JPWO2013018533A1 - Solar cell module - Google Patents

Abstract

Provided is a solar cell module in which the photoelectric conversion efficiency hardly decreases with time. The solar cell module (1) includes a plurality of solar cells (20) and a wiring member (30). The wiring member (30) electrically connects the adjacent solar cells (20). The wiring material (30) has a wiring material main body (32) and a connection part (31). The wiring material main body (32) is not electrically connected directly to the solar cell (20). The connection part (31) is connected to the wiring material main body (32). The connection part (31) is electrically connected directly to the solar cell (20). The solar cell module (1) further includes an insulating coating film (33). The insulating coating (33) covers at least a part of the surface of the wiring material body (32).

Description

  The present invention relates to a solar cell module.

  In recent years, a solar cell module having a back junction solar cell is known as a solar cell module having excellent photoelectric conversion efficiency. For example, Patent Document 1 describes a solar cell module including a plurality of back junction solar cells electrically connected by a wiring material.

JP 2009-266848 A

  In recent years, there has been an increasing demand for suppressing a decrease in the photoelectric conversion efficiency of a solar cell module over time.

  An object of the present invention is to provide a solar cell module in which the photoelectric conversion efficiency does not easily decrease with time.

  The solar cell module according to the present invention includes a plurality of solar cells and a wiring material. The wiring material electrically connects adjacent solar cells. The wiring material has a wiring material main body and a connection part. The wiring material body is not electrically connected directly to the solar cell. The connecting portion is connected to the wiring material body. The connection part is electrically connected directly to the solar cell. The solar cell module according to the present invention further includes an insulating coating film. The insulating coating film covers at least a part of the surface of the wiring material body.

  According to the present invention, it is possible to provide a solar cell module in which the photoelectric conversion efficiency does not easily decrease with time.

FIG. 1 is a schematic cross-sectional view of a solar cell module according to an embodiment of the present invention. FIG. 2 is a schematic back view of a solar cell in one embodiment of the present invention. FIG. 3 is a schematic back view of a solar cell string according to an embodiment of the present invention. In FIG. 3, although the part in which the coating film is formed is hatched, the part to which the hatching is attached does not represent a cross section. 4 is a schematic cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a schematic cross-sectional view taken along line VV in FIG. FIG. 6 is a schematic rear view of a solar cell string in a modified example. In FIG. 6, although the part in which the coating film is formed is hatched, the part to which the hatching is attached does not represent a cross section. FIG. 7 is a schematic plan view of the wiring member in the second modification. FIG. 8 is a schematic plan view of the wiring member in the third modification. FIG. 9 is a schematic plan view of a wiring member according to a fourth modification. FIG. 10 is a schematic plan view of the wiring member in the fifth modification. FIG. 11 is a schematic plan view of a wiring member according to a sixth modification.

  Hereinafter, an example of the preferable form which implemented this invention is demonstrated. However, the following embodiment is merely an example. The present invention is not limited to the following embodiments.

  Moreover, in each drawing referred in embodiment etc., the member which has a substantially the same function shall be referred with the same code | symbol. The drawings referred to in the embodiments and the like are schematically described, and the ratio of the dimensions of the objects drawn in the drawings may be different from the ratio of the dimensions of the actual objects. The dimensional ratio of the object may be different between the drawings. The specific dimensional ratio of the object should be determined in consideration of the following description.

  FIG. 1 is a schematic cross-sectional view of a solar cell module 1 according to this embodiment. The solar cell module 1 includes a solar cell string 10. The solar cell string 10 is disposed between the first protection member 11 located on the light receiving surface side and the second protection member 12 located on the back surface side. A filler layer 13 is provided between the first protective member 11 and the second protective member 12. The solar cell string 10 is sealed with a filler layer 13.

  The 1st protection member 11 can be comprised by the member which has translucency, such as a glass substrate and a resin substrate, for example. The second protective member 12 can be constituted by, for example, a resin sheet, a resin sheet with a metal foil interposed therebetween, a glass substrate, a resin substrate, or the like. The filler layer 13 can be made of, for example, a resin such as ethylene / vinyl acetate copolymer (EVA), polyvinyl butyral (PVB), polyethylene (PE), polyurethane (PU), or the like.

  The solar cell string 10 is configured by arranging wiring members 30 between a plurality of solar cells 20 along the x direction (first direction). The solar cell 20 has first and second main surfaces 20a and 20b. Solar cell 20 receives light on first main surface 20a. For this reason, the 1st main surface 20a may be called a light-receiving surface, and the 2nd main surface 20b may be called a back surface. The solar cell 20 may receive light only on the first main surface 20a constituting the light receiving surface and generate power, or can receive light on any of the first and second main surfaces 20a, 20b. A double-sided light receiving type that generates electricity may be used.

  In addition, the kind of solar cell 20 is not specifically limited. The solar cell 20 can be constituted by, for example, a crystalline silicon solar cell using a crystalline silicon substrate.

  FIG. 2 shows a schematic rear view of the solar cell 20. As shown in FIG. 2, the solar cell 20 includes first and second electrodes 21 and 22 on the second main surface 20b side. Specifically, the solar cell 20 includes a photoelectric conversion unit 23 and first and second electrodes 21 and 22 disposed on the main surface on the back surface side of the photoelectric conversion unit 23.

  Each of the first and second electrodes 21 and 22 is provided in a comb shape. The first electrode 21 and the second electrode 22 are arranged so that comb teeth are alternately arranged. Specifically, each of the first and second electrodes 21 and 22 has a plurality of finger portions 21a and 22a and bus bar portions 21b and 22b. Each of the plurality of finger portions 21a and 22a extends along the x direction. The plurality of finger portions 21a and 22a are spaced apart from each other along the y-th direction (2 direction) perpendicular to the x direction.

  The plurality of finger portions 21a are electrically connected to the bus bar portion 21b. The bus bar portion 21b is disposed on one side in the x direction of the plurality of finger portions 21a. The bus bar portion 21b is provided at one end portion in the x direction of the solar cell 20 from one end portion in the y direction to the other end portion.

  The plurality of finger portions 22a are electrically connected to the bus bar portion 22b. The bus bar portion 22b is disposed on the other side in the x direction of the plurality of finger portions 22a. The bus bar portion 22b is provided from one end portion in the y direction to the other end portion in the other end portion in the x direction of the solar cell 20.

  As shown in FIGS. 3 and 4, the plurality of solar cells 20 are electrically connected by a wiring member 30. Specifically, the first electrode 21 of one solar cell 20 of the solar cells 20 adjacent in the x direction and the second electrode 22 of the other solar cell are electrically connected by the wiring member 30.

  The wiring member 30 and the second main surface 20b of the solar cell 20 are bonded by an adhesive layer 40 shown in FIG. The adhesive layer 40 can be composed of, for example, a cured product of solder or resin adhesive. The wiring member 30 can be made of, for example, a metal foil such as Ag or Cu, a laminate of metal foils, or a metal foil whose surface is covered with solder or the like.

  Next, the configuration of the wiring member 30 in the present embodiment will be described in more detail with reference mainly to FIG.

  The wiring member 30 includes a wiring member main body 32 and a plurality of connection portions 31. The wiring material main body 32 is not directly bonded to the solar cell 20 and is not directly electrically connected to the solar cell 20.

  The wiring member body 32 has an elongated shape extending along the y direction perpendicular to the x direction. The wiring material body 32 is provided in a substantially linear shape. The wiring material main body 32 is provided from one end in the y direction of the solar cell 20 to the other end.

  The plurality of connection portions 31 are arranged at intervals in the y direction. The connection portion 31 is connected to the wiring material body 32. The connection portion 31 is bonded to the second main surface 20b of the solar cell 20 with the adhesive layer 40, and is electrically connected directly to the solar cell 20.

  At least a part of the surface of the wiring material body 32 is covered with an insulating coating 33. Specifically, in the present embodiment, substantially the entire surface including the first and second main surfaces and side surfaces of the wiring material main body 32 is covered with the insulating coating film 33. The coating film 33 does not cover the surface of the connection portion 31.

  In the present embodiment, the coating film 33 is composed of an electrodeposition coating film formed by electrodeposition coating.

  The constituent material of the coating film 33 is not particularly limited as long as it is an insulating material. The coating film 33 was selected from the group consisting of, for example, phenolic resin (PF) such as novolac resin, polyamide (PA) resin, polyimide (PI) resin, acrylic (PMMA) resin, epoxy (EP) resin, and urethane resin. It is preferable to consist of at least one.

  By the way, the thermal expansion coefficient differs between the solar cell and the wiring material. For this reason, when the temperature of the solar cell module changes, stress is applied to the solar cell and the wiring material, thereby changing the relative positional relationship between adjacent solar cells electrically connected by the wiring material and the wiring material. There is a case. Thereby, the part which was not directly electrically connected to the solar cell of a wiring material may contact a solar cell, and there exists a possibility that a short circuit may arise.

  On the other hand, in this embodiment, at least a part of the surface of the wiring material main body 32 is covered with the insulating coating film 33. For this reason, even if the relative positional relationship between the adjacent solar cells and the wiring material changes, the portion of the wiring material 30 that is not electrically connected directly to the solar cell 20 directly contacts the solar cell 20. To be suppressed. Therefore, a decrease in photoelectric conversion efficiency due to a short circuit can be suppressed. As a result, a decrease in the photoelectric conversion efficiency of the solar cell module 1 with time can be suppressed.

  Further, by protecting the wiring material body 32 with the coating film 33, the heat resistance of the wiring material 30 can be improved. In particular, when the coating film 33 is composed of an electrodeposition coating film, the heat resistance is more effectively improved.

  As a method for suppressing direct contact between the wiring material body and the solar cell, a method of attaching an insulating tape to the wiring material body is also conceivable. However, when the tape is attached to the wiring material body, the expansion and contraction of the wiring material is hindered by the tape. For this reason, when the temperature of a solar cell module changes and a thermal expansion amount difference arises between a wiring material and a solar cell, a big stress is added to a wiring material and a solar cell. Therefore, a big curvature generate | occur | produces in a solar cell, or a wiring material becomes easy to peel from a solar cell.

  On the other hand, in the case where the coating film 33 is provided on at least a part of the surface of the wiring material main body 32, the stretchability of the wiring material 30 is less likely to be lower than when a tape is applied. Therefore, even when the temperature of the solar cell module 1 changes and a difference in thermal expansion occurs between the wiring member 30 and the solar cell 20, the wiring member 30 and the solar cell are expanded and contracted by the wiring member 30. The stress applied to 20 can be relaxed. Therefore, it is possible to suppress the warpage of the solar cell 20 or the separation of the wiring member 30 from the solar cell 20.

  Moreover, when an insulating tape is affixed to the wiring material body, moisture may enter between the tape and the wiring material body, and the wiring material body may deteriorate. On the other hand, when the coating film 33 is provided as in the present embodiment, moisture hardly enters between the wiring material body 32 and the coating film 33. Accordingly, it is possible to suppress the deterioration of the wiring member 30 due to moisture.

(Modification)
In the present invention, the wiring material is not particularly limited as long as it has a wiring material main body and a connecting portion. For example, the wiring member may have a structure as shown in FIG.

  As shown in FIG. 6, in this modification, the portion located between adjacent connection portions 31 in the y direction of the wiring material body 32 is in the y direction perpendicular to the x direction, which is the arrangement direction of the solar cells 20. It includes curved portions 32a to 32h extending in a direction inclined with respect to it. Specifically, openings 34 a to 34 d are provided in the wiring material main body 32. As a result, curved portions 32a to 32h configured by at least one of at least one bent portion and at least one curved portion extending in a direction inclined with respect to the y direction, which is the direction in which the wiring material main body 32 extends, are provided. Yes. The curved portions 32a to 32h are excellent in stretchability. For this reason, when these curved parts 32a-32h expand / contract suitably, the stress added to the wiring material 30 or the solar cell 20 is relieve | moderated effectively. Moreover, in this modification, the curved parts 32a-32h are provided in the both sides in the y direction of the connection part 31. As shown in FIG. For this reason, the stress added to the wiring material 30 and the solar cell 20 is relieved more effectively.

  It is preferable that the openings 34a to 34d have shapes that do not have corners in their outlines. In particular, the opening 34b is preferably provided in a circular shape, an elliptical shape in which the major axis or the minor axis is in the y direction, or an ellipse shape in which the major axis or the minor axis is in the y direction. Thereby, it can suppress that the insulating coating film 33 accumulates in the outline of opening 34a-34d. As a result, it can suppress that the coating film 33 peels from the outline of opening 34a-34d.

  Also in this modification, since the at least part of the surface of the wiring material main body 32 is covered with the insulating coating film 33 as in the above embodiment, the wiring material main body 32 and the solar cell 20 are in direct contact with each other. The short circuit by this is suppressed. Unlike the case where a tape is applied to the wiring material main body 32, the coating material 33 hardly hinders the expansion and contraction of the wiring material main body 32, particularly the expansion and contraction of the curved portions 32 a to 32 h. The applied stress can be relaxed more effectively. As a result, it is possible to effectively suppress the wiring material 30 from being peeled off from the solar cell 20 or the solar cell 20 being warped.

  Further, from the viewpoint of alleviating the stress applied to the connection portion 31, the connection portion 31 may have a shape with a rounded tip portion extending in the x direction.

  From the viewpoint of further improving the stretchability of the wiring material body 32, the coating film 33 may not be provided on the surfaces of the curved portions 32a to 32h.

(Second to sixth modifications)
FIG. 7 is a schematic plan view of the wiring member in the second modification. In the second modification, one curved portion (specifically, a curved portion) 32c is provided in each part of the portion located between the connection portions 31 adjacent in the y direction of the wiring member main body 32.

  FIG. 8 is a schematic plan view of the wiring member in the third modification. In the third modified example, a curved portion 32d including a plurality of bent portions is provided in each part of the portion located between the connecting portions 31 adjacent in the y direction of the wiring member main body 32.

  FIG. 9 is a schematic plan view of a wiring member according to a fourth modification. FIG. 10 is a schematic plan view of the wiring member in the fifth modification. FIG. 11 is a schematic plan view of a wiring member according to a sixth modification. In the fourth to sixth modifications, substantially the entire portion of the wiring member main body 32 located between the connection portions 31 adjacent in the y direction is configured by a curved portion. Specifically, in the fourth modified example, substantially the entire portion located between the connecting portions 31 adjacent in the y direction of the wiring member main body 32 is composed of a curved portion constituted by a plurality of curved portions. In the fifth modified example, substantially the entire portion located between the connecting portions 31 adjacent in the y direction of the wiring member main body 32 is composed of a curved portion constituted by one curved portion. In the sixth modified example, a set of curved portions (specifically, substantially all of the portions located between the connection portions 31 adjacent in the y direction of the wiring material body 32 face each other and protrude in the opposite direction) Are curved portions) 32e and 32f. Even in such a case, the stress applied to the solar cell 20 and the wiring member 30 can be relieved because the curved portion can be expanded and contracted. Therefore, a solar cell module having improved reliability can be realized.

  The opening defined by the first and second curved portions may be, for example, an ellipse or an ellipse having a major axis or a minor axis facing the second direction.

  Thus, the present invention includes various embodiments not described herein. For example, at least one of the first and second electrodes may be a so-called bus bar-less electrode that does not have a bus bar portion and is configured by a plurality of finger portions. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1 ... Solar cell module 20 ... Solar cell 20a ... 1st main surface 20b ... 2nd main surface 21 ... 1st electrode 22 ... 2nd electrode 30 ... Wiring material 31 ... Connection part 32 ... Wiring material main body 33 ... Coating

Claims (9)

A plurality of solar cells;
A wiring material electrically connecting the adjacent solar cells;
With
The wiring material is
A wiring material body that is not electrically connected directly to the solar cell;
Connected to the wiring material body, and a connection part electrically connected directly to the solar cell;
Have
The solar cell module further provided with the insulating coating film which covers at least one part of the surface of the said wiring material main body.   The solar cell module according to claim 1, wherein the coating film is an electrodeposition coating film.   3. The solar cell module according to claim 1, wherein the coating film is made of at least one selected from the group consisting of a phenol resin, a polyamide resin, a polyimide resin, an acrylic resin, an epoxy resin, and a urethane resin. The solar cell has first and second electrodes on one main surface side,
4. The wiring member according to claim 1, wherein the wiring member electrically connects the first electrode of one solar cell of the adjacent solar cells and the second electrode of the other solar cell. 5. The solar cell module according to one item.   The part located between the adjacent connection parts of the wiring member body is in a direction inclined with respect to a second direction which is a direction perpendicular to the first direction which is the arrangement direction of the plurality of solar cells. The solar cell module as described in any one of Claims 1-4 containing the curved part extended.   The solar cell module according to claim 5, wherein the curved portion is provided on both sides of the connection portion. The part located between the adjacent connection parts of the wiring material body is
A first bend projecting toward one side of the first direction;
A second curved portion that is arranged to face the first curved portion in the first direction, and protrudes toward the other side of the first direction;
Have
The solar cell module according to claim 5 or 6, wherein an opening is defined by the first curved portion and the second curved portion.   The opening is provided in a circular shape, an elliptical shape in which a major axis or a minor axis faces the second direction, or an elliptical shape in which a major axis or a minor axis faces the second direction. The solar cell module according to.   The solar cell module according to any one of claims 5 to 8, wherein the curved portion includes at least one of a bent portion and a curved portion.

Images