JP2660138B2 - Solar cell module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roof-integrated solar cell module.

[0002]

Recently, is expected to global warming greenhouse of increased CO ₂ occurs, clean energy requirements that do not emit CO ₂ is increasingly.

[0003] Further, the problem of radioactive waste has not been solved in nuclear power generation that does not emit CO _2, and clean energy with higher safety is desired.

[0004] Among the clean energy expected in the future, solar cells are particularly expected from the viewpoint of their cleanliness, safety and ease of handling.

[0005] Among the solar cells, single-crystal silicon and polycrystalline silicon solar cell modules are vulnerable to impact, and therefore have a thick glass plate and an adhesive / filler EVA.
(Ethylene-vinyl acetate copolymer) is used to protect the surface of the solar cell, and furthermore, it is held by a frame of an aluminum agent or the like in order to prevent injuries due to the edge of the glass and breakage of the glass plate.

[0006] The surface of an amorphous silicon solar cell module formed on a glass substrate is protected by a thick glass plate like the crystalline silicon solar cell module.

Conventionally, a solar cell module using such a glass has a thickness of 13 to 15 per square meter.
When it is installed on a roof etc., it is not easy to handle due to its heavy weight.In addition, a heavy mounting base is installed and the solar cell module is fixed with bolts etc. It was necessary to fix using a tool. For this reason, installation time and a gantry cost have been required.

On the other hand, among solar cells, a polymer resin substrate or a metal substrate such as stainless steel is sometimes used as a substrate material. A solar cell module using these substrates has the advantages of being flexible, resistant to impact, and extremely light in weight per unit area and generated power.
For example, these solar cell modules can be installed on a gantry by holding the end face with an aluminum frame, as in the case of crystal-based modules, or through a through hole directly at the end of the solar cell module, and mechanically using fixing devices such as bolts. There was a method to fix it. Among these methods, there is a problem as described above when installing on a gantry, and in the method of forming a through hole and fixing with a fixture, it is necessary to make a hole in a module and a fixed object, For example, when a metal roof was installed with holes, there was a problem of rain.

Therefore, there has been a strong demand for the development of a solar cell module that does not require a mount and can be easily fixed without damaging a metal roof or a car roof.

[0010]

SUMMARY OF THE INVENTION The main object of the present invention is to:
It is an object of the present invention to provide a solar cell module which can be easily installed on a metal roof, is inexpensive, and has excellent long-term reliability.

[0011]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and achieves the above-mentioned objects, and the present invention provides a bendable conductive substrate and a first surface side of the substrate. It has a transparent electrode provided on the photoelectric conversion layer and the photoelectric conversion layer using amorphous silicon semiconductor provided, opposite to the first surface
Having a black resin film provided on the second surface side of the solar cell
A pond element, and a roof metal plate directly adhered to the back side of the black resin film via an adhesive material, and the solar cell element and the roof metal plate are integrally formed. It is a solar cell module which has.

Further, the adhesive for fixing the solar cell panel is preferably an elastic adhesive, and more preferably, the elastic adhesive has a Young's modulus of 10 ⁶ to 10 ⁸ dyne / cm ² . More preferably, the elastic adhesive contains a silicone component. Further, it is preferable that the solar cell panel has flexibility.

[0013]

The roof-integrated solar cell module of the present invention is very easy to install because the metal roof and the solar cell panel are fixed with an adhesive.

Further, since the solar cell panel has flexibility, it is necessary for a crystalline solar cell module having a thick glass plate, a polycrystalline solar cell module, an amorphous silicon solar cell module using a glass substrate, and the like. In addition, the metal frame is no longer necessary, and a stand for installing the solar cell module is not required.Thus, the weight of the solar cell module is reduced by the amount of the frame and the stand, and as a result, the solar cell panel is fixed. The amount of adhesive can be reduced. Moreover, the complicated work of installing the metal frame and the gantry can be eliminated, the workability is improved, and the danger is reduced.

The cost of the frame and the gantry in the total cost of the solar cell module is large, and in some cases, the cost of the frame and the gantry is higher than the cost of the solar cell panel. However, since the metal roof and the solar cell panel can be fixed with an adhesive, the cost of the solar cell module can be significantly reduced.

When the solar cell panel has flexibility, as shown in FIG. 2, when fixing the solar cell panel (2000) to the metal roof (2001) with the adhesive (2002), It can be sequentially attached from the end of the solar cell module while preventing air bubbles from entering between the and the metal roof. If air bubbles enter between the solar cell panel and the metal roof, the solar cell panel and the metal roof will gradually peel off from the air bubble part due to long-term outdoor exposure, but defoam from the end of the solar cell module By successively attaching them, a solar cell module having excellent long-term reliability can be provided.

Further, by using an elastic adhesive as the adhesive, it is possible to absorb a distortion caused by a difference in thermal expansion coefficient between the metal roof and the solar cell panel, and to provide a solar cell module having excellent long-term reliability. Can be provided.

Further, by using an adhesive containing silicone as the adhesive, a solar cell module having excellent heat resistance, weather resistance and moisture resistance can be provided. Silicone adhesives generally have flexibility up to about -50 ° C to 180 ° C, and thus exhibit an excellent effect for bonding materials having a large coefficient of thermal expansion such as metal roofs.

(Embodiments) Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an example in which a solar cell panel is fixed on a metal roof with an adhesive. FIG.
1A is a perspective view, and FIG. 1B is a sectional view taken along the line AA ′ of FIG.

In FIG. 1, (101) is a metal roof, (2)
01) to (204) are solar cell modules, (301)
Is an adhesive for fixing the solar cell panel and the metal roof. (401) is a junction box for extracting a terminal, (501) is a connection cord, and (502) is a connector for connecting an adjacent solar cell module.
(601) is a support plate of a metal roof.

The adhesive for bonding the solar cell panel and the metal roof used in the present invention is not particularly limited, but is preferably an elastic adhesive, and more preferably has a Young's modulus of 10 or more.
An adhesive having ⁶ to 10 ⁸ dyne / cm ² . Generally, since solar cells are used outdoors, the thermal expansion and contraction of the solar panels and metal roof will be repeated due to the temperature difference between day and night and the temperature difference between summer and winter. Due to the different expansion coefficients, there was a problem that the interface between the solar cell and the adhesive or the interface between the metal roof and the adhesive came off, but by using an elastic adhesive for the adhesive,
The elastic adhesive can absorb the distortion caused by the difference in the thermal expansion coefficient between the metal roof and the solar cell panel. Further, if the Young's modulus is less than 10 ⁶ dyne / cm ² , there is too much fluidity, so that when it is adhered to a roof with a strong inclination, a phenomenon occurs in which the adhesive flows. Also,
When the Young's modulus exceeds 10 ⁸ dyne / cm ² , the adhesive loses its elasticity, so that long-term reliability is required.

The adhesive is particularly preferably an adhesive containing silicone. The adhesive containing silicone has excellent heat resistance, weather resistance, and moisture resistance. Normally, a silicone-based adhesive has flexibility up to about -50 ° C to 180 ° C, so that it exhibits an excellent effect on a material having a large thermal expansion coefficient such as a metal roof.

When the solar cell panel and the metal roof are bonded with an adhesive, the solar cell panel may be bonded after applying the adhesive to the metal roof in advance, or the adhesive may be applied to the solar cell panel in advance. It may be pasted on a metal roof later.

The adhesive may be applied to the entire back surface of the solar cell panel, or may be applied only to a limited area according to the adhesive strength.

The method of fixing the solar cell panel of the present invention to a metal roof may be a method using only an adhesive, or may be used in combination with fixing using, for example, a double-sided tape, a magnet, a cable, or a frame. For example, in the case of installation on a vertical metal wall or on a metal roof under strong winds, the installation workability of the solar cell module becomes very poor. By fixing
Installation workability and work safety can be greatly improved.

Although there is no particular limitation on the solar cell panel of the present invention, it is preferable that the solar cell panel has flexibility. When the solar cell panel has flexibility, FIG.
As shown in (1), when the solar cell panel (2000) is fixed to the metal roof (2001) with the adhesive (2002), the ends of the solar cell module are fixed while preventing air bubbles from entering between the solar cell panel and the metal roof. It can be pasted sequentially from the section. If air bubbles enter between the solar cell panel and the metal roof, the solar cell panel and the metal roof will gradually peel off from the air bubble part due to long-term outdoor exposure, but defoam from the end of the solar cell module By successively attaching them, a solar cell module having excellent long-term reliability can be provided.

The solar cell element of the present invention is preferably an amorphous silicon semiconductor formed on a stainless steel substrate.
The amorphous silicon semiconductor formed on the stainless steel substrate can be thinned to a thickness of about 0.1 mm, and further, it is not necessary to use glass as a surface coating material, and a surface coating material such as a fluororesin film can be used. Therefore, the weight of the solar cell module itself can be greatly reduced to 1/2 to 1/4 as compared with the solar cell module using glass. The effect of the present invention is further exhibited by using such a lightweight and flexible solar cell panel. If the weight of the solar cell module itself is light, the amount of the adhesive can be reduced, and the adhesive strength can be small, so that the selection of usable adhesives can be widened, so that a lighter and cheaper solar cell module can be provided. It becomes possible.

FIG. 5 is a schematic sectional view showing an example of a solar cell element used in the solar cell module of the present invention. In FIG. 5, (613) is a conductive substrate, (614) is a back reflection layer, (615) is a semiconductor layer as a photoelectric conversion member, (6)
16) is a transparent conductive layer, and (617) is a current collecting electrode.

The back reflection layer of (614) can also serve as the conductive substrate of (613).

The conductive substrate (613) is made of stainless steel, aluminum, zirconium, molybdenum, tungsten, chromium, iron, tantalum, niobium, copper, titanium, carbon sheet, galvanized steel sheet, or a polyimide on which a conductive layer is formed. And resin films such as polyester, polyethylene naphthalide and epoxy, and ceramics.

As the thin film semiconductor layer (615), an amorphous silicon semiconductor, a polycrystalline silicon semiconductor, a crystalline silicon semiconductor, or a compound semiconductor such as copper indium selenide is suitable. In the case of an amorphous silicon-based semiconductor, a silane gas, a hydrogen gas, a gas that determines the conductivity type such as diborane, phosphine, or the like is introduced, and the semiconductor is formed by plasma CVD. In the case of a polycrystalline silicon semiconductor, it is formed by sheeting molten silicon or heat-treating an amorphous silicon semiconductor.

In the case of CuInSe ₂ / CdS, electron beam evaporation, sputtering, and electrodeposition (deposition by electrolysis of an electrolytic solution)
It is formed by such a method. The configuration of the semiconductor layer is pi
An n junction, a pn junction, and a Schottky junction are used.
The semiconductor layer has a structure sandwiched between at least a back reflection layer (614) and a transparent conductive layer (616). As the back reflection layer (614), a metal layer or a metal oxide, or a composite layer of a metal layer and a metal oxide layer is used. As the material of the metal layer, Ti, Al, Fe, C
u, Si, Cr, Mo, Ag, Ni, etc. are used, and ZnO, TiO ₂ , SnO _2, etc. are adopted as the metal oxide layer. Examples of the method for forming the metal layer and the metal oxide layer include resistance heating evaporation, electron beam evaporation, sputtering, spraying, CVD, and impurity diffusion.
Further, as a material of the current collecting electrode (617) on the grid for efficiently collecting current generated by photovoltaic power on the transparent conductive layer, Ti, Au, Zn,
A conductive paste such as Cr, Mo, W, Al, Ag, Ni, Cu, Sn, and silver paste is used. The grid electrode is formed by a sputtering method using a mask pattern, resistance heating, a CVD method or the like, a method of depositing a metal layer on the entire surface and then etching and patterning the same, or a method of directly forming a grid electrode pattern by optical CVD. And a method of forming a negative electrode pattern mask by grid plating and a method of printing a conductive paste. As the conductive paste, one obtained by dispersing a fine powder of gold, silver, copper, nickel, carbon or a mixture thereof with a binder polymer is usually used. Examples of the binder polymer include resins such as polyester, epoxy, acrylic, alkyd, polyvinyl acetate, rubber, urethane, and phenol.

As a bus bar material for further collecting and transporting the current collected by the grid electrode, tin, solder-coated copper, nickel, or the like is used.
The connection of the bus bar to the grid electrode can be made with a conductive adhesive or solder.

(Electrical Connection Between Solar Cell Panels) The method of electric connection between solar cell panels is not particularly limited, and can be arbitrarily determined according to the voltage, current, and power of the solar cell module used.

FIG. 1 shows solar cell panels (202) and (2)
01), (201) and (203), (203) and (20)
4) is an example of connecting in series. Here, (401) is a junction box, (501) is a lead wire, (50)
2) is a waterproof connector. The connection method of the solar cell panel does not need to use a junction box, etc.
The solar cell panels can also be connected by a connection cord using the space of the metal roof.

[0036]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

(Example 1) In this example, a solar cell panel in which an amorphous silicon solar cell element formed on a stainless steel substrate was resin-sealed, and a solar cell module in which a silicon resin adhesive was adhered on a metal roof. This is an example.

FIG. 1 shows a schematic view of the solar cell module of this embodiment. FIG. 1A is a perspective view of the solar cell module of the present embodiment, and FIG.
It is A 'sectional drawing.

FIG. 6 is a sectional view of the solar cell panel of FIG.

In FIG. 6, (7000) is a solar cell panel, (7002) is a fluororesin film (trade name: Tefzel / Dupont), and (7003) is EVA (ethylene-vinyl acetate) which is a filler for solar cells. United), (7
001) is an amorphous silicon-based solar cell element formed on SUS430, and (7004) is a black fluororesin film (trade name: Tedlar / DuPont).

The solar cell panel was manufactured as follows.

First, a photovoltaic element was prepared according to the following procedure. After forming Al / ZnO which is a back reflection layer on a stainless steel substrate having a thickness of 0.125 mm by a sputtering method,
N-type a-Si layer, i-type a-Si by plasma CVD
A semiconductor layer of a p-type microcrystalline Si layer was formed, and then In ₂ O ₃ as a transparent electrode layer was formed by vapor deposition of In by a resistance heating method in an O ₂ atmosphere. Further, an amorphous silicon-based photovoltaic element was prepared by screen printing silver paste as a collecting electrode.

Next, the solar cell element was vacuum-laminated using a fluororesin film and EVA to seal the resin as shown in FIG.

The terminal was taken out of the solar cell element by making a hole in the surface of the solar cell panel, sealing that part with a silicone resin, and then mounting a junction box thereon.

Next, a silicone resin adhesive was uniformly applied to the metal roof at the position where the solar cell panel was placed by extruding the adhesive from the tube. Then, on the adhesive,
As shown in FIG. 2, the solar cell panel was sequentially adhered from the end of the solar cell panel, and was adhered so as to prevent air bubbles from entering the inside of the adhesive, and then left at room temperature for 7 days to cure. Here, the cured Young's modulus of the silicone resin adhesive was 1 × 10 ⁷ dyne / cm ² . Next, the solar cell module was installed on a tile-type metal roof, and an outdoor exposure test was performed. The adjacent solar cell modules were connected by waterproof connectors.

The solar cell module of this example was easy to install on a metal roof, and did not come off the metal roof at all even in a one-year outdoor exposure test.

Further, the solar cell module of the present embodiment
Compared to a conventional solar cell module in which a solar cell panel is fixed by a frame and installed on a gantry, material costs and installation costs can be reduced to ３.

Example 2 In this example, the solar cell panel was bonded to the metal roof using both a 50% -50% mixed adhesive of silicone resin and epoxy resin and a double-sided tape.

FIG. 3 shows a solar cell module of this embodiment. FIG. 3A is a rear view of the solar cell panel before bonding to the metal roof, and FIG. 3B is a cross-sectional view of the solar cell module after bonding the solar cell panel to the metal roof. In FIG. 3, (3001) is a solar cell panel,
(3002) is an amorphous silicon solar cell element,
(3003) is a mixed adhesive of a silicone resin and an epoxy resin, (3004) is a double-sided tape having an acrylic adhesive on an acrylic foam having completely closed cells, (30)
05) is a tile-roof type metal roof.

The adhesive and the double-sided tape were adhered to a metal roof after being previously attached to the back surface of the solar cell panel. The curing conditions for the adhesive were the same as in Example 1.

The cured adhesive of this embodiment has a Young's modulus of 5
× 10 ⁷ dyne / cm ² .

The solar cell module of this embodiment has a double-sided tape attached to the periphery of the solar cell panel and an adhesive applied to the center, so that the adhesive does not protrude to the outside of the solar cell panel, so that the external appearance is improved. Improved.

Further, by bringing the Z side of the solar cell panel upward with respect to the flow direction of the rain, it was possible to prevent the rain from directly hitting the adhesive, thereby further improving the long-term reliability.

The solar cell panel and the metal roof of this embodiment were prepared in the same manner as in the first embodiment.

Example 3 In this example, a samarium-cobalt magnet was used in place of the double-sided tape in Example 2. FIG. 4 shows the solar cell module of the present embodiment. FIG. 4A is a rear view of the solar cell panel before bonding to the metal roof, and FIG. 4B is a cross-sectional view of the solar cell module after bonding the solar cell panel to the metal roof.

In FIG. 4, (3001) is a solar cell panel, (3002) is an amorphous silicon-based solar cell element, (3003) is a mixed adhesive of silicone resin and epoxy resin used in Example 2, and (4004) is Length 24
mm, 14 mm in width and 1 mm in height, and is bonded to the back surface of the solar cell panel with double-sided tape. (3005) is a tile-roof type metal roof.

The adhesive and the samarium-cobalt magnet were previously attached to the back of the solar cell panel and then adhered to the metal roof. The curing conditions for the adhesive were the same as in Example 1.

The solar cell module of this embodiment is a more excellent solar cell module having both the permanent adhesiveness of the samarium-cobalt magnet and the strong adhesive force of the adhesive.

[0059]

According to the solar cell module of the present invention, since the metal roof and the solar cell element are directly adhered to each other with an adhesive and integrally formed, when the solar cell element (solar cell panel) is installed on the roof, There is no need to provide a hole for fixing the solar cell element to the roof, which improves operability when the solar cell element is laid on the roof. The solar cell not only suppresses the deterioration promotion during long-term use caused by the holes, but also effectively suppresses the deterioration of the conversion efficiency by applying heat to the photoelectric conversion layer using amorphous silicon. Elementary
Since a black resin film is provided on the
The amorphous silicon is heated by the heat applied from the heat absorption when the black resin film of the solar cell module is exposed to sunlight, and the element and the metal roof are integrally formed. The deterioration of the conversion efficiency of the conversion layer was suppressed, and the life of the solar cell element was able to be substantially improved.

In addition, since the solar cell panel has flexibility, it is necessary for a crystalline solar cell module having a thick glass plate, a polycrystalline solar cell module, an amorphous silicon solar cell module using glass as a substrate, and the like. The need for a metal frame that is no longer required, and a stand for installing the solar cell module is not required, the weight of the solar cell module is reduced by the amount of the frame and the stand, and as a result, the The amount of adhesive could be reduced. Moreover, the complicated work of installing the metal frame and the gantry could be eliminated.

The cost of the frame and the gantry in the total cost of the solar cell module is large. In some cases, the cost of the frame and the gantry is higher than the cost of the solar cell panel. However, since the metal roof and the solar cell panel can be fixed with an adhesive, the cost of the solar cell module can be significantly reduced.

Further, since the solar cell panel is bendable, as shown in FIG. 2, when fixing the solar cell panel (2000) to the metal roof (2001) with an adhesive (2002), The solar cell module could be sequentially attached from the edge while preventing air bubbles from entering between the metal roof and the metal roof. When air bubbles enter between the solar cell panel and the metal roof, the solar cell panel and the metal roof gradually peel off from the air bubble part due to long-term outdoor exposure, but defoam from the end of the solar cell panel By successively attaching them, a solar cell module having excellent long-term reliability could be provided.

Further, by using an elastic adhesive as the adhesive, it is possible to absorb the distortion caused by the difference in the thermal expansion coefficient between the metal roof and the solar cell panel, and to provide a solar cell module having excellent long-term reliability. Could be provided.

Further, by using an adhesive containing silicone as the above-mentioned adhesive, a solar cell module excellent in heat resistance, weather resistance and moisture resistance could be provided. Silicone adhesives usually have flexibility up to about -50 ° C to 180 ° C, and thus have an excellent effect on bonding materials having a large thermal expansion coefficient such as metal roofs.

[Brief description of the drawings]

FIG. 1 is a diagram of a solar cell module according to an embodiment of the present invention.

FIG. 2 is an example of a method for producing a solar cell module of the present invention.

FIG. 3 is a diagram of a solar cell module according to an embodiment of the present invention.

FIG. 4 is a diagram of a solar cell module according to another embodiment of the present invention.

FIG. 5 is a diagram of a solar cell module according to another embodiment of the present invention.

FIG. 6 is a sectional view of a solar cell element of the solar cell module of the present invention.

[Explanation of symbols]

 101 Metal Roof 201, 202, 203, 204 Solar Panel 301 Adhesive 401 Junction Box 501 Lead Wire 502 Waterproof Connector 601 Purlin 2000 Solar Panel 2001 Metal Roof 2002 Adhesive 3001 Solar Panel 3002 Solar Cell Element 3003 Adhesive 3004 Double Side Tape 3005 metal roof 4004 samarium-cobalt magnet 613 conductive substrate 614 back reflection layer 615 semiconductor layer 616 transparent conductive layer 617 current collecting electrode 7000 solar cell panel 7001 solar cell element 7002 fluoro resin 7003 EVA 7004 black fluoro resin

Claims (6)

(57) [Claims] [Claim 1] have a transparent electrode provided on bendable conductive substrate, said substrate a first photoelectric conversion layer using amorphous silicon semiconductor provided on the side and the photoelectric conversion layer of the First side
Black resin film provided on the second surface side opposite to
A solar cell element, and a roof metal plate directly adhered to the back side of the black resin film via an adhesive, and the solar cell element and the roof metal plate are integrally formed. A solar cell module characterized by the above-mentioned. 2. The method according to claim 1, wherein the adhesive is provided near a center of the solar cell element, and furthermore, a double-sided tape is disposed on a peripheral portion of an overlapping portion between the solar cell element and the metal plate for roof, thereby forming the solar cell. The solar cell module according to claim 1, wherein the battery element and the roof metal are bonded. 3. The solar cell module according to claim 1, wherein the solar cell element is sealed with a filler and a resin film provided on a surface side of the transparent electrode. 4. The solar cell module according to claim 1, wherein a reflection layer is provided between the flexible conductive substrate and the solar cell element. 5. The solar cell module according to claim 1, wherein said adhesive is an elastic adhesive. 6. The solar cell module according to claim 5, wherein said elastic adhesive is an adhesive containing a silicone component.