JP2001111083A - Solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell module which can reduce an output degradation caused by a shadow of steps in the case of overlapping. SOLUTION: This device comprises solar cells 2 which are formed elongated, of which longitudinal direction rectanglarly crosses the longitudinal direction of an unit of a solar cell module 1, and which is provided in the longitudinal direction of the module unit in parallel, and the solar cells 2 are electrically connected with each other in series. Alternatively, the device comprises separated cell groups of the solar cells 2 of which adjacent solar cells 2 are electrically connected with each other in series.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horizontally elongated solar cell module laid on a roof or a wall of a building, and more particularly to a solar cell module laid in a stack like a tile. About what you did.

[0002]

2. Description of the Related Art As a horizontally long solar cell module laid on a roof or a wall of a building, as shown in FIG. 5, the longitudinal direction of a plurality of elongated solar cells 2 and the longitudinal direction of a module 7 are matched. , The plurality of solar cells 2
Are arranged in parallel in a direction orthogonal to the longitudinal direction, and there is a solar battery module configured by electrically connecting adjacent solar battery cells in series. In addition, a horizontally long solar cell module refers to a module that is laid in such a manner that the longitudinal direction of the module main body is aligned with the horizontal direction (hereinafter, appropriately referred to as “horizontal direction”).

When laying a large number of solar cell modules, it is general that the ends of the modules are butted to each other. Particularly, in the case of a solar cell module laid on a roof, an aesthetic appearance after the laying is obtained. In consideration of the effect, there is a case where the eaves-side end of the module adjacent to the ridge side is superimposed on the ridge-side end of the module like a roof tile, and is sequentially laid one upon another.

[0004]

However, when the horizontally long solar cell modules are laid one on top of the other as described above, as shown in FIG. Along the wing side, there is a horizontal shadow. The vertical length of the shadow changes depending on the altitude of the sun, the roof slope, and the height of the module in the tier, but the width (vertical length) of the solar cell is shorter than the length of the shadow. For example, no direct light of sunlight is incident on the solar cell closest to the water, and the solar cell becomes a resistance. The output of the whole module decreases.
In addition, the width of the solar cells must be as thin as 10 mm or less because it is necessary to increase the number of solar cells in series in order to secure an output voltage with respect to the limited module width (length in the vertical direction). If the height of the module in the stepped portion is about 20 mm, the influence of the above-mentioned shadow appears remarkably on the east and west sides when the roof surface is on the north side. Output drop occurs.

[0005] Such a situation is particularly problematic when the solar cell is made of amorphous silicon. This is because, in the process of manufacturing amorphous silicon, when a single thin film of amorphous silicon is divided into a plurality of solar cells by laser processing, the number of laser processing steps is reduced, and the manufacturing efficiency of the solar cell module is reduced. This is because, by dividing along the longitudinal direction, the longitudinal direction of the solar battery cell and the longitudinal direction of the solar battery module match. On the other hand, when using crystalline silicon, since the size of the solar cell is generally as large as 10 to 15 cm on a side, all of the solar cells on the most upstream side may be covered by the shadow of the step. Therefore, it can be said that the influence of the shadow is smaller than that in the case of amorphous silicon.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a horizontally long solar cell module capable of reducing a decrease in output due to a shadow of a stepped portion when stacked. It is in.

[0007]

A first feature of the solar cell module according to the present invention for achieving this object is to form a plurality of elongated solar cells as described in claim 1 of the claims. The solar cells are arranged in parallel in the longitudinal direction of the module main body with the longitudinal direction thereof and the longitudinal direction of the module main body orthogonal to each other, and the adjacent solar cells are electrically connected in series. It is in.

[0008] The second characteristic configuration is that, as described in claim 2 of the claims, a plurality of elongated solar cells are arranged so that the longitudinal direction thereof is perpendicular to the longitudinal direction of the module body. In this case, the plurality of solar cells are arranged in parallel in the longitudinal direction of the module main body, and the plurality of solar cells are divided into a plurality of cell groups in which the adjacent solar cells are electrically connected in series.

The operation and effect will be described below. According to the first or second characteristic configuration, when the solar cell modules are laid one on top of the other, only a part of the water side of each solar cell is covered by the shadow of the step, and the solar cell Some solar cells located on the water side are completely covered by the shadow of the step like the conventional horizontally long solar cell module where the longitudinal direction matches the longitudinal direction of the module body, and direct light enters. It is possible to avoid becoming a resistance without doing so. As a result,
It is possible to prevent the output of the entire solar cell module from decreasing more than the decrease in the amount of direct light received with respect to the entire amount of received light.

By the way, in the case of the first characteristic configuration, the cell width of the solar cell is smaller than that of a conventional horizontally long solar cell module in which the longitudinal direction of the solar cell coincides with the longitudinal direction of the module body. If they are the same, the total number of solar cells increases according to the aspect ratio of the entire light receiving portion.
For this reason, if all the solar cells are connected in series, the output voltage may be too high for a required voltage value. Therefore, even when the cell width is limited for the purpose of reducing the effect of the electric resistance of the transparent electrode, etc., according to the second characteristic configuration, the output voltage is determined by the number of series stages of each cell group. Therefore, when a plurality of solar cells are equally divided into a plurality of cell groups, the output voltage can be reduced to one-sixth of the output voltage when all the solar cells are connected in series. . When a plurality of solar cells are not equally divided into a plurality of cell groups, two or more types of output voltages can be set by cell groups having different numbers of series stages.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the solar cell module according to the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a solar cell module 1 according to the present invention is manufactured on the premise that the solar cell module 1 is laid one on top of another. The size of the working part exposed after laying is 439 x 9
10 mm, of which the overall size of the light receiving portion is 425 × 8
In the light receiving portion of 90 mm, the amorphous silicon solar cell 2 having 96 steps is divided and formed such that the longitudinal direction of the solar cell 2 is orthogonal to the longitudinal direction of the module main body of the solar cell module 1. The cell width of each solar cell 2 includes the space between adjacent cells,
9.27 mm. The height of the step is 20 mm.

As shown in FIG. 2, each solar cell 2 has a three-layer structure in which an amorphous silicon solar cell 3 is sandwiched between a transparent electrode 4 on the front side and a metal electrode 5 on the rear side. The end of one transparent electrode 4 of the battery cell 2 and the end of the other back metal electrode 5 are in contact with each other, and a total of 96 stages of solar cells 2 are connected in series. In FIG. 2, each solar cell 2 is shown upside down, and the upper direction in the figure indicates the solar cell module 1 at the time of laying.
On the back side of

In the method of manufacturing the solar battery cell 2, first, the transparent electrode 4 is formed into a thin film on the back side of the transparent glass substrate 6, and then the transparent electrode 4 is divided into 96 by laser processing. In this case, the width of the transparent electrode 4 is 9.2 including the cutting allowance.
7 mm. Subsequently, the amorphous silicon solar cell 3 is formed into a thin film on the back surface side of the divided transparent electrode 4, and then the amorphous silicon solar cell 3 is divided into 96 by laser processing. The cutting position at this time is
It is slightly shifted left or right from the cutting margin of the transparent electrode 4. Subsequently, after forming the back surface metal electrode 5 in a thin film shape on the back surface side of the divided amorphous silicon solar cell 3, the back surface metal electrode 5 is divided into 96 by laser processing. The cutting position at this time is shifted in the same direction as the cutting edge of the amorphous silicon solar cell 3 is slightly shifted.

After the solar cell 2 having 96 stages is manufactured and waterproofed in the above-described manner, a tile is formed of a plated steel plate around the periphery and on the side of the back metal electrode 5 and bonded and integrated with the solar cell.
The solar cell module 1 is completed by disposing the module frame 1b made of a synthetic resin backup material on the back surface.

The solar cell module 1 according to the present embodiment
According to the method for measuring the output of an amorphous solar cell module specified in IS-C-8935, the power generation amount is about 28 W under a standard condition of incident sunlight intensity of 1 kW / m ² and temperature of 25 ° C., and output voltage under load. Becomes about 60V.

Next, the solar cell module 1 of the present embodiment
Table 1 summarizes the results of trial calculations and simulations of the rate at which the annual power generation amount decreases due to the shadows of the steps when laid one on top of the other. The roof slope is 4.5
Dimensions and weather data used HASP (Dynamic air-conditioning load calculation program by computer) Osaka data from the Japan Society of Air Conditioning and Sanitary Engineers. The numerical values shown in Table 1 show the annual power generation when laying without step stacking in each roof orientation.
The figures show the respective annual power generation amounts when the value is set to 00.

In Table 1, the prototype pattern is an example of the above-described conventional horizontally long solar cell module, and as shown in FIG. 3, the outer shape of the solar cell module 7, the dimensions of the working portion, and the light receiving portion. The overall dimensions are exactly the same as the solar cell module 1 of the present embodiment, and
Amorphous silicon solar cells 2 having 48 stages are divided and formed with equal widths so that the longitudinal direction of the solar cells 2 coincides with the longitudinal direction of the module main body of the solar cell module 7. The cell width of each solar cell 2 of the prototype pattern is 8.85 m including the space between adjacent cells.
m. Each solar cell 2 has a three-layer structure in which an amorphous silicon solar cell is sandwiched between a transparent electrode on the front side and a rear metal electrode on the back side. The structure and manufacturing method of each solar cell 2 are cell width and number of stages. Are the same as the present embodiment except for the difference. An end of one transparent electrode of two adjacent solar cells 2 and an end of the other back metal electrode are in contact with each other, and a total of 48 stages of solar cells 2 are connected in series.

[0019]

[Table 1]

From Table 1, it can be seen that, in the prototype pattern, when the roof orientation is east, west, or north, no measures have been taken to reduce the influence of the shadows of the steps, and the annual power generation has been greatly reduced. On the other hand, in the solar cell module 1 of the present embodiment, the decrease in the annual power generation when the roof orientation is east, west, and north is greatly improved, and is almost the same as when there is no stacking throughout the year. It can be seen that the power generation amount can be obtained.

Hereinafter, another embodiment will be described. <1> In the above embodiment, the 96-stage solar cell 2
Are connected in series, and the output voltage at the time of load is 60 V, but the solar cell module is exemplified. However, instead of connecting all of the solar cells 2 in series, for example, FIG.
As shown in FIG. 2, a configuration in which two groups of cells 8 formed by connecting 48 solar cells 2 in series are connected in parallel, or
A configuration may be used in which three groups of cells 9 each having 32 stages of solar cells 2 connected in series are connected in parallel. The output voltage under load is 30 V in the former case, and 2 V in the latter case.
It becomes 0V. However, the output current is equal to all the solar cells 2
, The former is doubled and the latter is 3 times
The power generation amount is the same, and the power generation amount is the same. The improvement effect on the decrease in the annual power generation amount shown in Table 1 above is the same even in the configuration in which the cells are divided into cell groups. The cell structure of each of the cell groups 8 and 9 in FIGS. 4A and 4B is basically the same as the structure shown in FIG. 2; Cross-sectional structure. Note that the number of cell groups may be four or more, and the number of series stages in each cell group may not necessarily be equal.

<2> In the above embodiment, the outer dimensions of the solar cell module 1, the dimensions of the entire light receiving portion, the total number of solar cells 2, the cell width, and the number of series stages are limited to the numerical values of the above embodiments. Not something. Therefore, the electrical characteristics of each solar cell module 1 are not limited to the above values.

<3> The solar cell 2 may be formed of a solar cell other than an amorphous silicon solar cell. The present invention is applicable to all horizontally long solar cell modules.

<4> In the above embodiment, the case where the solar cell module 1 is laid on the roof is assumed.
The place where the solar cell module 1 is laid is not limited to the roof, and may be laid on the outer wall of the building.

[Brief description of the drawings]

FIG. 1 is a plan view (a) and a side view (b) showing a configuration of a first embodiment of a solar cell module according to the present invention.

FIG. 2 is a perspective view showing a cell structure of a solar cell used in a solar cell module according to the present invention.

FIG. 3 is a plan view (a) and a side view (b) showing a configuration of an example (a prototype pattern) of a conventional solar cell module.

FIG. 4 is a circuit diagram schematically showing the configuration of another embodiment of the solar cell module according to the present invention. (A): When the number of cell groups is 2, (B): When the number of cell groups is 3

FIG. 5 is an explanatory view showing a state where conventional solar cell modules are laid one on top of the other;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solar cell module 1a Overlap part 1b Module frame 2 Solar cell 3 Amorphous silicon solar cell 4 Transparent electrode 5 Back metal electrode 6 Glass substrate 7 Conventional solar cell module (original pattern) 7a Overlap of conventional solar cell module Part 7b Module frame of conventional solar cell module 8, 9 cell group

Claims (2)

[Claims] 1. A plurality of elongated solar cells are arranged in parallel in the longitudinal direction of the module main body with the longitudinal direction thereof orthogonal to the longitudinal direction of the module main body,
A horizontally long solar cell module in which adjacent solar cells are electrically connected in series. 2. A plurality of elongated solar cells are arranged side by side in the longitudinal direction of the module main body, with the longitudinal direction thereof orthogonal to the longitudinal direction of the module main body,
A horizontally long solar cell module in which the plurality of solar cells are divided into a plurality of cell groups in which adjacent solar cells are electrically connected in series.