JP2017188525A - Solar cell module and solar power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell module capable of forming a pattern such as letters and figures on a light receiving surface side without impairing conversion efficiency.SOLUTION: A solar cell module 110 includes, from a light receiving surface side, a surface protective layer 11, a fluorescent-emitting layer 12, a light receiving surface side sealing layer 13, a solar cell 15, a back surface side sealing layer 17 and a back surface protective layer 18, arranged in this order. The fluorescent-emitting layer 12 is a layer having a function of converting light having a wavelength of 400 nm or less into a wavelength in the visible light region, and forms a specific pattern at an opening of the fluorescent-emitting layer.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a solar cell module and a photovoltaic power generation system.

  While importance is placed on reducing the load on the global environment, great expectations are placed on solar cells that photoelectrically convert solar energy directly into electrical energy. There are various types of solar cells, but at present the mainstream is crystalline silicon solar cells.

  A crystalline silicon solar cell has a limited wavelength region with high spectral sensitivity, and there is a problem that light in an ultraviolet region contained in sunlight cannot be sufficiently photoelectrically converted. In order to solve this problem, a solar cell module having a wavelength conversion layer that converts light in the ultraviolet region into light having a wavelength in a region where the spectral sensitivity of the solar cell is high has been proposed.

  For example, Patent Document 1 discloses a structure in which a surface protective layer, a wavelength conversion layer, and a sealing resin layer that are outermost layers are provided on a light receiving surface of a solar battery cell. More specifically, a structure using a wavelength conversion film in which a phosphor substance is dissolved or dispersed in a transparent resin and formed into a film is disclosed as the wavelength conversion layer.

  Patent Document 2 discloses a solar battery module in which a front cover made of glass, a solar battery cell interposed between two sealing materials made of a conversion agent and EVA, and a back cover are laminated in this order. More specifically, a structure in which a sealing material having a wavelength conversion function for converting light into a light having a wavelength longer than the absorbed wavelength is disposed between the front cover on the light receiving surface side and the solar battery cell. It is shown.

  Patent Document 3 shows an example in which long-term reliability can be improved by providing a barrier layer between the wavelength conversion layer and the light-receiving surface side sealing layer.

  Moreover, in patent document 4, it shows about the wavelength conversion type sealing material used for a wavelength conversion layer.

JP 2013-4806 A JP-A-7-202243 Japanese Patent Laying-Open No. 2015-60945 WO2015-064690

  The solar cell module has a photoelectric conversion function for converting sunlight into electricity, but it has been difficult to add value. For example, it is possible to add value if patterns such as desired characters and figures can be formed on the surface of the solar cell module. However, if such a pattern is formed on the light receiving surface side of the solar cell, the most in the solar cell. The conversion efficiency, which is an important function, is impaired, and it has not been used so far.

  The present invention was devised to solve this problem, and an object of the present invention is to provide a solar cell module capable of forming a pattern such as letters and figures on the light receiving surface without impairing the conversion efficiency.

The solar cell module of the present invention is a solar cell module having a surface protective layer, a fluorescent light emitting layer, a light receiving surface side sealing layer, a solar cell, a back surface side sealing layer, and a back surface protective layer in this order from the light receiving surface side. The fluorescent light emitting layer has a function of converting light having a wavelength of 400 nm or less into a wavelength in the visible light region, the fluorescent light emitting layer has an opening, and the pattern is formed by the opening of the fluorescent light emitting layer. Features.

  ADVANTAGE OF THE INVENTION According to this invention, the solar cell module and solar power generation system which can form patterns, such as a character and a figure, on the surface, without impairing conversion efficiency can be provided.

It is a schematic diagram of the solar cell module which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the cross-sectional structure of the solar cell module main body which concerns on Embodiment 1 of this invention. It is a cross-sectional schematic diagram of the solar cell module which concerns on Embodiment 1 and 2 of this invention. It is a schematic diagram of the solar cell module which concerns on Embodiment 2 of this invention. It is a schematic diagram which shows the cross-sectional structure of the solar cell module which concerns on Embodiment 2 of this invention. It is a model of the solar energy power generation system which concerns on Embodiment 3 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Embodiment 1]
The solar cell module according to Embodiment 1 will be described below with reference to the drawings.
FIG. 1 is a schematic diagram showing a state in which the solar cell module of the present embodiment is viewed from the light receiving surface side. The solar cell module 100 includes a solar cell module main body 110 and a frame body 31 that covers the peripheral edge of the solar cell module main body 100. A plurality of solar cells 14 are arranged in the solar cell module body 110. A character pattern 120 was formed on the light receiving surface side of the solar cell module body 110. As will be described in detail later, the character pattern 120 corresponds to a region where the fluorescent light emitting layer is not disposed.

FIG. 2 is a schematic diagram showing a cross-sectional configuration of the solar cell module body of the present embodiment. The solar cell module body 110 includes, from the light receiving surface side, the surface protective layer 11, the fluorescent light emitting layer 12, the light receiving surface side sealing layer 13, the solar cell with wiring sheet 16, the back surface side sealing layer 17, and the back surface protective layer 18. Have. The solar cell 16 with wiring sheet includes a solar cell 14 and a wiring sheet 15. As the solar cell 14, a back contact type solar cell in which p-type and n-type electrodes were formed on the back side of the solar cell was used. The electrode of the solar battery cell 14 is electrically connected to the wiring formed on the wiring sheet 15. Further, adjacent solar cells are connected in series by wiring formed on the wiring sheet 15. In the present specification, the light incident side of the solar battery cell is the light receiving surface side, and the opposite side of the light receiving surface is the back surface side.
Although not shown in FIG. 2, a plurality of solar cells 14 are electrically connected in series by wires formed on the wiring sheet 15 in order to obtain sufficient output power as a solar cell module. Further, the solar cell module has two lead electrodes on the positive electrode side and the negative electrode side, one end of each lead electrode is electrically connected to the solar cell, and one end on the opposite side of the lead electrode is a terminal. Electrically connected to the box.

  A glass substrate having a thickness of about 3 mm was used as the surface protective layer 11 and an ethylene-vinyl acetate copolymer (EVA) to which a fluorescent material having a thickness of about 0.4 mm was added was used as the fluorescent light emitting layer 12. The fluorescent material has a function of absorbing light in a wavelength region of 300 to 450 nm and converting it into light in a wavelength region having higher spectral sensitivity than the crystalline silicon solar battery cell.

In this embodiment, a benzotriazole derivative is added as a fluorescent material to EVA as a main component as the fluorescent light emitting layer 12, but the present invention is not limited to this. As the fluorescent substance, an organic fluorescent material is desirable, and a benzotriazole derivative and a benzothiazole derivative are particularly preferable. Moreover, the fluorescent substance to be added is not necessarily one type, and a plurality of types may be added. Furthermore, in this embodiment, EVA is used as the resin that is the main component of the fluorescent light-emitting layer 12, but a resin such as an ionomer resin can also be used. Although a fluorescent material other than the wavelength conversion material that converts ultraviolet light into visible light can be used as the fluorescent light emitting layer 12, the conversion efficiency of the solar cell module is reduced in that case. By using a wavelength conversion material that converts ultraviolet light into visible light as the fluorescent light emitting layer 12, an effect of adding design properties while improving conversion efficiency can be obtained. By arranging the fluorescent light emitting layer 12, the conversion efficiency of the solar cell module is improved by 1.5 to 2%. In order to form patterns such as letters and figures, holes were formed in the fluorescent light emitting layer 12 to form a pattern 120 as shown in FIG. Since the fluorescent light emitting layer 12 emits blue light by ultraviolet rays under sunlight, the entire solar cell module has a color close to blue, and the pattern 120 portion without the fluorescent light emitting layer 12 has a color close to black. Can be recognized as. At this time, the conversion efficiency improvement of a solar cell module becomes small according to the area ratio with respect to the light-receiving surface of a solar cell module of a pattern with respect to the case where nothing is processed.
A pattern 120 was formed by opening a large number of small holes in the fluorescent light emitting layer 12 in the form of dots. By making a large number of small holes, it has become possible to easily manufacture the solar cell module. Although it is possible to form an opening in the shape of the pattern 20, if the area ratio of the pattern 120 to the fluorescent light emitting layer 12 is increased, it may be difficult to handle as a sheet. This is because the fluorescent light emitting layer 12 can be easily handled as a sheet by opening a large number of small holes.

  A back contact solar cell fabricated using EVA having a thickness of about 0.4 mm as the light-receiving surface side sealing layer 13 and a single crystal silicon wafer as the solar cell 14 was used. No fluorescent material is added to the light-receiving surface side sealing layer 13. The light-receiving surface side sealing layer 13 is preferably made of a material that has a high transmittance in the visible light region and that allows as much light in the visible light region that has been wavelength-converted by the fluorescent light-emitting layer 12 to reach the solar cells 14. In this embodiment, EVA is used as the light-receiving surface side sealing layer, but a resin such as an ionomer resin can also be used. As the solar battery cell 14, a single crystal silicon cell or a polycrystalline silicon cell in which a grid electrode is formed on the light receiving surface side may be used. It is also possible to use a thin film solar cell formed on glass or a film.

  Since the fluorescent light emitting layer 12 emits blue light by ultraviolet rays outdoors, if the surface color of the solar battery cell is close to blue, it becomes difficult to provide contrast with or without the fluorescent light emitting layer 12. Therefore, it is desirable that the solar battery cell 14 has a color close to black. In addition, if there is a grid electrode on the light receiving surface side, light is diffusely reflected by the grid electrode and it is difficult to obtain contrast. Therefore, a back contact solar cell without a grid electrode is desirable.

Further, EVA having a thickness of about 0.4 mm was used as the back surface side sealing layer 17, and a back sheet having a PET / Al / PET structure was used as the back surface protective layer 18. The back surface side sealing layer 17 is disposed on the back surface side opposite to the light receiving surface of the solar battery cell, and it is desirable to use a material having high adhesive strength with the solar battery cell 14 and the back surface protective layer 18. . In this embodiment, EVA to which an ultraviolet absorber is added is used as the back surface side sealing layer 17, but it is not limited to EVA, and a material such as an ionomer resin can also be used. In the present invention, the ultraviolet absorber means a substance having an absorption wavelength peak at 300 to 450 nm and other than a fluorescent substance. The ultraviolet absorber absorbs ultraviolet rays in the irradiated light and converts them into thermal energy within the molecule, and has a function of preventing active species that initiate photodegradation in the polymer from being excited by the ultraviolet rays. . In this embodiment, a benzophenone-based ultraviolet absorber is used, but the present invention is not limited to this.

  The manufacturing method of the solar cell module in this embodiment is demonstrated easily using FIG. FIG. 3A is a schematic cross-sectional view of a solar cell module main body 110 in which members arranged as shown in FIG. 2 are laminated and integrated. It is possible to manufacture by the same manufacturing process as the case where the fluorescent light emitting layer 12 is not provided, and there is an advantage that it is not necessary to consider a separate manufacturing process. FIG. 3B is a schematic cross-sectional view of the solar cell module 100, and the buffer agent 30 and the frame body 31 are arranged on the peripheral portion of the integrated solar cell module main body 110 to manufacture the solar cell module 100.

When the solar cell module of the present embodiment was placed outdoors, the pattern 20 shown in FIG. 1 could be clearly confirmed on a clear day. Since the amount of ultraviolet rays was about 60% on a cloudy day and about 30% on a rainy day, the pattern 120 tended to be less visible than on a clear day. In addition, since the amount of sunlight including ultraviolet rays decreases in the morning and evening, the pattern 120 tends to be difficult to visually recognize. Since the ultraviolet rays were hardly irradiated indoors, the formed pattern 20 was hardly visible.
With the structure described in the present embodiment, it is possible to provide a solar cell module having a high conversion effect and a desired pattern on the surface.
[Embodiment 2]
A solar cell module according to Embodiment 2 will be described with reference to the drawings. The difference from the first embodiment is that a fluorescent light emitting layer is previously formed on the surface protective layer, and then a member is placed and sealed. A description of the same parts as those in the first embodiment will be omitted.

  In FIG. 4, the model which looked at the solar cell module of this embodiment from the light-receiving surface side is shown. A wave pattern 220 is formed on the light receiving surface side of the solar cell module 200 including the solar cells 24.

  In FIG. 5, the schematic diagram of the cross section of the solar cell module of this embodiment is shown. As shown in FIG. 5, the solar cell module 210 of the present embodiment includes a surface protective layer 29 with a fluorescent light emitting layer, a light receiving surface side sealing layer 23, solar cells 24, a wiring sheet 25, a back surface side sealing layer 27, A back surface protective layer 28 is provided. The surface protective layer 29 with a fluorescent light emitting layer includes a surface protective layer 21 and a fluorescent light emitting layer 22, and the fluorescent light emitting layer 22 is on the back side of the surface protective layer 21.

  In this embodiment, the surface protective layer 29 with a fluorescent light emitting layer is composed of a surface protective layer 21 made of a glass substrate and a fluorescent light emitting layer 22 mainly composed of EVA to which a benzotriazole derivative as a fluorescent material is added. Moreover, the same member as Embodiment 1 was used regarding the light-receiving surface side sealing layer 23, the photovoltaic cell 24, the wiring sheet 25, the back surface side sealing layer 27, and the back surface protective layer 28.

The fluorescent light emitting layer 22 was printed on the surface protective layer 21 made of a glass substrate using a screen printing method. Needless to say, the method is not limited to the screen printing method, and other methods may be used. The fluorescent light-emitting material is kneaded with an acrylic resin, an epoxy resin, a phenol resin, or the like, and after printing, the resin is fixed by being polymerized by heat at several tens to hundreds of degrees. In the present embodiment, an acrylic resin having a high transmittance and a fluorescent light emitting material kneaded are used. Since the surface protective layer 21 made of a glass substrate generally used for solar cells is subjected to relatively large embossing on the side opposite to the light receiving surface, which is a printing surface, the front and back sides are used in reverse. The fluorescent light emitting layer 22 was printed and cured on a substantially flat surface to form a surface protective layer 29 with a fluorescent light emitting layer. In the present embodiment, there are advantages over Embodiment 1 described above that a complicated pattern can be freely formed and that the luminescent stability is excellent because the fluorescent light emitting layer does not melt. For this reason, it became possible to form a relatively complicated pattern as shown in FIG. That is, it has become possible to provide a solar cell module having high conversion efficiency and a complicated desired pattern on the surface.
[Embodiment 3]
A photovoltaic power generation system according to Embodiment 3 will be described with reference to FIG.
As shown in FIG. 6, the solar power generation system is formed by a plurality of solar cell modules 300. For this reason, a plurality of solar cell modules having design properties that are possible in the present invention are arranged and arranged. FIG. 6 is an example in which characters are expressed by combining solar cell modules 300 installed on a roof. Only the character part becomes a color close to black of the solar battery cell, and the periphery thereof appears to be a color close to blue due to fluorescence emission. The appearance changes depending on the time of day and the weather, and it is possible to have a design characteristic that is characteristic of the photovoltaic power generation system.

With the structure described in the present embodiment, it is possible to provide a photovoltaic power generation system having high conversion efficiency and a desired pattern on the surface. That is, it has become possible to provide design properties to a photovoltaic power generation system composed of a plurality of solar cell modules.
[Embodiment 4]
A photovoltaic power generation system according to Embodiment 4 will be described. A difference of the fourth embodiment from the third embodiment is that a fluorescent light emitting layer is arranged in a pattern portion. That is, the part other than the pattern becomes the opening of the fluorescent light emitting layer. Only the character portion appears to be a color close to blue due to fluorescence, and the other portions are close to black. The output of the solar power generation system is 1 in the third embodiment.
% Is considered to be advantageous, but the entire photovoltaic power generation system has a color close to black. When installing a solar power generation system on the roof, colors that are close to black tend to be preferred, and it has become possible to increase the choice of installers.

  With the structure described in this embodiment, it is possible to provide a photovoltaic power generation system having a color tone close to black, high conversion efficiency, and a desired pattern on the surface.

  As mentioned above, although Embodiment 1 to Embodiment 4 was specifically described, the present invention is not limited to them. Embodiments obtained by appropriately combining the technical means disclosed in the four embodiments described above are also included in the technical scope of the present invention.

  In addition, embodiment disclosed this time is an illustration in all the points, Comprising: It does not become the basis of limited interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-described embodiments, but is defined based on the description of the scope of claims. Moreover, all the changes within the meaning and range equivalent to a claim are included.

100, 200, 300 Solar cell module 110, 210 Solar cell module body 120, 220, 320 Pattern 11, 21 Surface protective layer 12.22 Fluorescent light emitting layer 13, 23 Light receiving surface side sealing layer 14, 24 Solar cell 15, 25 wiring sheet 16 solar cell with wiring sheet 17, 27 back side sealing layer 18, 28 back side protective layer 29 surface protective layer with fluorescent light emitting layer 30 buffer 31 frame

Claims (5)

A solar cell module having a surface protective layer, a fluorescent light emitting layer, a light receiving surface side sealing layer, a solar battery cell, a back surface side sealing layer, and a back surface protective layer in this order from the light receiving surface side,
The fluorescent light emitting layer has a function of converting light having a wavelength of 400 nm or less into a wavelength in the visible light region,
The fluorescent light emitting layer has an opening;
The solar cell module in which the pattern was formed by the opening part of the said fluorescence light emitting layer.   2. The solar cell module according to claim 1, wherein the fluorescent light-emitting layer is a layer to which a fluorescent material that converts light having a wavelength of 400 nm or less into a wavelength in a visible light region is added. The solar cell module according to claim 1, wherein the fluorescent light emitting layer is formed integrally with the surface protective layer.   2. The solar cell module according to claim 1, wherein the pattern formed in the fluorescent light-emitting layer has a plurality of openings arranged in a dot shape.   A solar power generation system comprising at least one solar cell module according to claim 1.

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