JP2021093469A - Solar battery module - Google Patents

Abstract

To provide a solar battery module that suppresses peeling or deviation of a wiring member.SOLUTION: A solar battery module 100 comprises: a plurality of solar battery cells 1; a wiring member 8 connecting the plurality of solar battery cells 1; a protective member for protecting principal surfaces of the plurality of solar battery cells 1; and a sealing material 6 that is provided between the protective member and the plurality of solar battery cells 1 to seal the plurality of solar battery cells 1 and the wiring member 8. The sealing material 6 includes a first sealing material 6a and a second sealing material 6b that have different loss tangents and are alternately provided in a direction along the principal surfaces of the plurality of solar battery cells 1. The first sealing material 6a's loss tangent is smaller than the second sealing material 6b's loss tangent.SELECTED DRAWING: Figure 1

Description

The present invention relates to a solar cell module.

In the solar cell module, a plurality of solar cell cells are arranged two-dimensionally and are electrically connected in series or in parallel by a wiring member such as an interconnector. In such a solar cell module, a pair of protective members that protect both main surfaces of the plurality of solar cells and a sealing material that seals the plurality of solar cells and wiring members between the pair of protective members are provided. (See, for example, Patent Document 1).

International Publication No. 2012/014965

In such a solar cell module, a relatively soft material is used as the material of the sealing material in order to obtain resistance to external stress. However, if the sealing material is excessively displaced due to external stress, the wiring member sealed by the sealing material may be peeled off or displaced from the solar cell.

An object of the present invention is to provide a solar cell module that suppresses peeling or displacement of wiring members.

The solar cell module according to the present invention includes a plurality of solar cells, a wiring member connecting the plurality of solar cells, a protective member for protecting the main surfaces of the plurality of solar cells, the protective member, and the above. It is provided between the plurality of solar cells and includes the plurality of solar cells and a sealing material for sealing the wiring member. The encapsulant has different loss tangents and has a first encapsulant and a second encapsulant alternately provided in a direction along the main surface of the plurality of solar cells. The loss tangent of the first encapsulant is smaller than the loss tangent of the second encapsulant.

According to the present invention, in the solar cell module, peeling or displacement of the wiring member can be suppressed.

It is the figure which looked at the solar cell module which concerns on 1st Embodiment from the back side. FIG. 2 is a sectional view taken along line II-II of the solar cell module according to the first embodiment shown in FIG. It is the figure which looked at the solar cell module which concerns on 2nd Embodiment from the back side. FIG. 3 is a sectional view taken along line IV-IV of the solar cell module according to the second embodiment shown in FIG. It is the figure which looked at the solar cell module which concerns on 3rd Embodiment from the back side. FIG. 5 is a sectional view taken along line VI-VI of the solar cell module according to the third embodiment shown in FIG.

Hereinafter, an example of the embodiment of the present invention will be described with reference to the accompanying drawings. In addition, the same reference numerals are given to the same or corresponding parts in each drawing. In addition, for convenience, hatching, member codes, and the like may be omitted, but in such cases, other drawings shall be referred to.

(First Embodiment)
FIG. 1 is a view of the solar cell module according to the first embodiment as viewed from the back surface side, and FIG. 2 is a sectional view taken along line II-II of the solar cell module according to the first embodiment shown in FIG. In FIG. 1, the back side protective member 4 described later is omitted. Further, the XY Cartesian coordinate system is shown in FIGS. 1 and 2, and the drawings described later. The XY plane is a surface along the light receiving surface and the back surface of the solar cell module.

As shown in FIGS. 1 and 2, the solar cell module 100 includes a plurality of solar cell cells 1, a light receiving side protective member 3, a back side protective member 4, a light receiving side sealing material 5, and a back side sealing material 6. And a wiring member 8.

The solar cell 1 is a back electrode type (also referred to as a back contact type or back contact type) solar cell. The plurality of solar cell 1s are arranged two-dimensionally in the X direction and the Y direction. Adjacent solar cell 1s are connected via a wiring member 8.

As the wiring member 8, a known interconnector such as a tab is used. For example, the wiring member 8 includes a ribbon wire made of a copper core material coated with a low melting point metal or solder, a conductive film formed of a thermosetting resin film containing low melting point metal particles or metal fine particles, or a plurality of pieces. (For example, see JP-A-2016-2199799 or JP-A-2014-3161) and the like.

The wiring member 8 and the electrode portion of the solar cell 1 are connected via a conductive adhesive member. Examples of the conductive adhesive member include a conductive film formed of a thermosetting resin film containing low melting point metal particles or metal fine particles, a low melting point metal fine particles or a conductive adhesive formed of metal fine particles and a binder, or a conductive adhesive. , Solder paste containing solder particles or the like is used.

The solar cell 1 and the wiring member 8 are sandwiched between the light receiving side protective member 3 and the back side protective member 4. A liquid or solid encapsulant (light-receiving side encapsulant 5 and back-side encapsulant 6) is filled between the light-receiving side protective member 3 and the back-side protective member 4, whereby the solar cell Cell 1 is sealed.

The light receiving side protective member 3 covers the light receiving surface of the solar cell 1 via the light receiving side sealing material 5 to protect the solar cell 1. The shape of the light receiving side protective member 3 is not particularly limited, but a plate shape or a sheet shape is preferable from the viewpoint of indirectly covering the planar light receiving surface.

The material of the light receiving side protective member 3 is not particularly limited, but a material having a property of transmitting light (translucency) and being resistant to ultraviolet light is preferable, and for example, glass or glass or Examples thereof include transparent resins such as acrylic resin and polycarbonate resin. Further, the surface of the light receiving side protective member 3 may be processed into an uneven shape, or may be coated with an antireflection coating layer. This is because the light receiving side protective member 3 makes it difficult to reflect the received light and can guide more light to the solar cell 1.

The back side protective member 4 covers the back surface of the solar cell 1 via the back side sealing material 6 to protect the solar cell string 2. The shape of the back side protective member 4 is not particularly limited, but like the light receiving side protective member 3, a plate shape or a sheet shape is preferable from the viewpoint of indirectly covering the surface back surface.

The material of the back side protective member 4 is not particularly limited, but a material that prevents the ingress of water or the like (highly water-impervious) is preferable. For example, a resin film such as polyethylene terephthalate (PET), polyethylene (PE), an olefin resin, a fluorine-containing resin, or a silicone-containing resin, or a plate-shaped resin member having translucency such as glass, polycarbonate, or acrylic. Examples thereof include a laminate with a metal foil such as an aluminum foil.

The light receiving side sealing material 5 and the back side sealing material 6 seal and protect the solar cell 1 and the wiring member 8. The light receiving side sealing material 5 is interposed between the light receiving side surface of the solar cell 1 and the light receiving side protective member 3. The back side sealing material 6 is interposed between the back side surface of the solar cell 1 and the back side protective member 4. The shapes of the light receiving side sealing material 5 and the back side sealing material 6 are not particularly limited, and examples thereof include a sheet shape. This is because if it is in the form of a sheet, it is easy to cover the front surface and the back surface of the planar solar cell 1.

The material of the light receiving side sealing material 5 and the back side sealing material 6 is not particularly limited, but it is preferable that the material has a property of transmitting light (translucency). Further, it is preferable that the materials of the light receiving side sealing material 5 and the back side sealing material 6 have adhesiveness for adhering the solar cell 1, the light receiving side protective member 3 and the back side protective member 4. Examples of such a material include a translucent resin such as a copolymerization polyolefin, a polyolefin, a thermoplastic elastomer, or an ionomer.

Here, in general, in a solar cell module, a material that is relatively soft as a sealing material in order to obtain resistance to external stress (for example, thermal shock or vibration when mounted on a vehicle or the like). Is used. However, if the sealing material is excessively displaced due to external stress, the wiring member sealed by the sealing material may be peeled off or displaced from the solar cell.

In particular, in a heterojunction type solar cell, the process temperature is limited (for example, 200 degrees or less), and the wiring member cannot be firmly adhered at a high temperature, so that the wiring member is peeled off or displaced due to external stress. It is expected to occur easily.

In this regard, the inventor of the present application devises to make the hardness of the encapsulant partially different.

Specifically, the back side encapsulant 6 has a first encapsulant 6a and a second encapsulant 6b. The first sealing material 6a is in contact with the wiring member 8 and covers the wiring member 8, and the second sealing material 6b is arranged between the first sealing materials 6a. As a result, the first sealing material 6a and the second sealing material 6b are alternately provided in the Y direction along the main surface of the solar cell 1.

The loss tangent (tan δ) of the first encapsulant 6a and the loss tangent (tan δ) of the second encapsulant 6b are different. Specifically, the loss tangent of the first encapsulant 6a is smaller than the loss tangent of the second encapsulant 6b. Here, the larger the loss tangent (tan δ), that is, the larger the viscoelasticity (dynamic viscoelasticity), the softer the material. As a result, the second encapsulant 6b is relatively soft, while the first encapsulant 6a is relatively hard.

As described above, the first encapsulant 6a and the second encapsulant 6b contain any one of a different copolymerized polyolefin, polyolefin, thermoplastic elastomer, or ionomer as a material. The magnitude of the loss tangent (tan δ) of these materials is as follows.
Copolymerized Polyolefin <Polyolefin <Thermoplastic Elastomer <Ionomer

As described above, according to the solar cell module 100 of the first embodiment, the first sealing material 6a in contact with the wiring member 8 has a relatively small loss tangent, that is, is relatively hard. As a result, excessive displacement of the sealing material 6 itself due to external stress can be suppressed, and peeling or displacement (short circuit) of the wiring member 8 due to displacement of the sealing material 6 can be suppressed.

Further, the second sealing material 6b that does not come into contact with the wiring member 8 has a relatively large loss tangent, that is, is relatively soft. As a result, stress from the outside can be absorbed, and resistance to stress from the outside can be obtained.

(Second Embodiment)
FIG. 3 is a view of the solar cell module according to the second embodiment as viewed from the back surface side, and FIG. 4 is a sectional view taken along line IV-IV of the solar cell module according to the second embodiment shown in FIG. In the second embodiment, the arrangement relationship between the first sealing material 6a and the second sealing material 6b is opposite to that of the first embodiment. That is, the second sealing material 6b having a relatively large loss tangent (tan δ) (that is, relatively soft) is in contact with the wiring member 8 to cover the wiring member 8, and the loss tangent (tan δ) is relatively large. A small (ie, relatively hard) first encapsulant 6a is placed between the second encapsulants 6b.

According to the solar cell module 100 of the second embodiment, the first sealing material 6a adjacent to the second sealing material 6b in contact with the wiring member 8 has a relatively small loss tangent, that is, is relatively hard. The second sealing material 6b in contact with the wiring member 8 is supported by the adjacent first sealing material 6a. As a result, excessive displacement of the sealing material 6 itself due to external stress can be suppressed, and peeling or displacement (short circuit) of the wiring member 8 due to displacement of the sealing material 6 can be suppressed.

Further, the second sealing material 6b has a relatively large loss tangent, that is, is relatively soft. As a result, stress from the outside can be absorbed, and resistance to stress from the outside can be obtained.

(Third Embodiment)
FIG. 5 is a view of the solar cell module according to the third embodiment as viewed from the back surface side, and FIG. 6 is a sectional view taken along line VI-VI of the solar cell module according to the third embodiment shown in FIG. In the third embodiment, both the first sealing material 6a and the second sealing material 6b are in contact with the wiring member 8 and cover the wiring member 8.

The solar cell module 100 of the third embodiment can also obtain the same advantages as the solar cell module 100 of the first embodiment and / or the solar cell module 100 of the second embodiment described above.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and modifications can be made. For example, in the above-described embodiment, in the solar cell module 100 including the back electrode type solar cell 1 and the wiring member 8 provided on the back side of the solar cell 1, the back side sealing material 6 is first sealed. An example of a form composed of a stopper 6a and a second sealing material 6b has been illustrated. However, the features of the present invention are not limited to this, and the present invention can be applied to a solar cell module including a double-sided electrode type solar cell and wiring members provided on the light receiving surface side and the back surface side of the solar cell. .. In this case, not only the back side encapsulant but also the light receiving side encapsulant may be formed by the first encapsulant and the second encapsulant.

Further, the feature of the present invention is also applicable to a solar cell module in which a plurality of solar cell cells are connected by using a single ring method. The single ring method is a method in which solar cells are connected in series by overlapping a part of the end portions of the solar cells. Specifically, one end of one of the adjacent solar cells overlaps below the other end of the other solar cell.

In this way, since a plurality of solar cells have a sedimentary structure that is uniformly tilted in a certain direction as if a roof tile is covered with roof tiles, a method of electrically connecting the solar cells in this way is adopted. , Called the single ring method. Further, a plurality of solar cell cells connected in a string shape are referred to as a solar cell string.

A wiring member may also be used in a form in which a plurality of solar cells are connected by using a single ring method. In this case, the back side encapsulant and / or the light receiving side encapsulant may be formed by the first encapsulant and the second encapsulant.

1 Solar cell 3 Light-receiving side protective member 4 Back-side protective member 5 Light-receiving side encapsulant 6 Back-side encapsulant 6a 1st encapsulant 6b 2nd encapsulant 8 Wiring member 100 Solar cell module

Claims (4)

With multiple solar cells
A wiring member connecting the plurality of solar cells and
A protective member that protects the main surfaces of the plurality of solar cells, and
A sealing material provided between the protective member and the plurality of solar cells and sealing the plurality of solar cells and the wiring member.
With
The encapsulant has different loss tangents, and has a first encapsulant and a second encapsulant alternately provided in a direction along the main surface of the plurality of solar cells.
The loss tangent of the first encapsulant is smaller than the loss tangent of the second encapsulant.
Solar cell module. The solar cell module according to claim 1, wherein the first encapsulant and the second encapsulant contain any one of a copolymerization polyolefin, a polyolefin, a thermoplastic elastomer, and an ionomer as a material. .. The solar cell module according to claim 1 or 2, wherein only one of the first sealing material and the second sealing material is in contact with the wiring member to cover the wiring member. The solar cell module according to claim 1 or 2, wherein both the first sealing material and the second sealing material are in contact with the wiring member to cover the wiring member.

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