JP2004335563A - Solar cell module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solar cell module which is capable of receiving sunlight well and much improved in power generation efficiency even when the solar cell module is used in an installation environment such as a vertical plane or the like where the module is installed. <P>SOLUTION: A transparent material which refracts sunlight is provided on the light receiving plane of the solar cell module, so that the light receiving plane of the solar cell module is capable of restraining sunlight from being reflected, and the solar cell module is capable of keeping its power generation output constantly high even in the case that the light receiving plane of the solar cell module is smooth, an incident angle of sunlight is large, and most of sunlight is reflected from the smooth surface of the solar cell module to deteriorate the solar cell module in light receiving efficiency. The transparent material refracting sunlight is formed into a corrugated structure composed of a plurality of wavy forms that are continuously connected in a lateral direction or formed into a structure having a plurality of pyramids on its front surface, so that the solar cell module is prevented from deteriorating in power generation efficiency due to the reflection of sunlight from its surface and capable of generating electric power without deteriorating its power generation efficiency. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a solar cell module that receives sunlight and generates power, and more particularly relates to a solar cell module that has improved light receiving efficiency and power generation efficiency.
[0002]
[Prior art]
The solar cell module has a structure in which solar cells that generate power by receiving sunlight are sandwiched between plate members using a sealing material such as EVA or silicone. In a general module, a single cell is insufficient in electromotive force, so that it is seldom composed of a single cell, and is configured by connecting a plurality of solar cells in series or in series / parallel. The plate material for sandwiching the solar cells is made of resin, glass, metal, or a plate obtained by laminating these plate materials, and is generally a plate having a smooth surface.
[0003]
In addition, when power generation is performed using a solar cell module, various devices for improving power generation efficiency have been made. For example, when fixing the solar cell module, the light receiving surface is inclined to the south side, or a device for automatically tracking the sun is provided so that the light always hits the light receiving surface vertically. (For example, Patent Documents 1 and 2) In addition, light condensed by using a lens or a mirror surface is applied to a solar cell (Patent Document 3), or a cell arrangement is devised (Patent Document 4). Various proposals have been made.
[0004]
[Patent Document 1]
JP 2001-290537 A [Patent Document 2]
JP 2002-317540 A [Patent Document 3]
Japanese Patent Application Laid-Open No. 2000-243983 [Patent Document 4]
JP 2001-217448 A
[Problems to be solved by the invention]
However, the automatic tracking device is not widely used at present because of its high cost and required maintenance. Generally, the installation orientation and installation angle of the solar cell are the most efficient throughout the year. Many are good, south facing, installed at an installation angle of 45 degrees. However, depending on the product, the solar cell module may not always be able to be installed in a preferred direction or installation angle. For example, when a solar cell module is provided on a transparent sound insulation plate of a road noise barrier, a panel of a fence, or the like, the installation direction is determined by the direction of the road, and the installation angle is also vertical.
[0006]
In addition, when installing a double-sided light receiving solar cell module, it is preferable that the installation angle is perpendicular to the ground, and for such a vertically installed solar cell module, the light receiving efficiency is improved and the power generation amount is increased. A way to increase it is desired.
[0007]
For example, as one of the causes of a decrease in the light receiving efficiency of the solar cell when the solar cell is installed vertically, when the sun is at a high position, the angle of incidence of the sunlight, that is, the perpendicular between the light receiving surface and the incident light, The angle becomes large, light is reflected on the module surface, and light does not reach the inside. When the incident angle increases, the proportion of light reflected on the surface increases, so that the amount of light reaching the solar cell inside the solar cell module decreases, and as a result, the amount of power generation decreases.
[0008]
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a solar cell module that can receive light well even in an installation environment such as a vertical surface and can obtain high power generation efficiency.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present inventor has conducted intensive studies and found that a light-receiving surface of a solar cell module installed on a vertical surface or the like is provided with a transparent body that refracts light. The present inventor has found that light can be satisfactorily received even during the time when the light receiving efficiency of the solar battery cell is reduced, and the present invention has been completed.
[0010]
In order to achieve the above object, the present invention has the following configuration. That is, a solar cell module in which a solar cell is sealed between two opposing plate members, and one or both of the plate members is a light receiving surface, and a light receiving surface is provided with a transparent body that refracts light. It is characterized by having.
[0011]
When the incident angle of sunlight on the solar cell module is large, on a smooth surface without irregularities, most of the light is reflected on the surface, does not reach the solar cell, and the light receiving efficiency is reduced. If a transparent body that refracts light is provided on the light receiving surface, the transparent body generally has a three-dimensional structure, and due to the uneven structure on the surface, a part where the incident angle of sunlight is small is formed, The solar light is prevented from being reflected, and the refraction of the light allows the incident light to be guided to the inside well.
[0012]
The structure of the transparent body that refracts light is not particularly limited as long as it is a structure that can introduce light well even when the angle of incidence is large, for example, a linear shape extending in a certain direction. And a pyramid structure. The transparent body for refracting light may be formed integrally with a plate material sandwiching the solar cell, or may be attached to the surface of the plate material.
[0013]
The plate material sandwiching the solar cell is not particularly limited as long as the light-receiving surface is translucent, and different materials may be used in combination. For example, a glass plate material, a resin plate material, a metal plate material, or a composite plate material thereof can be used. , Polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polyamide, polyurethane, polymethacrylate, polyacrylonitrile, ABS, phenolic resin, melamine resin, formaldehyde resin, It may be composed of a urea resin, an unsaturated polyester resin, an epoxy resin, a natural rubber or a derivative thereof, or two kinds of the above resins. May be one having the above may be one obtained by bonding two or more resin plate. Further, an inorganic filler such as aluminum hydroxide or calcium hydroxide, a flame retardant, or the like may be sutured to provide nonflammability and flame retardancy. Further, a foamed material may be added by adding a foaming agent or the like, and further, a plasticizer, a stabilizer, a foaming aid, an ultraviolet absorber, a pigment or the like may be added, and a metal foil is attached. It may be something.
[0014]
Further, the transparent body that refracts light has a plurality of continuous chevron structures extending in the horizontal direction, and an upwardly facing surface of the chevron structure is larger than a downwardly facing surface. It is.
[0015]
The structure of the transparent body that refracts light is a plurality of continuous chevron structures extending in the horizontal direction, and therefore, a structure in which a light-receiving surface is provided with diagonally upward and diagonally downward planes alternately. become. As a result, even when the sun is at a high position, the angle of incidence on the upward-facing surface of the mountain shape is small, and light can be introduced into the interior without being reflected too much, and the light is guided to the solar cells. Therefore, it is possible to prevent a decrease in power generation efficiency due to reflection on the surface, and to perform power generation without extremely lowering the efficiency. In addition, by making the area of the upwardly facing surface of the continuous chevron structure larger than the downwardly facing area, it is possible to efficiently receive light from the sun above it in a large area.
[0016]
In addition, the transparent body that refracts light has a plurality of pyramid structures on its surface.
[0017]
The structure of the transparent body that refracts light may have a plurality of pyramid structures, and like the plurality of continuous chevron structures, the pyramid has an upward-facing surface, and in this upward-facing surface, The angle of incidence is small, light can be introduced into the interior without much reflection, and light can be guided to the photovoltaic cells. Even at the position, power can be generated without the efficiency dropping extremely. In addition, by adopting a pyramid structure, sunlight can be efficiently introduced into the interior even when the angle of incidence of the module increases in the horizontal direction, for example, at dawn or in the evening when installed vertically in the south direction. can do.
[0018]
Although the shape of the pyramid is not particularly limited, a structure in which quadrangular pyramids or triangular pyramids are densely arranged in a plane is preferable. In order to arrange the triangular pyramids densely, the triangular pyramids may be arranged so that the directions of the adjacent triangular pyramids are opposite. In addition, the pyramid may not be a regular pyramid. For example, in the case of a quadrangular pyramid, the pyramid may be shifted in apex so that a surface facing upward is wider than other surfaces.
[0019]
Further, the two opposing plate members sealing the solar battery cells are both made of resin.
[0020]
By using a resin material as the plate material, it is possible to provide a lightweight solar cell module that is hardly cracked by impact. Conventional solar cell modules often use glass, which may be broken and scattered by impact, causing a secondary accident, or being heavy and time-consuming during construction. These problems can be solved by selecting an appropriate resin for the back plate and the front plate. The type of resin used on the light receiving surface side is not particularly limited as long as it has translucency, but polycarbonate, acrylic resin, polyethylene terephthalate, polybutylene terephthalate, polyvinyl chloride, or the like may be used. good. In addition, the resin used for the surface that is not the light receiving surface does not necessarily have to have translucency, for example, polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyethylene terephthalate, and polystyrene. Butylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polyamide, polyurethane, polymethacrylate, polyacrylonitrile, ABS, phenol resin, melamine resin, formaldehyde resin, urea resin, unsaturated polyester resin, epoxy resin, natural rubber and its derivatives Or a combination of two or more of the above resins, or a combination of two or more of the resin plates. Further, an inorganic filler such as aluminum hydroxide or calcium hydroxide, a flame retardant, or the like may be sutured to provide nonflammability and flame retardancy. Further, a foamed product by adding a foaming agent or the like may be used, and further, a plasticizer, a stabilizer, a foaming aid, an ultraviolet absorber, a pigment, or the like may be added. Further, a metal foil may be bonded to the opaque resin plate.
[0021]
Further, the solar cell is characterized in that it is of a double-sided light receiving type.
[0022]
The present invention relates to a solar cell module mainly installed on a vertical surface, the solar cell module is a double-sided light receiving type, and by providing a transparent body that refracts light on both light receiving surfaces, the position of the sun is increased. Even in a certain season, sufficient light reaches the solar cell, and good power generation can be performed throughout the year.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a schematic diagram showing an example of the solar cell module of the present invention. A plurality of solar cells 1 are sandwiched between plate members 2, and a transparent body 31 that refracts light is provided on the light receiving surface side of plate member 2. The transparent body 31 has a continuous plural chevron structure extending in the horizontal direction.
[0024]
FIG. 2 is an enlarged vertical cross-sectional view of an example of the solar cell module of the present invention. In FIG. 2, a double-sided solar cell is used, and sunlight can be received from both surfaces. Transparent bodies that refract light are also provided on both sides, and are integrated with the plate material. A plurality of solar cells are sandwiched between two plate members in which a transparent body 31 that refracts light is integrated by using a sealing material 4. The sealing material that seals the cell is not particularly limited, but a light-transmitting material such as ethylene-vinyl acetate (EVA), transparent modified polyethylene, modified polypropylene, acrylic resin, silicone resin, etc. Should be used.
[0025]
In the case of a single-sided light-receiving solar cell, at least the light-receiving surface side may be formed of a translucent plate material, and the transparent body that refracts light may be provided only on the light-receiving surface side. An opaque plate may be used for the surface other than the light receiving surface. In the case of a double-sided light receiving solar cell, it is preferable that both surfaces are formed of a light-transmitting material, and that a transparent body that refracts light is also formed on both surfaces. Further, the transparent body for refracting light may be formed directly on the plate material as shown in FIG. 2 and may be integrated, or a transparent body for refracting light separately formed on the front plate or the back plate may be attached. It may be done.
[0026]
The transparent body that refracts light has a plurality of continuous mountain-shaped structures extending in the lateral direction, and has a continuous V-shaped cross section in the vertical direction as shown in FIG. The light refracting surface has a structure in which an upward facing surface a and a downward facing surface b are alternately continued, and the upward facing surface a is larger than the downward facing surface b. FIG. 3a shows a schematic diagram of light incidence on the light refraction surface. FIG. 3B is a schematic diagram of sunlight reception when the surface is a smooth surface for reference. When the sun is at a high position, the sunlight is emitted from the direction of c. When the surface is a smooth surface as shown in FIG. 3B, the incident angle x on the surface is large and the ratio of the reflected light d is high, and the light does not sufficiently reach the solar cell. Therefore, by providing a V-shaped structure, the incident angle x on the surface can be reduced as shown in FIG. 3A, and the reflected light d can be reduced. Further, by making the upwardly facing surface a larger than the downwardly facing surface b, the area for receiving light from above can be increased, and the inclination angle y with respect to the vertical surface is necessarily smaller than 45 degrees. When light from above enters, the incident light e comes to an angle nearly perpendicular to the cell surface due to refraction.
[0027]
The pitch of the chevron structure is not particularly limited, but is preferably about 15 mm to 30 mm in consideration of the angle, the overall thickness, and the like. Further, the height of the peak of the unevenness is preferably about 3 mm to 10 from the valley to the peak. Exceeding this range is not preferred because the thickness is increased and hinders the construction and the weight increases.
[0028]
FIG. 4 is an enlarged schematic view showing the surface of another example of the solar cell module of the present invention. A plurality of solar cells 1 are sandwiched between plate members 2, and a transparent body 32 that refracts light is provided on the light receiving surface side of plate member 2. The transparent body 31 for refracting light has a shape in which a plurality of quadrangular pyramids are densely provided on the surface. The square pyramid is a square having a bottom surface of about 5 mm and a height of 3 mm. The square pyramids of this size are arranged vertically and provided on the entire surface of the solar cell module.
[0029]
Further, a functional coating layer may be formed on the surface of the resin plate of these solar cell modules, and a photocatalyst containing layer may be formed on the light-receiving side surface of the solar cell. Titanium dioxide is suitably used for the photocatalyst, and the titanium dioxide may be a rutile type, but is preferably an anatase type because of its high activity, and the titanium dioxide is irradiated with ultraviolet light having a wavelength region of about 300 to 400 nm. When activated, a strong oxidizing power is developed, and contaminants attached to the surface are decomposed. In addition, due to the activity of titanium dioxide, the surface becomes a superhydrophilic state having a contact angle with water of about 0 to 20 degrees, and even if contaminants adhere, it can be easily washed away by rain, and the surface can be cleaned for a long time. It can be kept clean.
[0030]
Further, the functional coating layer may be a snow-snow-ice coating layer. The snow gliding coating layer is a coating layer exhibiting water repellency having a surface tension of 35 dyne / cm or less and having a water droplet sliding angle of 40 degrees or less. If the coating layer is formed on the light-receiving surface of the solar cell, even if snow and ice adhere to the surface, it can be slid quickly, so that the time during which snow and ice adhere can be shortened as much as possible, and power can be generated. The time can be lengthened, and the load on the module due to snow can be reduced, so that breakage of the module due to overload and other problems can be prevented.
[0031]
【The invention's effect】
As described above, by providing a transparent body that refracts light on the light receiving surface on the light receiving surface of the solar cell module installed on a vertical surface or the like, the solar cell module having a smooth surface has a large incident angle of sunlight and is smooth. Even if the light receiving efficiency is reduced because most of the sunlight is reflected on the surface of the solar cell module on the surface, the reflection is suppressed, the light is received well, and the power generation amount can be maintained. In addition, the transparent body that refracts light is made up of a plurality of continuous mountain-shaped structures extending in the lateral direction, and the upward-facing surface of the mountain-shaped structure is made larger than the downward-facing surface, so that light from the sun above Can be satisfactorily received.
[0032]
In addition, by making the transparent body that refracts light a structure having a plurality of pyramid structures on the surface, an upward-facing surface is formed on the pyramid. Can be introduced into the inside of the solar cell without light emission, and light can be guided to the solar cells, preventing the power generation efficiency from decreasing due to surface reflection and reducing the efficiency extremely even when the sun is high. Electricity can be generated without the need. In addition, by adopting a pyramid structure, sunlight can be efficiently introduced into the interior even when the angle of incidence of the module increases in the horizontal direction, for example, at dawn or in the evening when installed vertically in the south direction. can do.
[0033]
In addition, by using a resin plate material to sandwich the solar battery cells, it is possible to provide a lightweight solar battery module that is hardly cracked by impact. In addition, if this solar cell module is a double-sided light receiving type, and if a transparent body that refracts light is provided on both light receiving surfaces, high power generation efficiency can be maintained even when the height of the sun is high, and good power generation can be performed throughout the year. It can be carried out.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an embodiment of the present invention.
FIG. 2 is a sectional view showing one embodiment of the present invention.
FIG. 3 is a schematic diagram of light incidence according to the present invention.
FIG. 4 is a sectional view showing one embodiment of the present invention.
[Explanation of symbols]
a upward surface of the uneven structure b downward surface of the uneven structure c sunlight d reflected light e incident light x incident angle y tilt angle 1 solar cell 2 plate material 31 transparent body for refracting light 32 transparent body for refracting light 4 Sealant

Claims (5)

A solar cell module in which a solar cell is sealed between two opposing plate members, and one or both of the plate members is a light receiving surface, and a light receiving surface is provided with a transparent body that refracts light. A solar cell module characterized by the above-mentioned. The transparent body that refracts light has a plurality of continuous mountain-shaped structures extending in the lateral direction, and an upward-facing surface of the mountain-shaped structure is larger than a downward-facing surface. A solar cell module according to item 1. The solar cell module according to claim 1, wherein the transparent body that refracts light has a plurality of pyramid structures on a surface. The solar cell module according to any one of claims 1 to 3, wherein the two opposing plate members sealing the solar cell are both made of resin. The solar cell module according to claim 1, wherein the solar cell is a double-sided light receiving type.

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