JP3760569B2 - Solar cell module - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solar cell module using a non-single-crystal semiconductor as a solar cell element, and in particular, by adjusting the operating temperature of the solar cell element, the amount of power generation can be increased and the durability of the solar cell module can be improved. The present invention relates to a solar cell module.
[0002]
[Prior art]
In recent years, practical use of photovoltaic power generation systems and development of cost reduction technologies have been promoted. In particular, thin-film solar cells are attracting attention as next-generation solar cells. Thin film solar cells are attracting attention as low-cost solar cells because they require few raw materials for production and can be easily produced directly on an insulator substrate as large-area integrated solar cells. Thin-film solar cells include thin-film polycrystalline silicon solar cells, amorphous silicon solar cells, and polycrystalline compound solar cells (CdS, CdTe, CIGS). Among them, amorphous silicon is most practically used. It is a solar cell. Amorphous silicon solar cells refer to those containing amorphous silicon-based semiconductors such as amorphous Si and amorphous Si _x Ge _1-x as solar cell elements.
[0003]
However, the amorphous silicon-based semiconductor solar cell has a problem that when it is used outdoors for a long time, a conversion efficiency is lowered due to the influence of sunlight, so-called light degradation occurs. Even in a thin-film polycrystalline silicon solar cell, photodegradation occurs because the thin-film polycrystal has a local structure in the vicinity of a hydrogen atom and presents an amorphous phase between crystal grains. However, in recent years, amorphous silicon solar cells and thin film polycrystalline silicon solar cells that can maintain a conversion efficiency of around 10% even after photodegradation have been developed, although photodegradation does not become zero. Accordingly, the demand for solar cell power generation systems used outdoors is expanding. Such a solar cell is used not in the form of a single photoelectric conversion element (solar cell element) but in the form of a solar cell panel having mechanical strength and weather resistance. This solar cell panel is fitted into a frame and used in the form of a solar cell module.
[0004]
As a countermeasure against light deterioration, many solar cell modules having a structure in which the operation temperature of the module is maintained at a high temperature to cause an annealing effect are known. For example, a tandem module in which a plurality of solar cells are stacked (Japanese Patent Laid-Open No. 61-306034), a concentrating module (Japanese Patent Laid-Open No. 61-17479), a solar cell module in which a heat insulating material is attached to the back surface of the solar cell ( JP-A-7-297435) is known. Since these solar cell panels have a multilayer structure or are provided with a heat insulating material on the back surface of the panel, they must be expensive.
[0005]
5 to 8 show typical examples of conventional solar cell modules. The solar cell module 30 in FIG. 5 is a view of the module 30 as viewed from the back side, and FIG. 6 is a cross-sectional view of the solar cell module 30 taken along the line BB. The solar cell module 30 includes a solar cell panel 31, a frame body 32 in which the panel 31 is fitted, and a terminal box 33 for taking out photoelectrically converted electric power from the panel 31. The outer edge portion of the solar cell panel 31 is fitted and bonded to a recess formed in the upper portion of the frame body with an adhesive 37 such as butyl rubber. Moreover, the solar cell panel 31 arranges a light transmitting substrate 33 made of a glass plate or the like on the light incident side, and on the back surface side of the light transmitting substrate 33, a photoelectric conversion element 34, an adhesive filler 35, Further, the sealing material 36 that protects the opposite surface on the light incident side is sequentially laminated. 7 and 8 show a solar cell module 40 provided with a heat insulating material 42 and a protective layer 43 for protecting the heat insulating material 42 on the back surface side of the solar cell panel 41. FIG. 7 is a view of the solar cell module 40 as seen from the back side, and FIG. 8 is a cross-sectional view of the solar cell module 40 taken along the line C-C.
[0006]
[Problems to be solved by the invention]
In the conventional solar cell module as described above, when a heat insulating material is provided on the back side of the solar cell panel, a special material having heat resistance must be used for the heat insulating material in order to guarantee the durability of the module. In addition, a durable and high-cost adhesive must be used for bonding the heat insulating material. Furthermore, a protective material such as an iron plate for protecting the heat insulating material from mechanical stress and ultraviolet rays and an adhesive for attaching the protective material are required. If these requirements are satisfied, the solar cell module can obtain the stability as a product, but it costs more than the effect of improving the characteristics of the solar cell, and becomes a drag on practical use.
[0007]
In addition, since many of the conventional solar cell modules using a heat insulating material use a porous material for the heat insulating material, the heat insulating material can be used in addition to protecting the solar cell element in order for the module to have a durability of 20 years or more. Protective material is also required. Although the effect of improving the characteristics can be obtained by the protective material of the heat insulating material, the cost exceeding this effect is required.
[0008]
The present invention adjusts the operating temperature of the solar cell module, causes an annealing effect, adjusts the humidity inside the solar cell module, prevents corrosion of the solar cell module and can withstand long-term use and is simple and inexpensive. An object is to provide a solar cell module.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a solar cell module according to the present invention includes a solar cell panel in which a non-single-crystal semiconductor solar cell element is formed on a substrate, and a frame that is fixed over the entire outer edge of the solar cell panel. And a plate member provided on the back side opening portion of the frame body and having a single or a plurality of openings for sealing the open portion with air permeability, the back side of the solar cell panel, the frame The body and the air layer surrounded by the plate member are formed. By retaining air in the air layer, it is possible to prevent heat from flowing out of the module. At the same time, the humidity of the air layer can be reduced by the single or a plurality of openings of the plate member, so that the life of the frame body and the solar cell panel is not shortened due to the influence of moisture contained in the air layer.
[0010]
The opening may be circular, square, rectangular, or slit.
[0011]
In addition, as the non-single-crystal semiconductor formed on the substrate, an amorphous silicon semiconductor and a thin film polycrystalline silicon semiconductor including one or both of them are used. With this structure, it is possible to set an operating temperature for causing an annealing effect and suppressing light degradation.
[0012]
When a plurality of the solar cell modules described above are connected and configured, a large-area solar cell module can be manufactured at low cost.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, various embodiments of the solar cell module according to the present invention will be specifically described with reference to the drawings. FIG. 1 is a view of a solar cell module 1 according to the present invention as viewed from the back side, and FIG. 2 is a cross-sectional view taken along the line AA. The solar cell module 1 is configured such that a solar cell panel 2 is fitted and bonded to a frame body 3, and a plate member 5 having an opening 4 is provided in an open portion on the back side of the frame body 3. With this configuration, an air layer 6 surrounded by the back surface of the solar cell panel, the frame body 3 and the plate member 5 is formed. Further, the outer edge portion of the solar cell panel 2 is fitted and bonded to the concave portions 8 and 8 formed in the upper portion of the frame body with an adhesive 7 such as butyl rubber. Further, the plate member 5 is fixed to the frame 3 at four locations with screws 13. The frame body 3 is used for protection of the panel and installation on a roof or the like, and the material thereof is made of aluminum alloy or resin.
[0014]
For the plate member 5 which is a sealing member, a vinyl chloride coated steel plate coated with vinyl chloride is used. The plate member 5 serves to protect the solar cell panel 2 from the outside air. Moreover, by ventilating through the opening part 4 provided in this board member 5, when using a solar cell, it can prevent that the air layer 6 will be in a saturated water vapor state, and can prevent dew condensation. Therefore, corrosion of the frame 3 and the solar cell panel 2 can be prevented. In the present invention, the shape of the opening 4 is not limited to a circle but may be a square or a rectangle. In the present invention, the opening 4 is preferably provided in the center of the plate member 5, but instead, it may be provided in a slit shape at several locations of the plate member 5. Further, in the present invention, a material other than the vinyl chloride-coated steel plate, such as a weather resistant resin material, an aluminum plate, or a building exterior material, can be used for the plate member 5 depending on the installation location. In the case of a solar cell module integrated with a roof, a simple material such as wood can also be adopted because the back side portion opposite to the light incidence is disposed indoors.
[0015]
Moreover, the solar cell panel 2 arrange | positions the translucent board | substrate 9 which consists of a glass plate etc. in the light-incidence side, and the photoelectric conversion element 10 containing an amorphous silicon film, adhesiveness is provided in the back surface side of this translucent board | substrate 9. The filler 11 and the sealing material 12 that protects the opposite surface of the light incident side are sequentially laminated. Here, EVA (ethylene vinyl acetate), PVB (polyvinyl butyral), polyisobutylene resin, silicon resin, or the like is used for the filler 11, and Tedlar (vinyl fluoride made by DuPont) is used for the sealing material 12. Registered trademark) or a laminate of this tedlar and aluminum foil in a sandwich shape.
[0016]
In this embodiment, an amorphous silicon semiconductor solar cell element is employed as the photoelectric conversion element. At this time, the air layer composed of the back surface of the solar cell panel, the frame body, and the plate member has a heat insulating function and plays a role of causing an annealing effect. That is, the heat of the solar cell panel is transmitted to the air layer on the back side of the solar cell panel, and this air convects and circulates in the air layer, so that heat outflow from the solar cell module is suppressed.
[0017]
The solar cell module according to the present invention is not limited to one using a single solar cell panel, but may be a solar cell module 20 having a configuration in which a plurality of solar cell modules are connected as shown in FIG. This figure shows an array structure in which the number of solar cell panels 21 is 3 × 3 = 9, and shows a state in which one of the nine solar cell panels of the module 20 is removed. On the back side of each solar cell panel 21, it has a plate member 23 having the opening 22 as described above, and an air layer surrounded by the solar cell panel 21, the plate member 23, and the frame body 24. Each air layer is independent and has a structure in which no air flows between the air layers.
[0018]
Next, a comparison experiment of module temperature between the conventional solar cell module and the solar cell module according to the present invention will be described below. The solar cell module according to the present invention is shown in FIGS. 1, 2, and 4 as the present embodiment, and the conventional solar cell module shown in FIGS. 5 and 6 is the conventional example 1, FIG. 7 and FIG. 8 is called Conventional Example 2. In this experiment, during the midsummer sunny day, the back surface temperature of the solar cell panel of this example, the back surface temperature of the solar cell panel of Conventional Example 1, the surface temperature of the protective layer of the heat insulating material of Conventional Example 2, and the air temperature , Measured using a thermoelectric thermometer.
[0019]
The solar cell module used in this experiment will be described below with reference to FIG. The solar cell panel is square with a side length S of about 910mm. The frame is about 2mm thick and the height H is about 35mm. The width T1 of the upper and middle fixing parts The width of the lower fixing portion is about 15 mm, and the width D1 of the recess formed in the upper part of the frame is about 8 mm. In addition, a back surface sealing material having a side length L of about 890 mm was used, and an opening having a diameter R of 50 mm was provided at the center of the sealing material. Example 1 removes the plate member which is a sealing member among this Example. In Example 2, a heat insulating material and its protective layer were provided on the back surface of the solar cell panel of Example 1, and a foamed polystyrene foam was used for this heat insulating material, and a square having a side length of 890 mm. A 20 mm thick one was used. A Tedlar film was used for the protective layer of this heat insulating material.
[0020]
The experimental results show that the temperature is 32 ° C., the back surface temperature of the solar cell panel of this example is 65 ° C., the back surface temperature of the solar cell panel of Conventional Example 1 is 55 ° C., and the surface temperature of the protective layer of the heat insulating material of Conventional Example 2 Was 70 ° C. As can be seen from this result, the temperature of the back surface of the solar cell panel of this example is slightly lower than the surface temperature of Conventional Example 2 using a heat insulating material, but is sufficient to cause an annealing effect in the solar cell element. . Therefore, the power generation characteristics of the amorphous silicon solar cell can be improved. In addition, no water droplets due to condensation appeared on the back surface of the solar cell panel, confirming the module's corrosion prevention effect.
[0021]
Note that the present invention can also be applied to a solar cell using a CdS / CdTe-based or CIGS (Cu (InGa) Se ₂ ) -based semiconductor. This solar cell has an advantage that it does not cause photodegradation. However, since it contains Cd, In, etc., a measure that does not adversely affect the environment is required. In the solar cell module structure according to the present invention, a structure that can remove moisture without completely sealing the back surface of the solar cell panel is employed, so that the module is hardly corroded. Therefore, the cost required for measures against leakage of Cd and In can be kept low.
[0022]
The solar cell module according to the present invention may be configured by providing a heat insulating material on the back surface of the solar cell panel. In this case, since the air layer mainly bears the heat insulating effect, the cost for the heat insulating material and its protective layer can be kept low.
[0023]
【The invention's effect】
A plate member having air permeability is provided at the open side of the back side of the frame of the solar cell module, and an air layer is formed on the back side of the solar cell panel, so that heat generated in the solar cell panel is generated in the air layer. It becomes possible to confine and suppress the heat outflow from the solar cell module. Therefore, since the operating temperature of the solar cell can be adjusted by adjusting the shape and number of the openings, it is possible to cause an annealing effect and reduce light degradation. Moreover, since the moisture in the air layer can be removed by providing the opening in the plate member , corrosion of the solar cell module can be prevented. Furthermore, since such a solar cell module can be easily produced at a low cost, a large-area solar cell module configured to be connected can be easily produced at a low cost.
[Brief description of the drawings]
FIG. 1 is an explanatory view of a solar cell module according to the present invention viewed from the back side.
2 is a cross-sectional view taken along line AA of the solar cell module shown in FIG.
FIG. 3 is an explanatory view showing a connecting structure of solar cell modules according to the present invention.
FIG. 4 is an explanatory diagram showing dimensions of a solar cell module according to the present invention.
FIG. 5 is an explanatory view of a conventional solar cell module as seen from the back side.
6 is a cross-sectional view of the conventional solar cell module shown in FIG. 5 taken along the line BB.
FIG. 7 is an explanatory view of a conventional solar cell module as seen from the back side.
8 is a cross-sectional view taken along the line CC of the conventional solar cell module shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Solar cell module 2 Solar cell panel 3 Frame body 4 Opening part 5 Plate member 6 Air layer 7 Adhesive material 8 Recessed part 9 Translucent substrate 10 Photoelectric conversion element 11 Filler material 12 Sealing material 13 Screw 20 Connection structure Solar cell module 21 having solar cell panel 22 opening 23 plate member 24 frame 30 solar cell module 31 showing first conventional example solar cell panel 32 frame 33 terminal box 34 photoelectric conversion element 35 filling material 36 sealing material 37 Adhesive 40 Solar Cell Module 41 Showing Second Conventional Example Solar Cell Panel 42 Heat Insulating Material 43 Protective Material 44 Frame 45 Translucent Substrate 46 Photoelectric Conversion Element 47 Filler 48 Sealing Material

Claims (4)

A solar cell panel in which a non-single-crystal semiconductor solar cell element is formed on a substrate, a frame that is fixed over the entire periphery of the outer edge of the solar cell panel, and an open portion that is provided on a back side open portion of the frame be more configuration as a plate member having a single or plurality of openings to seal a breathable back surface of the solar cell panel, wherein forming the frame, and the plate an air layer surrounded by the member A solar cell module. The solar cell module according to claim 1 , wherein the opening has a circular shape, a square shape, a rectangular shape, or a slit shape .   The solar cell module according to claim 1 or 2, wherein the non-single-crystal semiconductor includes one or both of an amorphous silicon-based semiconductor and a thin-film polycrystalline silicon semiconductor.   The solar cell module comprised by connecting the solar cell module of any one of Claims 1-3.

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