JP2011082256A - Photoelectric-conversion efficiency improving system for solar cell module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoelectric-conversion efficiency improving system for a solar cell module, capable of being provided at low cost using a simple constitution, while further improving the efficiency of a photoelectric conversion. <P>SOLUTION: In the solar cell module generates power, by arranging a plurality of silicon solar cells 1 in two dimensions, a light irradiating the outside at the ends of the solar cells is refracted by condensing means 2, disposed to upper parts at the positions of the ends of the adjacently disposed solar cells 1; and the condensing means are not arranged at positions opposed to the solar cells 1 on the light-receiving surfaces of the solar cells. In the solar cell module, the irradiating light is projected directly on the light-receiving surfaces of the solar cells. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a photoelectric conversion efficiency improvement system for a solar battery module, and in particular, by providing a special light collecting means only on the side of a solar battery cell, it can be provided at a low cost with a simple configuration, and photoelectric conversion is also provided. The present invention relates to a system for improving the photoelectric conversion efficiency of a solar cell module in which the efficiency is further improved.

Conventionally, in order to improve the photoelectric conversion efficiency of a solar cell module, in addition to improving the energy conversion efficiency of the solar cell, the surface reflection of the solar cell module is reduced, and the protective glass is improved. The surface reflection is reduced, and the light is condensed by a Fresnel lens.
For this reason, various proposals have been made such as a combination of a condensing lens that collects sunlight and a solar battery cell that generates power by the condensed sunlight.
For example, as shown in Patent Document 1, a Fresnel lens is used as a condensing lens for collecting sunlight, a silicon (Si) single crystal solar cell is used as a solar battery cell, and the Fresnel lens and the silicon single crystal solar battery cell are used. Proposed by interposing a transparent plate substrate between them, adhering multiple Fresnel lenses to the surface of the transparent plate substrate, and adhering multiple silicon single crystal solar cells to the back surface Has been.
Further, in the one shown in Patent Document 2, a prism sheet that deflects incident external light so that directivity in the thickness direction thereof is high, and light deflected by the prism sheet is incident and the incident light is incident. A Fresnel lens that collects light on the light receiving surface of the solar cell and a solar cell that converts light energy received by the light receiving surface into electrical energy are sequentially spaced from each other at a predetermined interval. The one configured to overlap is proposed.
Moreover, in what is shown to patent document 3, it arrange | positions so that the solar cell which receives solar energy and guide | induces the solar energy to a photovoltaic cell, and a photovoltaic cell may be piled up and down, and as this sunlight concentration device A Fresnel lens is used, and the surface curvature of the lens is divided into a plurality of parts, that is, a spherical part of the lens, a cylindrical part of the lens (one linear focal part), and an unpatterned part of the lens. Things have been proposed.

By the way, as shown in Patent Documents 1 to 3, in order to improve the photoelectric conversion efficiency of the conventional solar cell module, a Fresnel lens having a larger area than the surface area of the solar cell is disposed above the solar cell, and It arrange | positions so that the whole surface area of a photovoltaic cell may be covered, and it is comprised so that the electric power generation output per unit area of a photoelectric conversion element may be enlarged by improving condensing efficiency.
Since this Fresnel lens is formed by arranging only the curvatures of the lens on a plane, there is an advantage that a space and weight can be saved and a lens having a focal length shorter than the aperture can be made.

For this reason, the system which improves the photoelectric conversion efficiency of the conventional solar cell module is not particularly limited. For example, as shown in FIG. 6, the entire surface of the solar cell 1 is covered with a Fresnel lens L. Therefore, when all the sunlight passes through the Fresnel lens, the light is refracted and reaches the solar cell, so that the sunlight is attenuated when passing through the Fresnel lens, that is, passes through this Fresnel lens. The sunlight to be attenuated in proportion to the transmittance and the cosine of the refraction angle of the material constituting the lens.
In addition, the conventional solar cell module has a complicated configuration, and there is a limit in suppressing the unit price of the solar cell module. In particular, as shown in Patent Document 2, a prism sheet is further disposed above the Fresnel lens. Therefore, the structure is complicated and expensive, and the light attenuation rate is further increased due to the prism sheet.
Moreover, as shown in Patent Document 3, the solar light concentration device divides the surface curvature of the lens into a plurality of portions.

JP 2008-31408 A JP 2007-73774 A JP 2006-80524 A

  In light of the above-described problems of the conventional solar cell module photoelectric conversion efficiency improvement system, the present invention can be provided at a low cost with a simple configuration and further improve the photoelectric conversion efficiency. The purpose is to provide an efficiency improvement system.

  In order to achieve the above object, a photovoltaic conversion efficiency improvement system for a solar cell module according to the present invention is a solar cell module in which a plurality of silicon solar cells are two-dimensionally arranged to generate electric power, and the end portions of adjacent solar cells are arranged. The light condensing means disposed above the position refracts the light radiated to the outside of the solar cell end, and the light converging means is not disposed at the position facing the solar battery cell on the light receiving surface of the solar battery cell. It is characterized by being directly incident on the light receiving surface of the solar battery cell.

  In order to achieve the above object, a photovoltaic conversion efficiency improvement system for a solar cell module according to the present invention is a solar cell module that generates power by arranging a plurality of silicon solar cells in a two-dimensional manner. A condensing means is disposed above the end position to refract the light irradiated to the outside of the solar cell end, and irradiates the solar cell light receiving surface to the position facing the solar battery cell without providing the condensing means. The light is directly incident on the light receiving surface of the solar battery cell, and the light converging means is used to maintain the distance between the base for fixing the solar battery cell and the protective glass and to support the protective glass with the light collecting means. It is characterized in that it is also used in combination.

  In this case, the light condensing means can be disposed at the four peripheral ends of the adjacent solar cells.

  Further, the light condensing means can be a linear Fresnel lens.

  Further, the linear Fresnel lens can be formed on a spherical surface or a flat surface.

  According to the photoelectric conversion efficiency improvement system for a solar battery module of the present invention, in a solar battery module that generates power by arranging a plurality of silicon solar battery cells in a two-dimensional manner, the solar battery module is disposed above the end position of the adjacent solar battery cells. The light converging means refracts the light radiated to the outside of the solar cell end, and the light converging means is not disposed at the position facing the solar battery cell on the solar cell light receiving surface, and the light radiated is received by the solar cell light receiving surface. In the position facing the solar battery cell, the incident light is not attenuated at the position facing the solar battery cell, and the incident light can be refracted toward the solar battery cell at the side position of the solar battery cell. Since the light can enter the solar cell light receiving surface, the efficiency of photoelectric conversion can be improved by a simple and inexpensive method.

  Further, in a solar cell module that generates power by arranging a plurality of silicon solar cells in a two-dimensional manner, a condensing means is disposed above the end position of the adjacent solar cells and irradiated to the outside of the solar cell end. The light is refracted and the concentrating means is not provided at the position facing the solar cell on the light receiving surface of the solar cell, so that the irradiated light is directly incident on the light receiving surface of the solar cell and the solar cell is fixed. By keeping the distance between the base portion to be protected and the protective glass constant and also using the passivation process for supporting the protective glass as the condensing means, the incident light is attenuated at the position facing the solar cells. In addition, the incident light can be refracted to the solar cell side at the side position of the solar cell, and can enter the solar cell light receiving surface, so that the efficiency of photoelectric conversion can be improved by a simple and inexpensive method. It is possible to above the protective glass at passivation treatment, condensing unit, the solar cell module by integrating the solar cell or the like can be firmly formed.

  Further, by arranging the condensing means at the four peripheral ends of the adjacent solar cells, the light irradiated to the four peripheral ends of the solar cells can also be efficiently collected on the solar cell light receiving surface. Can be lighted.

  In addition, by using a linear Fresnel lens as the light condensing means, it is possible to condense light in a slit shape on only one side, so that the light irradiated to the end portion of the solar cell is efficiently put on the light receiving surface of the solar cell. It can be condensed.

  In addition, by forming the linear Fresnel lens on a spherical surface or a flat surface, the light irradiated to the end portion of the solar battery cell can be efficiently condensed according to the purpose.

It is explanatory drawing which shows 1st Example of the photoelectric conversion efficiency improvement system of the solar cell module of this invention. A linear Fresnel lens is shown, (A) is an explanatory diagram showing the refraction of light when the lens processing is a spherical surface, (B) is the light when the lens processing is processed to have a triangular or trapezoidal cross section on a plane. It is explanatory drawing which shows refraction of. It is an Example at the time of arrange | positioning a condensing means in two directions so that the four periphery of an adjacent photovoltaic cell may be surrounded, (A) is a top view, (B) is sectional drawing. It is an Example at the time of arrange | positioning a condensing means only to one direction of the adjacent photovoltaic cell, (A) is a top view, (B) is sectional drawing. It is a partially expanded sectional view which shows 2nd Example of this invention. It is a schematic explanatory drawing which shows the photoelectric conversion efficiency improvement system of the conventional solar cell module.

  Hereinafter, embodiments of a photovoltaic conversion efficiency improvement system for a solar cell module according to the present invention will be described with reference to the drawings.

1 to 4 show a first embodiment of a photoelectric conversion efficiency improvement system for a solar cell module according to the present invention.
In general, in Japan, located in the northern hemisphere, the orbit of the sun is about 60 degrees at sunrise, about 80 degrees in the south-middle altitude, and about 300 degrees in the sunset. In the winter solstice, the sunrise is about 120 degrees, the south-middle altitude is about 31 degrees, the sunset direction is about 240 degrees, and the solar trajectory varies greatly in direction and altitude, but the installation of solar cell modules is generally fixed. Although it is slightly different depending on the latitude of the installation, it is installed southward with an inclination of about 40 degrees, and it is efficiently condensed and photoelectrically converted for about 4 hours, 2 hours before and after the south-central time. Like to do.

This photovoltaic conversion efficiency improvement system of a solar cell module is a solar cell module that generates power by arranging a plurality of silicon solar cells in a two-dimensional manner, and condenses light only above the end position of the adjacent solar cells 1. The means 2 and 2 are provided, and the light collecting means 2 is not provided so that the light beam is directly incident at a position facing the solar battery cell 1.
The solar battery cell 1 is not particularly limited, and is manufactured in a required size using single crystal silicon, polycrystalline silicon, Amorphous, or the like.
For example, when a solar cell is manufactured from a 5-inch wafer, a solar cell having a side of about 100 mm can be manufactured when missing portions at four corners are allowed. Since most of the cost of the solar cell module is occupied by silicon solar cells, the area of the silicon solar cell can be reduced to reduce the cost of the silicon solar cell, and the light collection efficiency can be increased by using the light collecting means. Can be improved. However, if the structure of the members constituting the light condensing means is complicated as in the prior art, the cost of this portion increases. Therefore, in the present invention, the light condensing means 2 is downsized and the end of the solar battery cell 1 is used. It is arranged only above the position.

As this condensing means 2, the irradiation light 5 irradiated to the outside of the side end of the solar battery cell 1 is refracted to the solar cell light receiving surface side by passing through the condensing means 2. These are cylindrical lenses that are focused in a slit shape in only one direction, specifically, linear Fresnel lenses.
Moreover, the linear Fresnel lens as this condensing means 2 is arrange | positioned in the side edge part of the photovoltaic cell 1 to arrange | position, as shown in FIG. This is not particularly limited. For example, when a large number of solar cells 1 are arranged vertically and horizontally, as shown in FIG. 4, a linear Fresnel lens between solar cells 1 and 1 adjacent in the horizontal direction. 2 can be arranged.
Thereby, the irradiation light 5 from the horizontal direction of the photovoltaic cell 1 side part can be effectively condensed on the photovoltaic cell side.

  Moreover, as shown in FIG. 3, the linear Fresnel lens 2 can be arrange | positioned in the vertical direction and horizontal direction between the photovoltaic cells 1 and 1 adjacently arranged in the vertical and horizontal direction, respectively. Thereby, the irradiation light 5 from the four circumferential directions on the side of the solar battery cell 1 can be condensed without waste on the solar battery cell side.

  As described above, even when the linear Fresnel lens is disposed only in the lateral direction between the adjacent solar cells 1, 1, it is also disposed in both the longitudinal and lateral directions between the solar cells 1, 1. However, since only the linear Fresnel lens is provided at the side edge of the solar battery cell 1 and no linear Fresnel lens is provided at the part facing the solar battery light receiving surface, The light 6 incident from the front is directly incident on the light receiving surface of the solar battery cell without passing through the linear Fresnel lens, and the attenuation of light due to the lens passage can be prevented.

Therefore, since the light 6 incident from the front of the solar cell is directly incident without being collected by the linear Fresnel lens, the solar cell reaches the solar cell light receiving surface without being attenuated and is collected by the linear Fresnel lens. The solar cell is reached in total with the ambient light on the cell side.
The light passing through the Fresnel lens is attenuated in proportion to the transmittance of the lens material and the cosine of the refraction angle. However, in the case of acrylic resin as the material of the linear Fresnel lens, the refractive index is about 90%. .48 to 1.5 is almost the same value as soda glass and general engineering glass, and in the case of polycarbonate, the refractive index is 1.59, and lenses and prisms can be produced.
In order to form an image as a linear Fresnel lens, it is necessary to form a flat surface or spherical surface that has a uniform refractive index distribution and an accurate shape. In addition, the surface accuracy does not need to be high, and the lens can be produced at low cost by injection molding or extrusion molding. In particular, linear Fresnel lenses having the same cross section in the length direction can be easily mass-produced by extrusion.

  Further, as a linear Fresnel lens disposed at the outer end of the solar battery cell, when the lens processing is made spherical, the linear Fresnel lens acts as a convex lens, and the light transmitted through the linear Fresnel lens is As shown in FIG. 2 (A), when light is condensed at one point and the lens processing has a triangular or trapezoidal cross section, the light transmitted through the linear Fresnel lens is as shown in FIG. As shown in B), the light is refracted in parallel to guide light to the solar battery cell 1.

  In solar power generation, factors that are proportional to the sine of the incident angle incident on the solar cell module, factors that attenuate in the atmosphere in proportion to the cosine of the incident angle when sunlight is incident on the earth, clouds and in the air Because of the effect of scattered light due to water vapor, it is possible to generate power efficiently for about 3 to 4 hours with respect to the sunshine hours, so the south and middle time (near noon) where sunlight is the highest is sandwiched In order to improve efficiency between the two hours before and after, the linear Fresnel lens is made of acrylic resin having a refractive index of about 1.5, and the distance from the solar cell and the lens width are set to a ratio of about 1: 1 to 2: 1. In this case, a favorable result can be obtained.

  In addition, since the sun trajectory has less fluctuation in the direction of the azimuth angle and the direction of the altitude angle than the azimuth direction, when focusing the lens focusing only on the azimuth direction, as shown in FIG. The linear Fresnel lens is provided only between the lateral directions of the adjacent solar cells, and the solar cells are arranged at a minimum interval in the altitude direction. On the other hand, when condensing light in both the azimuth direction and the altitude direction, as shown in FIG. 4, it is possible to arrange the linear Fresnel lens in the azimuth direction and the linear Fresnel lens in the altitude direction between the four circumferences of the solar cells. it can.

In FIG. 5, 2nd Example of the photoelectric conversion efficiency improvement system of the solar cell module of this invention is shown.
In this embodiment, when the solar battery cell 1 is disposed in close contact with the base portion of the solar cell module and the linear Fresnel lens 2 is disposed above the solar cell module 1, the protective glass 4 and the base portion of the solar cell module are formed by the linear Fresnel lens 2. 3 is maintained at a constant distance, and the protective glass 4 is also integrally supported.
Further, when the protective glass 4 is supported at a position above the linear Fresnel lens 2, it also serves as a passivation process (passivation). As shown in FIG. 5, the linear Fresnel lens 2 can be a refractor such as a lens whose upper surface of a deformed cross section is a spherical surface or a prism whose surface is a flat surface. The linear Fresnel lens 2 can be formed by extrusion or injection molding of a transparent resin. Thereby, a solar cell module with few number of parts can be made.

Next, the design of a linear Fresnel lens suitable for the present invention will be described.
When refracting with a linear Fresnel lens having a refractive index n and an apex angle φ, when light is incident perpendicular to the linear Fresnel lens, the angle θ formed with the incident light of the light refracted by the linear Fresnel lens is
θ = (n−1) φ (rad)
Can be approximated by
To refract the linear Fresnel lens width W, where W is the width of the linear Fresnel lens and L is the distance from the linear Fresnel lens to the solar cell,
L = W / θ
= W / (n-1) φ
It becomes.
Here, when n = 1.52, φ = 30 degrees (0.52 rad), and W = 10 mm,
θ = 15.4 degrees (0.27 rad) and L = 37 mm.
When refracting 50% with respect to the width of the linear Fresnel lens, L = 37/2 and 19 mm.
When the width of the solar cell is 100 mm, the linear Fresnel lens width is 10 mm, and the ratio of the total width is δ = 10%,
The light receiving efficiency η is η = 1 + δCOSθ
= 1 + 0.1 × 0.96
Thus, the efficiency can be improved by almost δ in the solar cell having the same area.
When the distance L between the linear Fresnel lens and the solar cell is reduced and the amount of refraction is reduced, the efficiency decreases almost in proportion to the distance L. However, even if the distance L is zero, the efficiency is a minimum value of 1, so protection is achieved. If something is interposed between the base and the glass only to support the glass, it can be configured as shown in FIG.

  As mentioned above, although the photoelectric conversion efficiency improvement system of the solar cell module of this invention was demonstrated based on the several Example, this invention is not limited to the structure described in the said Example, It describes in each Example. The configurations can be appropriately changed without departing from the gist of the configurations, for example, by appropriately combining the configurations.

  The photovoltaic conversion efficiency improvement system of the solar cell module of the present invention has the characteristic of further improving the photoelectric conversion efficiency with a simple configuration by disposing a special condensing means only on the side of the solar cell. Therefore, it can be used suitably for the use of a solar cell module, for example, can also be used for the use of solar heat utilization equipment.

DESCRIPTION OF SYMBOLS 1 Solar cell 2 Condensing means (linear Fresnel lens)
3 Solar Cell Module Base 4 Protective Glass 5 Irradiation Light 6 Incident Light

Claims (5)

  In a solar cell module that generates power by arranging a plurality of silicon solar cells in a two-dimensional manner, the light irradiated to the outside of the solar cell end is refracted by the light collecting means disposed above the end position of the adjacent solar cell. The solar cell module is characterized in that no condensing means is disposed on the solar cell light receiving surface at a position facing the solar cell, and the irradiated light is directly incident on the solar cell light receiving surface. Photoelectric conversion efficiency improvement system.   In a solar cell module that generates power by two-dimensionally arranging a plurality of silicon solar cells, light is irradiated to the outside of the solar cell by disposing condensing means above the end position of the adjacent solar cells. The light collecting surface is refracted and no condensing means is provided at a position facing the solar battery cell so that the irradiated light is directly incident on the solar cell light receiving surface, and the solar battery cell is fixed. A system for improving the photoelectric conversion efficiency of a solar cell module, characterized in that the distance between the base and the protective glass is kept constant, and the passivating process for supporting the protective glass is also used as the light collecting means.   3. The system for improving photoelectric conversion efficiency of a solar cell module according to claim 1, wherein the light condensing means is arranged at the four peripheral ends of adjacent solar cells.   The photoelectric conversion efficiency improvement system for a solar cell module according to claim 1, 2 or 3, wherein the light condensing means is a linear Fresnel lens.   5. The system for improving photoelectric conversion efficiency of a solar cell module according to claim 1, wherein the linear Fresnel lens is formed on a spherical surface or a flat surface.

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