Solar cell modules and solar power generation systems

Abstract

To provide a solar battery module and a photovoltaic power generation system capable of enhancing a filling factor of cells to a module area without using a dummy cell in a corner module.SOLUTION: In a solar battery module M1, a plurality of solar battery cells C are respectively connected in series to configure a plurality of cell groups CG. The plurality of cell groups CG are respectively connected by intermediate electrode wirings La to configure a plurality of strings S. The plurality of strings S are connected in parallel with each other. The solar battery cell C is a division cell. The numbers of cells in columns of the cell groups CG are all different. A difference in the number of cells in the column between the adjacent cell groups CG is not constant.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a solar cell module and a solar power generation system using the same. [Background technology]

[0002] In recent years, split cells have become mainstream in solar cell modules (for example, Patent Document 1). Here, split cells refer to small cells that are formed by splitting a standard-sized cell (a cell equivalent to one solar cell wafer, also called a full cell), such as a half cell that is a full cell split in half. With a half cell, the current value per cell can be halved compared to a full cell, and the power loss of the solar cell module can be reduced accordingly.

[0003] If a solar cell module formed by connecting multiple full cells in series has a current of 10A, to obtain the same current in a solar cell module using half cells, two strings of multiple half cells connected in series must be connected in parallel. In other words, since one string generates a current of 5A, a current of 10A can be obtained by connecting two strings in parallel.

[0004] A typical use of solar cell modules is to line up a number of modules on a roof or the like and connect them to form a solar power generation system. When installing a solar power generation system on a hipped roof or the like, a rectangular module is combined with a polygonal (e.g., pentagonal) corner module (e.g., Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-98931 A [Patent Document 2] Patent No. 2017-112175 Summary of the Invention [Problem to be solved by the invention]

[0006] In a solar power generation system, when connecting a rectangular module and a corner module, it is necessary to align the output characteristics of each module. In a corner module in which cells are arranged in a stepped pattern, the number of cells is adjusted to align the output characteristics, and if the area without cells becomes large, the cell packing rate relative to the module area appears low, which can cause a problem in that it is not aesthetically pleasing.

[0007] Patent Document 2 discloses a corner module in which dummy cells are placed in the empty areas (areas where no cells are placed) of the corner module to prevent deterioration of the aesthetic appearance. However, providing dummy cells that do not contribute to power generation is disadvantageous in terms of cost.

[0008] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a solar cell module and a solar power generation system that can increase the cell filling rate relative to the module area without using dummy cells in the corner module. [Means for solving the problem]

[0009] In order to solve the above problems, a solar cell module according to a first aspect of the present invention is characterized in that a plurality of solar cell groups are formed by connecting a plurality of solar cell cells in series, the plurality of cell groups are connected by intermediate electrode wiring to form a plurality of strings, the plurality of strings are connected in parallel, the solar cell is a divided cell, the number of cells in each row of the cell groups is all different, and the difference in the number of cells in adjacent rows of the cell groups is not constant.

[0010] According to the above configuration, in the corner module, the packing rate of the cells relative to the module area can be increased, and the aesthetic appearance of the solar cell module can be improved.

[0011] Moreover, in the solar cell module, the difference in the number of cells between adjacent cell rows can be within the number of full cells.

[0012] According to the above configuration, it is possible to prevent a large space exceeding the size of one full cell from being generated in an area where no cells are installed, and it is possible to further improve the aesthetic appearance of the solar cell module.

[0013] Moreover, in the solar cell module, the difference in the number of cells between the adjacent cell rows can be configured to be smaller than the number of full cells.

[0014] According to the above configuration, the areas in each row of the cell group where no cells are installed can be made closer to an even space, thereby further improving the aesthetic appearance of the solar cell module.

[0015] In order to solve the above problem, a solar cell module according to a second aspect of the present invention has a plurality of cell rows formed in a stepped shape, and a plurality of solar cell groups are formed by connecting a plurality of solar cell groups in series, and the plurality of cell groups are connected by intermediate electrode wiring to form a plurality of strings, and the plurality of strings are connected in parallel, the solar cell is a divided cell, and in at least one of the cell rows, string switching is performed midway, and in the cell row where string switching is performed, an end electrode wiring connected to an end of the string is arranged midway in the cell row.

[0016] Moreover, the solar cell module may be configured such that the number of cells in each of the strings is the same.

[0017] According to the above configuration, the voltages in the respective strings can be made the same, the occurrence of backflow between different strings can be avoided, and power loss can be effectively prevented.

[0018] In order to solve the above problems, a solar power generation system according to a third aspect of the present invention is a solar power generation system comprising a combination of a corner module and a rectangular module, characterized in that the corner module is the solar cell module described above.

[0019] In the above solar power generation system, the corner module and the rectangular module may be configured to use the same type of divided cells.

[0020] According to the above configuration, by using the same type of divided cells in the corner module and the rectangular module, the aesthetic appearance of the entire photovoltaic power generation system can be improved. Effect of the Invention

[0021] The solar cell module and solar power generation system of the present invention have the advantage that the cell packing rate relative to the module area can be increased in the corner module, thereby improving the aesthetic appearance. [Brief description of the drawings]

[0022] [Figure 1] 1 is a plan view illustrating a schematic example of a solar cell module according to a first embodiment. [Diagram 2] FIG. 4 is a plan view illustrating a schematic configuration of a modified solar cell module according to the first embodiment. [Diagram 3] FIG. 11 is a plan view illustrating a schematic example of a solar cell module according to a second embodiment. [Figure 4] 13 is a plan view showing an example of an arrangement of corner modules and rectangular modules in a solar power generation system according to a third embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] [First embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[0024] Fig. 1 is a plan view showing a schematic example of a solar cell module M1 according to the present embodiment. The solar cell module M1 is a corner module having a polygonal shape (pentagonal shape in this example) with right-angled corners and corners with angles other than right angles, and is configured with a plurality of cell rows formed in a stepped shape. Note that the solar cell module M1 shown in Fig. 1 may be configured so that the polarity is reversed.

[0025] The solar cell module M1 includes two strings connected in parallel to each other, namely, a first string S(1) and a second string S(2). The first string S(1) includes a plurality of cell groups CG(1,1) to CG(1,n1) (n1 is an integer of 2 or more). The second string S(2) includes a plurality of cell groups CG(2,1) to CG(2,n2) (n2 is an integer of 2 or more). In the solar cell module M1 shown in FIG. 1, n1=2 and n2=4. In the configuration of FIG. 1, each cell group CG configures a different cell row, and there is a one-to-one correspondence between the cell groups CG and the cell rows.

[0026] The cell groups in the first string S(1) and the second string S(2) are connected by intermediate electrode wiring La (bus bar). In each of the first string S(1) and the second string S(2), the solar cell cells C are connected in series. The intermediate electrode wiring La is an electrode wiring that connects the ends of the cell groups CG included in the same string.

[0027] More specifically, in the first string S(1) and the second string S(2), the solar cell C is arranged in a predetermined arrangement direction X. The first string S(1) and the second string S(2) are arranged side by side in the perpendicular direction Y. In each of the first string S(1) and the second string S(2), the cell groups CG(1,1) to CG(1,n1) and CG(2,1) to CG(2,n2) are arranged side by side in the perpendicular direction Y. The end electrode wiring Lb (bus bar) connected to at least one side of the cell groups CG(1,1) to CG(1,n1) and CG(2,1) to CG(2,n2) is provided at an end on at least one side in the arrangement direction X. In the example shown in FIG. 1, the end electrode wiring Lb connected to both sides of the cell groups CG(1,1) to CG(1,n1) and CG(2,1) to CG(2,n2) is provided at an end on one side (X1) in the arrangement direction X. The end electrode wiring Lb is an electrode wiring connected to the end of each string.

[0028] In the example shown in Fig. 1, the end electrode wiring Lb of the cell group CG(1,1) and the end electrode wiring Lb of the cell group CG(2,n2) are connected to a cathode connecting electrode wiring (not shown). The end electrode wiring Lb of the cell group CG(1,n1) and the cell group CG(2,1) are connected to an anode connecting electrode wiring (not shown). This results in a parallel connection of the first string S(1) and the second string S(2) in the solar cell module M1.

[0029] In this embodiment, the solar cell C in the solar cell module M1 is exemplified as a solar cell (full cell) substrate having a size of about 160 mm square divided into two. In other words, the solar cell C after division is a half cell having an overall size of about 160 mm x 80 mm square. Note that the specific configuration of each solar cell C and the connection configuration of the solar cell C in the cell groups CG(1,1) to CG(1,n1) and CG(2,1) to CG(2,n2) are publicly known, so detailed description will be omitted here.

[0030] In the solar cell module M1, the number of solar cell cells C in the first string S(1) on one side is equal to the number of solar cell cells C in the second string S(2) on the other side. In the example shown in FIG. 1, the number of cells in each of the first string S(1) and the second string S(2) is 22. In this way, by making the number of solar cell cells C equal in the first string S(1) and the second string S(2), it is possible to make the voltage of one string S(1) and the voltage of the other string S(2) the same. This makes it possible to avoid the occurrence of backflow between the one string S(1) and the other string S(2), and effectively prevent power loss.

[0031] Also, the solar cell module M1 has six cell rows, but the number of cells in each cell row is different, and the cells are arranged in a stepped manner so that the number of cells changes monotonically along the orthogonal direction Y. Specifically, the number of cells in the cell group CG(1,1) is 12, the cell group CG(1,n1) is 10, the cell group CG(2,1) is 8, the cell group CG(2,2) is 6, the cell group CG(2,3) is 5, and the cell group CG(2,n2) is 3. In the solar cell module M1 in the first embodiment, since the cell groups CG and the cell rows correspond one-to-one, the number of cells in each cell group CG is also used to mean the number of cells in each cell row.

[0032] In addition, in solar cell module M1, the difference in the number of cells between adjacent cell rows is not constant. Specifically, the difference in the number of cells between cell group CG(2,2) and cell group CG(2,3) is one, but the difference in the number of cells between the other adjacent cell rows is two.

[0033] In a corner module in which solar cell C are arranged in a stepped pattern, it is necessary to efficiently lay out the cells on the polygonal module surface and prevent deterioration of the aesthetic appearance. Furthermore, when multiple strings are connected in parallel in a corner module, it is necessary to align the voltage in each string (i.e., align the number of cells in each string). By varying the difference in the number of cells between adjacent cell strings rather than keeping it constant, it is possible to efficiently lay out the cells in accordance with the shape of the polygonal module surface.

[0034] In the solar cell module M1 according to the first embodiment, the difference in the number of cells between adjacent cell rows is not constant, and by arranging the cells so that the number of cells is different in all cell rows (no cell rows with the same number of cells exist), it is possible to increase the cell packing rate relative to the module area and improve the aesthetic appearance. Also, because the number of cells is different in all cell rows, it is possible to reduce the distance between the hypotenuse of the polygonal module and cell C at the end of the cell row, which increases the cell packing rate relative to the module area and increases the output of the module.

[0035] As a more preferable condition, in the solar cell module M1, the difference in the number of cells between adjacent cell rows is within one full cell (two half cells) at most. Also, the difference in the difference in the number of cells between adjacent cell rows is smaller than one full cell. In the example of FIG. 1, the difference in the number of cells between adjacent rows is two half cells at the most and one half cell at the least (between cell group CG(2,2) and cell group CG(2,3)), so the difference in the difference in the number of cells is one half cell. Furthermore, the location where the difference in the number of cells differs is not the end side but the inside in the arrangement direction (orthogonal direction Y) of the cell rows. In the example of FIG. 1, the location where the difference in the number of cells between adjacent rows differs is between cell group CG(2,2) and cell group CG(2,3). As a result, even if the difference in the number of cells between adjacent cell rows is not constant, the difference in the difference in the number of cells is less noticeable, and the cell packing rate relative to the module area can be increased, thereby improving the aesthetic appearance.

[0036] In addition, in solar cell module M1, it is preferable that the number of cells in the cell row with the smallest number of cells is greater than the maximum difference in the number of cells between adjacent cell rows. In the example of Fig. 1, the cell row with the smallest number of cells is cell group CG(2,n2), which has three cells. Meanwhile, the maximum difference in the number of cells between adjacent cell rows is two. With this cell arrangement, solar cell module M1 appears to have a high cell filling rate.

[0037] FIG. 2 is a plan view that shows a schematic diagram of a modified example of the solar cell module M1 according to the present embodiment. In the example of FIG. 2, the solar cell cells C are arranged so that the polarity of the second string S(2) is reversed from that of FIG. 1. In the example shown in FIG. 2, the end electrode wiring Lb of the cell group CG(1,1) and the end electrode wiring Lb of the cell group CG(2,1) are connected to a cathode connecting electrode wiring (not shown). The end electrode wiring Lb of the cell group CG(1,n1) and the end electrode wiring Lb of the cell group CG(2,n2) are connected to an anode connecting electrode wiring (not shown). The solar cell cells C may be arranged so that the polarity of the first string S(1) is reversed from that of FIG. 1.

[0038] [Embodiment 2] In the first embodiment, a solar cell module M1 using half cells as the solar cell C is exemplified. However, the present invention is not limited to this, and other divided cells can be used as the solar cell C. In the second embodiment, a solar cell module M2 using 1 / 3 cells as the solar cell C is exemplified. Fig. 3 is a plan view that shows a schematic example of a solar cell module M2 according to the present embodiment.

[0039] The solar cell module M2 includes three strings connected in parallel to each other, namely, a first string S(1), a second string S(2), and a third string S(3). The first string S(1) includes a plurality of cell groups CG(1,1) to CG(1,n1) (n1 is an integer of 2 or more). The second string S(2) includes a plurality of cell groups CG(2,1) to CG(2,n2) (n2 is an integer of 2 or more). The third string S(3) includes a plurality of cell groups CG(3,1) to CG(3,n3) (n3 is an integer of 2 or more). In the solar cell module M2 shown in FIG. 1, n1=2, n2=2, and n3=3.

[0040] The cell groups CG(1,1) to CG(1,n1), CG(2,1) to CG(2,n2), and CG(3,1) to CG(3,n3) are each connected by intermediate electrode wiring La (bus bar). In these cell groups, the solar cell C is connected in series.

[0041] In the example shown in FIG. 3, the end electrode wiring Lb of the cell group CG(1,n1), the end electrode wiring Lb of the cell group CG(2,n2), and the end electrode wiring Lb of the cell group CG(3,n3) are connected to the cathode connection electrode wiring (not shown). The end electrode wiring Lb of the cell group CG(1,1), the cell group CG(2,1), and the cell group CG(3,1) are connected to the anode connection electrode wiring (not shown). As a result, the first string S(1), the second string S(2), and the third string S(3) in the solar cell module M2 are connected in parallel. In the example shown in FIG. 3, the number of cells in each of the first string S(1), the second string S(2), and the third string S(3) is 24. In addition, in the example of FIG. 3, the solar cell C may be arranged so that the polarity is inverted in any of the first string S(1), the second string S(2), and the third string S(3).

[0042] In this way, when a divided cell formed by dividing a full cell into 1 / m (m is a natural number greater than or equal to 2) is used as the solar cell C, a solar cell module in which m strings are connected in parallel can obtain the same current as a solar cell module formed by connecting one full cell in series.

[0043] In a corner module, since the solar cell C is arranged in a stepped manner, it is not easy to align the number of cells in each string in a configuration in which one cell group corresponds to one cell row. This is all the more true when trying to increase the cell packing rate in the module. In contrast, the solar cell module M2 in FIG. 3 allows one cell row to include multiple cell groups, and adopts a configuration in which strings are switched in the middle of the cell row. Specifically, the second cell row from the right in FIG. 3 includes a cell group CG(1,n1) belonging to the first string S(1) and a cell group CG(2,1) belonging to the second string S(2), and switching is performed from the first string S(1) to the second string S(2). In the example of FIG. 3, there is only one cell row in which string switching is performed in the middle, but there may be two or more cell rows in which string switching is performed in the middle.

[0044] In addition, when string switching is performed in the middle of a cell row, at the string switching point in this cell row, the end electrode wiring Lb is arranged using an area of ​​one cell in the middle of the cell row, which makes it easy to align the number of cells in each string. In addition, in a cell row where string switching is performed in the middle and the end electrode wiring Lb is arranged in the middle, the arrangement area of ​​the end electrode wiring Lb is also counted as the apparent number of cells. That is, in the cell row second from the right in Figure 3, the number of solar cell cells C actually arranged is 15, but the number of cells in this cell row is counted as 16.

[0045] Third Embodiment In the third embodiment, an example of a solar power generation system configured by combining a corner module and a rectangular module will be described.

[0046] 4 is a plan view showing an example of the arrangement of a solar cell module M1, which is a corner module, and a solar cell module M3, which is a rectangular module, in a solar power generation system. The number and layout of the corner modules and rectangular modules used in the solar power generation system according to the third embodiment are not particularly limited. However, the modules used in the solar power generation system are connected in series with each other, and the system currents in the modules need to be the same (for example, 10 A).

[0047] 4 uses half cells as solar cell C, and uses two strings in parallel, each string being made up of a plurality of half cells connected in series. Note that detailed explanations of the layout of the strings and electrode wiring within the solar cell module M3 will be omitted.

[0048] In a solar power generation system, when half cells are used in a rectangular module, it is preferable to also use half cells in a corner module, since this improves the aesthetic appearance of the solar power generation system. This is not limited to half cells, and it is preferable to use the same type of solar cell in the rectangular module and the corner module. For example, the solar cell used in both the rectangular module and the corner module may be 1 / 3 cells.

[0049] However, the present invention is not limited to this, and the solar cells used in the rectangular module and the corner module may be different. For example, the corner module may use half cells, and the rectangular module may use full cells. Even in this case, the current must be the same between the corner module and the rectangular module, so the corner module must use two half cells in parallel, and the rectangular module must use one full cell in series.

[0050] The embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present invention is not interpreted solely by the above-described embodiments, but is defined by the claims. Also, all modifications within the scope and meaning equivalent to the claims are included. [Explanation of symbols]

[0051] C. Solar cell CG Cell Group La Intermediate electrode wiring Lb end electrode wiring M1~M3 Solar cell modules S String

Claims

1. The solar cell array has a plurality of cell rows formed in a stepped shape, and a plurality of solar cell groups are formed by connecting the plurality of solar cell groups in series, and the plurality of cell groups are connected by intermediate electrode wiring to form a plurality of strings, and the plurality of strings are connected in parallel, The solar cell is a divided cell, The number of cells in each cell row is different; A solar cell module, characterized in that the difference in the number of cells between adjacent cell rows is not constant.

2. The solar cell module according to claim 1 , A solar cell module, characterized in that the difference in the number of cells between adjacent cell rows is within the number of full cells.

3. The solar cell module according to claim 1 or 2, A solar cell module, characterized in that the difference in the number of cells between adjacent cell rows is smaller than that of one full cell.

4. The solar cell array has a plurality of cell rows formed in a stepped shape, and a plurality of solar cell groups are formed by connecting the plurality of solar cell groups in series, and the plurality of cell groups are connected by intermediate electrode wiring to form a plurality of strings, and the plurality of strings are connected in parallel, The solar cell is a divided cell, A solar cell module characterized in that in at least one of the cell rows, string switching is performed midway, and in the cell row where string switching is performed, end electrode wiring connected to the end of the string is arranged midway through the cell row.

5. The solar cell module according to claim 1 , A solar cell module, characterized in that the number of cells in each of the strings is the same.

6. A solar power generation system comprising a combination of corner modules and rectangular modules, A photovoltaic power generation system, wherein the corner module is the solar cell module according to any one of claims 1 to 5.

7. The solar power generation system according to claim 6, A solar power generation system, wherein the corner module and the rectangular module use the same type of divided cells.

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