, the surrounding sealing material can prevent water and the like from entering through the interface between the first sealing material and the second sealing material, thereby providing higher sealing performance.

[0016] A preferred aspect is a solar cell having a plurality of solar cells, wherein the surrounding sealing material extends along the edge of the back substrate when viewed in a plane, surrounding the plurality of solar cells, and the shortest distance between the solar cell closest to the surrounding sealing material and the surrounding sealing material is 1.5 to 3 times the smallest width of the surrounding sealing material.

[0017] According to this aspect, the solar cell is spaced apart from the surrounding sealing material, so that water and the like are less likely to reach the solar cell.

[0018] In a preferred aspect, the solar cell has a laminated structure in which a semiconductor layer of a second conductivity type is laminated on a semiconductor substrate of a first conductivity type.

[0019] According to this aspect, power generation efficiency can be improved compared to thin-film solar cells.

[0020] The above aspects may be made dependent on each other, or some of the configurations may be quoted or substituted for each other, as long as they are included in the technical scope of the present invention.

[0021] The solar cell module of the present invention has superior sealing properties compared to conventional solar cell modules.

[0022] 1 is a perspective view of a solar cell module according to a first embodiment of the present invention; 2 is an exploded perspective view of the solar cell module of FIG. 1; 3 is an explanatory view of the solar cell module of FIG. 1, where (a) is a cross-sectional view taken along line A-A in FIG. 1 and (b) is a cross-sectional view taken along line B-B in FIG. 1; 4 is a plan view of the solar cell module of FIG. 1, omitting the back-side sealing material and back-side sealing substrate;

[0023] Hereinafter, embodiments of the present invention will be described in detail.

[0024] 1, the solar cell module 1 according to the first embodiment of the present invention is a plate-like panel having a first main surface serving as a light-receiving surface 2 and a second main surface serving as a back surface 3. As shown in FIGS. 2 and 3, the solar cell module 1 includes a light-receiving-side substrate 10, a light-receiving-side sealing material 11, solar cell strings 12 (12a to 12c), wiring members 13, a back-surface-side sealing material 14, an enclosure sealing material 15, and a back-surface-side substrate 16.

[0025] (Light-receiving-side substrate 10) As shown in Fig. 2, the light-receiving-side substrate 10 is a sealing substrate having sealing properties, and is also a light-transmitting insulating substrate having insulating properties and light-transmitting properties. The light-receiving-side substrate 10 is a rectangular substrate, and has horizontal sides 17a and 17b extending in the horizontal direction X and vertical sides 18a and 18b extending in the vertical direction Y, as shown in Fig. 4.

[0026] The light-receiving substrate 10 is not particularly limited as long as it has sealing, insulating, and light-transmitting properties, and for example, a glass substrate such as float glass or colored glass can be used.

[0027] (Light-Receiver-Side Sealing Material 11) The light-receiver-side sealing material 11 is a translucent insulating sealing material that has sealing properties, insulation properties, and light-transmitting properties and seals the solar cell strings 12 and the wiring members 13. As shown in FIGS. 2 and 3 , it also serves as an adhesive that bonds the solar cell strings 12 and the wiring members 13 to the back-side sealing material 14. As shown in FIGS. 2 and 3 , the light-receiver-side sealing material 11 is provided on the light-receiving surface 2 side of the solar cell strings 12, and is an elastic body that deforms to fit the shapes of the solar cell strings 12 and the wiring members 13. That is, the light-receiver-side sealing material 11 has a light-receiver-side accommodating portion that buries a portion of the solar cell strings 12 and the wiring members 13. The light-receiver-side sealing material 11 is not particularly limited as long as it has sealing properties, insulation properties, and light-transmitting properties, and a resin sealing material such as an ethylene-vinyl acetate copolymer resin (EVA) can be used, for example.

[0028] (Solar Cell String 12) As shown in Figures 3 and 4, the solar cell string 12 is a series-connected group in which one or more solar cell cells 20 (solar cells) are electrically connected in series via tab wires 21. The solar cell string 12 of this embodiment has ten solar cell cells 20 connected in series via tab wires 21. As shown in Figure 3, each solar cell 20 is plate-shaped and has a positive electrode portion 22 provided on one main surface and a negative electrode portion 23 provided on the other main surface. As shown in Figure 3, the positive electrode portion 22 of a first solar cell 20a constituting the solar cell string 12 is connected to the negative electrode portion 23 of an adjacent second solar cell 20b via tab wires 21, and the negative electrode portion 23 is connected to the positive electrode portion 22 of an adjacent third solar cell 20c via tab wires 21.

[0029] Solar cell 20 is a so-called crystalline solar cell, and has a layered structure in which a semiconductor substrate is used as a support substrate for each semiconductor layer, and a semiconductor layer of a second conductivity type is layered on a semiconductor substrate of a first conductivity type. Here, the "first conductivity type" refers to p-type or n-type, and the "second conductivity type" refers to the conductivity type opposite to the first conductivity type; when the first conductivity type is p-type, the second conductivity type is n-type, and when the first conductivity type is n-type, the second conductivity type is p-type.

[0030] (Wiring Member 13) The wiring member 13 is a member that extracts electric power from each solar cell string 12 to the outside, and is capable of electrically connecting each solar cell string 12 to a terminal box (not shown).

[0031] (Rear-side sealing material 14) The rear-side sealing material 14 is an insulating sealing material that has sealing and insulating properties and seals the solar cell strings 12 and the wiring members 13, and also serves as an adhesive material that bonds the light-receiving-side sealing material 11, the solar cell strings 12, and the wiring members 13 to the rear-side substrate 16, as shown in Figures 2 and 3 .

[0032] As shown in FIG. 2 , the back-surface-side sealing material 14 is a laminate in which a first sealing material 30 and a second sealing material 31 are stacked in the thickness direction. The first sealing material 30 is a translucent insulating sealing material having sealing, insulating, and translucent properties, and serves as an adhesive that bonds the light-receiving-side sealing material 11, the solar cell string 12, and the wiring member 13 to the second sealing material 31. The first sealing material 30 is provided on the back surface 3 of the solar cell string 12 and is an elastic body that deforms along the solar cell string 12 and the wiring member 13, and absorbs the thickness of the solar cell string 12 and the wiring member 13 together with the light-receiving-side sealing material 11. That is, the first sealing material 30 has a back-surface-side accommodating portion on the surface facing the light-receiving-side substrate 10 that buries a portion of the solar cell string 12 and the wiring member 13, and the surface facing the back-surface-side substrate 16 is smooth. In other words, the shapes of the solar cell string 12 and the wiring member 13 are not reflected on the surface of the first sealing material 30 facing the back-surface-side substrate 16.

[0033] The first sealing material 30 is not particularly limited as long as it has sealing, insulating, and light-transmitting properties, and for example, a resin sealing material such as ethylene-vinyl acetate copolymer resin (EVA) can be used.

[0034] The second sealing material 31 is an insulating sealing material having sealing and insulating properties, and is an adhesive material that bonds between the first sealing material 30 and the rear surface side substrate 16, as shown in Figures 2 and 3. The second sealing material 31 is a colored, non-transparent sealing material that does not substantially have translucency. Here, "colored" refers to a color other than colorless and transparent, and includes achromatic colors such as white and black.

[0035] The second sealing material 31 is a colored sealing material that is a different color from the first sealing material 30, and in this embodiment, the second sealing material 31 is colored with a dye or pigment to change its original color to the same color as the surrounding sealing material 15. The second sealing material 31 has smooth surfaces on both the surface facing the light-receiving-side substrate 10 and the surface facing the back-side substrate 16.

[0036] The second sealing material 31 is not particularly limited as long as it has sealing and insulating properties, and for example, a resin sealing material such as ethylene-vinyl acetate copolymer resin (EVA) can be used.

[0037] (Enclosure Sealing Material 15) The enclosure sealing material 15 is an insulating sealing material having sealing and insulating properties, and is an adhesive material that bonds the light-receiving-side substrate 10 and the back-side substrate 16 together as shown in FIG.

[0038] 3 and 4 , the surrounding sealing material 15 is a portion that surrounds and seals the light-receiving-side sealing material 11, the solar cell string 12, the wiring member 13, and the back-side sealing material 14 in a plan view. As shown in Fig. 4 , the surrounding sealing material 15 has laterally extending portions 40a and 40b extending in the horizontal direction X and vertically extending portions 41a and 41b extending in the vertical direction Y, and the ends of the extending portions 40a, 40b, 41a, and 41b are connected to each other.

[0039] As shown in FIG. 4 , the laterally extending portions 40a, 40b are provided near the horizontal sides 17a, 17b of the light-receiving-side substrate 10 and extend along the horizontal sides 17a, 17b. The vertically extending portions 41a, 41b are provided near the vertical sides 18a, 18b of the light-receiving-side substrate 10 and extend along the vertical sides 18a, 18b. The average width W1 of the laterally extending portions 40a, 40b shown in FIG. 4 is preferably 5 mm or more and 15 mm or less, and more preferably 8 mm or more and 10 mm or less. The average width W2 of the vertically extending portions 41a, 41b shown in FIG. 4 is preferably 5 mm or more and 15 mm or less, and more preferably 8 mm or more and 10 mm or less.

[0040] The surrounding sealing material 15 is not particularly limited as long as it has sealing and insulating properties, and may be, for example, a resin sealing material such as a styrene-based thermoplastic elastomer (TPS). The surrounding sealing material 15 is a colored, non-transparent sealing material that does not substantially transmit light, and in this embodiment, as described above, it has the same color as the second sealing material 31.

[0041] 2, the rear surface side substrate 16 constitutes the rear surface 3 and is a sealing substrate having sealing properties and also an insulating substrate having insulating properties. The rear surface side substrate 16 is not particularly limited as long as it has sealing properties and insulating properties, and for example, a glass substrate such as float glass can be used.

[0042] Next, the positional relationship between the various parts of the solar cell module 1 of this embodiment will be described.

[0043] 2 and 3, the solar cell module 1 has a light-receiving-side encapsulant 11 laminated on a light-receiving-side substrate 10. As shown in Fig. 2, the solar cell module 1 has a plurality of solar cell strings 12 (12a to 12c) arranged side by side at intervals in the lateral direction X on the light-receiving-side encapsulant 11, and the solar cell strings 12 are connected by wiring members 13.

[0044] As shown in Figure 3, the back-side sealing material 14 has a first sealing material 30 that seals each solar cell string 12 and wiring member 13 together with the light-receiving-side sealing material 11, and a second sealing material 31 that bonds the first sealing material 30 to the back-side substrate 16.

[0045] 3 and 4 , the surrounding sealing material 15 surrounds the light-receiving-side sealing material 11, the solar cell string 12, the wiring member 13, and the back-side sealing material 14, and covers the interfaces in the stacking direction of the light-receiving-side sealing material 11, the first sealing material 30, and the second sealing material 31 from the outside in the surface direction. As shown in Fig. 1 , the surrounding sealing material 15 forms end faces corresponding to each side of the solar cell module 1. In other words, the interfaces of the light-receiving-side sealing material 11, the first sealing material 30, and the second sealing material 31 are hidden by the surrounding sealing material 15 and are not exposed to the outside.

[0046] 3, when viewed in cross section, a portion of the second sealing material 31 has entered the gap between the surrounding sealing material 15 and the rear surface-side substrate 16. That is, the second sealing material 31 has a protruding portion that protrudes from above the first sealing material 30 toward the gap between the surrounding sealing material 15 and the rear surface-side substrate 16, and the protruding portion overlaps a portion of the surrounding sealing material 15 on the rear surface-side substrate 16 side. Specifically, as shown in FIG. 3(a), a portion of the second sealing material 31 has entered the gap between the vertical extension portions 41a, 41b and the rear surface-side substrate 16 in the horizontal direction X, and as shown in FIG. 3(b), a portion of the second sealing material 31 has entered the gap between the horizontal extension portions 40a, 40b and the rear surface-side substrate 16 in the vertical direction Y.

[0047] It is preferable that the shortest distance D2 between the surrounding sealing material 15 and the nearest solar cell 20 in the horizontal direction X shown in Fig. 4 is greater than the average width W2 of the surrounding sealing material 15 in the vertical direction Y, and is 1.5 to 3 times the minimum width of the surrounding sealing material 15. It is preferable that the shortest distance D1 between the surrounding sealing material 15 and the nearest solar cell 20 in the vertical direction Y shown in Fig. 4 is greater than the average width W1 of the surrounding sealing material 15 in the vertical direction Y, and is 1.5 to 3 times the minimum width of the surrounding sealing material 15.

[0048] According to the solar cell module 1 of this embodiment, the back side of the solar cell string 12 is sealed by the back-side sealing material 14, and the solar cell string 12 and the back-side sealing material 14 are further surrounded by the surrounding sealing material 15, and the light-receiving-side substrate 10 and the back-side substrate 16 are bonded together, so the interface between the light-receiving-side sealing material 11 and the back-side sealing material 14 is not exposed, and sealing performance can be improved compared to conventional solar cell modules. According to the solar cell module 1 of this embodiment, the back-side sealing material 14 penetrates between the surrounding sealing material 15 and the back-side substrate 16 on the back side of the solar cell string 12, so that water and the like can be prevented from entering through the interface between the surrounding sealing material 15 and the back-side substrate 16, and sealing performance can be improved compared to conventional solar cell modules.

[0049] According to the solar cell module 1 of this embodiment, the thickness of the solar cell string 12 is absorbed by the first sealing material 30, and the second sealing material 31 can seal the first sealing material 30 and the back side substrate 16 in a flat manner, resulting in good adhesion and preventing water and other contaminants from reaching the solar cell string 12 inside the first sealing material 30.

[0050] According to the solar cell module 1 of this embodiment, the back-side sealing material 14 has a portion of the second sealing material 31 that penetrates between the surrounding sealing material 15 and the back-side substrate 16. That is, the second sealing material 31, which is different from the first sealing material 30 that seals the solar cell strings 12, can prevent water and the like from entering through the interface between the surrounding sealing material 15 and the back-side substrate 16, thereby providing higher sealing performance. Furthermore, according to the solar cell module 1 of this embodiment, the light-receiving-side substrate 10, the light-receiving-side sealing material 11, and the first sealing material 30 are translucent, and the second sealing material 31 and the surrounding sealing material 15, which are of the same color, are arranged in a planar manner with overlapping portions. Therefore, when viewed from the light-receiving surface 2 side, the second sealing material 31 and the surrounding sealing material 15 provide a uniform background color overall, resulting in a unified appearance.

[0051] According to the solar cell module 1 of this embodiment, the surrounding sealing material 15 covers the interface between the first sealing material 30 and the second sealing material 31. Therefore, the surrounding sealing material 15 can block and suppress the intrusion of water and the like from the interface between the first sealing material 30 and the second sealing material 31, thereby providing higher sealing performance.

[0052] According to the solar cell module 1 of this embodiment, in plan view, the surrounding sealing material 15 extends along the edge of the light-receiving-side substrate 10 and surrounds the plurality of solar cells 20, and the shortest distances D1, D2 between the solar cell 20 closest to the surrounding sealing material 15 and the surrounding sealing material 15 are 1.5 to 3 times the minimum width of the surrounding sealing material 15. In other words, the distance between the solar cell 20 and the surrounding sealing material 15 is sufficient, so that water and the like are unlikely to reach the solar cell 20.

[0053] According to the solar cell module 1 of this embodiment, the solar cell 20 has a layered structure in which a semiconductor layer of a second conductivity type is stacked on a semiconductor substrate of a first conductivity type, and therefore, the power generation efficiency can be improved compared to a thin-film solar cell that uses an insulating substrate such as a glass substrate as a support substrate.

[0054] In the above embodiment, the back surface-side sealing material 14 has a two-layer structure in which two types of sealing materials, the first sealing material 30 and the second sealing material 31, are laminated, but the present invention is not limited to this. The back surface-side sealing material 14 may be composed of one sealing material, or may be composed of three or more types of sealing materials.

[0055] In the above embodiment, the second sealing material 31 and the surrounding sealing material 15 have the same color, but the present invention is not limited to this. The second sealing material 31 and the surrounding sealing material 15 may have different colors.

[0056] In the above-described embodiment, three solar cell strings 12a to 12c are provided, but the present invention is not limited to this. One to two solar cell strings 12 may be provided, or four or more solar cell strings 12 may be provided.

[0057] In the above embodiment, each solar cell string 12 is configured with 10 solar cells 20, but the present invention is not limited to this. Each solar cell string 12 may be configured with 1 to 9 solar cells 20, or may be configured with 11 or more solar cells 20. Furthermore, in the above embodiment, each solar cell string 12 is configured with the same number of solar cells 20, but the present invention is not limited to this. Each solar cell string 12 may be configured with a different number of solar cells 20.

[0058] In the above embodiment, the solar cell strings 12 are arranged in the horizontal direction X, but the present invention is not limited to this. The solar cell strings 12 may be arranged in the vertical direction Y.

[0059] In the above-described embodiment, crystalline solar cells are used as the solar cells 20, but the present invention is not limited to this. Other types of solar cells may also be used as the solar cells 20.

[0060] In the above-described embodiment, the positive electrode portion 22 and the negative electrode portion 23 of each solar cell 20 in the solar cell string 12 are connected via the tab wire 21, but the present invention is not limited to this. For example, the positive electrode portion 22 and the negative electrode portion 23 of each solar cell 20 in the solar cell string 12 may be directly connected, such as in a single connection.

[0061] In the above-described embodiments, each component can be freely substituted or added between the respective embodiments as long as it falls within the technical scope of the present invention.

[0062] REFERENCE SIGNS LIST 1 Solar cell module 10 Light-receiving side substrate 14 Rear surface sealing material 15 Surrounding sealing material 16 Rear surface substrate 20 Solar cell (solar cell) 20a First solar cell (solar cell) 20b Second solar cell (solar cell) 20c Third solar cell (solar cell) 30 First sealing material 31 Second sealing material

Claims

1. A solar cell module in which solar cells are arranged between a light-receiving substrate and a back-side substrate, and a back-side sealing material is arranged between the solar cells and the back-side substrate, wherein, when viewed in a plane, the solar cell has an surrounding sealing material that surrounds the solar cells and the back-side sealing material and bonds the light-receiving substrate and the back-side substrate, and when viewed in cross-section, a portion of the back-side sealing material has penetrated between the surrounding sealing material and the back-side substrate.

2. The solar cell module described in claim 1, wherein the back surface sealing material has a first sealing material and a second sealing material, the first sealing material is elastic and is provided on the solar cells, has a housing portion on the surface facing the light-receiving side substrate for housing a portion of the solar cells, and has a smooth surface on the back surface substrate side, and the second sealing material is provided on the first sealing material, and both the surface facing the light-receiving side substrate and the surface facing the back surface substrate are smooth.

3. The solar cell module according to claim 2, wherein the second sealing material in the rear surface side sealing material is partly inserted between the surrounding sealing material and the rear surface side substrate.

4. The solar cell module according to claim 3, wherein the second encapsulant and the surrounding encapsulant are substantially the same color.

5. The solar cell module according to claim 2, wherein the surrounding sealing material covers the interface between the first sealing material and the second sealing material.

6. A solar cell module according to any one of claims 1 to 5, comprising a plurality of solar cells, wherein the surrounding sealing material extends along the edge of the light-receiving substrate in a plan view to surround the plurality of solar cells, and the shortest distance between the surrounding sealing material and a solar cell of the plurality of solar cells that is closest to the surrounding sealing material is between 1.5 and 3 times the smallest width of the surrounding sealing material.

7. The solar cell module according to any one of claims 1 to 5, wherein the solar cell has a layered structure in which a semiconductor layer of a second conductivity type is layered on a semiconductor substrate of a first conductivity type.

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