JPS63102277A - Solar cell module - Google Patents

Abstract

PURPOSE:To effectively utilize a generating region and to reduce the weight of a solar cell module thereby to decrease a solar light generating cost by so laminating an intermediate member of a support which causes a transmissibility to reduce as to superposed on a bus bar of a collecting electrode of a nongenerating region. CONSTITUTION:An optically generating element 20 is bonded to a composite layer plate 10 to form a module so that the bus bar (a) of the collecting electrode of the element 20 is overlapped on an intermediate member 11 of the plate 10. Since the bar (a) which does not contribute to a photoelectric conversion, and a series connection unit are superposed at a position of a rib 11 of the intermediate member of the plate 10 in this module, a reduction in the area of a substantial photoelectric conversion region upon moduling is minimized as required. Thus, a short-circuit current increases to enhance the conversion efficiency.

Description

[Detailed description of the invention] Field of use〉 The present invention relates to a solar cell module suitable for electric power.

More specifically, the present invention relates to a solar cell module in which sufficient strength can be obtained using an in-container method.

<Prior art> A solar cell module (hereinafter referred to as "module") is
Tempered glass is used for the transparent window, various solar cells are used as the photovoltaic elements, and metal sheets are used as the sealing material. These structural elements are laminated together using polyvinyl butyral or ethylene vinyl acetate resin as the filler, and then the metal frame or plastic is used. Structures sealed with a frame are known (for example, Takahashi,
Co-authored by Konagai (published by Shokodo) “Amorphous Solar Cell” 1
(See pages 7-18).

A module with such a structure inevitably has a large weight, and in order to install such a heavy object as a power generation unit, it is necessary to construct a building (array) with a reliable foundation and frame. Solar power generation costs consist of the costs of peripheral components in addition to the cost of solar cell modules, and it is necessary to reduce not only the module cost but also the cost of peripheral components in order to bring solar power generation to a practical level. .

From this perspective, in order to reduce the weight of solar cell modules, reduce the burden on the foundation and frame, and reduce the cost of surrounding components, aluminum honeycomb structures and paper honeycomb structures are used as sealing materials and supports against wind pressure. Proposals have been made to reduce the weight of modules while maintaining mechanical strength by using structures and rib structures.
est of the internationala
(See pages 665-668).

However, even in this case, it is necessary to use tempered glass with a thickness of 3.2 or higher to ensure strength against frost and wind pressure, especially in the case of amorphous solar cells using glass substrates. , the window on the side where sunlight enters is double-glazed, which limits the ability to reduce the weight of the module.

In addition, such honeycomb structures and rib structures act as a heat insulating layer, increasing the surface temperature of the solar cell and reducing photoelectric conversion efficiency.

From this point of view, we previously proposed in Japanese Patent Application No. 141421/1982 a solar cell module in which a hollow transparent multilayer plate is laminated as a support on the daylight side of a photovoltaic element. However, this structure has a problem in that the photoelectric conversion efficiency decreases due to a decrease in transmission in the portion of the support that overlaps with the intermediate member of the transparent multilayer plate.

<Objective of the Invention> The object of the present invention is to solve these drawbacks of the prior art, reduce the weight of the solar cell module, and make it possible to reduce the cost of solar power generation and expand various applications accordingly. Our goal is to provide solar cell modules.

<Structure 9 of the Invention> In other words, the present invention provides a transparent structure with a hollow structure in which a plurality of transparent plates made of a non-metallic material are connected by an intermediate member arranged at predetermined intervals on the daylighting side of a solar power generation element. A solar cell module in which supports made of multilayer plates are laminated, characterized in that the bus bars of the collecting electrodes of the photovoltaic elements and the intermediate members of the supports are laminated so as to overlap with each other. It is.

With this configuration, the intermediate member of the support, which causes a decrease in transmittance, overlaps the bus bar of the collecting electrode, which is the non-generating area, so that the generating area can be used effectively and more power can be obtained. become.

By the way, the transparent multi-layer board used as the window material of the present invention is
It is a hollow, lightweight transparent multi-layer board in which a plurality of transparent plates are connected at predetermined intervals via intermediate members. For example, ribs at predetermined intervals are connected between synthetic resin plates with high impact resistance and good workability.
It is a structure in which strength is ensured by connecting intermediate members such as corrugated plates with VA connections, and weight reduction is achieved by leaving gaps between the transparent plates. The synthetic resin used for this transparent plate is not particularly limited as long as it is transparent, and all known transparent plate materials such as polycarbonate resin and acrylic resin can be used. Polycarbonate resin is excellent in terms of impact resistance and is preferred. Further, the intermediate member is not particularly limited as long as it is lightweight and strong, but it is preferably one that does not reduce the light transmittance of the multilayer board. Therefore, plate-shaped bodies, columnar bodies, framework structures of these bodies, etc. can be used as the intermediate member, but from the viewpoint of strength and light transmission, a cell structure in which plate-shaped bodies are arranged so as to have a large number of cells is preferable. Applicable. Examples of such a cell structure include a multi-rib structure in which transparent sheets are joined by ribs at regular intervals to have columnar cells parallel to the sheet surface.

A multi-rib structure multi-layer board can be obtained by extruding polycarbonate resin or the like through a die having a rib structure of the same type as the side cross-sectional structure of the multi-rib structure. In particular, from the viewpoint of sunlight transmittance and productivity of the obtained multilayer structure, the above-mentioned multi-layer board made of a transparent synthetic resin with an integrally molded multi-rib structure with an air layer in the middle is considered to be the best choice. It can be suitably used as a window material of the invention. Incidentally, as a multi-layer board having such a multi-rib structure, Panlight Uni (trade name: manufactured by Yojin Kasei@) is commercially available as a light-transmitting heat insulating material.

However, if such a synthetic resin has a high water vapor permeability, there will be movement of water through the plurality of sheets.

As a result, dew condensation is observed within the hollow portion, causing the transparent window to become foggy and the light transmittance to decrease. Furthermore, when the permeated moisture reaches the surface of the photovoltaic element, it promotes corrosion of the electrode surface, which is unfavorable in terms of long-term stability.

Furthermore, such a multilayer plate acts as a heat insulating layer and increases the surface temperature of the photovoltaic element, inevitably reducing the photoelectric conversion efficiency.

In order to avoid such drawbacks and fully realize the advantages of the multilayer board, the present inventor made further improvements. That is, in order to reduce the water vapor permeability of the synthetic resin, the multilayer plate was provided with a moisture permeability prevention film on the surface facing the photovoltaic element. In addition, the hollow part of the multilayer board is structured to communicate with the outside, and the hollow part is sealed while remaining open to the atmosphere, thereby reducing the heat insulating effect of the hollow part. The multi-rib structure described above with columnar cells in which the hollow portions are parallel is preferred in terms of easy ventilation. Particularly when assembling a structure using such multilayer board modules, it is preferable to arrange the columnar cells at an angle with respect to the horizontal plane.

With this structure, the columnar cells exhibit multiple chimney effects,
This creates a flow of air and prevents the surface temperature from rising. Furthermore, moisture that had permeated the synthetic resin and condensed inside the columnar cells was removed by this air flow.

On the other hand, by providing the moisture permeation prevention film on the side of the multilayer plate facing the solar power generation element, it is possible to prevent moisture from entering the solar power generation element. Such moisture permeation prevention films include amorphous silicon films, indium oxide films, etc., and organic thin films such as polyvinylidene fluoride films. Among them, indium oxide films have excellent transparency and adhesion to adjacent layers. Preferable from this point of view.

Further, if necessary, it is preferable to provide a transparent scratch-resistant film made of a photocurable or thermosetting resin layer on the surface of the multilayer board for the purpose of improving scratch resistance and abrasion resistance. Any known scratch-resistant film can be used as is. Furthermore, for the purpose of improving light resistance, an ultraviolet absorber may be included in these layers, or may be laminated thereunder.

Next, the solar power generating element used in the present invention is not particularly limited, and known solar cells can be applied as they are, such as single crystal,
Silicon-based solar cells that use not only polycrystalline silicon semiconductor layers but also amorphous silicon semiconductor layers as electromotive force layers, ■-
Examples include so-called compound-based solar cells that use a semiconductor layer of group (1) or m-v group as an electromotive force layer. Among these, an integrated solar cell having a so-called integrated structure in which a plurality of solar cells formed on the same electrically insulating substrate are connected in series and parallel can be suitably used. Typical examples of such integrated solar cells are amorphous silicon solar cells and II-VI group compound semiconductor solar cells, but especially amorphous silicon solar cells formed on a flexible electrically insulating substrate. An integrated solar cell is preferable because it can take advantage of characteristics such as being a thin film structure and being lightweight, and it can be continuously stacked using rolls as shown in Examples below. Integrated Hole II using a curved amorphous silicon semiconductor layer as an electromotive force layer
The pond can be realized by the following method.

For example, as an electrically insulating substrate, a polymer film, a ceramic plate, a glass plate, or a metal foil with an insulating layer on the surface can be used, and a long flexible substrate that can be used for continuous film formation and segmentation is particularly advantageous. It is. In addition, the metal electrode layer provided thereon includes Ti, Ag, W, Pt, and Ni.
, Go, chrome.

Single metal 9 alloy metals such as nichrome can be used.

Also, p
bale of in, pin /pin, pin /pin
Not only a multilayer tandem structure such as /pin, but also a narrow bandgap or wide bandgap amorphous silicon semiconductor layer such as amorphous silicon germanium or amorphous silicon carbide can be used as appropriate.

Further, as the transparent electrode layer, a known transparent conductive layer such as tin oxide or cadmium stannate can be used. After dividing the power generation layer of the continuous amorphous silicon solar cell with a predetermined area into cells with an appropriate area using a laser scoring method, knife cutting method, etc., the cells are electrically connected to form an integrated solar cell. Get the battery. The method for electrically connecting divided cells is not particularly limited, as long as the upper electrode of one cell to be connected and the lower electrode of the cell being used can be electrically connected, and connection with lead wires is possible. Known methods such as a method of forming a connection layer made of a thin metal film by a PVD method, a method of forming a connection layer of a conductive resin layer by a screen printing method, etc. can be applied. Among these, electrical connection by screen printing is preferably applied from the viewpoint of productivity and equipment.

Such a method provides an integrated solar cell, which is a photovoltaic layer or an amorphous silicon semiconductor wire on a flexible polymeric film substrate.

Next, the sealing material for sealing the solar power generation element mentioned above may be any material that can prevent moisture from entering, such as a corrosion-resistant metal sheet, aluminum metal foil, polyester film, polyvinylidene fluoride film, etc. A so-called moisture-proof film is used. Among these, a moisture-proof film made by laminating aluminum metal foil with a polyester film or the like is one of the preferable materials because it is light in weight and satisfies the purpose of the present invention.

In addition, a filler that adheres and seals the above-mentioned support, the solar power generation element, and the sealing material, and also serves as a cushion layer (
Polyvinyl butyral resin, ethylene vinyl acetate resin, etc., which are light-resistant and have excellent adhesion to each component, are used as the "bottant".

The solar cell module of the present invention is a transparent multilayer structure.

If necessary, the photovoltaic power generation element is constructed by laminating the above-mentioned filler as a resin material in order from the sunlight incident side with a sealing material, and further sealing the periphery with a frame if necessary.

By the way, in order to effectively collect the photocurrent, the photovoltaic element uses a bus bar (A) as a collection electrode as shown in Figure 1.
and fingers (b) are screen printed with Ag-based resin or Ag, A! :1, etc., by vapor deposition, sputtering, or adhesion of metal foil. The feature of the present invention is that the bus bar of the collector electrode and the intermediate member of the transparent multi-layer plate having a hollow structure are laminated in an overlapping manner. In the case of the above-mentioned integrated structure in which electrical connections are made in series and parallel, it is preferable that a bus bar of a collecting electrode be formed at the connection portion, since this increases the number of photoelectric conversion units.

The solar cell module of the present invention includes, for example, a polycarbonate multi-rib multilayer structure with a thickness of 4 ends, an integrated amorphous silicon solar cell using a polyester film substrate with a thickness of 0.1 ffffi, and a polyfluoride polyester film substrate. When constructed from a sealing material (thickness 0.3 m) consisting of vinylidene/An metal foil/polyvinylidene fluoride, the total thickness is at most 4.5 m, the weight is approximately 1,000 kg/end, and the impact resistance is high. can withstand a drop height of 5 m from a steel ball 5 (10 g).On the other hand, in the case of a solar cell with the same configuration using tempered glass with a thickness of 3.2 mm instead of the multilayer structure, the overall thickness is 3.2 mm. 7M, which is slightly thinner than the structure of the present invention, but the weight has increased to about 9.0, which is 9/lri, and the impact resistance is higher than the drop height of a steel ball of 225g.
It goes down to a width of 5m. As is clear from this fact, it has been found that the solar cell module of the present invention can be made lighter without impairing its mechanical strength, and can also have a simpler laminate structure.

The present invention will be explained below based on examples.

<Example> photovoltaic elements FIG. 2 shows a side sectional view of the photovoltaic element of the example.

In this example, a plurality of power generation units provided on a polymer film substrate 21 are connected in series, and a collector electrode bus bar is formed at the connection part. Almost the same except for

The polymer film of the illustrated substrate 21 may be any polymer film that has the heat resistance necessary for amorphous silicon deposition, but preferably polyethylene terephthalate (
PET) film, polyimide film, etc. are used. The example shown uses PET film.

As the metal electrode layer 22, an Al1 layer of about 0.5 μm and 30
An AN/SUS laminate in which human-sized stainless steel (SLJS) layers were sequentially deposited on a substrate 21 using a sputtering method was used.

The amorphous silicon semiconductor layer 23 of the photovoltaic layer is a well-known Pi
An n-type structure was adopted and deposited on the stainless steel layer of the metal electrode layer 22 using a glow discharge decomposition method using silane gas or the like similar to that disclosed in JP-A-59-34668.

Next, an amorphous silicon semiconductor is used as an electrically insulating insulating resin layer 25 provided at the interface between the amorphous silicon semiconductor layer 23 and the transparent electrode layer 24 to prevent short circuits between electrodes during division by laser scribing, etc. Epoxy resin was previously provided on the layer 23 at the groove portions to be divided into cells 20a using a laser using a screen printing method.

Next, as a transparent electrode layer 24, an ITO (indium oxide/tin oxide) layer is deposited by electron beam evaporation or sputtering to form a PET film. A large-area amorphous thin film solar cell having a patterned epoxy resin layer/TTO structure was obtained.

Then, this P E T // A S / S U S
//Amorphous silicon piny patterned epoxy resin layer〃■T○ structure amorphous solar cell 10czX10
The metal electrode layer 2 is formed by scanning the c+++ square cell with a YAG laser over the above-mentioned insulating resin layer 25 made of an epoxy resin layer.
2 and the transparent electrode layer 24, respectively, and remove them as necessary to form a dividing groove 26, which is then filled with the same insulating resin as above to form three approximately 3c#r.
It was divided into cells 20a of x10 cffi square. In addition, in order to connect these three divided cells 20a in series,
As shown in FIG.
a by using a screen printing method.

A laser beam is irradiated to the connection point 28 of one part of the return bus bar to melt and connect the collecting electrode 27, that is, the transparent electrode 24 of the adjacent cell 20a, and one metal electrode layer 22 to establish an electrical connection, thereby generating photovoltaic power generation. As the element 20, an integrated amorphous solar cell with three cells 20a connected in series was fabricated.

The double-layer board 10 serving as the multilayer structure window and support was used by cutting Panlite Uni (trade name) manufactured by Teijin Chemicals Ltd., manufactured by extrusion molding from polycarbonate resin, into a 110 m x 110 mm piece using a tip saw. Figure 3.

As shown in FIG. 4, the panlite uni used consists of two sheets 12 and 13 each having a thickness of 1 shoe connected by an intermediate member 11 consisting of ribs 1 mm thick and 7 ai in height spaced apart by 30 ia. 30W! It had a multi-rib structure with RX7m+ prismatic cells to 14, the total thickness was 9#I1m, and the weight was about 2Ky/rd. And on one side about 3
(Moisture-resistant vA15 made of indium oxide of 10% was installed.

Manufacture of module When laminating the multilayer plate 10 and the photovoltaic element 20 made of the integrated amorphous silicon solar cell described above, an ethylene vinyl acetate resin having a thickness of 0.4 M is inserted between them as a filling layer 31. do. On the other hand, on the opposite side of the photovoltaic element 20, a sealing material 40 was similarly laminated as a second filling layer 32 via an ethylene vinyl acetate resin having a thickness of 0.4M. Note that the sealing material 40 is an aluminum metal foil with a thickness of 0.015#.

A three-layer moisture-proof film consisting of ethylene vinyl acetate resin and a 0.075 m thick polyester film was used. Next, this stacked body was fed between 90° C. and 180° C. hot rolls with the multilayer plate 10 facing the 90° C. hot roll side, and the whole was thermocompression bonded to obtain a solar cell main module of the present invention.

Next, seal this main module with butyl rubber using sealant 3.
3 and sealed with an aluminum frame 50.
The following solar cell module shown in FIG. 4 was formed.

FIG. 3 is a plan view, and FIG. 4 is a sectional view taken along the line A-B.

When manufacturing these modules, as shown in FIG.
0 and the multilayer board 10 were bonded together to obtain a module of an example. As a comparative example, a module was created in which these components were pasted together so that they intersected each other at right angles. And A.M.I.
The cell performance of both modules was measured under (10 mw/cti) solar simulator light. The cell performance measurement results are shown in Table 1.

Table 1 As can be seen from the results in Table 1, in the module of the present invention, part of the bus bar (A) does not contribute to photoelectric conversion.

Since the series connection portion 28 overlaps the position of the rib 11 of the intermediate member of the multilayer plate 1o of the support body, the actual reduction in the area of the photoelectric conversion region due to modularization is kept to the necessary minimum. As a result, short circuit current increases and conversion efficiency improves compared to the comparative example.

[Brief explanation of the drawing]

FIG. 1 shows a bus bar of a photovoltaic element according to the present invention,
A plan view showing the fingers, FIG. 2 is a side sectional view of the photovoltaic element of the example, FIG. 3 is a plan view of the solar cell module of the example, and FIG. 4 is a sectional view taken at FIG. 3-B. , FIG. 5 is an explanatory diagram of the laminated structure of the embodiment. 10: Multilayer board 2o: Photovoltaic element 31. 32: Filled layer 4o 2 sealing material 33: Sealing agent 5o: Frame

Claims (11)

[Claims] (1) A solar cell in which a support consisting of a transparent multilayer plate with a hollow structure connected by an intermediate member in which a plurality of transparent plates made of non-metallic materials are arranged at predetermined intervals is laminated on the daylighting side of the photovoltaic element. 1. A solar cell module characterized in that, in the module, a bus bar of a collection electrode of the solar power generation element and an intermediate member of the support are stacked so as to overlap. (2) The solar power generation element has an integrated configuration in which a plurality of power generation units provided on the same flexible electrically insulating substrate are connected in series and/or in parallel, and the solar power generation elements are connected in series and/or in parallel. 2. The solar cell module according to claim 1, wherein a bus bar of the collector electrode is formed at a location where the collector electrode is formed. (3) The solar cell according to claims 1 and 2, wherein all the hollow parts of the transparent multilayer plate communicate with the outside, and the hollow parts are sealed so as to communicate with the atmosphere. module. (4) The solar cell module according to claim 3, wherein the intermediate member of the transparent multilayer plate is ribs arranged at regular intervals, and the hollow portion is divided into parallel columnar cells. (5) The solar cell module according to claim 4, wherein the columnar cells are arranged to be inclined. (6) The solar cell module according to any one of claims 1 to 5, wherein the transparent multilayer plate is made of synthetic resin. (7) The solar cell module according to claim 6, wherein the transparent multilayer plate is made of polycarbonate resin. (8) The solar cell according to claim 6 or 7, wherein the transparent multi-layer plate is a transparent multi-layer plate on which a transparent moisture-resistant film is formed on the side facing the photovoltaic element. battery module. (9) The transparent multi-layer board is a transparent multi-layer board on which a transparent scratch-resistant film is formed on the surface facing the atmosphere. solar cell module. (10) The solar cell module according to any one of claims 1 to 8, wherein the back side of the solar power generation element is sealed with a sealing material. (11) Claim 1, wherein the flexible substrate is a polymer film, and the power generation unit is an amorphous semiconductor.
The solar cell module according to item 0.