JP2017059794A - Solar cell module, and glass plate for solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell module capable of suppressing the cracking of glass plate in the event of a fire.SOLUTION: A solar cell module includes a solar cell module body having a light-receiving surface, a back surface on the opposite side to the light-receiving surface, and an end face, and having a glass plate, a solar cell, and a back plate, in this order, from the light-receiving surface side, and a support frame for supporting the solar cell module body. The support frame has a groove into which the end of the solar cell module body is inserted. The glass plate is a chemically strengthened glass plate, and has an end face where only compressive stress remains.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a solar cell module and a glass plate for a solar cell module.

  The solar cell module includes a solar cell module main body and a support frame that supports the solar cell module main body (see, for example, Patent Document 1). The solar cell module main body has a light receiving surface, a back surface opposite to the light receiving surface, and an end surface, and a glass plate, solar cells, and a back plate in this order from the light receiving surface side. The solar battery cell is sealed with a sealing material such as a resin between the glass plate and the back plate. The support frame has a groove portion into which the end portion of the solar cell module body is inserted.

  As the glass plate of the solar cell module main body, a physically tempered glass plate is generally used. However, in recent years, a chemically tempered glass plate may be used for the purpose of weight reduction, PID (Potential Induced Degradation), or the like. The chemically strengthened glass plate has a surface strengthened by chemical strengthening. Chemical strengthening generates compressive stress on the surface by exchanging ions having a small ionic radius (for example, Na ions) with ions having a large ionic radius (for example, K ions). Due to the reaction, tensile stress is generated inside the glass plate.

  As the glass plate of the solar cell module main body, a glass plate having a plurality of sizes is chemically strengthened, then cut into a product size, and a cut surface is chamfered in some cases. Productivity is improved by collectively strengthening a plurality of glass plates in size. Since cutting is performed after chemical strengthening, there is a region where tensile stress remains on the cut surface.

Japanese Patent No. 5468664

  The solar cell module is installed on a roof or the like, and the light receiving surface of the solar cell module main body faces upward. The light receiving surface is exposed to a flame in the event of a fire. The flame is difficult to wrap around the back.

  If the glass plate breaks due to thermal stress during a fire, the encapsulant is exposed to the flame and burns. When the back plate is formed of resin, the back plate is also exposed to the flame and burns.

  This invention is made | formed in view of the said subject, Comprising: It aims at provision of the solar cell module which can suppress the crack of a glass plate at the time of a fire.

In order to solve the above problems, according to one aspect of the present invention,
A solar cell module body having a light receiving surface, a back surface opposite to the light receiving surface, and an end surface, and from the light receiving surface side, a glass plate, a solar battery cell, and a back plate in this order;
A support frame for supporting the solar cell module body,
The support frame has a groove portion into which an end of the solar cell module body is inserted,
The said glass plate is a chemically strengthened glass plate, Comprising: The solar cell module which has an end surface in which only a compressive stress remains is provided.

  According to one embodiment of the present invention, a solar cell module is provided that can suppress breakage of a glass plate during a fire.

It is sectional drawing which shows the principal part of the solar cell module by one Embodiment of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the drawings, the same or corresponding components are denoted by the same or corresponding reference numerals, and description thereof is omitted. In this specification, “to” representing a numerical range means a range including numerical values before and after the numerical range.

  FIG. 1 is a cross-sectional view showing a main part of a solar cell module according to an embodiment of the present invention. The solar cell module includes a solar cell module body 10 and a support frame 20 that supports the solar cell module body 10. The solar cell module is installed such that the light receiving surface 10a of the solar cell module body 10 faces upward.

  The solar cell module body 10 includes a light receiving surface 10a, a back surface 10b opposite to the light receiving surface 10a, and an end surface 10c. The solar cell module body 10 includes an antireflection film 11, a glass plate 12, a solar cell 13, and a back plate 14 in this order from the light receiving surface 10a side. The solar cell module body 10 may not have the antireflection film 11.

  The antireflection film 11 is formed on the light receiving surface 12 a of the glass plate 12. Light reflection on the glass plate 12 can be reduced, and sunlight capture efficiency can be improved.

  The glass plate 12 has water resistance, fire resistance, durability, and the like. The glass plate 12 has translucency with respect to sunlight. The light transmitted through the glass plate 12 is taken into the solar battery cell 13.

  The glass plate 12 has a plate thickness of 1 mm or less, for example. If the plate | board thickness of the glass plate 12 is 1 mm or less, the solar cell module main body 10 can be reduced in thickness.

  The glass plate 12 has a light receiving surface 12a, a back surface 12b opposite to the light receiving surface 12a, and an end surface 12c. The end surface 12c may be chamfered. The chamfering of the end surface 12c is a C chamfering in FIG. 1, but may be an R chamfering. The end face 12c may be polished after chamfering. By polishing, processing scratches generated during chamfering can be removed.

  The glass plate 12 is a chemically strengthened glass plate. The chemically strengthened glass plate has a surface strengthened by chemical strengthening. Chemical strengthening is a method of strengthening the surface by generating compressive stress on the surface by exchanging ions with a small ionic radius (for example, Na ions) with ions having a large ionic radius (for example, K ions). Due to the reaction, tensile stress is generated inside the glass plate. The chemically tempered glass plate has a surface compressive stress CS of, for example, 350 to 700 MPa, and a compressive stress layer formed on the surface has a thickness DOL of 10 to 50 μm.

The glass plate 12 is expressed in terms of oxide-based mole percentage, and SiO ₂ is 56 to 75%, Al ₂ O ₃ is 1 to 20%, Na ₂ O is 8 to 22%, K ₂ O is 0 to 10%, MgO 0-14%, ZrO ₂ 0-5% and CaO 0-10%. Hereinafter, although each component is demonstrated,% means mol%.

SiO ₂ is known as a component that forms a network structure in the glass microstructure, and is a main component constituting the glass. The content of SiO ₂ is 56% or more, preferably 60% or more, more preferably 63% or more, and further preferably 65% or more. Further, the content of SiO ₂ is 75% or less, preferably 73% or less, more preferably 71% or less. When the content of SiO ₂ is 56% or more, it is advantageous in terms of stability and weather resistance as glass. On the other hand, when the content of SiO ₂ is 75% or less, it is advantageous in terms of meltability and moldability.

Al ₂ O ₃ has an effect of improving ion exchange performance in chemical strengthening, and particularly has a large effect of improving surface compressive stress (CS). It is also known as a component that improves the weather resistance of glass. Moreover, there exists an effect | action which suppresses the penetration | invasion of the tin from a bottom surface at the time of float forming. The content of Al ₂ O ₃ is 1% or more, preferably 3% or more, more preferably 5% or more. The content of Al ₂ O ₃ is 20% or less, preferably 17% or less, more preferably 12% or less, still more preferably 10% or less, and particularly preferably 7% or less. When the content of Al ₂ O ₃ is 1% or more, desired CS is obtained by ion exchange, and an effect of suppressing infiltration of tin is obtained. On the other hand, if the content of Al ₂ O ₃ is 20% or less, the devitrification temperature does not increase greatly even when the viscosity of the glass is high, which is advantageous in terms of melting and forming in the soda lime glass production line. .

The total SiO ₂ + Al ₂ O ₃ content of SiO ₂ and Al ₂ O ₃ is preferably 80% or less. If it exceeds 80%, the viscosity of the glass at high temperature may increase and melting may be difficult, and it is preferably 79% or less, more preferably 78% or less. _Further, it is preferable that SiO 2 + _Al 2 _{O 3} is 70% or more. If it is less than 70%, the crack resistance when an indentation is attached is lowered, more preferably 72% or more.

Na ₂ O is an essential component that forms compressive stress by ion exchange, and has the effect of increasing the depth (DOL) of the compressive stress layer. Moreover, it is a component which lowers the high temperature viscosity and devitrification temperature of glass, and improves the meltability and moldability of glass. The content of Na ₂ O is 8% or more, preferably 12% or more, more preferably 13% or more. Further, the content of Na ₂ O is 22% or less, preferably 20% or less, more preferably 16% or less. When the content of Na ₂ O is 8% or more, a desired compressive stress can be formed by ion exchange. On the other hand, when the content of Na ₂ O is 22% or less, sufficient weather resistance can be obtained.

K ₂ O is not essential, but may be contained because it has the effect of increasing the ion exchange rate and deepening the DOL. On the other hand, if the amount of K ₂ O is excessive, sufficient CS cannot be obtained. Preferably 10% or less when they contain K ₂ O, preferably 8% or less, more preferably 6% or less. When the content of K ₂ O is 10% or less, sufficient CS can be obtained.

  MgO is not essential, but is a component that stabilizes the glass. The content of MgO is 2% or more, preferably 3% or more, more preferably 3.6% or more. Further, the content of MgO is 14% or less, preferably 8% or less, more preferably 6% or less. When the content of MgO is 2% or more, the chemical resistance of the glass becomes good. The meltability at high temperature becomes good and devitrification hardly occurs. On the other hand, when the content of MgO is 14% or less, the difficulty of devitrification is maintained, and a sufficient ion exchange rate is obtained.

ZrO ₂ is not essential, but it is generally known that ZrO ₂ has an action of increasing the surface compressive stress in chemical strengthening. However, even if a small amount of ZrO ₂ is contained, the effect is not great for the cost increase. Therefore, an arbitrary proportion of ZrO ₂ can be contained as long as the cost permits. When it contains, it is preferable that it is 5% or less.

  CaO is not essential, but is a component that stabilizes the glass. Since CaO tends to inhibit the exchange of alkali ions, it is preferable that the content is reduced or not contained particularly when it is desired to increase the DOL. On the other hand, in order to improve chemical resistance, it is preferable to contain 2% or more, preferably 4% or more, more preferably 6% or more. The amount in the case of containing CaO is 10% or less, preferably 9% or less, more preferably 8.2% or less. When the content of CaO is 10% or less, a sufficient ion exchange rate is maintained, and a desired DOL is obtained.

  SrO is not essential, but may be contained for the purpose of lowering the high temperature viscosity of the glass and lowering the devitrification temperature. Since SrO has the effect of lowering the ion exchange efficiency, it is preferable not to contain it especially when it is desired to increase the DOL. When contained, the amount of SrO is 3% or less, preferably 2% or less, more preferably 1% or less.

  BaO is not essential, but may be contained for the purpose of lowering the high temperature viscosity of the glass and lowering the devitrification temperature. Since BaO has the effect of increasing the specific gravity of the glass, it is preferably not contained when the weight is intended to be reduced. The BaO content when contained is 3% or less, preferably 2% or less, more preferably 1% or less.

TiO ₂ is abundant in natural raw materials and is known to be a yellow coloring source. The content of TiO ₂ is 0.3% or less, preferably 0.2% or less, more preferably 0.1% or less. If the content of TiO ₂ exceeds 0.3%, the glass becomes yellowish.

  The glass plate 12 may contain other components, for example, components resulting from a fining agent. As the clarifier, chloride, fluoride, or the like is used. The total content of other components is preferably 5% or less, more preferably 3% or less, and typically 1% or less. Hereinafter, the other components will be described as an example.

  ZnO may be contained up to 2%, for example, in order to improve the meltability of the glass at a high temperature. However, when it is produced by the float process, it is preferably not contained because it is reduced by a float bath and becomes a product defect.

B ₂ O ₃ may be contained in a range of less than 1% in order to improve the meltability at high temperature or the glass strength. In general, when an alkali component of Na ₂ O or K ₂ O and B ₂ O ₃ are contained at the same time, volatilization becomes intense and the brick is remarkably eroded. Therefore, it is preferable that B ₂ O ₃ is not substantially contained.

Li ₂ O is a component that lowers the strain point and facilitates stress relaxation, and as a result makes it impossible to obtain a stable compressive stress. Therefore, Li ₂ O is preferably not contained, and even if it is contained, its content is 1 % Is preferable, more preferably 0.05% or less, and particularly preferably less than 0.01%.

  The solar cell 13 is sealed between the glass plate 12 and the back plate 14 with a sealing material 15 such as a resin. The solar battery cell 13 may be any of silicon, compound, organic and the like. A plurality of solar cells 13 may be provided in one solar cell module body 10, and the plurality of solar cells 13 are connected in series or in parallel.

  The back plate 14 is waterproof. The back plate 14 may or may not have translucency. The back plate 14 is made of resin or glass. When the back plate 14 is formed of glass, the back plate 14 may be a chemically strengthened glass plate, similarly to the glass plate 12.

  The support frame 20 is formed of a metal such as aluminum or an aluminum alloy. The support frame 20 may be a rectangular frame, for example, an assembly of two vertical frames and two horizontal frames. The support frame 20 suppresses deformation of the solar cell module body 10 by supporting the four sides of the rectangular solar cell module body 10.

  The support frame 20 has a groove 21 into which an end of the solar cell module body 10 is inserted. The groove portion 21 is formed on the inner peripheral surface of the support frame 20. The support frame 20 supports the solar cell module main body 10 via the buffer material 25.

  The buffer material 25 is formed of rubber or the like and softens the impact. Moreover, the buffer material 25 prevents passage of water. The buffer material 25 may be fitted into the groove 21 after molding, or may be solidified after being injected into the groove 21. The buffer material 25 may be disposed in the back of the groove portion 21.

  By the way, the solar cell module is installed on a roof or the like, and the light receiving surface 10a of the solar cell module body 10 is directed upward. The light receiving surface 10a is exposed to a flame during a fire. It is difficult for the flame to wrap around the back surface 10b.

  During the fire, the glass plate 12 is heated. Since the edge part of the glass plate 12 is covered with the support frame 20, it becomes high temperature more slowly than the part which is not covered with the support frame 20. FIG. A tensile stress is generated at the end of the glass plate 12 due to the temperature difference.

  The glass plate 12 of the present embodiment is obtained by chemically strengthening the entire surface (the light receiving surface 12a, the back surface 12b, and the end surface 12c), and chemically strengthening the product size. Cutting, chamfering, and polishing are performed before chemical strengthening, and only an area where compressive stress remains on the end face 12c exists. Therefore, the strength of the end surface 12c is higher than when the region where the tensile stress remains in the end surface 12c, and cracking of the glass plate 12 during a fire can be suppressed.

  The end face 12c of the glass plate 12 may be polished before chemical strengthening.

  In Example 1, a flame propagation test of the solar cell module was performed.

  As the glass plate of the solar cell module body, a rectangular chemically strengthened glass plate having a thickness of 0.8 mm, a length of 1476 mm, and a width of 979 mm was used. The chemically tempered glass plate was obtained by chemically strengthening the entire surface and chemically strengthening the product size. Prior to chemical strengthening, cutting, chamfering, and polishing were performed, and there were only areas where compressive stress remained on the end face. The surface compressive stress was 550 MPa, and the thickness of the compressive stress layer was 25 μm.

  The flame propagation test complied with IEC (International Electrotechnical Commission) standard. Specifically, first, the solar cell module was attached to the support base, and the slope of the support base was adjusted in order to simulate installation on the roof. Subsequently, the gas burner was installed in parallel with the lower edge of the outer periphery of the solar cell module. After heating the lower edge of the outer peripheral edge of the solar cell module uniformly with a gas burner, the presence or absence of cracking of the glass plate was confirmed.

  In Example 1, the glass plate of the solar cell module main body was cut, chamfered, and polished before chemical strengthening, and only the region where the compressive stress remained was present on the end face. The glass plate was not broken by the propagation test.

  On the other hand, in Comparative Example 1, the flame propagation test of the solar cell module was performed under the same conditions as in Example 1 except that the glass plate of the solar cell module body was cut, chamfered and polished after chemical strengthening. It was.

  In Comparative Example 1, since the glass plate of the solar cell module main body has a region where tensile stress remains on the end face, the glass plate was broken by the flame propagation test.

  As mentioned above, although the embodiment etc. of the solar cell module were described, the present invention is not limited to the above embodiment etc., and various modifications and improvements are possible within the scope of the gist of the present invention described in the claims. It is.

DESCRIPTION OF SYMBOLS 10 Solar cell module main body 10a Light-receiving surface 10b Back surface 10c End surface 11 Antireflection film 12 Glass plate 12a Light-receiving surface 12b Back surface 12c End surface 13 Solar cell 14 Back plate 15 Sealing material 20 Support frame 21 Groove part 25 Buffer material

Claims (4)

A solar cell module body having a light receiving surface, a back surface opposite to the light receiving surface, and an end surface, and from the light receiving surface side, a glass plate, a solar battery cell, and a back plate in this order;
A support frame for supporting the solar cell module body,
The support frame has a groove portion into which an end of the solar cell module body is inserted,
The glass plate is a chemically tempered glass plate, and has an end face in which only compressive stress remains. The glass plate, a SiO ₂ 56 to 75% by mole percentage based on oxides, _{Al 2 O 3 1~20%, 8~22} % of Na ₂ O, 0% to _{K 2} O, MgO The solar cell module according to claim 1, wherein 0 to 14%, ZrO ₂ is contained in 0 to 5%, and CaO is contained in 0 to 10%. A glass plate used in a solar cell module,
The glass plate is a chemically strengthened glass plate, and has an end face on which only compressive stress remains, and is a glass plate for a solar cell module. The glass plate, a SiO ₂ 56 to 75% by mole percentage based on oxides, _{Al 2 O 3 1~20%, 8~22} % of Na ₂ O, 0% to _{K 2} O, MgO the 0-14%, a ZrO ₂ 0 to 5% containing CaO 0% glass plate for a solar cell module according to claim 3.

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