JP4099692B2 - Solar cell integrated roof material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solar cell integrated roof member, and more particularly, to a sealing structure with improved waterproofness of a solar cell module.
[0002]
[Prior art]
Currently, clean energy research and development is underway from the standpoint of environmental protection. Among them, solar cells are attracting attention because their resources (sunlight) are infinite and pollution-free. A typical example of a solar cell (photoelectric conversion device) in which a plurality of solar cell elements formed on the same substrate are connected in series is a thin film solar cell.
[0003]
Thin-film solar cells are expected to become the mainstream of solar cells in the future because they are thin and lightweight, inexpensive to manufacture, and easy to increase in area, and are attached to roofs and windows of buildings in addition to power supply. Demand is also expanding for commercial and general residential use. Roof tiles with solar cells have also been developed for general housing.
[0004]
In recent years, research and development of flexible type solar cells using plastic films has been promoted, and mass production is possible by using a roll-to-roll method or a step-roll method by making use of this flexibility.
[0005]
As a thin film solar cell module, a solar cell formed on an electrically insulating film substrate is sealed with an electrically insulating protective material on both the light-receiving surface side and the non-light-receiving surface side of the solar cell. Those provided with a protective layer are known.
[0006]
FIG. 3 is a side sectional view showing an example of a schematic structure of a conventional solar cell module. In FIG. 3, a solar cell 1 has one or a plurality of solar cell elements connected in series or in parallel, a surface protection member 2 such as a glass plate on the light receiving surface side, and one surface on both sides of aluminum foil on the back surface side. A back surface protection member 3 bonded with ethylene fluoride is provided, and is heat-sealed and sealed with an adhesive resin sealing material 40 such as EVA (ethylene-vinyl acetate copolymer resin) which is excellent in adhesive sealing property and inexpensive. Yes.
[0007]
The solar cell 1 has internal lead wires 5 and 6 electrically connected to the positive (+) and negative (−) electrodes, and the internal lead wires 5 and 6 are bonded and fixed to the back surface protection member 3. The connection terminal box 70 is guided through the back surface protection member 3 and is electrically connected to the core wires 9 and 10 of the cable 8 as an external lead wire inside the connection terminal box 70. Forming.
[0008]
In addition, as the surface protection member 2, an organic material such as a transparent acrylic plate may be used in addition to an inorganic material such as a glass plate. Further, as the back surface protection member 3, in addition to the resin containing the metal foil, an organic film alone such as a fluorine film, a composite material obtained by bonding an organic film and a metal foil, or a metal such as a metal plate or a glass plate・ Inorganic materials may be used.
[0009]
In addition, as described above, roof tiles with solar cells and the like have been developed, and are described in, for example, Japanese Patent Application Laid-Open Nos. 2000-204717 and 2000-226909.
[0010]
The roof tile with a solar cell described in JP-A-2000-204717 has a structure in which a solar cell is disposed in a recess provided on the surface of a tile base material made of a hydraulic inorganic material, for example, lightweight concrete. Therefore, an invention relating to the thickness and shape of the recess is described. As the solar cell, the solar cell module having the above-described configuration is used. However, in the roof tile with the solar cell described in the above publication, if the end seal of the solar cell module is insufficient, the lightweight concrete is used. There is a problem that the solar cell module is corroded by the eluted alkaline component.
[0011]
The above Japanese Patent Application Laid-Open No. 2000-226909 describes an invention related to an end seal structure of a solar cell module for solar cell storage tiles. The roof tile with a solar cell described in JP 2000-226909 A comprises a roof tile body and a solar cell structure (solar cell module), and the roof tile body is formed by pressing a cement composition. A recess for inserting the solar cell structure is provided in the approximate center of the upper surface of the roof tile body, and eight nailing hole bases are provided on the water side, and the approximate center of the nailing hole base is provided. A nail hole is drilled into the roof so that it can be fixed to the roof.
[0012]
FIG. 4 shows an example of an enlarged cross-sectional structure of the peripheral portion of the solar cell structure described in Japanese Patent Application Laid-Open No. 2000-226909. A solar cell structure 62 shown in FIG. 4 is a laminate in which a peripheral portion of a solar cell laminate (solar cell module) 62a is covered with an elastic sealing material or adhesive tape 7, and the elastic sealing material or adhesive tape 7 is attached. The peripheral part of the body 62a is configured to be press-fitted into the opening of the frame 4 having a U-shaped cross section. This solar cell structure 62 is inserted into the concave portion of the roof tile main body to obtain a roof tile with solar cells.
[0013]
The adhesive tape 7 is a tape-shaped EPDM (ethylene / propylene terpolymer) foam sheet having a width of about 9 mm and a thickness of about 5 mm, for example, provided with a butyl rubber-based pressure-sensitive adhesive layer. After being attached to the peripheral portion of the laminated body 62a, the peripheral portion of the laminated body 62a to which the adhesive tape 7 is bonded is inserted into the U-shaped opening of the frame 4 while compressing the adhesive tape 7. Yes.
[0014]
In this case, the adhesive tape 7 having a thickness of about 5 mm is inserted in a compressed state into a gap of about 1 mm between the peripheral edge of the laminated body 62a and the inner surface of the flange of the frame 4. Therefore, the solar cell structure 62 can be easily manufactured simply by inserting the adhesive tape 7 into the opening having a U-shaped cross section while compressing the adhesive tape 7, and the manufactured solar cell structure 62 has the peripheral edge of the laminate 62 a. Since the compressed adhesive tape 7 is affixed to the portion, the compressed adhesive tape 7 presses the inner surface of the flange of the frame 4 and the peripheral portion of the laminated body 62a as a result of returning to the original shape. The space between the tape 7 and the peripheral edge of the laminated body 62a is watertight, and rainwater does not enter from this portion to the solar cell inside.
[0015]
In the above publication, an embodiment using a silicone rubber molded body instead of the adhesive tape 7 is also described.
[0016]
Furthermore, as a method for joining the solar cell module and the roof of the house (including tiles), a method using a modified silicone elastic adhesive is also known (see Japanese Patent Laid-Open No. 10-176158).
[0017]
[Problems to be solved by the invention]
By the way, the conventional solar cell integrated roof member and the adhesive sealing method described in the above publications have the following problems.
[0018]
In the case where the elastic sealing material inserted in the U-shaped frame described in JP 2000-226909 A is a moisture-curing modified silicone system, there is a drawback that it takes 1 hour or more to cure. Further, when the elastic sealing material is putty-like butyl rubber, since it has a high viscosity, there is a drawback that a dedicated device is required for filling the U-shaped frame or press-fitting the module. Furthermore, when using a sheet-like foam as a sealing material to be inserted into a U-shaped frame, in order for the sheet-like foaming sealing material to exhibit good sealing properties, it is necessary to take a sufficient compression allowance. The thickness of the glass plate increases, and there is a drawback that dust is accumulated on the surface of the glass plate.
[0019]
In the case of the method using the U-shaped frame, the U-shaped portion is more or less than the glass surface, so that dust or the like accumulates on the glass surface of the solar cell, and power generation efficiency is lowered.
[0020]
Furthermore, when the modified silicone-based elastic adhesive described in JP-A-10-176158 is used as an adhesive for a solar cell module with a roof tile, the elastic adhesive has insufficient weather resistance for many years. If the adhesive surface peels off from the peeling surface, water enters the gap in the solar cell module housing of the roof tile due to surface tension, and if the drainage of water is bad, the water eventually enters the module, causing failure of the solar cell. There is a problem that causes it.
[0021]
In addition, the elastic seal adhesive has a high viscosity, and it is difficult to uniformly apply it to the surface of the concave portion of the roof tile or the back surface of the solar cell module. It is necessary to extrude the material from the gap between the roof tile and the solar cell module. At this time, the glass surface of the solar cell module is often contaminated. As described above, the elastic seal adhesive has a drawback that the workability is poor.
[0022]
Moisture that has entered the module penetrates into the adhesive resin sealing material 40 from the end surface of the adhesive resin sealing material 40 at the peripheral edge of the solar cell module located on the side surface around the solar cell module 11, and finally. Reaches the solar cell 1 and the internal lead wires 5 and 6 and their connecting portions and causes corrosion. In particular, when EVA (ethylene-vinyl acetate copolymer resin) is used for the adhesive resin sealing material 40, EVA is hydrolyzed with moisture to produce acetic acid, which further accelerates corrosion.
[0023]
When the solar cell 1 or the like is corroded, not only the power generation characteristics are deteriorated, but also the conductor cross-sectional area of the internal lead wires 5 and 6 is reduced or disconnected, and further, contact failure or disconnection of the connection portion with the solar cell 1 is caused. As a result, local heat generation occurs, and in the worst case, the output cannot be taken out.
[0024]
This invention was made in order to solve the above problems, and the object of the present invention is excellent in workability and sealability of water intrusion, and water intrusion occurs due to breathing with outside air. Even in such a case, it is an object to provide a solar cell integrated roof member which has a function of preventing water accumulation in the module housing recess and high waterproofness, and which prevents dust accumulation on the solar cell light receiving surface.
[0025]
[Means for Solving the Problems]
In order to solve the above-described problems, in the present invention, a solar cell module formed by sealing a solar cell with an adhesive resin sealing material between a translucent surface protection member and a back surface protection member is provided as a roof member body. A solar cell-integrated roof member disposed in a concave portion provided on the surface of the solar cell module via an adhesive sheet having a predetermined thickness, wherein the bottom surface and side surface of the solar cell module and the inner surface of the concave portion of the roof member body A liquid foamable sealing material is filled in the gap between the two and the foamed and cured, and the solar cell module and the roof member main body are integrated (invention of claim 1).
[0026]
By the said structure, the solar cell module peripheral part used as a water | moisture-content intrusion path | route can be covered with a foamable sealing material, and while a water | moisture content penetration can be interrupted | blocked, workability | operativity improves.
[0027]
In the above-described configuration, the liquid foamable sealing material is formed by inserting a part of a thin needle-like inlet into the gap and moving the inlet to the peripheral part of the module while disposing the closed-cell type liquid foamable sealing material on the entire module. Inject around. The liquid foamable sealing material is foamed and cured after being filled in the gap by the action of gravity and surface tension.
[0028]
In order to efficiently inject the liquid foamable sealing material and increase the internal pressure to cure and improve the sealing performance, the end of the translucent surface protection member (for example, a glass plate) used in the solar cell module is improved. It is desirable to take a sufficient R, widen the injection port of the liquid foamable sealing material, and gradually narrow the injection port to provide a flow restriction portion of the liquid foamable sealing material in the gap.
[0029]
In addition, when water enters a recess provided on the surface of the roof member body due to breathing with the outside air, it is desirable to have a structure that allows the water to be easily discharged from the recess. It is desirable to have a structure with the property. From this viewpoint, the inventions of claims 2 and 3 below are preferable.
[0030]
That is, in the solar cell integrated roof member according to claim 1, the roof member main body is a lightweight concrete roof tile, and the concave portion is provided with a drain hole penetrating from the bottom surface of the concave portion to the bottom surface of the roof tile. Is provided with a drain hole lid member for preventing the drain hole from being blocked by the foaming sealing material and being unable to drain the water (Invention of claim 2). ).
[0031]
Furthermore, the solar cell integrated roof member of Claim 1 or 2 WHEREIN: The back surface protection member of the said solar cell module is made into the sheet | seat which laminated | stacked the resin film on both surfaces of metal foil (invention of Claim 3). According to this invention, even if water infiltrates into the solar cell module from the bottom surface of the recess, the water does not enter the inside from the metal foil (for example, aluminum foil), and thus the safety of the solar cell module can be ensured.
[0032]
Further, as the liquid foamable sealing material, the invention of claim 4 below is preferable. That is, in the solar cell integrated roof member according to any one of claims 1 to 3, the liquid foamable sealing material is any one of silicone-based, modified silicone-based, urethane-based, and phenol-based foamable resins. .
[0033]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0034]
FIG. 1 shows a schematic sectional view of the solar cell integrated roof member of the present invention, and shows a sectional view taken along the line AA in FIG. FIG. 2 is a schematic sectional view showing a state in which the solar cell integrated roof member is attached to the roof.
[0035]
In FIG. 1, the solar cell module 11 is the same as that of the conventional structure shown in FIG. 3, and the same function members are denoted by the same reference numerals and partially simplified. The solar cell module 11 used in the present invention is formed by sealing the solar cell 1 with an adhesive resin sealing material 40 between the translucent surface protection member 2 and the back surface protection member 3.
[0036]
As the translucent surface protection member 2, a glass plate, a polycarbonate resin plate, an acrylic resin plate, or the like can be used, but a glass plate is most preferable. When a glass plate is used, it is desirable to take a sufficient R at the end of the glass plate as described above.
[0037]
Examples of the resin sealing material 40 include EVA (ethylene-vinyl acetate copolymer), ethylene-acrylic acid ester copolymer resin, urethane resin, silicone resin, tetrafluoroethylene-6 fluoropropylene-fluoride. A vinylidene copolymer or the like is used. The use form of the resin is preferably a sheet form.
[0038]
As the solar cell 1, known solar cells such as crystalline Si-based, polycrystalline Si-based solar cells, and a-Si solar cells using various substrates can be used.
[0039]
The back surface protection member 3 is preferably an aluminum foil in which ethylene monofluoride (trade name: Tedlar, manufactured by DuPont) having a corona-treated surface is laminated with an adhesive on both surfaces. In addition, in place of the ethylene monofluoride, tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-6 fluoropropylene copolymer (FEP), polyethylene terephthalate (PET), polyethylene telena Plastic sheets such as phthalate (PEN) and modified polyphenyl ether can be used. Further, instead of aluminum foil, iron foil or the like whose surface is treated with a zinc alloy can also be used.
[0040]
The solar cell module is laminated at a module temperature of 150 ° C. by a known method. EVA that protrudes from the end of the solar cell module 11 is removed by a cutter or the like. Thereafter, a terminal box for pulling out a lead wire to a predetermined position is bonded and fixed.
[0041]
The solar cell module is bonded to the concave portion 20a provided on the surface of the roof member main body 20 made of, for example, a lightweight concrete tile, via an adhesive sheet 30 having a predetermined thickness, and the bottom and side surfaces of the solar cell module The liquid foamable sealing material 50 is filled in the gap between the inner surface of the concave portion of the roof member main body and foamed and cured, so that the solar cell module 11 and the roof member main body 20 are integrated.
[0042]
As shown in FIG. 2, a plurality of integrated solar cell integrated roof members 100 are arranged along a roof slope on a roof base plate 60 having a roofing material 61 disposed on the surface thereof. Here, as shown in FIG. 2, for example, the roof member body 20 is formed so that a cavity is formed along the slope of the roof between the surface facing the roof and the roof. In the figure, a wiring portion indicated by 80 is provided.
[0043]
The schematic dimensions of the lightweight concrete roof tile 20 are 900 mm long and 300 mm to 500 mm wide. The roof tile has a recess 20a for housing the solar cell module, and a drain hole 21 is formed in the recess 20a in order to discharge water that enters due to breathing with outside air to the outside of the roof tile. This drain hole 21 is formed in the lowest part of the roof tile. Further, it is preferable that a plastic or inorganic fiber nonwoven fabric is laid as the lid member 22 so that the inlet portion of the drain hole 21 is not blocked by the liquid foamable sealing material 50.
[0044]
The side gap D between the recess and the solar cell module is preferably 1 mm or more, and preferably as small as possible. Considering the dimension due to temperature change, 0.5 mm or more is sufficient, but at least 1 mm is necessary as a dimension tolerance and a dimension necessary for injecting the liquid foamable sealing material. When the gap is 1 mm or less, there is a problem in that foaming starts before the liquid foamable sealing material reaches the bottom of the roof tile.
[0045]
For the adhesion between the solar cell module and the roof tile, a double-sided adhesive sheet 30 having a minimum thickness of 1 mm or more and about 2 mm is preferable. As this adhesive sheet, an acrylic, silicone, butyl, polyester, or other adhesive sheet can be used. When the thickness is 1mm or less, liquid moisture that has entered due to breathing with outside air, etc., will not flow down. There is a fear.
[0046]
As the liquid foamable sealing material 50, as described above, a foamable resin such as silicone, modified silicone, urethane, phenolic foamable resin, silicone, or urethane is used. Among these, silicone resin is most preferable particularly from the viewpoint of weather resistance.
[0047]
The expansion ratio of the liquid foamable sealing material 50 is preferably in the range of 2 to 10 times. When the expansion ratio is high, the sealing property is deteriorated. When the expansion ratio is low, a large amount of liquid is required, and there is a disadvantage that the injection time is long. As a viscosity of a liquid foamable sealing material, the range of 1-200 poise (P) is preferable. More preferably, it is 10-50P.
[0048]
The liquid foamable sealing material 50 is injected by an injection device in which the injection port can move around the module after the solar cell module and the roof tile are bonded. When the liquid foamable sealing material reaches the bottom of the concave portion of the tile by gravity, foaming starts and hardens. The liquid foamable sealing material partially rises from the tile surface due to foam hardening. Cut the raised part with a knife.
[0049]
【Example】
An embodiment of the present invention will be described below with reference to FIG.
[0050]
The solar cell module 11 includes a 3 mm thick glass plate as the surface protection member 2, a 0.4 mm thick sheet EVA as the resin sealing material 40, and a 200 mm × 800 mm plastic film substrate as the solar cell 1. As the a-Si solar cell and the back surface protective member 3, an aluminum foil in which ethylene monofluoride (trade name: Tedlar, manufactured by DuPont) having a corona-treated surface was laminated with an adhesive on both surfaces was used. The solar cell module was laminated by a known method at a module temperature of 150 ° C., and EVA that protruded from the end of the solar cell module 11 was removed with a cutter.
[0051]
The lightweight concrete roof tile 20 was manufactured using a mold. The roof is provided with a recess 20a for storing the solar cell module, and the recess has a drain hole 21 for discharging water that invades by breathing with outside air to the outside of the roof. Provided in the part. Moreover, the glass fiber nonwoven fabric 22 was filled in the drain hole entrance so as not to be blocked by the liquid foamable sealing material 50.
[0052]
A side gap D between the recess and the solar cell module was 1 mm, and an acrylic adhesive sheet 30 having a thickness of 2 mm was used for bonding the solar cell module and the roof tile. As the liquid foamable sealing material 50, a silicone resin having a foaming ratio of 3 times and a viscosity of 50 poise was used. After the module and the roof tile were bonded, the liquid foamable sealing material was injected and cured by an injection device in which the injection port could move around the module. A portion that was raised from the tile surface due to foam curing was cut off with a knife.
[0053]
It was confirmed that the solar cell-integrated roof member manufactured as described above has the desired effects such as excellent workability and sealability against water intrusion.
[0054]
【The invention's effect】
According to this invention, as described above, the solar cell module formed by sealing the solar cell with the adhesive resin sealing material between the translucent surface protection member and the back surface protection member is provided on the surface of the roof member body. A solar cell-integrated roof member disposed in a recessed portion provided via an adhesive sheet having a predetermined thickness, the gap between the bottom and side surfaces of the solar cell module and the inner surface of the concave portion of the roof member body The liquid foamable sealing material is filled and foamed and cured, and the solar cell module and the roof member body are integrated (invention of claim 1),
Further, the roof member body is made of lightweight concrete tiles, and the concave portion is provided with a drain hole penetrating from the bottom surface of the concave portion to the bottom surface of the tile, and the drain hole is blocked with a foaming sealing material on the concave portion bottom surface. By disposing a lid member for a drain hole for preventing the water from becoming undrainable (invention of claim 2),
Excellent workability and sealability for water intrusion, and even if water intrusion occurs due to breathing with the outside air, it has a function to prevent water accumulation in the module housing recess and high waterproofness, and to the light receiving surface of the solar cell It is possible to provide a solar cell integrated roof member that prevents the accumulation of dust.
[Brief description of the drawings]
FIG. 1 is a side sectional view of a schematic configuration of a solar cell integrated roof member according to an embodiment of the present invention. FIG. 2 is a cross sectional view showing a state in which a plurality of solar cell integrated roof members of FIG. FIG. 3 is a side sectional view of a schematic configuration showing an example of a conventional solar cell module. FIG. 4 is a partially enlarged cross-sectional view showing an example of a peripheral portion of a solar cell module attached to a conventional roof tile with solar cells. Explanation of]
1: solar cell, 2: surface protection member, 3: back surface protection member, 11: solar cell module, 20: roof member main body (lightweight concrete tile), 20a: recess, 21: drain hole, 22: lid member, 30 : Adhesive sheet, 40: Resin sealing material, 50: Liquid foamable sealing material.

Claims (4)

A solar cell module formed by sealing a solar cell with an adhesive resin sealing material between the translucent surface protection member and the back surface protection member is placed in a recess provided on the surface of the roof member body with a predetermined thickness. A solar cell-integrated roof member disposed via an adhesive sheet having a thickness, wherein a gap between a bottom surface and a side surface of the solar cell module and a concave inner surface of the roof member body is filled with a liquid foamable sealing material. A solar cell integrated roof member, wherein the solar cell module and the roof member body are integrated by foam curing. The roof member-integrated roof member according to claim 1, wherein the roof member main body is a lightweight concrete roof, and the concave portion is provided with a drain hole penetrating from the bottom surface of the concave portion to the bottom surface of the roof tile. A roof member integrated with a solar cell, wherein a drain hole cover member is provided to prevent the drain hole from being blocked by a foaming sealing material and becoming unable to drain water. The solar cell integrated roof member according to claim 1 or 2, wherein the back surface protection member of the solar cell module is a sheet in which a resin film is laminated on both surfaces of a metal foil. . The solar cell integrated roof member according to any one of claims 1 to 3, wherein the liquid foamable sealing material is one of silicone-based, modified silicone-based, urethane-based, and phenol-based foamable resins. A solar cell integrated roof member.

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