JP6748877B2 - Solar cell module - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell module, and more particularly to a solar cell module capable of allowing light to enter both sides.

Since one solar cell element generates a small electric output, a solar cell module is formed by enclosing a plurality of solar cell elements with a filler having a thermoplastic resin as a main component. In order to contribute to the power generation of light that passes through the gaps between adjacent solar cell elements and light that enters from the back surface side, a grid-shaped light-reflecting sheet has been placed on the back surface side of multiple solar cell elements so far. (For example, see Patent Document 1).

JP 2006-73707 A

The lattice shape of the light-reflecting sheet is formed by punching out the portion where the solar cell element is arranged. In order for the light-reflecting sheet to reflect the light that passes through the gaps between adjacent solar cell elements and not to block the light that enters from the back side, the alignment of the reflective sheet is important. The manufacturing difficulty of the module increases.

The present invention has been made in view of such circumstances, and an object thereof is to provide a technique of suppressing an increase in manufacturing difficulty while improving power generation efficiency.

In order to solve the above problems, the solar cell module according to one embodiment of the present invention is capable of entering light on both sides, and a solar cell in which electrodes are arranged on both sides, and one surface side of the solar cell A first protective member disposed on the first protective member, a first sealing member disposed between the first protective member and the solar cell, and a second protective member disposed on the other surface side of the solar cell, A second sealing member arranged between the second protective member and the solar cell, wherein the second sealing member contains incident light scattering particles dispersed therein, and the second sealing member is It transmits a part of the incident light and scatters another part of the incident light.

According to the present invention, an increase in manufacturing difficulty can be suppressed while improving power generation efficiency.

FIG. 1 is a perspective view showing a state in which the solar cell module according to the first embodiment is installed. FIG. 2A is a sectional view showing a configuration of a solar cell module of a comparative example. FIG. 2B is a cross-sectional view showing the configuration of the solar cell module according to Embodiment 1. FIG. 3 is a diagram showing a relationship between particle number density and solar cell light absorptance in the solar cell module according to Embodiment 1 shown in FIG. 2B. FIG. 4 is a diagram showing the relationship between the particle size of silica particles and the particle number density in the solar cell module according to Embodiment 1 shown in FIG. 2B. FIG. 5 is a diagram showing the relationship between the particle size of silica particles and the solar cell light absorptance at the optimum particle number density in the solar cell module according to Embodiment 1 shown in FIG. 2B. FIG. 6A is a diagram showing light scattered in the second sealing member in the solar cell module according to Embodiment 1 shown in FIG. 2B. FIG. 6B is a diagram showing a relationship between incident light and transmitted light at the second sealing member in the solar cell module according to Embodiment 1 shown in FIG. 2B. FIG. 6C is a diagram showing a relationship between incident light and transmitted light in the second sealing member (when the silica particles are randomly arranged) in the solar cell module according to Embodiment 1 shown in FIG. 2B. FIG. 7A is a cross-sectional view showing an outline when infrared light is incident on the solar cell module of the comparative example shown in FIG. 2A. FIG. 7B is a cross-sectional view showing an outline when infrared light is incident on the solar cell module according to the first embodiment shown in FIG. 2B. FIG. 8 is a diagram showing experimental results for the solar cell module according to the second embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each of the embodiments described below shows a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, connection forms, and the like shown in the following embodiments are examples and are not intended to limit the present invention. Therefore, among the constituent elements in the following embodiments, the constituent elements that are not described in the independent claims showing the highest concept of the present invention are described as arbitrary constituent elements.

Each drawing is a schematic diagram, and is not necessarily strictly illustrated. Further, in each of the drawings, substantially the same components are denoted by the same reference numerals, and overlapping description will be omitted or simplified.

(Embodiment 1)
First, before specifically describing the first embodiment, the basic knowledge will be described. The first embodiment relates to a solar battery module including a plurality of solar battery cells. The solar battery module and the solar battery cell here are types in which light can be incident on both sides and power is generated on both sides. In addition, one side (hereinafter sometimes referred to as the "front side") of the solar cell module faces the south direction, and the other surface (hereinafter sometimes referred to as the "back side") side faces the north direction. , A solar cell module is installed. Therefore, the power generation amount on the front surface side of the solar battery cell is larger than the power generation amount on the back surface side of the solar battery cell.

Even in such a situation, in order to improve the power generation efficiency, it is necessary to allow the light incident between the adjacent solar cells to be taken into the solar cells without being transmitted. In addition, it is necessary that the light incident from the back surface side is also taken into the solar battery cell. Furthermore, it is desired that the solar cell module has a configuration considering the ease of manufacturing. The purpose of the present embodiment is to realize a configuration in which light incident between adjacent solar cells and light incident from the back surface side are taken into the solar cells and the ease of manufacturing is taken into consideration.

FIG. 1 is a perspective view showing a state where the solar cell module 100 according to the first embodiment is installed. As illustrated, the solar cell module 100 is installed while being supported by the two leg portions 102. As described above, the front surface of the solar cell module 100 faces the south direction, and the back surface of the solar cell module 100 faces the north direction. The direction in which the front surface is directed is not limited to true south and may include southeast and southwest, and the direction in which the back surface is directed is not limited to true north and may include northwest and northeast. That is, the front surface and the back surface may be oriented in the direction of the incident light amount during the period in which sunlight can be incident from sunrise to sunset, and the difference in the incident light amount in the situation where the change in the weather is small becomes large. .. For example, the solar cell module 100 is installed so that the amount of incident light on the front surface is 1.5 times or more the amount of incident light on the back surface. Therefore, the case where the front surface faces the east direction and the back surface faces the west direction is excluded.

FIG. 2A is a cross-sectional view showing a configuration of a solar cell module 200 of a comparative example, which is a comparison target of solar cell module 100 according to the first embodiment. FIG. 2B is a cross-sectional view showing the configuration of solar cell module 100 according to the first embodiment.

As shown in FIG. 2A, the solar cell module 200 of the comparative example includes a first solar cell 210 a, a second solar cell 210 b, a first protective member 212, and a first sealing member 214, which are collectively referred to as a solar cell 210. , A second protection member 216, and a second sealing member 218. Here, the first protection member 212 side corresponds to the above-mentioned front surface side, and the second protection member 216 side corresponds to the above-mentioned back surface side. Further, the first solar battery cell 210a includes a first front surface side electrode 240a and a first back surface side electrode 242a, and the second solar battery cell 210b includes a second front surface side electrode 240b and a second back surface side electrode 242b. Here, the first front surface side electrode 240a and the second front surface side electrode 240b are collectively referred to as the front surface side electrode 240, and the first back surface side electrode 242a and the second back surface side electrode 242b are collectively referred to as the back surface side electrode 242.

The solar cell 210 absorbs incident light to generate a photovoltaic power, and is formed of a semiconductor material such as crystalline silicon, gallium arsenide (GaAs), or indium phosphide (InP). The structure of solar cell 210 is not particularly limited, but here, as an example, it is assumed that crystalline silicon and amorphous silicon are stacked. In particular, the solar battery cell 210 can enter light on both sides and generates power on both sides. Therefore, the front surface side electrode 240 is arranged on the front surface side of the solar battery cell 210, and the rear surface side electrode 242 is arranged on the rear surface side of the solar battery cell 210.

The front surface side electrode 240 and the back surface side electrode 242 are, for example, finger electrodes. The finger electrode is an electrode that collects electric power generated by receiving light. Since the finger electrodes are electrodes formed on the surface, they are thinly formed so as not to block incident light. A plurality of finger electrodes are arranged on the surface at predetermined intervals so that the generated electric power can be efficiently collected. In addition to the finger electrodes, bus bar electrodes (not shown) are arranged on both surfaces of the solar cell 210. The bus bar electrode is an electrode for connecting a plurality of finger electrodes to each other. The bus bar electrode is formed thin enough not to block incident light, and is formed thick to some extent so that the electric power collected from the plurality of finger electrodes can be efficiently flowed. A plurality of bus bar electrodes are arranged on the surface so as to intersect the plurality of finger electrodes. Furthermore, the bus bar electrodes provided in each of the adjacent solar cells 10 are connected by tab wires (not shown).

The first protection member 212 is arranged on one surface side of the solar cell 210. As described above, the side where the first protection member 212 is arranged is the front side, and is oriented in the south direction. The first protection member 212 protects the solar cell 210 from the external environment and transmits the light to be absorbed by the solar cell 210. The solar cell 210 is, for example, a glass substrate. In addition to the glass substrate, the solar cell 210 may be made of polycarbonate, acrylic, polyester, or fluorinated polyethylene.

The first sealing member 214 is arranged between the first protective member 212 and the solar cell 210. The first sealing member 214 is a protective material that prevents moisture from entering the solar battery cells 210 and improves the strength of the entire solar battery module 200. The 1st sealing member 214 is transparent resin which has transparency which can fully penetrate sunlight. The first sealing member 214 is formed of a resin material such as ethylene vinyl acetate copolymer (EVA), polyvinyl butyral (PVB), polyimide, polyethylene, polypropylene, or polyethylene terephthalate (PET). Here, the first sealing member 214 is assumed to be EVA.

The second protection member 216 is arranged on the other surface side of the solar cell 210. As described above, the side where the second protection member 216 is arranged is the back surface side, and is oriented in the north direction. The second protection member 216 is configured similarly to the first protection member 212. The second sealing member 218 is arranged between the second protection member 216 and the solar cell 210. The second sealing member 218 is configured similarly to the first sealing member 214. Thus, in the solar cell 210, the first protective member 212, the first sealing member 214, the solar cell 210, the second sealing member 218, and the second protective member 216 are arranged in this order.

The first protection member side incident light 230 is light incident on the solar cell module 200 from the front surface side. Part of the incident light 230 on the first protection member side is taken into the solar battery cell 210. On the other hand, the first protective member side incident light 230 passing between the first solar cell 210a and the second solar cell 210b goes out of the second protective member 216 and becomes transmitted light. On the other hand, the second protection member side incident light 232 is light incident on the solar cell module 200 from the back surface side. Therefore, the amount of the second protective member side incident light 232 is smaller than the amount of the first protective member side incident light 230. Similarly to the first protective member side incident light 230, a part of the second protective member side incident light 232 is taken in by the solar battery cell 210, and a portion between the first solar battery cell 210a and the second solar battery cell 210b is provided. The rest that passes through goes out from the first protection member 212.

In the solar cell 210 having such a configuration, it is necessary to reduce the amount of transmitted light in order to increase power generation efficiency. In order to reduce the amount of transmitted light, it is effective to reflect the incident light at the sealing member, but this makes it possible for the first protective member-side incident light 230 and the second protective light incident on the solar cell 210 to enter. It is necessary to suppress the reduction of the amount of the member-side incident light 232.

As shown in FIG. 2B, the solar battery module 100 according to the present embodiment includes a first solar battery cell 10a, a second solar battery cell 10b, a first protective member 12, and a first seal, which are collectively referred to as a solar battery cell 10. The stop member 14, the second protection member 16, and the second sealing member 18 are included. The second sealing member 18 also includes incident light scattering particles 20. Further, the first solar battery cell 10a includes a first front surface side electrode 40a and a first rear surface side electrode 42a, and the second solar battery cell 10b includes a second front surface side electrode 40b and a second rear surface side electrode 42b. The first front surface side electrode 40a and the second front surface side electrode 40b are collectively referred to as the front surface side electrode 40, and the first back surface side electrode 42a and the second back surface side electrode 42b are collectively referred to as the back surface side electrode 42.

Here, the solar cell 10 corresponds to the solar cell 210, the first protection member 12 corresponds to the first protection member 212, the first sealing member 14 corresponds to the first sealing member 214, and the second The protection member 16 corresponds to the second protection member 216, and the second sealing member 18 corresponds to the second sealing member 218. The front surface side electrode 40 corresponds to the front surface side electrode 240, and the back surface side electrode 42 corresponds to the back surface side electrode 242. Below, it demonstrates centering around difference with FIG. 2A.

The second sealing member 18 has the same structure as the second sealing member 218, but contains the incident light scattering particles 20 dispersed therein. Here, the dispersion corresponds to being uniformly included in the entire second sealing member 18, and it can be said that the dispersion is included at random. The incident light scattering particles 20 are, for example, silica particles. Thus, the inclusion of the incident light scattering particles 20 allows the second sealing member 18 to transmit a part of the incident light and scatter another part of the incident light. For example, as shown in FIG. 2B, a part of the incident light 30 on the first protective member side passes through the second sealing member 18 and goes out from the second protective member 16 to become the transmitted light 34. The other part of the incident light 30 on the first protection member side is scattered by the second sealing member 18 to become scattered light (reflected light) 36. That is, in the configuration of FIG. 2A, the light between the first solar cell 210a and the second solar cell 210b cannot be used for power generation, whereas in the configuration of FIG. 2B, the first solar cell Light between the cells 10a and the second solar cells 10b can be used for power generation. In the following, the particle size and particle number density of silica particles suitable for the configuration of FIG. 2B will be derived by simulation calculation.

FIG. 3 is a diagram showing a relationship between particle number density and solar cell light absorptance in solar cell module 100 according to Embodiment 1 shown in FIG. 2B. In FIG. 3, the horizontal axis represents the particle number density N [particles/mm ³ ] and the vertical axis represents the solar cell light absorptance [%]. The particle number density is the number of silica particles contained per cubic millimeter, and can also be called a silica particle number density. The particle size d of the silica particles, which is the size of the silica particles, is changed as a parameter between d=0.1 μm and 10 μm.

Here, a simulation calculation that combines the Mie scattering and the ray tracing method is executed. In the simulation calculation, the thickness of the first protective member 12 is 3.2 mm, the thickness of the first sealing member 14 is 0.6 mm, the thickness of the solar cell 10 is 0.115 mm, and the second sealing member 18 is The thickness is 0.6 mm, and the thickness of the second protective member 16 is 3.2 mm. The light scattering intensity distribution of the incident light scattering particles 20 included in the second sealing member 18 is Mie scattering. The front surface side electrode 40 and the back surface side electrode 42 provided on both surfaces of the solar battery cell 10 are made of silver. Furthermore, it is assumed that the ratio of the light amounts of the first protective member side incident light 30 and the second protective member side incident light 32 is "1:0.3".

In FIG. 3, a line 50 (d=10 μm) indicated by a circle (∘) indicates a solar cell light absorptivity when the particle number density is changed when the particle size of the silica particles is 10 μm. This is the result of calculation. The particle number density at which the solar cell light absorptance reaches its peak is defined as the optimum particle number density Nopt, which is the point at which the amount of power generation is maximized. Moreover, in FIG. 3, when the number of silica particles is “0”, that is, when the incident light scattering particles 20 are not included in the second sealing member 18, the solar cell light absorption rate is Shown as absorptivity threshold (dashed line 90). The particle number density when the line 50 (d=10 μm) intersects with the solar cell light absorptivity threshold value (dashed line 90) except for the number “0” of silica particles is defined as the allowable particle number density Nplus. It This is the maximum value of the particle number density at which the solar cell light absorptance increases due to the inclusion of silica particles.

In the range smaller than the optimum particle number density Nopt, the solar cell light absorption rate increases as the particle number density increases. On the other hand, in the range of the optimum particle number density Nopt or higher and the allowable particle number density Nplus or lower, the solar cell light absorption rate decreases as the particle number density increases, but compared with the case where silica particles are not mixed. The solar cell light absorption rate is increasing. Further, in the range of the allowable particle number density Nplus or less, the larger the particle number density, the more the solar cell light absorptivity decreases. This corresponds to deterioration of power generation efficiency. Such a tendency is shown by a line 52 (d=3 μm) indicated by a triangle mark (Δ), a line 54 (d=1 μm) indicated by a square mark (□), and a line 56 (d) indicated by a cross mark (x). =0.3 μm) and the line 58 (d=0.1 μm) indicated by the diamond mark (⋄), the same applies, but the optimum particle number density Nopt and the allowable particle number density Nplus are determined according to the particle size of the silica particles. Is different.

FIG. 4 is a diagram showing the relationship between the particle size of silica particles and the particle number density in solar cell module 100 according to Embodiment 1 shown in FIG. 2B. In FIG. 4, the horizontal axis represents the particle diameter d [μm] of the silica particles, and the vertical axis represents the particle number density N [particles/mm ³ ]. The optimum particle number density line 60 shows the change of the optimum particle number density Nopt calculated as shown in FIG. 3 with respect to the particle diameter of silica particles. When the particle size and particle number density of silica particles are determined so as to match the optimum particle number density line 60, the power generation efficiency is maximized. In the optimum particle number density line 60, the particle diameter d [μm] of the silica particles and the particle number density N [particles/mm ³ ] have a relationship of logN=−2.4×logd+7.6. On the other hand, the allowable particle number density line 92 shows the change in the allowable particle number density Nplus calculated as shown in FIG. 3 with respect to the particle diameter of the silica particles. When the particle size and particle number density of silica particles are determined based on the allowable particle number density line 92, power generation efficiency is improved. In the allowable particle number density line 92, the particle diameter d [μm] of the silica particles and the particle number density N [particles/mm ³ ] have a relationship of logN=−2.2×logd+8.0. Further, the particle volume occupancy rate 100% line 62 shows the case where 100% of silica particles are mixed, and can be said to be the maximum value at which silica particles can be mixed.

The descending region 66 is a region where the solar cell light absorptance falls due to an increase in the incident light 32 on the second protective member side when the particle diameter d of silica particles is d=0.1 to 10 μm. This is because the silica particles are contained too much and the second protection member side incident light 32 does not easily reach the solar battery cell 10. On the other hand, the rising region 64 is a region where the solar cell light absorptance rises irrespective of the increase in the incident light 32 on the second protective member side when the particle diameter d of silica particles is d=0.1 to 10 μm. In the rising region 64, the particle diameter d [μm] of the silica particles and the particle number density N [particles/mm3] have a relationship of logN<−2.2×logd+8.0.

Summarizing the calculation results so far, the silica particles have a particle diameter d [μm] and a particle number density N [particles/mm3] of logN≦−2.2×logd+8.0. The particle size and the number density of the particles should be determined. The particle diameter d of the silica particles at that time is 0.1 [μm] or more and 10 [μm] or less.

FIG. 5 is a diagram showing the relationship between the particle size of silica particles and the solar cell light absorptance at the optimum particle number density in the solar cell module 100 according to Embodiment 1 shown in FIG. 2B. In FIG. 5, the horizontal axis represents the particle diameter d [μm] of the silica particles, and the vertical axis represents the solar cell light absorptance [%]. Here, as the relationship between the light quantity of the first protection member side incident light 30 and the light quantity of the second protection member side incident light 32, a first condition indicated by a line 70 connecting triangle marks (▲), a square mark (■). Three conditions will be examined: a second condition indicated by a line 72 connecting the lines and a third condition indicated by a line 74 connecting the circles (◯). The ratio of the light amount of the first protective member side incident light 30 and the light amount of the second protective member side incident light 32 is 1:0 under the first condition (line 70) and 1: under the second condition (line 72). 0.1 and 1:0.3 under the third condition (line 74). These conditions are in the range assumed when the first protective member side incident light 30 is the light incident from the south direction and the second protective member side incident light 32 is the light incident from the north direction. is there.

Considering all the conditions, if the silica particles are not mixed in the second sealing member 18, the solar cell light absorptivity is 79.9 to 80.4%. On the other hand, when silica particles having a particle diameter d=10 μm are mixed in, the solar cell light absorptivity becomes 81.7 to 82.2%. In this way, the light absorptance of the solar battery cell is improved by mixing the silica particles. In addition, the particle diameter d of the silica particles is preferably in the range of 0.1 [μm] or more and 10 [μm] or less, and the silica particles to be mixed preferably have a large particle diameter.

Here, the relationship between incident light and transmitted light at the second sealing member 18 in the solar cell module 100 according to Embodiment 1 shown in FIG. 2B will be described with reference to FIGS. 6A, 6B, and 6C. FIG. 6A is a diagram showing light scattered in the second sealing member 18 in the solar cell module 100 according to Embodiment 1 shown in FIG. 2B, and shows the second sealing member 18 used in the simulation calculation. The structure of the incident light scattering particles 20 included is shown. So far, the silica particles that are the incident light scattering particles 20 are assumed to be spherical. On the other hand, actual silica particles may have a spherical shape and a distorted shape. Here, such a difference in shape is examined. As described above, in the simulation calculation, since the Mie scattering is performed on the silica particles, the light scattered on the silica particles in the second sealing member 18 is shown as an arrow in FIG. 6A. Be done. According to such scattering, the relationship between the light ray incident on the second sealing member 18 and the light ray emitted from the second sealing member 18 is shown as in FIG. 6B. FIG. 6B is a diagram showing a relationship between incident light and transmitted light at second sealing member 18 in solar cell module 100 according to Embodiment 1 shown in FIG. 2B. In FIG. 6B, the arrow directed to the second sealing member 18 indicates the light beam incident on the second sealing member 18, and the arrow emerging from the second sealing member 18 radiates from the second sealing member 18. Indicates the rays that are made.

On the other hand, when a cube is assumed as the shape of the silica particles and the silica particles are randomly arranged in the second sealing member 18, a light beam incident on the second sealing member 18 and the second sealing member 18 The relationship of the light rays emitted from is shown in FIG. 6C. FIG. 6C is a diagram showing a relationship between incident light and transmitted light at the second sealing member 18 (when the silica particles are randomly arranged) in the solar cell module 100 according to Embodiment 1 shown in FIG. 2B. As shown, the relationship in FIG. 6C is similar to the relationship in FIG. 6B. That is, if the silica particles are arranged regularly, even if the shape of the silica particles is not spherical, light scattering behavior equivalent to that in which the spherical particles are arranged is exhibited. In addition, in the manufacturing process of the second sealing member 18 in which the incident light scattering particles 20 are mixed, it is generally difficult to provide regularity in the arrangement of the silica particles.

Next, an outline of a case where infrared light is incident on the solar cell module will be described with reference to FIGS. 7A and 7B. FIG. 7A is a cross-sectional view showing an outline when incident infrared light 280 is incident on the solar cell module 200 of the comparative example shown in FIG. 2A. As shown in FIG. 7A, the incident infrared light 280 is incident from the first protection member 212 side, that is, from the front surface side. At least a part of the incident infrared light 280 passes through the solar battery cell 210 and is emitted as the transmitted infrared light 282 to the second protective member 216 side, that is, to the back surface side.

FIG. 7B is a cross-sectional view showing an outline when infrared light is incident on solar cell module 100 of the first embodiment shown in FIG. 2B. As shown in FIG. 7B, incident infrared light 80 is incident on the solar cell module 100. Specifically, the incident infrared light 80 is incident from the first protective member 12 side, that is, from the front surface side. At least a part of the incident infrared light 80 is transmitted through the solar battery cell 10 and is radiated as the transmitted infrared light 82 toward the second protective member 16 side, that is, the back surface side. On the other hand, the incident light scattering particles 20 in the second sealing member 18 scatter the reflected infrared light 84, which is a part of the infrared light transmitted through the solar cell 10, and guide it to the solar cell 10. To be done.

As described above, according to the solar cell module 100 according to the present embodiment, silica particles are dispersed in the second sealing member 18 arranged on the back surface side of the solar cell on which light can enter on both sides. Since it is included, the light scattering phenomenon of silica particles can be exhibited. Further, since the light scattering phenomenon of the silica particles occurs, the first protective member side incident light 30 incident between the adjacent solar battery cells 10 is controlled by the solar cell while suppressing the attenuation of the second protective member side incident light 32. Light can be guided to the cell 10. Further, since the attenuation of the second protective member side incident light 32 is suppressed and the first protective member side incident light 30 incident between the adjacent solar battery cells 10 is guided to the solar battery cells 10, the power generation efficiency is improved. Can be improved.

Moreover, since the second sealing member 18 contains the silica particles in a dispersed state, the procedure of locally collecting the silica particles can be omitted. Moreover, since the silica scattering particles are dispersed and contained in the second sealing member 18, the sheet of the second sealing member 18 including the silica particles can be used for manufacturing. Thereby, the manufacturing process can be simplified. Moreover, since the manufacturing process is simplified, it is possible to suppress an increase in manufacturing difficulty while improving power generation efficiency.

Further, since the silica particles are mixed so that the particle diameter d [μm] of the silica particles and the particle number density N [particles/mm ³ ] have a relationship of logN≦−2.2×logd+8.0, power generation is performed. The efficiency can be improved. Moreover, since the particle diameter d of the silica particles is 0.1 [μm] or more and 10 [μm] or less, the power generation efficiency can be improved. Further, by mixing the silica particles, the infrared light transmitted through the solar battery cell 10 can also be guided to the solar battery cell 10 side. Further, since infrared light is also guided to the solar battery cell 10 side, power generation efficiency can be improved.

The outline of the present embodiment is as follows. The solar cell module 100 according to the present embodiment is capable of allowing light to enter on both sides, and includes the solar cell 10 in which the front surface side electrode 40 and the back surface side electrode 42 are arranged on both sides, and one of the solar cell module 100. The first protection member 12 arranged on the surface side, the first sealing member 14 arranged between the first protection member 12 and the solar cell 10, and the other surface side of the solar cell 10 The second protection member 16 and the second sealing member 18 arranged between the second protection member 16 and the solar cell 10 are provided. The incident light scattering particles 20 are dispersedly contained in the second sealing member 18, and the second sealing member 18 transmits a part of the incident light and scatters another part of the incident light. Let

The incident light scattering particles 20 are silica particles, and the particle diameter d [μm] of the silica particles and the silica particle number density N [pieces/mm ³ ] have a relationship of logN≦−2.2×logd+8.0. You may.

The particle diameter d of the silica particles may be 0.1 [μm] or more and 10 [μm] or less.

(Embodiment 2)
Next, a second embodiment will be described. Similarly to the first embodiment, the second embodiment also relates to a solar cell module including a plurality of solar battery cells 10 and having incident light scattering particles mixed in the second sealing member 18. In the first embodiment, the relationship between the particle size and the particle number density of silica particles that are incident light scattering particles to be mixed in the second sealing member 18 is derived by simulation calculation. On the other hand, in the second embodiment, the ranges of transmittance and reflectance to be set are derived by experiments. The configuration of the solar cell module 100 according to the second embodiment is similar to that of the first embodiment, and therefore the description thereof is omitted here.

In this experiment, in addition to the solar cell module 100 according to the present embodiment, two types of solar cell modules to be compared are used. The configurations of the two types of solar cell modules to be compared are the same as those in FIG. 2A, but the materials used are different. First, these configurations will be described. In the first comparison target solar cell module (hereinafter, also referred to as “first comparative example”), a 3.2 mm glass substrate is used as the first protective member 212, and the first sealing member 214 and the first sealing member 214 are used. A 0.6 mm transparent EVA is used for the second sealing member 218, and a 0.11 mm transparent PET film is used for the second protective member 216. On the other hand, in the second comparative solar cell module (hereinafter, also referred to as “second comparative example”), the first protective member 212, the first sealing member 214, and the second protective member 216 are compared with each other in the first comparative example. Similar to the example. Further, a white EVA of 0.6 mm is used for the second sealing member 218.

The first protective member 12, the first sealing member 14, and the second protective member 16 in the solar cell module 100 (hereinafter, also referred to as “Example”) are the first protective member 212 and the first sealing member in the first comparative example. It is similar to the member 214 and the second protection member 216. The second sealing member 18 is made of 0.6 mm opaque EVA. Here, in the cloudy EVA, 1 vol% of silica particles having a particle diameter d=1 μm is mixed in the EVA. Note that the particle volume occupancy of 1 Vol% corresponds to a particle number density of 0.95×10 7, which is a value close to the optimum particle number density Nopt when the particle diameter d=1 μm.

The measurement is performed by irradiating the front surface side and the back surface side with the solar simulator light for the first comparative example, the second comparative example, and the example. The ratio of the amount of light incident from the front surface side to the amount of light incident from the back surface side is 1:0.1. Furthermore, the final output is derived by adding the output when light is incident from the front side and the output when light is incident from the back side. As a result, the output of the example increases by 1.4% with respect to the output of the first comparative example, and increases by 5.3% with respect to the output of the second comparative example.

In addition to the output measurement, the transmittance T and the reflectance R are also measured. Furthermore, T/(1-R) is calculated based on these. T/(1-R) is a value from the first protective member 12 to the second protective member 16 in the embodiment. FIG. 8 shows experimental results for the solar cell module 100 according to the second embodiment. In the first comparative example, the transmittance T is 80%, the reflectance R is 10.8%, and T/(1-R) is 89.7%. Further, in the second comparative example, the transmittance T is 0%, the reflectance R is 80%, and T/(1-R) is 0%. Further, in the example, the transmittance T is 68%, the reflectance R is 13.6%, and T/(1-R) is 78.7%. Therefore, in the embodiment, T/(1-R) should be 5% or more and 85% or less.

Further, the first protection member 12 and the first sealing member 14 in the example have the same configuration as the first comparative example, and it can be said that it is a part of the first comparative example. T/(1-R) in such part should be higher than T/(1-R) of the first comparative example as a whole. Therefore, T/(1-R) of at least one of the first protection member 12 and the first sealing member 14 is set to 85% or more.

According to the solar cell module 100 (Example) of the present embodiment, T/(1-R) from the first protective member to the second protective member 16 is incident such that T/(1-R) is 5% or more and 85% or less. Since the light scattering particles are mixed in the second sealing member 18, the power generation efficiency can be improved. Further, since T/(1-R) of at least one of the first protective member 12 and the first sealing member 14 is set to 85% or more, T from the first protective member 12 to the second protective member 16 is increased. It is possible to realize /(1-R) of 5% or more and 85% or less.

The outline of the present embodiment is as follows. When the transmittance is represented by T and the reflectance is represented by R, T/(1-R) from the first protective member 12 to the second protective member 16 may be 5% or more and 85% or less. ..

T/(1-R) of at least one of the first protection member 12 and the first sealing member 14 may be 85% or more.

(Modification)
Although the solar cell module according to the present invention has been described above based on the embodiment, the present invention is not limited to the above embodiment.

For example, in Embodiments 1 and 2, silica particles are used as the incident light scattering particles 20, but the present invention is not limited to this, and particles other than silica particles may be used, for example. According to this modification, the degree of freedom of the configuration can be improved.

In addition, it is realized by making various modifications to the above-described embodiment that a person skilled in the art can think of, and by arbitrarily combining the components and functions of the above-described embodiment without departing from the spirit of the present invention. The form is also included in the present invention.

10 solar cell 12 1st protection member 14 1st sealing member 16 2nd protection member 18 2nd sealing member 20 incident light scattering particles 30 1st protection member side incident light 32 2nd protection member side incident light 34 transmitted light 36 Scattered light 40 Surface side electrode (electrode)
42 Backside electrode (electrode)
100 solar cell module

Claims (7)

It is possible to enter light on both sides, and a solar cell in which electrodes are arranged on the both sides,
A first protective member that is disposed on one surface side of the solar cell and has a light-transmitting property,
A first sealing member arranged between the first protective member and the solar cell;
A second protective member that is disposed on the other surface side of the solar cell and has a light-transmitting property,
A second sealing member disposed between the second protection member and the solar cell,
Incident light scattering particles are dispersed and contained in the second sealing member,
The second sealing member transmits a part of both of the incident light of both the light transmitted through the first protective member and the light transmitted through the second protective member, and both of the incident light. A solar cell module that scatters other parts of incident light. The incident light scattering particles are silica particles,
The particle diameter d [μm] of the silica particles and the silica particle number density N [particles/mm ³ ] are
logN≦−2.2×logd+8.0
The solar cell module according to claim 1, having the following relationship. The solar cell module according to claim 2, wherein the particle diameter d of the silica particles is 0.1 [μm] or more and 10 [μm] or less. When the transmittance is represented by T and the reflectance is represented by R, T/(1-R) from the first protective member to the second protective member is 5% or more and 85% or less. The solar cell module described in 1. The solar cell module according to claim 4, wherein T/(1-R) of at least one of the first protection member and the first sealing member is 85% or more. The incident light scattering particles are silica particles.
The solar cell module according to any one of claims 1 to 5. The second sealing member is cloudy.
The solar cell module according to any one of claims 1 to 6.

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