JP2005235842A - Solar cell module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solar cell module which has excellent insulation durability which tends to be lowered by a long-time use and hence has high reliability. <P>SOLUTION: The solar cell module 10 has such a structure that each solar cell sub-module 1 is sealed by an insulating sealing material 5 between a front protection material 3 and a rear protection material 4. The solar cell sub-modules 1 which are adjacent to each other are separated from each other together with support substrates 2. By this structure, the solar cell sub-modules 1 which are adjacent to each other can be formed separately on the separate support substrates 2, and therefore the solar cell sub-modules 1 adjacent to each other can be separated together with the support substrates 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a solar cell module, and in particular, a solar cell in which a plurality of integrated element groups each including a plurality of photovoltaic elements electrically connected to each other are sealed between a surface protective material and a back surface protective material. Regarding modules.

Photovoltaic power generation systems are becoming popular as residential power generation systems as clean energy sources, and are expected to spread to industrial power generation systems in the future.
A typical solar power generation system is composed of a solar cell array composed of a plurality of solar cell modules and an inverter that converts the DC output generated by the solar cell array into an AC output, and is connected to an external commercial power system. Yes.

  In order to take out the electric power generated by the solar cell array without loss and supply it to the external commercial power system, it is desirable to set the operating voltage of the solar cell array to 200 V or higher according to the rated voltage of the inverter. However, since the voltage obtained from one solar battery cell is about 1V, in order to increase the operating voltage of the solar battery array to 200V or higher, the solar battery module generally performs many series connection and parallel connection inside thereof. Thus, the required output voltage and output current are satisfied.

FIG. 9 is a schematic cross-sectional view of a conventional solar cell module.
The solar cell module 100 shown in FIG. 9 insulatively seals a plurality of solar cells 101 between a front surface protective material 102 disposed on the light receiving surface side and a back surface protective material 103 disposed on the non-light receiving surface side. It has a structure sealed with a material 104. For the surface protective material 102, glass, a light-transmitting film, or the like is used. Further, as a photoelectric conversion material used for the solar battery cell 101, wafer type single crystal silicon, polycrystalline silicon, and the like are known.

  As described above, since the number of solar cells that can be sealed in one solar cell module 100 is limited in the solar cell module 100 configured by a plurality of solar cells 101, the output voltage is 100 V or less. Become. Therefore, in order to obtain the high output voltage as described above, it is necessary to further connect the solar cell modules 100 in series.

  On the other hand, a solar cell module using a solar cell sub-module has been developed as a solar cell module that can obtain a high output voltage with one module without performing serial connection as described above. .

  The solar cell sub-module is made of amorphous silicon (a-Si), polycrystalline silicon, compound semiconductor, etc. on a support substrate and then divided into a plurality of power generation regions and connected in series and in parallel. It has been made. In the solar cell submodule, each power generation region formed on the support substrate corresponds to a solar cell. A solar cell module constituted by such solar cell submodules can generate a high output voltage by connecting a plurality of solar cells in series on a support substrate, and can easily increase the area. Therefore, it is expected as a high output voltage type solar cell module.

  Conventionally, as such a solar cell module, a structure in which a plurality of solar cell submodules are formed on one support substrate and the positive and negative electrodes of solar cell submodules adjacent to each other are connected by a wiring member is known. In this solar cell module, in order to separate the solar cell submodules adjacent to each other to ensure insulation, a groove having a predetermined width is provided as a separation portion between the two.

  However, in the above solar cell module, for example, when a high voltage of about 200 V is output, a potential difference of 200 V at maximum is generated between adjacent solar cells that constitute each solar cell sub-module and sandwich the separator. To do. When such a high potential difference is generated between adjacent solar cells, the insulation performance by the separating portion is reduced, leak current is generated, and the photoelectric conversion characteristics of the solar cell module are deteriorated.

In order to improve such a problem, a technique is disclosed in which a separation portion in which the width of a groove is determined according to a potential difference between adjacent solar cells (see, for example, Patent Document 1).
FIG. 10 is a diagram showing a structure of a conventional solar cell module having a separation portion determined according to a potential difference between adjacent solar cells, and FIG. 11 is a cross section taken along line AA in FIG. FIG.

In this solar cell module 200, a solar cell sub-module 210 composed of solar cells 210a and a solar cell sub-module 211 composed of solar cells 211a are formed adjacent to each other on a support substrate 201, and a surface protective material 202 and a back surface It has a structure sealed with an insulating sealing material 204 between the protective material 203. The solar cell sub-modules 210 and 211 are connected in series by the wiring member 205, and insulation is ensured by the separation part D provided between them. The width of the separation portion D is determined according to the potential difference generated between the adjacent solar cells 210a and 211a with the separation portion D interposed therebetween.
JP 2001-36105 A (paragraph numbers [0029] to [0036], FIG. 1)

  By the way, in the technique disclosed in Patent Document 1, adjacent solar cell submodules are formed on a common support substrate. In such a structure, in order to form a separation part between the two, it is necessary to remove the photoelectric conversion layer and the electrode layer made of a conductor formed at this position by a laser or the like. However, due to processing defects at this time, the insulation of the separation portion is liable to decrease, the leakage current generated between the two increases, the photoelectric conversion characteristics deteriorate, and the reliability of the solar cell module decreases. It was. In addition, since the adjacent solar cell submodules are connected to each other at the interface between the support substrate and the insulating sealing material, the same problem as described above may occur due to a decrease in adhesiveness between the support substrate and the insulating sealing material. It was easy to occur.

  Furthermore, since the migration due to the conductor remaining in the separation part occurs due to the hygroscopic action of the insulating sealing material, the frequency of occurrence of insulation failure increases with long-term use. In particular, when a translucent film is used as the surface protection material, the moisture intrusion path is wider than that of glass or the like, and therefore the frequency of occurrence of insulation failure is increased. As described above, the solar cell module has a problem in that the insulation durability decreases with long-term use.

  This invention is made | formed in view of such a point, and it aims at providing the solar cell module excellent in the insulation durability accompanying long-term use, and having high reliability.

  In the present invention, in order to solve the above-described problem, a plurality of integrated element groups formed of a plurality of photovoltaic elements formed on a support substrate and electrically connected to each other are provided between a surface protective material and a back surface protective material. In the solar cell module formed by sealing with an insulating sealing material, the integrated element group adjacent to each other is separated including the support substrate. .

  According to said structure, it becomes possible to form the integrated element group which adjoins mutually on a separate support substrate, and can also isolate | separate both including a support substrate.

  In the present invention, since the integrated element groups adjacent to each other can be separated including the support substrate, it is possible to suppress the deterioration of the photoelectric conversion characteristics due to the leakage current, and to improve the reliability. Since the insulation durability between both improves, the insulation durability accompanying a long-term use can be improved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 2 is a schematic diagram showing an example of the wiring structure of the solar cell module according to the first embodiment of the present invention, and FIG. 1 is a cross-sectional view taken along line AA of FIG.

  The solar cell module 10 of the present embodiment has a plurality of solar cell submodules 1, a surface protection material 3, and a back surface protection material 4 arranged in a matrix, and includes a surface protection material 3 and a back surface protection material 4. Each solar cell sub-module 1 is sealed with an insulating sealing material 5 between them.

  The solar cell submodule 1 is formed by forming a thin film having a photoelectric conversion function on a support substrate 2 and then dividing the thin film into a plurality of solar cells 1a and electrically connecting them to each other. It functions as an electromotive force element group. As the material of the thin film, amorphous silicon (a-Si), polycrystalline silicon, a compound semiconductor, or the like can be used. The support substrate 2 can be a glass substrate, a film substrate, or the like.

  The surface protective material 3 is disposed on the light receiving surface side of the solar cell module 10. As a material of this member, for example, a film material or glass having translucency can be used. As the film material, for example, a fluororesin film such as polyethylene tetrafluoroethylene (ETFE), polytrifluoride ethylene, polyvinyl fluoride, or the like can be used. When a fluororesin-based film is used, it is desirable that a surface treatment such as corona discharge treatment is performed on the adhesive surface with the insulating sealing material 5 so that the insulating sealing material 5 can be easily adhered. . In this embodiment, polyvinyl fluoride is used.

  The back surface protective material 4 is disposed on the non-light-receiving surface side of the solar cell module 10. As a material of this member, for example, a metal plate such as a steel plate, an aluminum plate, a stainless steel plate, carbon fiber, FRP (glass fiber reinforced plastic), ceramic, glass, a fluororesin film, and a laminate of these are used. Can do. In the case where the back surface protective material 4 is mainly composed of a conductive material such as a metal plate, it is desirable that at least the surface to be bonded to the insulating sealing material 5 is coated with an insulating resin. Thereby, insulation with the solar cell submodule 1 can be made more reliable. In this embodiment, a laminated sheet in which an aluminum foil is sandwiched with polyvinyl fluoride (PVF) is used.

  The insulating sealing material 5 is mainly used to ensure insulation between the solar cell submodules 1 and between the solar cell submodule 1 and the wiring member. As a material of this member, for example, a transparent resin such as ethylene vinyl acetate copolymer (EVA) resin, butyral resin, silicon resin, epoxy resin, and fluorinated polyimide resin can be used. Furthermore, it is also possible to perform crosslinking by adding a crosslinking material. Moreover, in order to suppress photodegradation, it is desirable to contain an ultraviolet absorber. In this embodiment, EVA is used.

  In the solar cell module 10 of the present embodiment, as shown in FIG. 2, the solar cell submodules 1 are arranged in a matrix form with 2 vertical submodules and 4 horizontal submodules (8 submodules in total). In each solar cell submodule 1 arranged in this way, each of the solar cell submodules 1 constituting the left half and the right half of the solar cell module 10 in the horizontal direction of the drawing is connected in series with each other by the serial connection wiring member 6. Connected. Further, the positive electrode side and the negative electrode side of the solar cell submodules 1 connected in series in this way are connected in parallel by the parallel connection wiring member 7. And the output lead wire 8 is connected to each parallel connection wiring member 7, respectively, is taken out to the non-light-receiving surface side, and the electric power generated by the solar cell module 10 is supplied to the outside.

  In this solar cell module 10, as shown in FIG. 1, the solar cell submodules 1 adjacent to each other are separated including the support substrate 2. By adopting such a structure, it is possible to form solar cell submodules 1 adjacent to each other on separate support substrates 2 and to separate the two including the support substrate 2.

  As described above, in the solar cell module 10 of the present embodiment, the solar cell submodules 1 adjacent to each other are separated from each other including the support substrate 2, so that the support substrate 2 is included between the two. It is possible to separate the two without using a conventional groove formed on the support substrate. Therefore, a leakage current generated between the two due to processing defects or the like at this time is suppressed, and a decrease in photoelectric conversion characteristics can be suppressed, and the reliability of the solar cell module 10 can be improved. Further, since the groove as described above becomes unnecessary, the residue of the conductor between them can be prevented and the occurrence of migration can be greatly suppressed. This makes it possible to improve the insulation durability between the two. For example, even when a voltage difference of 200 V or more is generated between the solar cell submodules 1 adjacent to each other, sufficient insulation is provided between the two. Durability can be obtained. Therefore, it becomes possible to improve the insulation durability accompanying the long-term use of the solar cell module 10.

  Further, even when a film material having a large moisture intrusion route is generally used as the surface protective material 3, the occurrence of migration can be greatly suppressed. By adopting such a configuration, it is possible to obtain the solar cell module 10 that allows a lightweight and flexible configuration while allowing a high output voltage.

(Second Embodiment)
FIG. 3 is a cross-sectional view of the solar cell module according to the second embodiment of the present invention, and corresponds to the cross-sectional view taken along the line AA of FIG. The same parts as those in FIG.

  The solar cell module 20 of the present embodiment has a plurality of solar cell submodules 1 arranged in the same manner as the solar cell module 10 described above, and has a surface protective material 3 and a non-light-receiving surface side arranged on the light-receiving surface side. The solar cell submodule 1 is sealed with an insulating sealing material 5 between the back surface protective material 4 and the back surface protecting material 4. In addition, the surface protection material 3, the back surface protection material 4, and the insulating sealing material 5 of this Embodiment used the same material as used in the solar cell module 10 described above.

  In this solar cell module 20, the solar cell submodules 1 adjacent to each other are separated from each other including the support substrate 2, similarly to the solar cell module 10 described above. Moreover, the insulating layer 21 is directly formed in the solar cell submodule 1 between both.

  The insulating layer 21 functions as an insulating part different from the insulating part made of the insulating sealing material 5. Insulating layer 21 of the present embodiment is formed on the side end portion of solar cell submodule 1 on the left side of the drawing, on the side end portion of solar cell submodules 1 adjacent to each other, from the light receiving surface side to the non-light receiving surface side. Is formed continuously. Examples of the material of the insulating layer 21 include insulating adhesive materials such as insulating films made of fluororesin or silicon resin materials, and insulating films such as fluororesin films, polyimide films, and polyethylene films. An attached insulating tape or the like can be used. When an insulating tape is used, it is desirable that a surface treatment such as a corona discharge treatment is performed on the adhesive surface with the insulating sealing material 5 so that the insulating sealing material 5 can be easily adhered.

  By adopting such a structure, it is possible to form the solar cell submodules 1 adjacent to each other on separate support substrates 2 in the same manner as the solar cell module 10 described above. Can be separated. Further, the insulating layer 21 formed between the solar cell submodules 1 adjacent to each other further suppresses the leakage current caused by the voltage difference between the two compared to the case of the insulating sealing material 5 alone. In addition, migration that occurs between the two is further suppressed. Moreover, since the insulating layer 21 is directly formed on the solar cell submodule 1, the solar cell submodule 1 itself can be reinforced.

  As described above, in the solar cell module 20 of the present embodiment, the insulating layer 21 directly formed on the solar cell submodule 1 is interposed between the solar cell submodules 1 adjacent to each other, thereby improving reliability and long-term use. As a result, the durability of the solar cell submodule 1 itself on which the insulating layer 21 is formed can be improved.

  In addition, by forming the insulating layer 21 on one of the opposite side end portions of the solar cell submodules 1 adjacent to each other, the above-described effects can be obtained while suppressing an increase in the component cost.

  Furthermore, by continuously forming the insulating layer 21 from the light receiving surface side to the non-light receiving surface side of the solar cell submodule 1, it becomes possible to further suppress the leakage current between the two, and the reliability of the solar cell module 20 The property can be further improved.

Hereinafter, each modification of the present embodiment will be described.
FIG. 4 is a cross-sectional view of a solar cell module showing a first modification of the second embodiment, and corresponds to a cross-sectional view taken along the line AA of FIG. The same parts as those in FIG.

  The solar cell module 20a of this modification is different from the solar cell module 20 described above in that the same insulating layer 21 as described above is formed on both side end portions of the solar cell submodule 1 adjacent to each other. ing. Other configurations are the same as those of the solar cell module 10 described above.

  By adopting such a structure, compared to the solar cell module 20 described above, leakage current due to a voltage difference between the solar cell submodules 1 adjacent to each other is further suppressed, and between the two, The generated migration is further suppressed. Moreover, each solar cell submodule 1 itself adjacent to each other can be reinforced.

  As described above, in the solar cell module 20a shown in FIG. 4, the component cost is increased as compared with the solar cell module 20 described above, but the reliability and the insulation durability associated with long-term use are further improved and adjacent to each other. The durability of each solar cell submodule 1 itself can also be improved.

  FIG. 5 is a cross-sectional view of a solar cell module showing a second modification of the second embodiment, and corresponds to a cross-sectional view taken along the line AA of FIG. The same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

  The solar cell module 20b of this modification is similar to the solar cell module 20a described above in that the same insulating layer 21 as described above is also formed on the outer side end portions of the solar cell submodules 1 adjacent to each other. It is different. Other configurations are the same as those of the solar cell module 10 described above.

  By adopting such a structure, as compared with the solar cell module 20a described above, insulation at the outer side ends of the solar cell submodules 1 adjacent to each other becomes more reliable, and each solar cell sub-unit The module 1 itself can be further reinforced.

  As described above, in the solar cell module 20b shown in FIG. 5, the component cost is increased as compared with the solar cell module 20a described above, but the reliability is further improved and each of the solar cell submodules 1 adjacent to each other itself. The durability can be further improved.

  FIG. 6 is a cross-sectional view of a solar cell module showing a third modification of the second embodiment, and corresponds to a cross-sectional view taken along the line AA of FIG. The same parts as those in FIG.

  The solar cell module 20c of this modified example is different from the above-described solar cell module 20b in that the solar cell module 20c has insulating layers 22 formed on the entire light receiving surface side in addition to both side ends of the solar cell submodules 1 adjacent to each other. It is different. Other configurations are the same as those of the solar cell module 10 described above.

  The insulating layer 22 has translucency, and is continuously formed from the light receiving surface side to the non-light receiving surface side of both end portions of the adjacent solar cell submodules 1 and further formed on the entire light receiving surface side. Has been.

  By adopting such a structure, as compared with the solar cell module 20b described above, the insulation on the entire light receiving surface side of each of the solar cell submodules 1 adjacent to each other becomes more reliable, and the respective solar cell submodules. 1 itself can be further reinforced.

  As described above, in the solar cell module 20c shown in FIG. 6, the component cost is the highest as compared with the solar cell modules 20a and 20b of the modified examples as described above, but the reliability and the solar cells adjacent to each other are increased. The durability of the battery submodule 1 itself can be maximized.

(Third embodiment)
FIG. 7 is a cross-sectional view of the solar cell module according to the third embodiment of the present invention, and corresponds to the cross-sectional view taken along the line AA of FIG. The same parts as those in FIG.

  The solar cell module 30 of the present embodiment has a plurality of solar cell submodules 1 arranged in the same manner as the solar cell module 10 described above, and the surface protective material 3 arranged on the light receiving surface side and the non-light receiving surface side The solar cell submodule 1 is sealed with an insulating sealing material 5 between the back surface protective material 4 and the back surface protecting material 4. In addition, the surface protection material 3, the back surface protection material 4, and the insulating sealing material 5 of this Embodiment used the same material as that used in the above-described solar cell module 10.

  In this solar cell module 30, the solar cell submodules 1 adjacent to each other are separated from each other including the support substrate 2, as in the solar cell module 10 described above. An insulating member 31 is provided in the insulating sealing material 5 between them.

  The insulating member 31 functions as an insulating part different from the insulating part made of the insulating sealing material 5. In the present embodiment, a plate-shaped member having a U-shaped cross section in which both end portions are bent in the horizontal direction with respect to the solar cell submodule 1 is used. As a material of this member, for example, an insulating film such as a fluororesin film, a polyimide film, and a polyethylene film can be used. When an insulating film is used, it is desirable that a surface treatment such as a corona discharge treatment is performed on the adhesive surface with the insulating sealing material 5 so that the insulating sealing material 5 can be easily adhered.

  By adopting such a structure, it becomes possible to form the solar cell submodules 1 adjacent to each other on separate support substrates 2 as in the above-described solar cell module 10, and the support substrate 2 is also formed between the two. Can be separated. Furthermore, both of the insulating members 31 provided between the adjacent solar cell submodules 1 can be compared with the case of only the insulating sealing material 5 without directly processing the solar cell submodule 1. Leakage current due to a voltage difference between the two is further suppressed, and migration occurring between the two is further suppressed.

  As described above, in the solar cell module 30 of the present embodiment, the insulating member 31 is interposed between the solar cell submodules 1 adjacent to each other, so that reliability and It is possible to further improve the insulation durability associated with long-term use. Further, since it is not necessary to directly process the solar cell submodule 1, the insulating member 31 is formed in a predetermined manner as compared with the solar cell module 20 as described above and the solar cell modules 20a, 20b, and 20c of the modified examples. However, the manufacturing process of the solar cell module 30 can be simplified.

  FIG. 8 is a cross-sectional view of a solar cell module showing a modification of the third embodiment, and corresponds to a cross-sectional view taken along the line AA of FIG. The same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

  In the solar cell module 30a of this modification, each end portion of the insulating member 31a having both end portions bent in the same manner as the insulating member 31 is directly above any one of the solar cell submodules 1 adjacent to each other. And it is different from said solar cell module 30 by the point formed so that it may be located directly below. Other configurations are the same as those of the solar cell module 10 described above.

  In the present embodiment, one end of the insulating member 31a is located immediately above the solar cell submodule 1 on the left side of the drawing, and the other end is located directly below the solar cell submodule 1 on the right side of the drawing. It is formed to do. Each end portion may be formed so as to be located immediately above and directly below one of the solar cell submodules 1.

  By adopting such a structure, it becomes possible to further suppress the leakage current between the solar cell submodules 1 adjacent to each other as compared with the solar cell module 30 described above. Therefore, in the solar cell module 30a shown in FIG. 8, it is possible to further improve the reliability as compared with the solar cell module 30 described above.

It is sectional drawing in the AA line of FIG. It is a schematic diagram which shows the wiring structural example of the solar cell module of the 1st Embodiment of this invention. It is sectional drawing of the solar cell module of the 2nd Embodiment of this invention. It is sectional drawing of the solar cell module which shows the 1st modification of 2nd Embodiment. It is sectional drawing of the solar cell module which shows the 2nd modification of 2nd Embodiment. It is sectional drawing of the solar cell module which shows the 3rd modification of 2nd Embodiment. It is sectional drawing of the solar cell module of the 3rd Embodiment of this invention. It is sectional drawing of the solar cell module which shows the modification of 3rd Embodiment. It is a schematic sectional drawing of the conventional solar cell module. It is a figure which shows the structure of the conventional solar cell module which has the isolation | separation part determined according to the electrical potential difference between adjacent photovoltaic cells. It is sectional drawing in the AA of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solar cell submodule 1a Solar cell 2 Support substrate 3 Surface protective material 4 Back surface protective material 5 Insulating sealing material 21 Insulating layer 31 Insulating member

Claims (9)

A plurality of integrated element groups formed of a plurality of photovoltaic elements formed on a support substrate and electrically connected to each other are sealed with an insulating sealing material between a front surface protective material and a back surface protective material. In the solar cell module
The solar cell module, wherein the integrated element groups adjacent to each other are separated including the support substrate.   The solar cell module according to claim 1, wherein the surface protective material is made of a film material.   2. The solar cell according to claim 1, wherein when the back surface protective material is a metal plate, an insulating resin is coated on at least a surface of the metal plate to be bonded to the insulating sealing material. module.   2. The solar cell module according to claim 1, wherein a second insulating portion different from the first insulating portion made of the insulating sealing material is interposed between the integrated element groups adjacent to each other.   5. The solar cell module according to claim 4, wherein the second insulating portion is formed of an insulating layer directly formed on the integrated element group.   The solar cell module according to claim 5, wherein the insulating layer is formed on at least one of side end portions of the adjacent integrated element groups facing each other.   The solar cell module according to claim 5, wherein the insulating layer is continuously formed from a light receiving surface side to a non-light receiving surface side of the integrated element group.   The solar cell module according to claim 4, wherein the second insulating portion is made of an insulating member provided in the insulating sealing material. The insulating member is formed of a plate-like member whose both end portions are bent in a horizontal direction with respect to the integrated element group, and one end portion is positioned directly above one of the integrated element groups adjacent to each other. The solar cell module according to claim 8, wherein the other end portion is formed immediately below one of the integrated element groups adjacent to each other.

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