Method of arranging solar cell modules and solar cell array

Abstract

To provide an arrangement method of a solar cell module, and a solar cell array, which are capable of alleviating a decrease in power generation amount even when other adjacent solar cell modules, etc., become a sunlight shield.SOLUTION: Provided is an arrangement method of a solar cell module, the solar cell module including; a plurality of solar cells, at least some of which are connected in series; a wiring material that is disposed in contact with a light-receiving surface of the solar cells, that collects current in each of the solar cells, and that is filamentous with a cross-sectional shape of one of a perfect circular shape, an elliptical shape, and an oval shape; and a translucent protective member provided on a light-receiving side of the solar cells and covering the wiring material. When the solar cell module is arranged in a structure, the solar cell module is arranged such that a direction in which the wiring material extends is along a direction in which a horizontally long shield extends, in an arrangement condition where there is the shield so that shadows cast on a solar cell located at an end portion of the plurality of solar cells depending on the angle of incidence of sunlight with respect to the solar cell module.SELECTED DRAWING: Figure 5B

Description

Technical Field

[0001] The present invention relates to a method for arranging solar cell modules and a solar cell array.

Background Art

[0002] Conventionally, a plurality of solar cell modules arranged on the roof of a house or the like have been proposed (Patent Document 1). Each solar cell module includes a glass substrate, a plurality of solar cells provided on the glass substrate, and a frame portion provided on the outer peripheral edge.

[0003] In this solar cell module, there is a case where sunlight is blocked from some solar cells by other adjacent solar cell modules or the like. In such a case, the solar cells whose sunlight is blocked become resistors in the solar cell module, and there is a possibility that the power generation efficiency of the entire solar cell module, including the solar cells whose sunlight is not blocked, may decrease. On the other hand, in this solar cell module, the solar cells that may be blocked by sunlight are configured to have a wider width than other solar cells.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, with such a configuration, since the types of solar cells included in the solar cell module increase, there is a risk that the manufacturing cost of the solar cell module may increase.

[0006] An object of the present invention is to provide a method for arranging solar cell modules and a solar cell array that can mitigate a decrease in power generation even when other adjacent solar cell modules or the like become sunlight blockers. [Means for solving the problem]

[0007] The present invention provides a method for arranging a solar cell module, which comprises a plurality of solar cells, at least a portion of which are connected in series; a linear wiring material having a circular, elliptical, or oblong cross-section, arranged in contact with the light-receiving surfaces of the plurality of solar cells and performing current collection at each of the plurality of solar cells; and a transparent protective material provided on the light-receiving surface side of the plurality of solar cells and covering the wiring material. When arranging the solar cell module in a structure, the arrangement conditions are such that, depending on the angle of incidence of sunlight on the solar cell module, a horizontally elongated shield exists such that a shadow falls on the solar cells located at the ends of the plurality of solar cells, and the solar cell module is arranged so that the direction in which the wiring material extends is aligned with the direction in which the shield extends.

[0008] In this configuration, the wiring material has a curved outer surface because its cross-sectional shape is either circular, elliptical, or oblong. Therefore, in the solar cell, light reflected from the outer surface of the wiring material, or light reflected from the outer surface of the wiring material and then re-reflected from the surface of the protective material, can reach areas that would otherwise be shaded by the shielding material if direct light were present. This reduces the effect of shading by reflected light. As a result, the resistance for other solar cells connected in series that are not shaded is reduced, and the overall power generation of the solar module can be increased. In this way, the reduction in power generation due to shielding in the solar module can be mitigated.

[0009] Furthermore, in the arrangement method of the solar cell module, multiple wiring materials may be arranged parallel to each other in directions approaching or moving away from the shielding object.

[0010] With this configuration, since multiple wiring materials are provided in parallel, if a solar cell located at the edge of the multiple solar cells is shaded, at least one of the multiple wiring materials located in the region close to the shade, and which is exposed to sunlight, can be used for re-incidence into the shaded region.

[0011] Furthermore, in the solar cell module, the solar cell module may have a substantially rectangular shape in plan view, and the wiring material may be arranged in a direction along the long side of the solar cell module.

[0012] With this configuration, reflection from the wiring material can be utilized along the long side of the solar cell module, thus more effectively reducing the effects of shading.

[0013] The solar cell array of the present invention is a solar cell array composed of a plurality of solar cell modules, each having a plurality of solar cells that are at least partially connected in series, a linear wiring material having a circular, elliptical, or oblong cross-section that is arranged in contact with the light-receiving surface of the plurality of solar cells and collects current from each of the plurality of solar cells, and a transparent protective material that is provided on the light-receiving surface side of the plurality of solar cells and covers the wiring material, wherein in two adjacent solar cell modules, the other solar cell module is positioned on the side closer to the trajectory of the sun's movement in the air and above the other solar cell module, so that depending on the angle of incidence of sunlight on the solar cell array, the other solar cell module is positioned so that the solar cells located at the ends of the plurality of solar cells are shaded, and the direction in which the wiring material extends is along the direction in which the other solar cell module extends.

[0014] In this configuration, the wiring material has a curved outer surface because its cross-sectional shape is either circular, elliptical, or oblong. Therefore, in the solar cell, light reflected from the outer surface of the wiring material, or light reflected from the outer surface of the wiring material and then re-reflected from the surface of the protective material, can reach areas that would otherwise be shaded by the shielding material if direct light were present. This reduces the effect of shading by reflected light. As a result, the resistance for other solar cells connected in series that are not shaded is reduced, and the power generation of the entire solar module can be increased. In this way, the reduction in power generation due to shielding in a solar cell array can be mitigated.

[0015] Furthermore, in the solar cell array, multiple wiring materials may be arranged parallel to each other in directions approaching or moving away from the other solar cell module.

[0016] With this configuration, since multiple wiring materials are provided in parallel, if a solar cell located at the edge of the multiple solar cells is shaded, at least one of the multiple wiring materials located in the region close to the shade, and which is exposed to sunlight, can be used for re-incidence into the shaded region.

[0017] Furthermore, in the solar cell module, the solar cell module has a substantially rectangular shape in plan view, and the wiring material is arranged in a direction along the long side of the solar cell module.

[0018] With this configuration, reflection from the wiring material can be utilized along the long side of the solar cell module, thus more effectively reducing the effects of shading. [Effects of the Invention]

[0019] Based on the above, the present invention provides a method for arranging solar cell modules and a solar cell array that can mitigate the reduction in power generation even when adjacent solar cell modules or the like act as shields from sunlight. [Brief explanation of the drawing]

[0020] [Figure 1] FIG. 1 is a schematic side view of the installation state of the solar cell array according to the present embodiment. [Figure 2] FIG. 2 is a schematic plan view of the solar cell module according to the present embodiment. [Figure 3] FIG. 3 is a schematic enlarged cross-sectional view of the solar cell module of FIG. 2. [Figure 4A] FIG. 4A is an enlarged view of the region indicated by IV in FIG. 3 and is an enlarged view for explaining the light L1. [Figure 4B] FIG. 4B is an enlarged view of the region indicated by IV in FIG. 3 and is an enlarged view for explaining the light L2. [Figure 5A] FIG. 5A is a diagram for explaining the effect of the solar cell module and is a schematic plan view of the solar cell module according to the comparative example. [Figure 5B] FIG. 5B is a diagram for explaining the effect of the solar cell module and is a schematic plan view of the solar cell module.

Embodiments for Carrying Out the Invention

[0021] Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 5B.

[0022] As shown in FIG. 1, the solar cell array 100 of the present invention is configured by combining a plurality of solar cell modules 1. The solar cell array 100 of the present embodiment is configured by combining three solar cell modules 1, but two or four or more solar cell modules 1 may be combined. Further, the solar cell array 100 is disposed on a structure C such as a roof of a building or a pedestal for ground grounding.

[0023] In this solar cell array 100, as shown in the partially enlarged view of Figure 1, in two adjacent solar cell modules 1, the other solar cell module 12 (solar cell module 12 in the figure) is positioned above the other solar cell module 12 (solar cell module 12 in the figure) relative to the trajectory of the sun as it moves through the air (on the left side in the figure). As a result, depending on the angle of incidence of sunlight on the solar cell array 100, the other solar cell module 12 is positioned such that it casts a shadow on the solar cell 2 located at the end (left end in the figure) of the multiple solar cell 2. Specifically, in the Northern Hemisphere, when the solar cell array 100 is installed with the solar cell modules 1 facing north, as shown in the figure (on the north side of a gable roof), direct sunlight is blocked by the solar cell module 12 located above it, causing a shadow to be cast on the eaves side of the solar cell module 12, and this shadow may fall on the ridge side of the solar cell module 11 located below it.

[0024] Each solar cell module 1, as shown in Figures 2 and 3, comprises a plurality of solar cells 2 (20 in this embodiment) that are at least partially connected in series, a linear wiring material 3 with a circular cross-section that is arranged in contact with the light-receiving surfaces 20 of the plurality of solar cells 2 and collects current from each of the plurality of solar cells 2, and a transparent protective material 4 that is provided on the light-receiving surface 20 side of the plurality of solar cells 2 and covers the wiring material 3. The solar cell module 1 is also plate-shaped. The cross-sectional shape of the wiring material 3 may be elliptical or oblong, in addition to circular. Furthermore, the direction in which the wiring material 3 extends is aligned with the direction in which the other solar cell module 12 extends. In this embodiment, the direction in which the other solar cell module 12 extends will be described as the horizontal direction, and the direction in which adjacent solar cell modules 11 and 12 are arranged will be described as the vertical direction.

[0025] The protective material 4 is made of, for example, a transparent, rigid material. The protective material 4 is a plate-shaped member, specifically a glass plate. The thickness of the protective material 4 is, for example, 2 mm to 8 mm. In the solar cell module 1 of this embodiment, the protective material 4 is provided only on the surface (light-receiving surface) 20 of the solar cell 2 (see Figure 3). In this case, a resin sheet 6 is provided on the back surface 21 of the solar cell 2. The protective material 4 may also be provided on both the light-receiving surface 20 (front surface 20) and the back surface 21 of the solar cell 2.

[0026] The solar cell 2 is, for example, a rectangular plate. Furthermore, the solar cell 2 is a crystalline solar cell. In the solar cell module 1 of this embodiment, each solar cell 2 provided in the solar cell module 1 is the same in size and shape.

[0027] The wiring material 3 is a component that collects current from each solar cell 2. Current is also collected from the busbar electrodes by the wiring material 3. In this embodiment, the wiring material 3 is placed in contact with the light-receiving surface 20 of the solar cell 2 and is embedded in the sealing material 5. Furthermore, on the light-receiving surface 20, the wiring material 3 is provided so as to intersect with the finger electrodes (not shown). The wiring material 3 may be provided only on the solar cell 2, or it may connect adjacent solar cells 2 among a plurality of solar cells 2. Furthermore, the wiring material 3 may be provided across a plurality of solar cells 2. When the wiring material 3 is provided only on each solar cell 2, the wiring material 3 of each solar cell 2 is connected by an interconnector (connecting material).

[0028] In this embodiment, the wiring material 3 connects adjacent solar cells 2 in the lateral direction. In this embodiment, four wiring materials 3 are arranged for each solar cell 2. However, the number of wiring materials 3 for each solar cell 2 may be other than four, and the number is not limited.

[0029] Furthermore, if the cross-sectional shape of the wiring material 3 is elliptical or oblong, it is preferable that the wiring material 3 be arranged so that its longitudinal direction in a cross-sectional view is aligned with the vertical direction in order to reduce the area over which the wiring material 3 covers the solar cell 2.

[0030] The lateral ends of the wiring material 3 provided on a row of solar cells 2 are each connected to a current collector member 7 that extends laterally. The current collector member 7 is a component that collects the current collected by multiple wiring materials 3 in multiple solar cells 2, and extends, for example, in the vertical direction. The wiring material 3 is made of a metal such as copper or aluminum. The diameter of the cross-section of the wiring material 3 is 0.2 to 0.5 mm. In addition, the outer surface 30 of the wiring material 3 is a glossy surface that reflects light.

[0031] If the cross-sectional shape of the wiring material 3 were rectangular, the top surface of the outer surface of the wiring material 3 would be a plane facing upwards. Therefore, the light reflected by the outer surface 30 of the direct light would travel forward (to the right in Figure 3), and in the solar cell 2, the reflected light would not reach the part P that is shaded by the other solar cell module 12. In contrast, in the solar cell array 100, the outer surface 30 of the wiring material 3 is curved. Therefore, in the solar cell 2, as shown in Figure 4A, the light L1 reflected by the outer surface 30 of the wiring material 3 travels backward (to the left in the figure). Also, as shown in Figure 4B, the light L2 that is reflected by the outer surface 30 of the wiring material 3 and then re-reflected by the surface 40 of the protective material 4 travels backward (to the left in the figure). Therefore, when direct light is incident, the portion P that is shaded by the other solar cell module 12 can be made to receive either light L1 reflected from the outer surface 30 of the wiring material 3, or light L2 that is reflected from the outer surface 30 of the wiring material 3 and then re-reflected from the surface 40 of the protective material 4.

[0032] Furthermore, even if the outer surface 30 of the wiring material 3 is curved, as shown in Figure 5A, if the direction in which the wiring material 3 extends is perpendicular to the direction in which the other solar cell module 12 extends (the vertical direction shown), then in the light reflected by the outer surface 30 of the direct light having a downward vector shown, there will be a large component that travels downward (in the direction of the eaves in the example of Figure 1).

[0033] Furthermore, for a rectangular solar cell module, as shown in Figure 2, if the direction in which the wiring material 3 extends is aligned with the longitudinal direction of the solar cell module 12, the wiring material 3 becomes longer, and its resistance (electrical resistance) increases. Therefore, according to the usual knowledge of those skilled in the art, it is chosen to wire in the short direction of the solar cell module. The reason for this is that, in particular, when using linear wiring material 3, the cross-sectional area may be larger than when using rectangular wiring material (flat tab wiring material) with a thin cross-section, and in this case, the influence of the length of the wiring material 3 on the resistance becomes even greater. In addition, the rated output of a solar cell module is to be determined under standard test conditions that are free from the effects of shading. For this reason, it has been considered more important to reduce the resistance of the wiring material 3 and improve the rated output than to mitigate the effects of shading in actual installation environments.

[0034] In contrast, in the solar cell array 100, the direction in which the wiring material 3 shown in Figure 5B extends is aligned with the direction in which the other solar cell module 12 extends (lateral direction). Therefore, when direct light with a downward vector is reflected by the outer surface 30, a larger component of the light travels upward (in the example of Figure 1, in the direction of the roof). As a result, the effect of shading can be reduced by the reflected light (lights L1 and L2). In this way, in the solar cell module 11, the resistance is reduced not only for the shaded solar cell 2 but also for the other multiple unshaded solar cells 2 connected in series, thereby increasing the power generation of the entire solar cell module 11. This mitigates the decrease in power generation caused by the other solar cell module 12 in the solar cell array 100.

[0035] The solar cell module 1 of this embodiment includes a transparent sealing material 5 provided between the solar cell 2 and the protective material 4 (see Figure 3). Furthermore, the arrangement of the solar cell module 1 is such that when the solar cell module 12 is placed in the structure C, the other solar cell module 11 is positioned such that, depending on the angle of incidence of sunlight on the solar cell module 1, the solar cell 2 located at the end (for example, the end located on the upper side in Figure 5B) of the multiple solar cell 2 is shaded.

[0036] The solar cell module 1 has a roughly rectangular shape when viewed from above (see Figure 2). The wiring material 3 is arranged along the long side of the solar cell module 1. When multiple of these roughly rectangular solar cell modules 1 are arranged under the above arrangement conditions (specifically, with the long sides of adjacent solar cell modules 1 facing each other), shadows fall on the ends of the solar cell modules 1 in the short direction. In contrast, the solar cell array 100 can utilize reflection from the wiring material 3 along the long side of the solar cell module 1, thus more effectively reducing the effect of shading.

[0037] As shown in Figure 5B, multiple wiring materials 3 are arranged parallel to each other in the direction of approaching and moving away from the shield (the other solar cell module 12) (vertical direction). With this configuration, since multiple wiring materials 3 are provided in parallel, if a solar cell 2 located at the end of the multiple solar cell 2 in the direction of approaching and moving away from the other solar cell module 12 is shaded, at least one of the multiple wiring materials 3 located in the region close to the shade, and exposed to sunlight, can reflect the direct sunlight, and this wiring material 31 can be used for re-incidence into the shaded region.

[0038] The inventors of this application conducted simulations to reduce the effect of shading in this solar cell module 1. In this solar cell module 1, the radius of the wiring material 3 is 0.2 mm, and the thickness of the sealing material 5 from the surface 20 of the solar cell 2 (the dimension between the surface 20 of the solar cell 2 and the interface between the sealing material 5 and the protective material 4) is 1 mm. The angle of incidence of sunlight on the solar cell module 1 is 45°, and the dimension of the part P that is shaded by the shielding part (the other solar cell module 12) in the case of direct sunlight is 10 mm from the edge of the solar cell 2.

[0039] When examining the reflection trajectory of light striking each wiring material 3 in this solar cell module 1, it was found that sunlight incident on the wiring material 3 is reflected from the point where the light strikes the wiring material 3, then re-reflected at the interface between the sealing material 5 and the protective material 4, and then re-incidentated to the solar cell 2. Furthermore, when the distance from the edge of the solar cell 2 to the wiring material 31 closest to that edge is set to 11.11 mm, and the spacing between adjacent wiring materials 3 is set to 11.11 mm, it was found that among the direct light incident on the wiring material 3 closest to the area P shaded by the shielding part (the other solar cell module 12) in the case of direct light, the light whose re-incident position to the solar cell 2 is 1.11 mm to 11.11 mm away from the incident position becomes the incident light for the area P shaded by the shielding part (the other solar cell module 12) in the case of direct light.

[0040] The simulation results showed that 29.9% of the direct light incident on the wiring material 31 closest to the shaded area P was re-incident to the shaded area P of the solar cell 2. Furthermore, 2.0% of the direct light incident on the wiring material 3 second closest to the shaded area P was re-incident to the shaded area P of the solar cell 2. Additionally, 0.7% of the direct light incident on the wiring material 3 third closest to the shaded area P was re-incident to the shaded area P of the solar cell 2. Thus, in the solar cell 2, light incident on the wiring material 3 and reflected is re-reflected at the interface between the sealing material 5 and the protective material 4 before being re-incident, thus reducing the effect of shading.

[0041] The solar cell module arrangement method and solar cell array of the present invention are not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. For example, the configuration of one embodiment can be added to the configuration of another embodiment, and a part of the configuration of one embodiment can be replaced with the configuration of another embodiment. Furthermore, a part of the configuration of one embodiment can be deleted.

[0042] In the embodiments described above, direct sunlight reaching the solar cell module 1 was shielded by adjacent solar cell modules 12. However, it is also conceivable that the sunlight may be shielded by a horizontally elongated shield other than the solar cell modules 12. Even in this case, when arranging the solar cell module 1 in the structure C, the horizontally elongated shield should be positioned such that, depending on the angle of incidence of sunlight on the solar cell module 1, the solar cell 2 located at the end of the plurality of solar cells 2 is shaded. Furthermore, the solar cell module 1 should be positioned so that the direction in which the wiring material 3 extends is aligned with the direction in which the shield extends. In addition, it is preferable that multiple wiring materials 3 are arranged parallel to each other in directions approaching and moving away from the shield. [Explanation of Symbols]

[0043] 1...Solar cell module, 2...Solar cell, 3...Wiring material, 4...Protective material, 5...Sealing material, 6...Resin sheet, 7...Current collector, 11, 12...Solar cell module, 20...Surface (light-receiving surface), 21...Back surface, 30...Outer surface, 40...Surface, 100...Solar cell array, 101...Solar cell module, C...Structure, L1, L2...Light, P...Part

Claims

1. Multiple solar cells, at least partially connected in series, A wiring material is arranged so as to be in contact with the light-receiving surfaces of the plurality of solar cells and collects current from each of the plurality of solar cells, and is linear in shape with a cross-sectional shape of a circle, an ellipse, or an oblong shape, When arranging a solar cell module having a transparent protective material that covers the wiring material and is provided on the light-receiving surface side of the plurality of solar cells in a structure, Depending on the angle of incidence of sunlight on the solar cell module, the arrangement of the horizontally elongated shielding material is such that it casts a shadow on the solar cells located at the ends of the plurality of solar cells. Multiple wiring materials are arranged parallel to each other in directions approaching and moving away from the shielding object. The solar cell module is positioned such that the direction in which the wiring material extends is aligned with the direction in which the shielding material extends. The outer surface of the aforementioned wiring material is curved, Of the curved surfaces constituting the outer surface of the wiring material, the portion facing the light-receiving surface is in contact with the transparent sealing material. A method for arranging a solar cell module, wherein the wiring material allows light reflected from the outer surface of the wiring material, or light reflected from the outer surface of the wiring material and then re-reflected by the surface of the protective material, to reach the portion of the solar cell that is shaded by the shielding material.

2. The aforementioned solar cell module has a roughly rectangular shape in plan view, The method for arranging a solar cell module according to claim 1, wherein the wiring material is arranged in a direction along the long side of the solar cell module.

3. Multiple solar cells, at least partially connected in series, A solar cell array is formed by combining multiple solar cell modules, each having a linear wiring material with a circular, elliptical, or oblong cross-section, which is arranged in contact with the light-receiving surfaces of the plurality of solar cells and collects current from each of the plurality of solar cells, and a transparent protective material provided on the light-receiving surface side of the plurality of solar cells and covering the wiring material, In two adjacent solar cell modules, the other solar cell module is positioned on the side closer to the trajectory of the sun's movement in the air and above the other solar cell module, so that depending on the angle of incidence of sunlight on the solar cell array, the other solar cell module is positioned such that it casts a shadow on the solar cell cells located at the ends of the plurality of solar cells. Multiple wiring materials are arranged parallel to each other in directions approaching and moving away from the other solar cell module. The direction in which the wiring material extends is aligned with the direction in which the other solar cell module extends. The outer surface of the aforementioned wiring material is curved, Of the curved surfaces constituting the outer surface of the wiring material, the portion facing the light-receiving surface is in contact with the transparent sealing material. The wiring material allows light reflected from the outer surface of the wiring material, or light reflected from the outer surface of the wiring material and then re-reflected from the surface of the protective material, to reach the portion of the solar cell that is shaded by the other solar cell module, in a solar cell array.

4. The aforementioned solar cell module has a roughly rectangular shape in plan view, The solar cell array according to claim 3, wherein the wiring material is arranged in a direction along the long side of the solar cell module.

Images