JPH08306942A - Protective sheet for solar cell module - Google Patents

Abstract

(57) [Summary] [Purpose] To increase the light transmittance. [Structure] In a solar cell module protective sheet 10 to be attached to a sunlight transmitting surface of a solar cell module, a surface on a light incident side is surface-treated to form geometrical irregularities 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell module which is used by being attached to a solar light transmitting surface of the solar cell module in order to protect the solar cell module against external impact and chemical corrosion. Regarding protective sheet.

[0002]

2. Description of the Related Art In recent years, as global environmental problems have become more serious due to increased consumption of fossil fuels, solar cells have been installed on the roofs of houses, etc. The solar systems for homes that are supplied are receiving attention.

Such an inexhaustible solar cell utilizing solar energy deteriorates in its function when directly exposed to the outside air. Therefore, it is put in a sealed case having a transparent glass on its surface and modularized. There is.

FIG. 4 shows a cross-sectional structure of a generally known solar cell module 1. In the figure, reference numeral 2 is a front surface glass as a transparent substrate, and a solar cell 5 is enclosed under the front surface glass by using a transparent filling material 3 and a back surface coat 4. Examples of the filling material 3 include PVB (polyvinyl butyral) and EV, which have a small decrease in light transmittance due to ultraviolet rays.
A (ethylene vinyl acetate) and the like are mainly used. Further, as the back surface coat 4, a material processed to have moisture resistance and insulation is used. In the figure, only the moisture-proof film made of polyvinyl fluoride is shown as the back coat 4.

In addition, the solar cell module 1 whose surface is covered with the glass 2 as described above is provided with the glass 2 as a protection against chemical erosion (burn) which is caused by external impact, rain water, and contact with moisture in the air. The protective sheet described in JP-A-4-325531 is attached to the surface (sunlight transmitting surface) of the above.

[0006]

By the way, the most required performance of a solar cell module is to take in solar energy more efficiently. However, the conventional protective sheet has a flat light-incident surface. Therefore, the reflectance was high and the light transmittance was low. Therefore, the light collection rate of the solar cell module cannot be increased, and it is difficult to increase the amount of power generation per unit module.

The present invention has been made in view of the above circumstances, and provides a protective sheet for a solar cell module, which can increase the light transmittance and thereby increase the light collection rate of the solar cell module. The purpose is to do.

[0008]

In order to solve the above-mentioned problems, the invention according to claim 1 is a protective sheet for a solar cell module, which is attached to a sunlight transmitting surface of a solar cell module, and has a surface on a light incident side. Is characterized in that geometrical irregularities are formed by applying a surface treatment.

[0009]

According to the first aspect of the invention, when sunlight hits the surface of the protective sheet, most of the light is transmitted as it is and some of the remaining is reflected, but some of the reflected light is Further, reflection is further repeated in the concave portions of the geometrical unevenness on the surface, and each time, some of the light is transmitted into the protective sheet. Therefore, as a result, the total amount of light transmitted is increased.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a solar cell module 1A in which a protective sheet 10 according to an embodiment of the present invention is attached to the surface of a glass 2 (sunlight transmitting surface). The solar cell module 1 of FIG. 4 except that the protective sheet 10 is attached.
Since it has the same structure as, the description thereof will be omitted.

The protective sheet 10 of this embodiment is shown in FIG.
As shown in (a), the surface on the light incident side is subjected to a surface treatment so as to have geometrical irregularities 11 (concave portion 11a, convex portion 11).
It is formed innumerable of b). Unevenness 11 in this case
The cross-sectional shape of the is shown in FIG.
It is an isosceles triangle having 0 degrees or less) and is formed continuously on the surface of the protective sheet 10.
The geometrical irregularities 11 are formed by heat treatment (applying a high temperature metal plate mold) to the surface of the protective sheet 10 or by cutting. As the material of the protective sheet 10, acrylic resin, silicone resin, polyvinyl butyral, or the like is used.

Next, the operation will be described. When the sunlight H hits the surface of the protective sheet 10, most of it is transmitted as it is and some of the remaining is reflected, but some of the reflected light is as shown in FIG. Further, the reflection is further repeated in the concave portion 11a of the geometrical unevenness 11 on the surface, and each time, some of the light is transmitted to the inside of the protective sheet 10. In the drawing, the transmitted light is shown by the dotted line. Therefore, by repeating reflection, as a result, the overall amount of light transmitted can be increased, and the light collection rate of the solar cell module 1A can be increased. Therefore, the amount of power generation per unit module is increased.

Incidentally, considering only the increase of the amount of light taken in, as shown in FIG.
Make the vertical angle of the In such a case, it is possible to prevent the reflected light from going out of the recess 11a to the outside, so that the transmittance can be further increased.

The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific structure is not limited to this embodiment, and there are design changes and the like within a range not departing from the gist of the present invention. Also included in the present invention. For example, the cross-sectional shape of the unevenness is not limited to the isosceles triangle, and may not necessarily be a pure triangle.

[0015]

As described above, according to the invention described in claim 1, since the surface is provided with the geometrical unevenness,
The light is repeatedly reflected in the concave portion, resulting in an increase in the amount of sunlight transmitted. Therefore, the light collection rate of the solar cell module can be increased, and the amount of power generation per unit module can be increased.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a solar cell module to which a protective sheet according to an embodiment of the present invention is attached.

2A and 2B show details of a protective sheet according to an embodiment of the present invention, FIG. 2A is a sectional view, and FIG. 2B is an enlarged view showing how light is transmitted.

FIG. 3 is a sectional view of a protective sheet according to another embodiment of the present invention.

FIG. 4 is a perspective view showing a schematic configuration of a conventional solar cell module.

[Explanation of symbols]

 10 Protective sheet 11 Unevenness

Claims (1)

[Claims] 1. A protective sheet for a solar cell module, which is attached to a solar light transmitting surface of a solar cell module, characterized in that a surface on a light incident side is subjected to surface treatment to form geometrical irregularities. A protective sheet for solar cell modules.