JP2001358346A - Cover glass for solar battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cover glass for solar batteries wherein soils are hardly accumulated and its glare resistance can be improved. SOLUTION: The glossiness of the light projecting surface of the cover glass is specified to be not smaller than 5 and not larger than 40, and its ten-point mean roughness Rz is specified to be not smaller than 50 μm and not larger than 300 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a solar cell panel,
In particular, the present invention relates to a cover glass for a solar cell of a solar cell panel installed on a roof of a building.

[0002]

2. Description of the Related Art As part of effective use of natural energy, it has been proposed to construct a roof of a building with solar panels. In such a solar panel,
When a float plate glass is applied to a cover glass of a solar cell, a problem of reflected light pollution that sunlight is reflected on the surface of the float plate glass is pointed out because the outer surface of the float plate glass is smooth.

Japanese Unexamined Patent Application Publication No. 11-298030 discloses that the surface of the cover glass on the light incident side is formed with irregularities, the maximum surface roughness is set to 0.1 to 5 μm, and the arithmetic mean A cover glass for a solar cell having a reflection light preventing function (anti-glare property) by regulating the roughness to 0.01 to 0.3 μm has been proposed.

[0004]

However, in the cover glass disclosed in Japanese Patent Application Laid-Open No. H11-298030, the antiglare property is insufficient because the unevenness formed on the light incident surface is too small.

[0005] By the way, the solar cell panel is generally installed only on the south-facing roof, but recently it has been proposed to install the entire roof including the north-facing roof with the solar cell panel. In this case, since the north-facing roof is assumed to face the south-facing living room of the northern neighbor, if the anti-glare property of the cover glass is not enhanced, it will cause discomfort to residents who are relaxing in the living room. Problems arise. Further, when only the anti-glare property is emphasized and the degree of the unevenness is excessive, there is a problem that dirt is easily accumulated.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a cover glass for a solar cell, in which dirt hardly collects and antiglare property can be enhanced.

In order to achieve the above object, the present invention provides a cover glass for a solar cell, wherein the light incident surface of the cover glass has a glossiness of 5 or more and 40 or less. 10 points average roughness Rz of 50 μm or more and 30
It is characterized in that it is not more than 0 μm.

[0007] The applicant of the present application has confirmed through experiments that if the glossiness of the light incident surface of the cover glass exceeds 40, the reflected light of sunlight from the light incident surface becomes remarkably dazzling. When it is smaller than 5, the unevenness of the light incident surface becomes rough,
It was confirmed by an experiment that it was easily stained.

Further, in order to achieve the object of the present invention, the gloss factor alone is not sufficient, and it is necessary to consider the ten-point average roughness Rz of the light incident surface. If the ten-point average roughness Rz exceeds 300 μm, the light incident surface becomes too rough, so that the light incident surface is easily stained. If the ten-point average roughness Rz is less than 50 μm, the light incident surface becomes uneven. It was confirmed by experiments that the reflected light of sunlight from the light incident surface became remarkably dazzling because the particle size was too fine.

Accordingly, in the cover glass of the present invention, the glossiness of the light incident surface is specified to be 5 or more and 40 or less, and the ten-point average roughness Rz of the light incident surface is specified to be 50 μm or more and 300 μm or less. Are hardly accumulated, and the antiglare property can be improved. In particular, the glossiness is preferably from 15 to 40, and Rz is preferably from 50 μm to 150 μm.

[0010] Such a cover glass can be manufactured by a method of manufacturing a template glass. That is, an uneven portion having a ten-point average roughness Rz of 50 μm or more and 300 μm or less is engraved on the surface of the roll of the template glass manufacturing apparatus. This allows
Since the concave and convex portions of the roll are transferred to the glass plate, post-processing such as polishing, etching, and blasting is not required, and the cover glass for a solar cell of the present invention can be manufactured.

According to the second aspect of the present invention, since the visible light transmittance of the cover glass is specified to be 89% or more, the cover glass has sufficient light transmittance to obtain excellent photovoltaic efficiency. The thickness of the cover glass is 3 to 10 mm, especially 3.2 to 10 mm.
5 mm is preferred.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a cover glass for a solar cell according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a plan view schematically showing the structure of a solar cell panel 10, and FIG. 2 is a side view thereof. This solar cell panel 10 has 6 × 6 rows of single crystal cells 16, 16... Laminated on a flat back surface 12 A of a solar cell cover glass 12 via an EVA film 14. A back glass 17 is laminated on the back glass 16, and a terminal box 18 connected to the single crystal cells 16 is fixed to the back surface of the back glass 17.

The cover glass 12 has a light incident surface 13 having a glossiness of 5 or more and 40 or less, and a ten-point average roughness Rz (hereinafter, referred to as the light incident surface 13) in order to prevent dirt from being easily collected and enhance antiglare properties. , “Rz”) is 50 μm or more and 3
A glass plate of not more than 00 μm is applied.

Such a cover glass 12 is manufactured by a template glass manufacturing apparatus 20 shown in FIG. The template glass manufacturing apparatus 20 includes a tank kiln 22, a pair of upper and lower water cooling rolls 24, 26, and transport rolls 28, 28, and the like. The molten glass G stored in the tank kiln 22 is continuously supplied from the weir of the tank kiln 22 between the water-cooled rolls 24 and 26, and is formed into a glass ribbon 30 having a thickness substantially equal to the gap between the water-cooled rolls 24 and 26. The glass ribbon 30 is drawn out by the rotation of the water-cooling rolls 24, 26, and is fed into a layer (not shown) by the transport rolls 28, 28, where it is gradually cooled to room temperature. Thereby, the cover glass 12 is manufactured.

At the time of manufacture, an irregular pattern is formed on the surface of the water-cooled roll 26 (or the water-cooled roll 24) so that Rz of the light incident surface 13 of the cover glass 12 is 50 μm or more and 300 μm or less. I have. As a result, the irregular pattern of the water-cooled roll 26 is transferred to the surface of the glass ribbon 30 (corresponding to the light incident surface 13 of the cover glass 12), so that post-processing such as polishing, etching, and blasting is not required. , Rz having a roughness of 50 μm or more and 300 μm or less can be manufactured.

The solar cell cover glass 12 is used not only for a solar cell cover glass for a building roof, but also for a solar cell cover glass for a fence or a wall surface.
Further, the solar cell may be any of polycrystalline, single crystalline, and non-crystalline. In addition, the surface of the solar cell cover glass 12 opposite to the light incident surface may have an uneven shape. In the above example, the back glass 17 was used.
Instead, a plate-like glass, a film-like organic material or an inorganic material can be used.

[0018]

EXAMPLES Table 1 is a table in which a comparative product and an example product were evaluated in terms of antiglare properties and stains based on the glossiness and Rz of the light incident surface of the cover glass. The gloss was measured with a gloss meter (trade name: Gloss Checker (IG-310): manufactured by Horiba Ltd.), and Rz was measured with a roughness measuring device (trade name:
Surfcom: Tokyo Seimitsu).

The thickness of the solar cell cover glass is 3.2 mm, and the visible light transmittance is about 91%. Furthermore,
As a test sample, a cover glass for a solar cell is formed by connecting single crystal cells of 103 mm square in 36 series as shown in FIG.
It was modularized using mm square glass. The production method is as follows. The laminated body having the structure shown in FIG. 1 is put in a rubber bag, and after being decompressed, heated in an oven at 150 ° C. for about 30 minutes.
Modularized by natural cooling. After cooling, the terminal box was attached.

In the antiglare test, the above-mentioned module was mounted on a 30-degree mount, and the degree of reflection of sunlight was visually observed during the middle of a sunny day on a sunny day.

For the dirt test, the module was mounted on a 30-degree mount and observed for half a year. The degree of contamination was visually observed. The evaluation results are shown below.

[0022]

[Table 1] Antiglare property ◎: Sufficient antiglare property.

○: The antiglare property is not sufficient, but there is no practical problem.

X: The antiglare property is insufficient, and the reflected light of sunlight is dazzling.

Dirt A: Slight dirt that does not impair the appearance.

○: Stain was observed but no problem in practical use.

×: Large dirt As can be seen from the above experimental results, the glossiness of the light incident surface of the cover glass is specified to be 5 or more and 40 or less, and the ten-point average roughness Rz of the light incident surface is set to 50 μm or more and 300 μm or less. Example product No. Cover glasses for solar cells 1 to 5 are:
Dirt does not easily accumulate and antiglare properties can be improved. The cover glass for a solar cell according to the embodiment, in which dirt hardly accumulates,
Appearance is maintained in a favorable condition even when used for a long time,
A decrease in photoelectric exchange efficiency can also be prevented.

It has also been found that irregularities formed on the incident surface are more effective for antiglare properties than irregular ones.

Furthermore, since the visible light transmittance of the cover glass 12 is specified to be 89% or more, excellent photovoltaic efficiency equal to or higher than that of the conventional product can be obtained.

[0030]

As described above, according to the solar cell cover glass of the present invention, the glossiness of the light incident surface is specified to be 5 to 40 and the ten-point average roughness Rz of the light incident surface is 50.
Since the thickness is specified to be not less than μm and not more than 300 μm, dirt hardly accumulates and antiglare property can be enhanced.

According to the present invention, since the visible light transmittance of the cover glass is specified to be 89% or more, the cover glass has a sufficient light transmittance to obtain excellent photovoltaic efficiency.

[Brief description of the drawings]

FIG. 1 is a plan view of a solar cell panel to which a cover glass of the present invention is applied.

FIG. 2 is a side view of the solar cell panel shown in FIG.

FIG. 3 is a schematic structural diagram of an apparatus for manufacturing a template glass.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Solar cell panel, 12 ... Solar cell cover glass, 14 ... EVA film, 16 ... Single crystal cell, 17 ... Back glass, 18 ... Terminal box, 20 ... Shaped glass manufacturing apparatus, 22 ... Tank kiln, 24, 26 ... water-cooled roll, 28 ...
Conveyance roll, 30 ... Glass ribbon

Claims (2)

[Claims] 1. A cover glass for a solar cell, wherein a glossiness of a light incident surface of the cover glass is 5 or more and 40 or less, and a ten-point average roughness Rz of the light incident surface is 50 μm or more and 300 μm or less. Features cover glass for solar cells. 2. The cover glass has a visible light transmittance of 8%.
The solar cell cover glass according to claim 1, wherein the content is 9% or more.