JP2021048147A - Solar battery cover - Google Patents

Abstract

To provide a solar battery cover which can be structured in a thin film with a simple structure, and in which a solar tracking is not required and a generating efficiency is improved.SOLUTION: A solar battery cover 1 covering a light reception surface of a solar cell panel, comprises: an incidence plane 2 of a light in a top face; an emission surface 3 of the light in a bottom face; a transparent column-like member 5 having a boundary surface 4 reflecting the light in a side face; a plurality of net boundary transparent cover boards 6 which are bundled so that both side faces are adjacent, so is structured in a flat tabular so that each of the top face and the bottom face becomes one surface, in which the boundary surface 4 is viewed in a net shape when viewing it from the top face or the bottom face. Each net boundary transparent cover board 6 is mounted to the solar cell panel so that the bottom face of the column-like member 5 is faced to the light reception surface.SELECTED DRAWING: Figure 3

Description

The present invention relates to a solar cell cover that covers a light receiving surface of a solar cell panel, and more particularly to a solar cell cover that has a simple configuration and has improved power generation efficiency.

As a cover covering the light receiving surface of the solar cell panel, one in which light is collected by a lens (see Patent Document 1) and one in which light is collected by a reflector (see Patent Document 2) are known. When light is collected by a reflector or a reflector, the power generation area is small, solar tracking is required, and the entire device becomes complicated and large.

As a thin solar cell cover that does not require sun tracking and has a simple structure, a reflective groove with a triangular cross section is formed on the back surface of a transparent plate as the cover body, and light is collected by a prism. However (see Patent Document 3), light is not emitted directly under the triangular groove, the current flow of the solar cell is poor, and there is a possibility that it becomes a resistance and partially generates heat. Partial heat generation (hot spot) accelerates the deterioration of the solar cell, so there is room for improvement.

Further, it is known that sunlight is collected by a plurality of optical fibers and guided to a solar cell (see Patent Document 4), but the power generation area is similar to that of light collected by a lens or a reflector. narrow. In addition, the optical fiber makes the entire device large and cannot be stacked on the solar cell panel, so that the panel assembly cannot be compactly configured. Both methods are difficult to attach to the existing solar cell panel.

Japanese Unexamined Patent Publication No. 2017-228709 Japanese Unexamined Patent Publication No. 2017-191854 JP-A-2010-238830 Japanese Unexamined Patent Publication No. 55-96906

The object of the present invention, which was conceived in consideration of the above circumstances, is that it can be constructed lightly with a simpler structure than the reflector type, lens type, and optical fiber type, has a larger power generation area than the prism type, does not require solar tracking, and has power generation efficiency. The purpose is to provide a solar cell cover that can be attached to an existing solar cell panel.

According to the present invention, which was devised to achieve the above-mentioned object, it is a solar cell cover that covers a light receiving surface of a solar cell panel, and has a light incident surface on the top surface, a light emitting surface on the bottom surface, and light on the side surface. When a plurality of transparent columnar members having a reflective boundary surface are bundled so that the side surfaces are adjacent to each other and are formed in a flat plate shape so that the top surface and the bottom surface of each are flush with each other, when viewed from the top surface or the bottom surface. A solar cell cover is provided with a mesh boundary transparent cover plate whose boundary surface looks like a mesh, and the mesh boundary transparent cover plate is mounted on a solar cell panel so that the bottom surface of a columnar member faces the light receiving surface. Provided.

In the solar cell cover according to the present invention, when the critical angle of the columnar member is θ1 and the refractive index of the columnar member is n2, the refraction angle θ2 of the columnar member is obtained by the following equation.
θ2 = arcsin ((sin θ1) / n2)
The width w1 between the side surfaces of the columnar member, the height t1 of one unit of the columnar member, and the refraction angle θ2 of the columnar member have the following relations.
tan θ2 = w1 / t1
When the height t1 = t of the columnar member, the width w between the side surfaces of the columnar member was determined by the following equation.
w = (t / n) tan θ2 n may be a solar cell cover characterized by being a natural number.

In the solar cell cover according to the present invention, in order to increase the reflection efficiency at the boundary surface of the columnar member, the side surface of the columnar member may be in a mirror surface state, or the side surface of the columnar member may be metal-deposited.

In the solar cell cover according to the present invention, a plurality of columnar members are bundled with an adhesive, and an adhesive may be interposed between the side surfaces of adjacent columnar members.

In the solar cell cover according to the present invention, the columnar member has a cross section of any of a square, a rectangle, a circle, a regular hexagon, and a regular triangle, and the entrance surface and the exit surface are parallel to each other. On the other hand, the boundary surface may be vertical.

According to the solar cell cover according to the present invention, the structure is simpler than that of the reflector type, the lens type, and the optical fiber type, and the structure can be made lighter. It can also be attached to the solar panel of.

It is a perspective view of the solar cell cover which concerns on one Embodiment of this invention. It is explanatory drawing of the transmitted light passing through a solar cell cover, (a) shows the present invention having a boundary surface, (b) shows a comparative example without a boundary surface. It is explanatory drawing which shows the state that the transmitted light which passes through a solar cell cover is diffused, (a) is a comparative example which does not have a boundary surface, (b) shows the present invention which has a boundary surface. It is explanatory drawing which shows the difference of the incident area and the exit area by the difference in the plate thickness of the solar cell cover, and (a), (b), (c) are the top view, side when the plate thickness is twice one unit. Cross-sectional views and bottom views are shown, and (d), (e), and (f) show top views, side cross-sectional views, and bottom views when the plate thickness is 1 times one unit, and (g), (h). , (I) show a top view, a side sectional view, and a bottom view when the plate thickness is 0.5 times one unit. It is explanatory drawing for finding the cover plate thickness t and the boundary surface distance w of a solar cell cover, (a) is a side sectional view which shows incident light, a solar cell cover, and emitted light, and (b) is a refraction angle θ2. It is a mathematical formula showing the relationship between the boundary surface distance w1 and the plate thickness t1, (c) is a table showing the critical angle, the refractive index, etc., and (d) is a mathematical formula for calculating the refraction angle θ2. It is a graph which shows the relationship between the time and the amount of solar radiation on January 1st in Tokyo.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, other specific numerical values, etc. shown in the embodiment are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are designated by the same reference numerals to omit duplicate description, and elements not directly related to the present invention are not shown. To do.

(Outline of solar cell cover 1)
The solar cell cover 1 according to the embodiment of the present invention shown in FIG. 1 is a cover that covers the light receiving surface of the solar cell panel, and as shown in FIG. 2A, has a light incident surface 2 on the top surface and a bottom surface. A plurality of transparent columnar members 5 having a light emitting surface 3 and a boundary surface 4 for reflecting light on the side surfaces are bundled so that the side surfaces are adjacent to each other, and a flat plate is provided so that the top surface and the bottom surface of each are flush with each other. It is provided with a mesh boundary transparent cover plate 6 which is configured in a shape and the boundary surface 4 looks like a mesh when viewed from the top surface or the bottom surface. The mesh boundary transparent cover plate 6 is mounted on the solar cell panel so that the bottom surface (emission surface 3) of the columnar member 5 faces the light receiving surface.

As shown in FIG. 2A, the solar cell cover 1 according to the present embodiment has a boundary surface 4 for reflecting light, so that the incident light (incident surface 2) obliquely incident on the top surface (incident surface 2) is (incident surface 2). The arrow) is reflected by the boundary surface 4 and is emitted from the bottom surface (exit surface 3). This route can be considered in the same manner as the vertical light 6 in that the bottom surface directly below the incident portion on the top surface is the emitting portion. On the other hand, as shown in FIG. 2 (b), since the conventional solar cell cover 1a is merely a transparent plate body 7, incident light obliquely incident on the top surface passes through the plate body 7 and remains as it is on the bottom surface. Emit from. In this route, since the bottom surface diagonally below the incident portion on the top surface is the emitting portion, the oblique light 8 is obtained.

As shown in FIG. 3A, in the conventional solar cell cover 1a having no boundary surface 4, the incident light incident from the top surface is diffused in the transparent plate body 7 to become diffused light 9, and the diffusion width is increased. It emits from the bottom surface in a state where w1 is spread to some extent. On the other hand, as shown in FIG. 3B, in the solar cell cover 1 of the present embodiment, the incident light incident from the top surface (incident surface 2) is diffused but reflected at the boundary surface 4 and is on the opposite side. It is further reflected at the boundary surface 4, diffused at each reflection, and is emitted from the bottom surface (emission surface 3) in a state limited to the area partitioned by the boundary surface 4 (width w2, w2 <w1). As a result, the density (illuminance, brightness) of the light emitted from the bottom surface is higher than that of the conventional solar cell cover 1a, and the power generation efficiency is improved. Hereinafter, each component of the solar cell cover 1 according to the present embodiment will be described.

(Column member 5)
As the material of the columnar member 5 shown in FIGS. 2 (a) and 3 (b), glass, acrylic, polycarbonate, polystyrene or the like is used as a transparent material. As shown in FIGS. 4 (a), 4 (b), and 4 (c), the columnar member 5 has a square cross section, the incident surface 2 and the exit surface 3 are parallel to each other, and the incident surface 2 and The boundary surface 4 is perpendicular to the exit surface 3. The cross-sectional shape of the columnar member 5 is not limited to a square, but may be a rectangle, a circle, a regular hexagon, or an equilateral triangle. Further, in order to increase the reflection efficiency on the boundary surface 4, the side surface of the columnar member 5 may be mirror-finished, and the side surface of the columnar member 5 may be vapor-deposited with a metal such as silver or gold.

The incident surface 2 of the columnar member 5 may be surface-treated to improve diffusivity in order to increase the uniformity of transmitted light (eliminate unevenness). Similarly, the emitting surface 3 of the columnar member 5 may be subjected to a surface treatment for improving the diffusivity in order to increase the uniformity of the emitted light. For the surface treatment, it is conceivable to apply (coat) a transparent resin or paint containing a light diffusing agent on the entrance surface 2 and the exit surface 3. As the light diffusing agent, silicon dioxide (glass), calcium carbonate (lime), a fluorescent agent and the like are used. In addition, as a surface treatment, blasting may be considered in which particles are sprayed to form concave lens-shaped depressions on the surfaces of the entrance surface 2 and the exit surface 3.

(adhesive)
A plurality of columnar members 5 are bundled and adhered to each other via an adhesive, and an adhesive is interposed between the side surfaces (boundary surfaces 4) of adjacent columnar members 5. Since the adhesive is sandwiched between the boundary surface 4 of the adjacent columnar member 5 and the boundary surface 4, the reflective function of the boundary surface 4 of each columnar member 5 is maintained. By using an adhesive having a low viscosity, the thickness of the adhesive between the columnar members 5 can be reduced, and the adhesive is adjacent to the top surface (incident surface 2) and the bottom surface (exit surface 3) of the solar cell cover 1. The area of the adhesive (area that blocks light) that appears in a mesh pattern so as to partition the columnar member 5 can be made as small as possible.

The adhesive is preferably a transparent material that does not dissolve the surface (side surface) of the columnar member 5. For example, a cyanoacrylate-based instant adhesive (Aron Alpha (registered trademark), etc.) can be considered. In order to return the transmitted light penetrating the boundary surface 4 to the columnar member 5 in FIG. 2A, a diffusing agent such as glass beads or a fluorescent agent may be added to the adhesive.

(Aspect ratio of columnar member 5)
As shown in FIGS. 4 (b) and 4 (e), the ratio (aspect ratio) between the height t of the columnar member 5 and the width w between the side surfaces (boundary surfaces) is the top surface 2 of the columnar member 5. When the angle of the incident light (direct light of sunlight) is the set maximum incident angle (for example, the critical angle of the material of the columnar member 5), the incident area (FIGS. 4 (a) and 4 (d)) and the exit An aspect ratio that is equivalent to the area (FIGS. 4 (c) and 4 (f)) is desirable.

For example, as shown in FIG. 4 (e), when the height when the light incident from the incident point (west upper apex) reaches the reflection point (east lower apex) is set to the plate thickness tx, FIG. 4 (e). The incident area shown by hatching in d) and the exit area shown by hatching in FIG. 4 (f) are equal.

Further, as shown in FIG. 4 (b), the height from the incident point (west upper apex) to the reflection point (east reflection point) and the height from the reflection point (east reflection point) to the exit point (west lower apex). Even if the plate thickness ty is the same, the incident area shown in FIG. 4 (a) and the emitted area shown in FIG. 4 (c) are equal.

On the other hand, as shown in FIG. 4 (h), in the plate thickness tz in which the light incident from the incident point (west upper apex) does not reach the reflection point (east lower apex), the incident area shown in FIG. 4 (d) Therefore, the emission area shown in FIG. 4 (f) is reduced, and the non-emission portion 10 is formed, which is not preferable.

(Action / effect)
The mesh boundary transparent cover plate 6 constituting the solar cell cover 1 according to the present embodiment shown in FIG. 1 is installed so as to overlap the light receiving surface of the solar cell (not shown) without a gap. The exit area of the bottom surface of the mesh boundary transparent cover plate 6 is equal to the light receiving area of the solar cell.

As shown in FIG. 2A, the transmitted light transmitted through the mesh boundary transparent cover plate 6 is refracted at the incident surface 2, transmitted through the inside of the columnar member 5, is refracted again at the exit surface 3, and is emitted. .. The transmitted light inside the cover plate 6 is reflected (totally reflected) at the boundary surface 4 of the transparent columnar member 5 and directed toward the exit surface 3. The principle of reflection refraction follows Snell's law. For example, on the incident surface 2 of the columnar member 5, the upstream medium A of light is air and the downstream medium B is the columnar member 5. On the boundary surface 4 after bonding, the upstream medium A of light serves as a columnar member 5, and the downstream medium B serves as an adhesive.

As shown in FIG. 3A, the transmitted light transmitted through the inside of the transparent plate 7 is generally diffusive. As shown in FIG. 3B, in the present embodiment, the diffused transmitted light is reflected (totally reflected) at the boundary surface 4 of the columnar member 5 and directed toward the exit surface 3, so that the diffusion region can be expanded. It can be suppressed (w2 <w1). Therefore, the density of the light emitted from the bottom surface (exiting surface 3) (the amount of emitted light per unit area) is higher than that of the transparent plate 7 having no boundary surface (see FIG. 3A). Therefore, the power generation efficiency is improved.

By the way, as shown in FIG. 5, sunlight hits and scatters direct light (shown by a broken line) that linearly reaches the mesh boundary transparent cover plate 6 and molecules and fine particles such as water vapor in the atmosphere, and then the cover plate 6 It is composed of scattered light (indicated by dots) that reaches. The incident angle of the direct light changes with respect to the incident surface 2 of the cover plate 6 from sunrise to sunset, and the scattered light reaches the incident surface of the cover plate 6 perpendicularly without changing the incident angle. Therefore, the non-emission portion 10 of the direct light generated by the change in the incident angle (see FIGS. 4 (h) and 4 (i)) is also irradiated with the transmitted light of the scattered light.

Therefore, the unevenness of illuminance (difference in overlapping of light) on the exit surface 3 of the columnar member 5 shown in FIG. 5, that is, the light receiving surface of the solar cell is the transmitted light (light transmitted through the atmosphere while being scattered). Light transmitted linearly through the columnar member 5 (indicated by dots) and direct light (light linearly passed through the atmosphere) transmitted light (light linearly transmitted through the columnar member 5 (indicated by broken lines)) ) Is alleviated by the diffused light (light diffused when passing through the transparent columnar member 5 (indicated by fine hatching)). Therefore, the bottom surface (emission surface 3) of the cover plate 6 has no complete non-emission portion 10 (see FIGS. 4 (h) and 4 (i)), and there is no portion on the light receiving surface of the solar cell that does not generate power, resulting in power generation efficiency. Is improved.

As described above, according to the solar cell cover 1 using the mesh boundary transparent cover plate 6 according to the present embodiment, for example, it is compared with the case where the reflection groove having a triangular cross section is formed on the back surface of the transparent plate described in Patent Document 3. As a result, hot spots cannot be formed on the light receiving surface of the solar cell panel, so that deterioration of the solar cell is suppressed.

Further, unlike the one described in Document 3, the manufacturing accuracy of the groove spacing and the mounting position accuracy according to the position of the electrode are not required, and the solar cell panel is used as opposed to the reflection type of Document 2 and the lens type of Document 1. The necessary support structure is not required. That is, since it has a simple and frivolous structure, it is lightweight and the product cost can be suppressed.

Compared to the reflection type of Document 2, the lens type of Document 1, and the optical fiber type of Document 4, the distance between the entrance surface 2 and the exit surface 3 of the mesh boundary transparent cover plate 6 is the reflection plate, the focal length of the lens, and the optical fiber, respectively. It becomes narrower than the length of the lens, and the thickness of the entire device becomes thin. Therefore, the weight load on the solar cell panel can be reduced, the mesh boundary transparent cover plate 6 can be stacked on the light receiving surface of the solar cell panel without a support structure, and the panel assembly can be compactly configured.

(Power generation time)
By the way, assuming that the material of the columnar member 5 is acrylic (PMMA), as shown in FIG. 5, the incident angle at which light from the air (medium A) begins to enter the columnar member 5 (medium B) while refracting, and the air (medium). The critical angle θ1'of the reflection angle at which the light from A) begins to be totally reflected by the columnar member (medium B) is 42.2 °. Therefore, the range of the angle at which the direct light of sunlight enters the columnar member 5 is theoretically 84.4 ° (= 42.2 × 2), but in reality, the incident angle range θ3 is considered with a margin. Consider = 80 °. In this case, the practical critical angle (incident angle) θ1 = 40 °.

Since the earth rotates 360 ° in 24 hours, the incident angle range θ3 = 80 ° (θ1 × 2) is 5 hours and 20 minutes in terms of time. 5 hours and 20 minutes are divided into morning and afternoon, and the time zone of 2 hours and 40 minutes before and after 12:00 (noon) is from 9:20 to 14:40. As shown in FIG. 6, considering the amount of solar radiation (horizontal plane solar radiation = direct solar radiation + scattered solar radiation) from 9:20 to 14:40 for 5 hours and 20 minutes, the above-mentioned power generation is 82% of the total solar radiation. It can be effective.

In addition, the angle range of the inclination of the sun from the summer solstice to the winter solstice is 47 °, which is twice the inclination angle (23.5 °) of the earth's axis, with respect to the incident angle range θ3 = 80 °. Appropriate power generation effect can be exhibited throughout the year.

(Determination of height t of columnar member 5 and width w between side surfaces)
The thickness t of the mesh boundary transparent cover plate, which is the height of the columnar member 5, and the distance w between the boundary surfaces 4, which is the width between the side surfaces of the columnar member 5, are determined as follows.

First, in FIG. 5A, from the critical angle θ1'= 42.2 ° at which total reflection occurs on the incident surface 2 of the acrylic columnar member 5, the critical angle (incident) in practice is considered in consideration of the margin during actual operation. Angle) θ1 = 40 ° is determined, and the refraction angle θ2 in the columnar member 5 is obtained from the critical angle θ1 = 40 ° as follows.

The refractive index θ2 is the following equation (Snell's law) from the incident angle θ1 = 40 ° of the incident light (direct light of sunlight), the refractive index n2 = 1.49 of the columnar member 5, and the refractive index n1 = 1 of the air. (See FIG. 5 (c) and FIG. 5 (d)).
n2 (sinθ2) = n1 (sinθ1)
When the above equation is transformed to obtain the refraction angle θ2,
n2 = sinθ1 / sinθ2
θ2 = sin ^ -1 ((sinθ1) / n2) = arcsin ((sinθ1) / n2) = 25.6 °
Will be.

As shown in FIG. 5B, a rectangle in which two right triangles having the hypotenuse as the hypotenuse and the angle between the hypotenuse and the adjacent side as the refraction angle θ2 are combined with each other is formed by one of the side surfaces of the columnar member 5. The unit is. The length of the opposite side of the right triangle is the distance w1 between the boundary surfaces, the length of the adjacent side is the plate thickness t1 of 1 unit, and if either one is set, 1 unit is determined. One unit or more is stacked to obtain a desired plate thickness t.

That is, as shown in FIG. 5B, assuming that the width w1 between the side surfaces of one unit of the columnar member 5 and the height t1 of one unit of the columnar member 5, the refraction angle θ2 of the columnar member has the relationship of the following equation. Become.
tan θ2 = w1 / t1
When the above equation is modified and the height t1 = t of the columnar member 5, the width w between the side surfaces of the columnar member 5 is calculated by the following equation.
w = (t / n) tan θ2 ... Equation X (n is a natural number)
5 (a) and 4 (b) are n = 2 and two 1 units are stacked, and FIG. 4 (e) is n = 1 and 1 unit. In addition, one unit may be stacked three or more.

The height t of the columnar member 5 and the width w between the side surfaces emphasize any of the angle range θ3 for taking in sunlight, the difficulty of manufacturing, and the economic efficiency (material, weight, cost) shown in FIG. 5 (a). The optimum specifications are determined for each.

For example, when emphasizing the angle range θ3 that takes in sunlight, by using a columnar member 5 made of a material having a wide incident angle (critical angle in practice) θ1, the amount of sunlight taken in increases, so that the amount of power generation increases. More. When the difficulty of manufacturing is emphasized, the thickness (width w) of the columnar member 5 is increased and the number of bundled columnar members 5 is reduced, so that the columnar members 5 can be easily adhered to each other and the manufacturing is easy. It becomes. When economic efficiency (weight, cost) is emphasized, the height t of the columnar member 5 is lowered to reduce the plate thickness t of the cover plate 6, the number of bundled columnar members 5 is reduced, and the cover plate is used. By reducing the volume of No. 6, the amount of material used for the columnar member 5 is reduced, so that the economy is improved.

In the present embodiment, as shown in FIG. 5, acrylic is used as the material of the columnar member 5, and since the direct light of sunlight is taken in for the longest time, the incident is slightly smaller than the critical angle θ1'= 42.2 ° of acrylic. The refraction angle θ2 = 25.6 °, which is determined from the angle θ1 = 40 °, is used as a reference for one unit.

Further, in consideration of the weight of the mesh boundary transparent cover plate 6, the plate thickness (height of the columnar member 5) t (adjacent side of the right triangle in FIG. 5B) of the cover plate 6 is set to a predetermined value in advance. Then, the width w between the side surfaces of the columnar member 5 is calculated. The product number of one unit is set to two units that reflect twice because the diffusivity of transmitted light increases as the number of reflections on the boundary surface 4 of the columnar member 5 increases.

Assuming that the refraction angle θ2 = 25.6 °, the plate thickness t = 5 mm, and two units are stacked, the width w between the side surfaces of the columnar member 5 is calculated by the above formula X.
w = (t / n) tan θ2 n is a natural number (n = 2)
= (5/2) tan25.6
= 1.2 mm
In this case, the width w between the side surfaces of the columnar member 5 is determined to be 1.2 mm.

With the same refraction angle θ2 = 25.6 °, with a plate thickness of t = 5 mm and 3 units stacked,
w = (t / n) tan θ2 n is a natural number (n = 3)
= (5/3) tan25.6
= 0.8mm
In this case, the width w between the side surfaces of the columnar member 5 is determined to be 0.8 mm.

With the same refraction angle θ2 = 25.6 °, with a plate thickness of t = 3 mm and 2 units stacked,
w = (t / n) tan θ2 n is a natural number (n = 2)
= (3/2) tan25.6
= 0.7mm
In this case, the width w between the side surfaces of the columnar member 5 is determined to be 0.7 mm.

As described above, the thickness of the cover plate 6 (height of the columnar member 5) t and the width between the side surfaces of the columnar member 5 (distance between the boundary surfaces) w can be accurately obtained by a simple calculation. The product number of one unit, which is the maximum amount of power generation, is determined from the actual test results in consideration of the influence of diffused light (see FIGS. 3 (b) and 5 (a)).

Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments, and various modifications in the scope of claims are described. It goes without saying that the modified examples also belong to the technical scope of the present invention.

The present invention relates to a solar cell cover that covers a light receiving surface of a solar cell panel, and can be used for a solar cell cover that aims to improve power generation efficiency with a simple configuration.

1 Solar cell cover 2 Incident surface 3 Exit surface 4 Boundary surface 5 Columnar member 6 Mesh boundary transparent cover plate t Height of columnar member w Width between side surfaces (boundary surface) of columnar member θ1 Critical angle of columnar member θ2 Critical angle of columnar member Refractive angle n2 Refractive index of columnar member

Claims (5)

A solar cell cover that covers the light receiving surface of the solar cell panel.
A plurality of transparent columnar members having a light incident surface on the top surface, a light emitting surface on the bottom surface, and a boundary surface for reflecting light on the side surfaces are bundled so that the side surfaces are adjacent to each other, and the top surface and the above surface are each bundled. It is configured in a flat plate shape so that the bottom surface is flush with each other, and is provided with a mesh boundary transparent cover plate in which the boundary surface looks like a mesh when viewed from the top surface or the bottom surface.
The mesh boundary transparent cover plate is a solar cell cover that is mounted on the solar cell panel so that the bottom surface of the columnar member faces the light receiving surface. When the critical angle of the columnar member is θ1 and the refractive index of the columnar member is n2, the refraction angle θ2 of the columnar member is obtained by the following equation.
θ2 = arcsin ((sinθ1) / n2)
The width w1 between the side surfaces of the columnar member, the height t1 of one unit of the columnar member, and the refraction angle θ2 of the columnar member have the following relations.
tan θ2 = w1 / t1
When the height t1 = t of the columnar member, the width w between the side surfaces of the columnar member was determined by the following equation.
The solar cell cover according to claim 1, wherein w = (t / n) tan θ2 n is a natural number. Claim 1 or claim 1, wherein the side surface of the columnar member is in a mirror surface state, or the side surface of the columnar member is metal-deposited in order to increase the reflection efficiency at the boundary surface of the columnar member. 2. The solar cell cover according to 2. Any one of claims 1 to 3, wherein a plurality of the columnar members are bundled with an adhesive, and the adhesive is interposed between the side surfaces of the adjacent columnar members. The solar cell cover described in. The columnar member has a cross section of any of a square, a rectangle, a circle, a regular hexagon, and a regular triangle, the entrance surface and the emission surface are parallel to each other, and the interface surface with respect to the entrance surface and the emission surface. The solar cell cover according to any one of claims 1 to 4, wherein is vertical.

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