WO2021200418A1

WO2021200418A1 - Solar cell module

Info

Publication number: WO2021200418A1
Application number: PCT/JP2021/012096
Authority: WO
Inventors: 賢吾前田; 秀樹松尾; 澤田　徹
Original assignee: 株式会社カネカ
Priority date: 2020-03-30
Filing date: 2021-03-24
Publication date: 2021-10-07
Also published as: JPWO2021200418A1; TW202145592A

Abstract

A solar cell module (1) in which a plurality of cell strings (2) are each configured by electrically connecting a plurality of elongated cells, each having a long side that is not less than ten times longer than the short side of thereof in a plan view, the cells being connected in the direction of extension of the long sides thereof extend, in which the plurality of cell strings (2) are disposed in parallel in the direction of extension of the short sides, with gaps therebetween, and in which sealing materials (3) that are transparent and that have fluidity at the time of disposition are disposed in the gaps, said solar cell module (1) being provided with pressure receivers (5) which are respectively disposed outward of and parallel to the two cell strings (2) that, among the plurality of cell strings (2) disposed in parallel, are positioned at either end in the direction of extension of the short sides, and which are not electrically connected to said two cell strings.

Description

Solar cell module

Cross-reference of related applications

The present application claims priority based on Japanese Patent Application No. 2020-60103 and is incorporated in the description of the present application by citation.

The present invention relates to a solar cell module constituting a daylighting solar cell.

Daylighting solar cells are applied to windows of large buildings, etc. As for the daylighting type solar cell, when particularly excellent design is required, a type in which the power generation area of the thin film solar cell is locally removed to transmit light is used, but in recent years, per window area. From the viewpoint of the output of the above, a solar cell of a type in which substantially square cells are arranged with a gap is often used (for example, described in Japanese Patent Application Laid-Open No. 2001-339087).

However, a solar cell using such a substantially square-shaped cell has a difficulty in design because the substantially square-shaped cell becomes conspicuous, and the cell is chromatically inconspicuous, or the metal electrode of each cell or the like. Ingenuity such as hiding the wiring between cells is required. One solution to this problem is to connect a large number of elongated cells in one direction to form a cell string, and arrange multiple cell strings arranged at regular intervals to form a blind-like see-through. It is to be a solar cell (for example, described in International Publication No. 2019/181689).

By the way, the cell strings of a blind-like see-through solar cell are extremely elongated (the ratio of the length and width of each cell string is very large), and it is necessary to arrange a plurality of cell strings in parallel at regular intervals. Since it is necessary to sandwich and seal this with a sealing material made of transparent resin, each cell string is easily distorted due to pressure applied from the sealing material to each cell string when sealing. It is extremely difficult to maintain the straightness of the cell strings after sealing and the parallelism between the cell strings, which are elements that are directly related to the design.

Japanese Patent Application Laid-Open No. 2001-339087 International Publication No. 2019/181689

Therefore, it is an object of the present invention to provide a solar cell module in which it is easy to maintain the straightness of the cell strings after sealing and the parallelism between the cell strings.

The present invention comprises a plurality of cells, each of which is an elongated rectangular cell having a short side and a long side having a length of 10 times or more the length of the short side in a plan view. The plurality of cell strings are composed of a plurality of cell strings formed by electrically connecting to each other along the extending direction of the long side, and the plurality of cell strings are the extending directions of the short side between the adjacent cell strings. In a solar cell module made of a sealing material which is arranged in parallel to each other with a gap, is arranged in each of the gaps, is transparent, and has fluidity at the time of arrangement, the solar cell module is arranged in parallel. Of the plurality of cell strings, the cells are arranged outside the two cell strings located at both ends in the extending direction of the short side, parallel to each of the two cell strings, and with respect to each of the two cell strings. It is a solar cell module characterized by including a pressure receiving body that is not electrically connected.

Further, it can be assumed that the pressure receiving body is made of a material having a Young's modulus of 10 GPa or more.

Further, the pressure receiving body can be made of metal.

Further, the plan view shape of each cell string and the plan view shape of each pressure receiving body can be the same.

Further, the plurality of cell strings and the sealing material can be sandwiched between two transparent plates.

FIG. 1 is a front view showing an example of the appearance of the solar cell module according to the embodiment of the present invention, with the light receiving surface side facing forward. FIG. 2 is an exploded cross-sectional view of the solar cell module. FIG. 3A is a perspective view of a pressure receiving body according to an embodiment of the present invention. FIG. 3B is a diagram showing various variations in the cross-sectional shape of the pressure receiving body. FIG. 3C is a diagram showing various variations in the cross-sectional shape of the pressure receiving body. FIG. 3D is a diagram showing various variations in the cross-sectional shape of the pressure receiving body. FIG. 3E is a diagram showing various variations in the cross-sectional shape of the pressure receiving body. FIG. 4A is a schematic vertical sectional view showing a configuration related to the pressure receiving body of the solar cell module. FIG. 4B is a schematic vertical sectional view showing a configuration related to the pressure receiving body in the comparative example.

Regarding the solar cell module 1 according to the present invention, one embodiment will be taken up and the following description will be given together with the drawings.

As shown in FIG. 1, the solar cell module 1 of the present embodiment constitutes a blind-like see-through solar cell that transmits light in the thickness direction. As shown in FIGS. 1 and 2, the solar cell module 1 includes a plurality of

cell strings

2 and 2, a sealing material 3, a transparent plate 4, and a pressure receiving body 5 as main components related to the present invention. As shown in FIG. 1, the frame portions 6 located at the four edge edges are combined into a single piece. The solar cell module 1 is attached to a window frame of a building, for example, and is used as a window.

As shown in FIG. 2, the configuration (layer configuration) of the solar cell module 1 is substantially the same size as the highly transparent (float) unreinforced glass as the first transparent plate 4A and the first transparent plate 4A from the light receiving surface side. The transparent first sealing material 3A is arranged, and from the back surface side opposite to the light receiving surface side, it is substantially the same as the highly transparent (float) unreinforced glass as the second transparent plate 4B and the second transparent plate 4B. A transparent second sealing material 3B having the size of is arranged. Then, a plurality of cell strings 2 to 2 (see FIG. 1) are arranged between the first sealing material 3A on the upper side of the drawing and the second sealing material 3B on the lower side of the drawing. In the following description, the first sealing material 3A and the second sealing material 3B are collectively referred to as a sealing material 3, and the first transparent plate 4A and the second transparent plate 4B are collectively referred to as a transparent plate 4. Refer to. Further, a connection-related member 9 is sandwiched between the ends of each cell string 2. As shown in FIG. 2, the connection-related member 9 is connected to the interconnector 91 provided at both ends of each cell string 2, the wiring sheet 92 supporting the interconnector 91, and the outside of the solar cell module 1 for extracting electricity. The electric wiring 93 and the above-mentioned members 91 to 93 are provided with a shielding sheet 94 for hiding the members 91 to 93 so as not to appear in the appearance of the solar cell module 1.

Each cell string 2 is configured by electrically connecting a plurality of cells (individual cells are not shown). Each cell is in the shape of a plate having a semiconductor substrate and a plurality of current collecting electrodes formed on the semiconductor substrate. Since the basic configuration of each cell for power generation and current collection is the same as that of a known solar cell, detailed description here will be omitted. Each cell has an elongated rectangular shape having a short side and a long side having a length of 10 times or more the length of the short side in a plan view (plan view for each cell).

Each cell string 2 is formed by electrically connecting a plurality of cells having the above shape along the extending direction of the long side of each cell (longitudinal direction, left-right direction in FIGS. 1 and 2). The connection can be made by various means. For example, a "singling connection" can be adopted in which the end portions in the longitudinal direction of each cell are sequentially arranged so as to overlap in the thickness direction.

The solar cell module 1 is configured by arranging a plurality of cell strings 2 to 2 in the plane direction. Specifically, a plurality of

cell strings

2 and 2 are arranged parallel to each other with a gap in the extending direction (width direction, vertical direction in FIG. 1) of the short side between the

adjacent cell strings

2 and 2. .. The gap contributes to daylighting. In the plurality of

cell strings

2 and 2, one end (for example, the right end) of the reference cell string 2 and another cell string 2 adjacent to each other at the upper side in FIG. 1, for example, are electrically connected to each other. Further, the reference cell string 2 and the other end portion (for example, the left end portion) of the other cell strings 2 adjacent to each other at the lower side in FIG. 1 are electrically connected to each other. In this way,

several cell strings

2 and 2 are connected in series. In one solar cell module 1, a plurality of the units connected in series are connected in parallel.

Regarding the fixing of each cell string 2 in the solar cell module 1, the sealing material 3 is arranged in each of the gaps between the

adjacent cell strings

2 and 2 in a state where the plurality of

cell strings

2 and 2 are arranged in parallel. There is. That is, the sealing material 3 is interposed between the

adjacent cell strings

2 and 2. The sealing material 3 is in the form of a transparent sheet before being incorporated into the solar cell module 1, and is softened (liquefied) by heating when arranged in the gap between the adjacent cell strings 2 and 2. ) Has fluidity. It should be noted that this fluidity is sufficient to enter the gap. As a material constituting the sealing material 3, for example, EVA (ethylene vinyl acetate copolymer), POE (polyolefin), PVB (polyvinyl butyral), and ionomer can be used.

The transparent plate 4 (specifically, the first transparent plate 4A) constitutes the outer layer of the solar cell module 1. In the present embodiment, a hard glass plate is used as the transparent plate 4, and the transparent plate 4 is transparent and can transmit light in the thickness direction for daylighting. Various constituent members for power generation, including a plurality of

cell strings

2 and 2, and the sealing material 3 are sandwiched between two

transparent plates

4 and 4 which are overlapped in the thickness direction.

The pressure receiving body 5 is an elongated plate-shaped body (ribbon-shaped body) or rod-shaped body. The length dimension of the pressure receiving body 5 is substantially the same as the length dimension of each cell string 2, but the length of each cell string 2 is hidden because the end portion is hidden by the frame portion 6 and the shielding sheet 94. The length of plus or minus 20% with respect to the dimension is allowed. The pressure receiving body 5 is outside of the two

cell strings

2 and 2 located at both ends in the extending direction (width direction) of the short side of the plurality of

cell strings

2 and 2 arranged in parallel (in the present embodiment). , It is arranged on the upper and lower outer sides of the upper and

lower cell strings

2 and 2 shown in FIG. The pressure receiving body 5 is arranged in parallel with each of the two

cell strings

2 and 2. However, the pressure receiving body 5 is not electrically connected to each cell string 2. That is, the pressure receiving body 5 does not contribute to power generation. Further, unlike the cell string 2 in which a plurality of cells are connected, the pressure receiving body 5 is basically a single body formed continuously. However, it is also possible to connect a plurality of members to form one pressure receiving body 5. By shielding each pressure receiving body 5 with, for example, a sheet similar to the shielding sheet 94, the solar cell module 1 can be made inconspicuous in appearance.

The shape of the pressure receiving body 5 is not particularly limited, but since the pressure receiving body 5 is also sandwiched between the two

transparent plates

4 and 4 together with the plurality of

cell strings

2 and 2, the thickness dimension of the plurality of

cell strings

2 and 2 It is preferable that the thickness dimensions are substantially the same as or larger than each thickness dimension. By setting such a thickness dimension, the pressure receiving body 5 can fill the space between the two

transparent plates

4 and 4 facing each other, so that the sealing material 3 tends to flow. The pressure receiving body 5 can effectively receive the pressure. In the present embodiment, the thickness dimension of the pressure receiving body 5 is set to about 50% of the thickness dimension of the sealing material 3 (before softening). Specifically, it is set to 20 μm to 5 mm.

Further, in terms of design (aesthetics), it is preferable that the plan view shape of each cell string 2 and the plan view shape of the pressure receiving body 5 are substantially the same. This is because even if the pressure receiving body 5 that does not contribute to power generation is provided, the appearance of the solar cell module 1 is unlikely to be uncomfortable. Further, as compared with the case where the pressure receiving body 5 is made wider, it is possible to suppress a reduction in the effective power generation area (area in which a plurality of cell strings 2 to 2 can be arranged) in the solar cell module 1. The width dimension of the pressure receiving body 5 is set between 2 mm and 100 mm. In this embodiment, it is set to 5 mm.

The cross-sectional shape of the pressure receiving body 5 in the width direction can be as shown in FIGS. 3A to 3E, for example. FIG. 3A is a rectangle, FIG. 3B is a substantially circular shape, FIG. 3C is an ellipse, and FIG. Is formed by alternately forming a plurality of portions 51 having a large thickness dimension and a plurality of portions 52 having a small thickness dimension, and aligning the respective portions at the center in the thickness direction. In particular, since FIGS. 3A to 3C have simple shapes, it is advantageous from the viewpoint of manufacturing and from the viewpoint of obtaining materials that general-purpose rods and plates can be easily diverted. On the other hand, the shapes shown in FIGS. 3D and 3E are advantageous in that the bending strength in the longitudinal direction can be improved by alternately forming the portions having a large thickness dimension and the portions having a small thickness dimension.

The pressure receiving body 5 is composed of a material having a Young's modulus of 10 GPa or more, preferably a material having a Young's modulus of 50 GPa or more. However, even if the Young's modulus is a single material less than the above value, it can be molded by incorporating a reinforcing material such as glass fiber, or the width dimension can be set larger than the width dimension of each cell string 2. , Can be used for the pressure receiving body 5. By configuring the pressure receiving body 5 as described above, the pressure receiving body 5 can reliably receive the pressure of the sealing material 3.

Examples of the material constituting the pressure receiving body 5 include copper, aluminum, silver, iron, alloys thereof (stainless steel alloy, etc.), and surface-treated materials (copper plated, etc.) in the case of metal. ) Can be used. When the pressure receiving body 5 is made of metal, it is advantageous because the pressure receiving body 5 can be formed of an easily available material. Metal rods and metal wires can be used as easily available materials. In the case of non-metals, for example, glass fiber reinforced unsaturated polyester can be used. Since the pressure receiving body 5 does not contribute to power generation, it is not a problem to use a non-conductor such as a non-metal. However, in terms of the design, if the plan view shape of each cell string 2 and the plan view shape of the pressure receiving body 5 are substantially the same, when a non-metal is used, for example, the pressure of the sealing material 3 is used. Since it is necessary to increase the width dimension in order to reliably receive the metal, it is difficult to make it substantially the same as the plan view shape of each cell string 2, and the metal is selected due to the ease of material selection and cost. It can be said that it is preferable to use it.

Here, arranging a foreign substance different from the sealing material 3 at the outer module end of the plurality of

cell strings

2 and 2 is insane from the viewpoint of ensuring the reliability of the sealing end portion in the technical field of the solar cell. It can be said that it is an act. Moreover, using a metal material as the foreign substance as in the present embodiment is an insane act from the viewpoint of ensuring insulation. In the present embodiment, without being bound by the common sense of those skilled in the art, by daringly arranging and sealing a dummy metal body that does not contribute to power generation on the outside of the outermost cell string 2 in parallel with the cell string 2. In addition to the significant improvement in the positional accuracy of each cell string 2 in the solar cell module 1, the reliability of the sealing end portion and the insulation property can be ensured without any problem. This is an unprecedented original point of this embodiment.

A pressure receiving body 5 that is parallel to the cell string 2 and is not electrically connected to the cell string 2 on the outside of the outermost cell string 2 near the end (lower end in the drawing) of the solar cell module 1. Place and seal. Since the pressure receiving body 5 is arranged in the solar cell module 1, the sealing material 3 tends to flow when the sealing material 3 having fluidity is arranged in the gap between the cell strings 2 and 2. The pressure receiving body 5 receives the pressure generated accordingly. The pressure receiving body 5 functions as a so-called "breakwater" with respect to the sealing material 3. Then, since the pressure receiving body 5 receives the pressure of the sealing material 3, the sealing material 3 is less likely to flow inside the solar cell module 1. In this way, it is possible to suppress the deformation of each cell string 2 by the pressure of the sealing material 3 or by being flown through the flowing sealing material 3. Therefore, the straightness of each cell string 2 and the parallelism between the

adjacent cell strings

2 and 2 are greatly improved.

Further, in the present embodiment, the plurality of

cell strings

2 and 2 and the sealing material 3 are sandwiched between the two transparent plates 4 and 4 (specifically, the first transparent plate 4A and the second transparent plate 4B). ing. When a plurality of cell strings 2 to 2 are sandwiched between two

transparent plates

4 and 4 with a pressure P1 in the thickness direction (see FIG. 4A), pressure is applied to the heated sealing material 3 to apply pressure to the sealing material 3. A flow is generated in which the cells enter the gap between the

adjacent cell strings

2 and 2 and further move outward in the width direction of the plurality of

cell strings

2 and 2.

Here, the solar cell module 1X shown as a comparative example in FIG. 4B has a configuration in which only a plurality of

cell strings

2 and 2 are arranged between the two

transparent plates

4 and 4. In this example, the pressure P2 in the surface direction is generated by the flow of the sealing material 3 due to the pressure P1 in the thickness direction. Of the plurality of cell strings 2 to 2 arranged in parallel, those at both ends (left and right ends in the drawing) lose to this pressure P2, and the cell strings 2 and 2 at both ends are U-shaped in a plan view. It was sometimes distorted in an S shape. If this happens, the solar cell module 1 will be defective.

On the other hand, in the present embodiment, even if a pressure in the surface direction is generated due to the flow of the sealing material 3 due to the pressure P1 in the thickness direction being applied, the

pressure receiving bodies

5 and 5 receive this pressure. , It is possible to prevent the sealing material 3 from pushing the

inner cell strings

2 and 2 in the width direction. As a result, it is possible to suppress the deformation of each cell string 2. Therefore, the solar cell module 1 constituting the blind-like see-through solar cell can be manufactured with good yield while suppressing the occurrence of defective products.

Although the present invention has been described above by taking up one embodiment, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

The configuration and operation related to the above embodiment are summarized below. The embodiment is a plurality of cells, each of which is an elongated rectangular cell having a short side and a long side having a length of 10 times or more the length of the short side in a plan view. The plurality of cell strings 2 are formed by electrically connecting the two to each other along the extending direction of the long side, and the plurality of cell strings 2 are the short sides between the adjacent cell strings. In the solar cell module 1 made of a sealing material 3 which is arranged in parallel with each other with a gap in the extending direction of the above, is arranged in each of the gaps, and is transparent and has fluidity at the time of arrangement. Of the plurality of cell strings 2 arranged in parallel, the two cell strings 2 located at both ends in the extending direction of the short side are outside and parallel to each of the two cell strings 2. The solar cell module 1 is provided with a pressure receiving body 5 that is arranged and is not electrically connected to each of the above.

According to this configuration, when the sealing material 3 having fluidity is arranged in the gap between the cell strings 2, the pressure receiving body 5 receives the pressure caused by the sealing material 3 trying to flow, so that the sealing material 5 is sealed. It is possible to prevent the cell string 2 from being deformed by the pressure of the stop member 3.

Further, it can be assumed that the pressure receiving body 5 is made of a material having a Young's modulus of 10 GPa or more.

According to this configuration, the pressure receiving body 5 can reliably receive the pressure of the sealing material 3.

Further, the pressure receiving body 5 can be made of metal.

According to this configuration, the pressure receiving body 5 can be formed of an easily available material.

Further, the plan view shape of each cell string 2 and the plan view shape of each pressure receiving body 5 can be the same.

According to this configuration, even if the pressure receiving body 5 is provided, the appearance of the solar cell module 1 is unlikely to be uncomfortable.

Further, the plurality of cell strings 2 and the sealing material 3 can be sandwiched between two transparent plates 4.

According to this configuration, it is possible to effectively suppress the deformation of the cell string 2 with respect to the flow of the sealing material 3 due to the pressure when the plurality of cell strings 2 are sandwiched between the two transparent plates 4.

In this embodiment, it is possible to prevent the cell string 2 from being deformed by the pressure of the sealing material 3. Therefore, it is possible to easily maintain the straightness of the cell string 2 after sealing and the parallelism between the cell strings 2.

1 Solar cell module 2 Cell string 3 Encapsulant 4 Transparent plate 5 Pressure receiving body

Claims

A plurality of cells, each of which is a slender rectangular cell having a short side and a long side having a length of 10 times or more the length of the short side in a plan view, is the long side. Consists of multiple cell strings constructed by electrically connecting to each other along the extending direction of
The plurality of cell strings are arranged in parallel with each other with a gap in the extending direction of the short side between the adjacent cell strings.
In a solar cell module made of a sealing material that is arranged in each of the gaps and is transparent and has fluidity when arranged.
Of the plurality of cell strings arranged in parallel, the cell strings arranged in parallel with each of the two cell strings are arranged outside the two cell strings located at both ends in the extending direction of the short side. A solar cell module characterized by having a pressure receiving body that is not electrically connected to each of them.
The solar cell module according to claim 1, wherein the pressure receiving body is made of a material having a Young's modulus of 10 GPa or more.
The solar cell module according to claim 2, wherein the pressure receiving body is made of metal.
The solar cell module according to any one of claims 1 to 3, wherein the plan view shape of each cell string and the plan view shape of each pressure receiving body are the same.
The solar cell module according to any one of claims 1 to 4, wherein the plurality of cell strings and the sealing material are sandwiched between two transparent plates.