JP5233034B2 - Solar cell module - Google Patents

Description

It is a technology related to crystalline solar cell panels that contribute to the realization of a low-carbon society. It relates to the reduction of wiring peeling, improvement of heat dissipation characteristics, weight reduction, and ensuring moisture resistance.

The thickness of a single-crystal or polycrystalline silicon cell, which is a material for a crystalline solar cell panel, is about 200 μm and is vulnerable to impact, and a structure that relaxes this is essential.

Power extraction from the three-crystal solar cell is performed by laying a conductor with silver paste on the wiring pattern on the three-crystal solar cell. Since the output current of a solar cell is as large as about 7.5 A, a solder-plated copper wire with a width of about 2 mm and a thickness of about 0.3 mm is usually used as a conductive wire laid on a wiring pattern on a three-crystal solar cell. used.

Since moisture is formed and corroded when moisture enters the part where the wiring pattern on the three-crystal solar cell and the copper wire with solder plating to be laid are in contact, it is important to prevent moisture from entering. is there.

In order to alleviate the impact and prevent moisture, the front and back surfaces of the three-crystal solar cell are completely sealed with 13 EVA. However, it is important not to leave air inside in order to prevent destruction due to air expansion.

In order to alleviate the impact and prevent moisture from entering and to ensure assembly, 12 hard glass, 3 crystal solar cells completely sealed with 13 EVA, and 14 reflective film are stacked in order from the sunlight incident side. The 15 packing materials to be bundled and the sturdy 16 side frame are important.

When stacking 12 hard glass, 3 crystalline solar cells fully sealed with 13 EVA, and 14 reflective film in order, it is necessary to leave no air between any of the layers to prevent destruction due to air expansion. is there.

Since the output of a three-crystal solar cell decreases as the temperature rises, a structure that takes heat dissipation into account is important.

JP-A-11-87757
JP2009-32852A

Although both front and back surfaces of the three-crystal solar cell are sealed with 13 EVA for shock mitigation and moisture prevention, the thickness is about 0.3 mm because the amount of sunlight transmitted decreases as the thickness increases. However, the thermal conductivity of 13EVA is poorer than that of metal, and it is difficult to efficiently radiate the heat received by the tricrystalline solar cells from sunlight through 13EVA. For this reason, the heat received from sunlight is accumulated inside, and in sunny weather, the temperature of the three-crystal solar cell rises by about 40 ° C with respect to the outside air temperature, and the forbidden band width (-0.45% / Since the output is reduced by about 18% due to (° C.), it is a problem to prevent the temperature rise.

Since the output of a three-crystal solar cell decreases with increasing temperature, a structure that efficiently dissipates heat must be adopted. However, when a heat sink is attached to the back of a 14-reflective film, heat is generated by 13 EVA or 14-reflective film. Because of this, the heat conduction is hindered, and sufficient heat dissipation effect cannot be obtained.

The portions on the 12 hard glass and the tricrystalline solar cells without the wiring pattern are flat. In addition, 12 hard glass, 13 EVA, 13 EVA, and 3 crystal solar cells are in close contact with each other. On the other hand, the copper wire with solder plating laid on the wiring pattern on the three-crystal solar cell is raised about 0.3 mm from the surface of the three-crystal solar cell, and the thickness of 13EVA in the portion without the wiring is Since 13EVA is thicker than a certain part and is surrounded by copper wire laid on the wiring pattern on the three-crystal solar cell, when EVA expands due to temperature rise, 13EVA is on the three-crystal solar cell. The copper wire laid on the wiring pattern is pushed from the side. The lateral force applied to the surface wiring of the five solar cells arranged at the center of the three-crystal solar cell is almost the same on the left and right, but in the wiring arranged at the ends, the force from the center is applied from the outside. Since the force is weak and the left / right balance of the force applied to the wiring cannot be achieved, even if it does not lead to peeling, a microcrack is inserted between the wiring pattern and the silver paste, and the silver paste and the copper wire, resulting in an increase in resistance and power loss. Produce. Or, in some rare cases, separation may occur and the generated electricity cannot be collected.

Mainly due to the weight of 12 hard glass and 16 side frames, which are mainly used for one surface plate of 150W class crystal solar panel, one 150W class crystal solar panel weighs about 20Kg (130g / W). It is also a problem that is not easy.

15 packing material used for impact mitigation and prevention of moisture intrusion on solar panels with 12 hard glass, 13 crystalline solar cell units fully sealed with 13 EVA, and 14 reflective films in order. There is a problem that the original purpose cannot be achieved, for example, a crack occurs or elasticity becomes poor.

Features a structure in which 3 crystal solar cells are attached to the heat sink via 7 adhesives or double-sided adhesive tape, and soft resin is filled between and around the surface plate and the light receiving surface of the 3 crystal solar cells And That is, by attaching the three crystal solar cells to the heat sink via seven adhesives or double-sided adhesive tape, heat can be more efficiently propagated to the heat sink and the temperature rise can be suppressed. In addition, as shown in FIG. 1, by arranging the recesses of the 4 heat sink assembly in correspondence with the rising of the back wiring of the 6 solar cells, the short circuit between the 4 heat sink assembly and the 6 solar cell back wiring can be prevented. Is possible.

In crystalline solar panels, output decreases due to temperature rise, due to differences in coefficient of thermal expansion with respect to temperature of 3-crystal solar cells, wiring materials, 2 sealing resin and 7 adhesives or double-sided adhesive tape due to temperature rise. It is possible to improve reliability and ease of handling by reducing the weight with respect to wiring separation, disconnection, and ensuring confidentiality.

It is sectional drawing of a crystalline solar cell part. It is sectional drawing of a crystalline solar cell panel edge part. It is a perspective view of a heat sink assembly. It is a perspective view of the edge part of a heat sink assembly. It is a layout view of crystalline solar cells in a crystalline solar panel. It is sectional drawing of the conventional crystalline solar cell panel edge part.

FIG. 1 is a cross-sectional view showing the arrangement of main members used in a crystalline solar cell module, wherein 1 is a surface plate, 2 is a sealing resin, 3 is a crystalline solar cell, and 4 is a radiator plate assembly.

One surface plate is a flat plate of weather-resistant transparent resin mainly composed of polycarbonate, and has a side of about 70 cm, a thickness of about 2 mm, and a weight of about 1.3 kg.

2 Sealing resin is a transparent resin that is viscous but has high fluidity, softness, and weather resistance. The thickness of the 2 sealing resin at the top of the 3-crystal solar cell is approximately 0.5 mm, as shown in FIG. The entire area surrounded by 1 surface plate and 4 heat sink assembly is filled, and its weight is about 400g.

The three-crystal solar cell has a size of about 15.5 cm square, and a rated output of about 55 W can be obtained by arranging 16 pieces as shown in FIG. The total weight of the 16 three-crystal solar cells is very small compared to the weight of the 1 surface plate, 2 sealing resin, and 4 heat sink assembly.

As shown in Fig. 3 and Fig. 4, the 4 heat sink assembly consists of two thin aluminum plates with an uneven groove depth of about 3mm to the end, that is, 18 surface heat sink and 8 back heat dissipation. It is composed of plates, arranged so that the grooves are orthogonal, and the part where both plates touch is joined by welding or other methods. One side of the assembly is about 70 cm, the thickest part is about 6 mm thick, and the weight is about 800 g.

The width and depth of the groove provided in the 4 heat sink assembly are secured so as not to short-circuit with the 6 solar cell back surface wiring. Further, the position of the groove is determined by the position of the wiring pattern of the three crystal solar cells, and the number of grooves is appropriate to be about two to three per one three crystal solar cell.

4 As shown in Fig. 4, the end of the heat sink assembly is not grooved, and the two heat sinks are not in contact with each other. Fit. The 11 spacer is not particularly limited as long as it is a light resin that does not deform at a temperature of about 100 ° C. This weight is about 400 g.

4 The aluminum plate used for the heat sink assembly should be less than 1mm thick and about 0.3mm. In addition, surface treatment such as anodizing is applied.

FIG. 2 is a cross-sectional view showing the arrangement of main members used near the ends of the crystalline solar cell panel, 10 is an outer frame, 11 is a spacer, and 9 is a vent hole provided in 10 outer frame and 11 spacer. , Natural convection of air is obtained through this vent.

The three crystal solar cells arranged and wired as shown in FIG. 5 are arranged so that the back wiring of the six crystal solar cells is positioned at the approximate center of the groove of the four heat sink assemblies. Glue.

Adhesion of tricrystalline solar cells is achieved by applying acrylic or butyl adhesive to 4 heat sink assemblies with a thickness of about 50 μm, or double-sided adhesive tape with an acrylic or butyl thickness of about 4 μm to 4 heat sink assemblies. A three-crystal solar cell is bonded by pressure.

While aligning the position of the 1 surface plate with 2 sealing resin pasted on the opposite side of the sunlight incident surface on the 4 heat sink assembly to which the 3 crystalline solar cells are bonded Put.

A 10 outer frame is attached to this assembly. The weight of the 10 outer frame is about 1 kg.

The total weight of the unit by the above structure and assembly is approximately 4.0 Kg, which is 73 g per W, which can be suppressed to about 56% of the conventional product.

In a performance test using this crystalline solar cell panel prototype, when the outside air temperature is 31 ° C, the surface temperature of one surface plate that is exposed to direct sunlight for a time sufficient for thermal saturation is 46 ° C, and it is exposed to direct sunlight. The surface temperature of the four heat radiating plate assemblies was 32 ° C. Similarly, a three-crystal solar cell made of a resin equivalent to 13EVA, which has been used frequently in the past, has a thickness of about 0.5 mm as a substitute for the four heat sink assembly, under the condition that it is exposed to direct sunlight for a sufficient time to saturate. When the cell was sealed, the resin surface temperature on the back side not exposed to direct sunlight was 46.5 ° C., and it was proved that the structure shown in FIGS. 1 to 4 was effective for heat dissipation.

The width of 11 spacer is about 3 cm, which is roughly the same as the width of 10 outer frame. Since the three-crystal solar cells are not arranged during this period, the distance from the end face of the outer frame 10 to the three-crystal solar cells is about 3 cm, which is sufficient for preventing moisture from entering.

6 solar cell back surface wiring is arrange | positioned in the groove | channel recessed part of 18 surface heat sink, and since this groove | channel is interrupted | blocked with external air by 2 sealing resin, moisture-proof property is maintained.

As for solar cells, it is a challenge to ensure reliability, reduce weight, and mitigate the decrease in power generation efficiency due to temperature rise.

DESCRIPTION OF SYMBOLS 1 Surface plate 2 Sealing resin 3 Crystalline solar cell 4 Heat sink plate assembly 5 Solar cell surface wiring 6 Solar cell back surface wiring 7 Adhesive 8 Back surface heat sink 9 Vent hole 10 Outer frame 11 Spacer 12 Hard glass 13 EVA
14 Reflective film 15 Packing material 16 Side frame 17 Crystalline solar cell unit 18 Surface heat sink

Claims (2)

A solar battery panel, wherein a crystal solar battery cell is attached to a heat sink having a concave groove in a portion corresponding to a back surface wiring of the crystal solar battery cell using an adhesive or a double-sided adhesive tape. The solar cell panel according to claim 1, wherein a resin is filled between the surface plate and the light receiving surface of the crystalline solar cell.

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