Solar Cell Module and Photovoltaic Power Generator Using This

Abstract

A surface electrode (5) is installed on the light receiving surface of a solar cell element, the surface electrode (5) comprises three bus bar electrodes (5a) for extracting light-produced at the solar cell element to the outside and collecting finger electrodes (5b) connected to these bus bar electrodes (5a), and the bus bar electrodes (5a) are not less than 0.5 mm and not more than 2 mm in width and the finger electrodes (5b) are not less than 0.05 mm and not more than 0.1 mm in width. A high-efficient solar cell module can be obtained with substantially lowered resistance by increasing the number of bus bar electrode (5a) and thereby decreasing the lengths of the finger electrodes (5b).

Description

TECHNICAL FIELD [0001] The present invention relates to a solar cell module using solar cell elements including a surface electrode on the light receiving surface thereof and a photovoltaic power generator using this. BACKGROUND ART [0002] A solar cell is a device for converting energy of incident light into electrical energy. [0003] The major types of solar cells are classified into crystalline, amorphous and compound types. Most of the solar cells that are currently distributed in the market are crystalline silicon solar cells. The crystalline silicon solar cells are further classified into monocrystalline type and multicrystalline type. An advantage of monocrystalline silicon solar cells is that improvement of the conversion efficiency is easy because of the high quality of the substrates, while a disadvantage thereof is high production cost of the substrates. [0004] On the other hand, multicrystalline silicon solar cells have a drawback that improvement of the conversion efficie...

AI Technical Summary

Benefits of technology

[0045] With this structure, while in the case of two bus bar electrodes, when the widths of the finger electrodes are narrowed for preventing light energy loss at the light receiving surfaces of the solar cell elements, the fill factor FF tends to deteriorate due to the series resistance component in the finger electrodes, providing three bus bar electrodes allows the lengths of the finger electrodes to be shortened, so that deterioration of the fill factor FF due to the series resistance component of the finger electrodes can be suppressed. A solar cell module with high output characteristics and high efficiency can therefore be obtained.

[0073] In addition, by determining the widths of the wiring members to be not less than 0.8 mm and not more than 2.0 mm, the wiring members can be prevented from being noticeable.

Problems solved by technology

An advantage of monocrystalline silicon solar cells is that improvement of the conversion efficiency is easy because of the high quality of the substrates, while a disadvantage thereof is high production cost of the substrates.

On the other hand, multicrystalline silicon solar cells have a drawback that improvement of the conversion efficiency is difficult due to inferior quality of the substrates, and an advantage that they can be produced at low cost.

However, a problem is that, in particular, when finger electrodes are thinned to decrease the electrode area, the resistance within the electrode increases, resulting in loss.

However, in reality, there is a limit to the thickness of electrodes when electrodes are formed by screen printing, and the desired thickness can only be obtained through a process including a plural times of printing, and by using expensive equipment, namely, that for sputtering or vapor deposition.

This leads to the problem of increase in solar cell production cost.

This is because even the silicon solar cell element that is dominant in the market produces only a low voltage on the order of 600 V when used as a single element and is not practical, the cells therefore need to be series connected to increase the voltage.

This difference in color is one factor to deteriorate the design quality of the solar cell module.

However, in such a case, the following problems arise: the cost for the glass material increases; large scale equipment is necessary for forming an antireflective film on the surface of the glass; and the production cost increases because the number of processes increases.

In addition, when irregularities are formed on the surface of the glass, dirt and dust tend to adhere to the solar cell module that is set outside due to exposure to the elements, which intercept the sunlight before it enters the solar cell module, causing the solar cell module to have degraded output characteristics.

Similarly, in the case of a solar cell module provided with an anti-glare film inside thereof, although the problem of light pollution can be prevented, additional materials are required and the production cost increases.

In addition, the effect to enhance light diffusion / reflection obtained by using white color for the filler member 10 or a back surface protective member 11 located on the back surface side of the solar cell elements of a solar cell module cannot be expected, which hinders improvement of the properties of the solar cell module.

However, since covering the surfaces of the wiring members 8 and connecting members 6 causes the problem of increase in material cost and the number of steps, and large scale equipment is required for forming a film on all of the solar cell elements connected through the wiring members 8, the production cost increases.

However, since this requires an additional step of coloring the translucent panel 9 and positioning between the translucent panel 9 that has predetermined, preliminarily colored regions and the solar cell elements connected through wiring members 8, the process becomes complicated.

In addition, the effect to enhance light diffusion / reflection obtained by using white color for the filler member 10 or the back surface material 11 located on the back surface side of the solar cell elements cannot be expected, hindering improvement of the properties of the solar cell module.

As described so far, despite the highmarket demand, it has been difficult to realize the production of a solar cell module with high efficiency and high design quality at low cost.

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