JP2009290037A - Solar cell module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide such a solar cell module having a high conversion efficiency that even a slanting light incident may be incident on a surface of a solar cell as vertically as possible, since if an angle of the light's incidence on the surface of the solar cell becomes greater, a reflection factor becomes greater to reduce the conversion efficiency. <P>SOLUTION: This concentrating solar cell module includes a first lens array 103 on one face of a transparent plate and a second lens array 104 on the other face of the transparent plate. An optical axis of each lens of the first lens array substantially coincides with an optical axis of each lens of the second lens array, and a solar cell 105 is provided coming into contact with a surface of the second lens array. Thus, the conversion efficiency rises irrespective of the angle of incidence and an incident location. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a concentrating solar cell module that can improve conversion efficiency.

  Solar cells are widely used in calculators, home roofs, cars, power plants and the like. In order to increase the conversion efficiency of a solar cell, it is important to reduce the reflectance of light on the surface of the solar cell and guide a large amount of light to the solar cell. If the angle at which light is incident on the surface of the solar cell increases, the reflectance increases and the efficiency decreases. It is desirable to convert light incident from an angle so that it is incident as close to the solar cell surface as possible.

  In order to improve the conversion efficiency, a solar cell is proposed in which a condenser lens is provided to improve the efficiency (see Patent Document 1 and Patent Document 2). However, with the condenser lens alone, if the incident angle of light increases to some extent, the incident angle to the surface of the solar cell also increases and the reflectance increases.

  Therefore, a module has been proposed in which an optical element as shown in FIG. 5 is installed on the surface of the solar cell to further improve the conversion efficiency (see Patent Document 3). In FIG. 5, 501 is an optical element, 502 is its optical axis, 503 and 504 are refractive surfaces, 505 is a solar cell, and 506 is a coating agent. Like the light ray A in FIG. 5, the light incident from an oblique direction is refracted by the refracting surfaces 503 and 504 so as to enter the solar cell 505 at a small angle. Therefore, the conversion efficiency can be increased.

However, the incident light such as the light beam B in FIG. 5 has a large incident angle with respect to the refractive surface 504 and the transmittance decreases. Further, if the incident angle becomes too large (generally about 45 degrees), light is not transmitted by total reflection. That is, the conversion efficiency decreases depending on the position where the light enters the refractive surface 503. Even if an antireflection film is provided on the refracting surface 504, there is a limit in reducing the reflectance over a wide angle range. A solar cell module with high conversion efficiency is required regardless of the incident position.
JP-A-6-37344 JP-A-8-330619 JP 2005-285948 A

  The present invention solves the above-described conventional problems, and an object thereof is to provide a solar cell module having high conversion efficiency regardless of an incident angle and an incident position.

  The solar cell module of the present invention has a first lens array on one side of a transparent plate, a second lens array on the other side of the transparent plate, and the optical axis of each lens of the first lens array The optical axes of the lenses of the second lens array are substantially coincident, and a solar cell is provided in contact with the surface of the second lens array. Thereby, it is possible to provide a concentrating solar cell module with high conversion efficiency regardless of the incident angle and the incident position.

  In the solar cell module of the present invention, the light incident on the first lens array is refracted and collected, and enters the second lens surface at a small angle. Since the solar cell is formed in contact with the second lens array, the incident angle is small and the conversion efficiency can be increased.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)

  FIG. 1 is a cross-sectional view of a solar cell module according to Embodiment 1 of the present invention. In FIG. 1, 101 is an optical element, 102 is an optical axis, 103 is a first lens array, and 104 is a second lens array. The optical axis of the first lens array 103 and the optical axis of the second lens array 104 are substantially coincident. Reference numeral 105 denotes a solar cell, which is installed in contact with the second lens array surface 104. Alternatively, a solar cell is formed directly on the surface 104. Thin film solar cells can be formed on curved surfaces such as 104.

  Although the incident positions on the first lens surface are different, the light rays A and B in FIG. 1 are both refracted by the lens surface 103 and collected toward the surface 104. Since the surface 104, that is, the surface of the solar cell also has a lens shape, the light rays A and B are incident on the solar cell at a small angle. Therefore, the reflectance is small and the conversion efficiency can be increased.

  Also in the case of providing an antireflection film between the second lens array and the solar cell, it is not necessary to consider a very wide range of angles, so that film design and film formation are relatively easy.

FIG. 2 is a perspective view of the solar cell module according to Embodiment 1 of the present invention. Both the first lens array and the second lens array are single lens arrays. In the configuration of FIG. 2, the conversion efficiency can be improved with respect to light incident from any direction of east, west, south, and north.
(Embodiment 2)

FIG. 3 is a perspective view of the solar cell module according to Embodiment 2 of the present invention. Both the first lens array and the second lens array are arrays of cylindrical lenses. In the configuration of FIG. 3, the conversion efficiency can be improved with respect to light incident from any direction of east and west. Although there is no effect on the change of incident light in the north-south direction, the conversion efficiency can be improved as compared with a simple planar solar cell.
(Embodiment 3)

  Similarly to the conventional FIG. 5, a coating agent can be provided on the surface of the first lens array. In FIG. 4, sectional drawing of the solar cell module of Embodiment 3 is shown. In FIG. 4, the same components as those in FIG. 106 is a coating agent. If the optical element 101 is made of polycarbonate, the refractive index is about 1.58. In that case, PMMA or the like can be used as the coating agent, and the refractive index is about 1.5. As shown in rays A and B in FIG. 4, the conversion efficiency can be improved by reducing the incident angle on the surface of the solar cell as in FIG.

  The first to third embodiments disclosed above are merely examples of the present invention, and the present invention is not construed as being limited by these embodiments. The scope of the present invention is shown not by the above embodiments but by the scope of claims for patent, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims for patent.

  The field of application of the solar cell module of the present invention is not particularly limited, but is useful for solar cells installed on roofs, cars, and power plants in general homes. Moreover, since electric power can be obtained without worrying about the direction of light, it can be applied to portable devices such as a calculator.

Sectional drawing of the solar cell module in Embodiment 1 of this invention. The perspective view of the solar cell module in Embodiment 1 of this invention. The perspective view of the solar cell module in Embodiment 2 of this invention. Sectional drawing of the solar cell module in Embodiment 3 of this invention. Sectional drawing of the conventional solar cell module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Optical element 102 Optical axis 103 1st lens array 104 2nd lens array 105 Solar cell 106 Coating agent 501 Optical element 502 Optical axis 503 Refraction surface 504 Refraction surface 505 Solar cell 506 Coating agent

Claims (3)

A first lens array is provided on one side of the transparent plate, a second lens array is provided on the other side of the transparent plate, and an optical axis of each lens of the first lens array and each lens of the second lens array The solar cell module is characterized in that the optical axes of the solar cell module and the solar cell module are provided in contact with the surface of the second lens array. The solar cell module according to claim 1, wherein the first lens array and the second lens array are single lens arrays. The solar cell module according to claim 1, wherein the first lens array and the second lens array are cylindrical lens arrays.

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