JPH1131837A - Light collecting type solar generator and module using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the area of an optoelectric transducer, by setting the axial direction maximum height of a projection image of a part made of a semiconductor material on a flat plane parallel to the axis, in the optoelectric transducer positioned in a space, at a specified value or more to the minimum width of the projection image on a flat plane vertical to the axis. SOLUTION: A shape 107 projected to a flat plane 110, which is vertical to the axis 8 of a part that exists within a space formed by a spherical semiconductor material, is made circular, and its width 109 is equivalent to the diameter of the circle of a part where the spherical semiconductor material contacts with a reflection plane 3. A shape 108 projected to a flat plane parallel to the axis 8 is a part of the circle, and the height 110 of the shape 108 in the direction of the axis 8 is varied by a position where an optoelectric transducer is arranged. In the case of arranging the optoelectric transducer in such manner, the height in the axis 8 is set to be 1/5 or more of the width 109 of the circle. Thus, the area of the optoelectric transducer is reduced and charging efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concentrating solar power generation device using a photoelectric conversion device.

[0002]

2. Description of the Related Art Conventionally, a semiconductor substrate having a diameter of several to several tens of cm is used and processed to form a photoelectric conversion device. However, in the photovoltaic power generation system, cost reduction of the photovoltaic power generation device is required in order to reduce the power generation cost. As one of the means, there is a photovoltaic power generation device shown in FIG. This photovoltaic power generation device does not use the above-mentioned wafer, but uses a spherical semiconductor material that can be manufactured at lower cost,
This is fixed to an aluminum support substrate 4 to form the photoelectric conversion device 1. This method is described in, for example, “The 22nd IEEE
Photovoltaic Specialist Conference ", 1991, pp. 1045-1048.

[0003]

In the above prior art, when a plurality of spherical photoelectric conversion devices 1 are arranged on the aluminum support substrate 4, the surface of the aluminum support substrate 4 is filled 100% with the photoelectric conversion device 1. Can not. Therefore, the incident light 16
Of the light, most of the light that does not directly enter the photoelectric conversion device 1 does not enter the spherical photoelectric conversion device 1 and escapes outside the device and does not contribute to power generation. Therefore, the photoelectric conversion efficiency of the solar power generation device using the same is reduced. I can't raise it.

[0004]

Instead of simply arranging a plurality of photoelectric conversion devices such as spheres on a substrate as in the above-mentioned prior art, a concentrating solar power generation device in which the photoelectric conversion device is combined with a condensing device. To form Specifically, a condensing reflector, and a photoelectric conversion device installed so that at least a part thereof is located in a space surrounded by the curved reflecting surface and the opening surface of the condensing reflector. Having a medium with a higher refractive index than air filling the space, wherein the shape of the reflective surface is a cross section of the reflective surface cut out by any surface including an axis passing through the opening surface and the space. The relationship that the side on the opening surface side of the arbitrary two points on both sides of the axis is located at the same distance from the other axis as the point on the opening surface side and the relationship that is located outside the other point. The shape in which the axis having the relationship located at least on the outside exists, and a projection image of a portion formed of the semiconductor material of the photoelectric conversion device located in the space on a plane parallel to the axis. The maximum height in the axial direction is the minimum of the projected image on a plane perpendicular to the axis. 5 of
The above problem can be solved by a concentrating solar power generation device that is at least one-half.

The semiconductor material may be spherical or rectangular parallelepiped. Further, the shape of the reflecting surface of the condensing reflector may be a rotating body. In this case, the axis is the rotation axis of the rotating body.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the shape of a condensing reflector will be described. In order to facilitate the description, an example in which the shape of the reflection surface of the condensing reflection mirror is a rotating body will be described with reference to FIGS. In FIG. 2, the shape of the three-dimensional structure of the curved reflecting surface of the condensing reflector is a straight line around the rotation axis 8 (curve with no curvature).
3 is a cone shape obtained by rotating the circular arc 6, and in FIG. 3 is a torus shape obtained by rotating the circular arc 6 around the rotation axis 8. The photovoltaic power generation device 1 is installed in a space surrounded by an opening surface and a reflection surface of a condenser mirror, and this space is filled with a medium having a higher refractive index than air. 2 and 3
In the above example, the reflection surface has a shape that spreads outward as it approaches the light incident surface side, but a portion having a shape having the same width without spreading outward may be present in a part thereof. That is, a part of the reflecting surface having the shape of the rotating body may be parallel to the rotation axis.

In view of the essence of the present invention, there is a case where an effect is obtained even if such a rotating body is not used. That is,
It is not necessary to use a rotating body as long as the reflecting surface has a shape that spreads outward as it approaches the light incident surface side. In addition, a part of a shape having the same size without spreading outward may be present in a part thereof. FIG. 10 shows an example. In FIG.
A part of the side surfaces of two rotating bodies obtained by rotating two curves having different curvatures with a single rotation axis is used, and these side surfaces are joined by another surface to be combined into one curved surface. I have. This XZ cross-sectional shape is an ellipse.

Next, the shape of a portion of the photoelectric conversion device existing in the space will be described.

When the portion of the photoelectric conversion device made of a semiconductor material has a spherical shape, when the portion is set in a space surrounded by a curved reflecting surface and an opening surface of a light reflecting mirror, FIG.
As shown in FIG. 3, the shape 107 of a portion of the spherical semiconductor material existing in the space projected on the plane 110 perpendicular to the axis 8 becomes a circle as shown in FIG.
Reference numeral 9 denotes the diameter of a circle where the spherical semiconductor material is in contact with the reflection surface 3. The shape 108 projected on a plane parallel to the axis becomes a part of a circle as shown in FIGS. 3C, 3D, and 3E, and the height 110 in the axial direction of this shape is It changes depending on the position where the converter is installed. When the photoelectric conversion device is installed as described above, by installing the photoelectric conversion device so that the height is one fifth or more of the width,
A concentrating photoelectric conversion device with high optical efficiency can be formed.

Further, when a rectangular parallelepiped is used as the shape of the semiconductor material of the photoelectric conversion device and the axis is arranged at right angles to one surface of the rectangular parallelepiped, as shown in FIG. As shown in (b), the width of the opposite side is shorter, and the height 110 is the same as that shown in FIGS.
The height of the rectangle is as shown in FIG. Also in this case, by setting the height so as to be one fifth or more of the width, a concentrating photoelectric conversion device with high optical efficiency can be formed.

When the shape of the reflecting surface and the arrangement of the photoelectric conversion device are further generalized, the description of the means for solving the above-mentioned problem is as described in the first paragraph.

Next, an opening surface forming a space surrounded by the reflection surface and the reflection surface will be described with reference to FIG. FIG.
As shown in (a), when the end of the reflecting surface 3 has no irregularities, the opening surface should be a plane having the outer end 104 as the end of the reflecting surface 3 on the light incident surface side (upper part in the figure). Is easy to understand. Further, as shown in FIG. 22 (b), when the end of the reflection surface has irregularities, the plane 105 including the point 106 located at the innermost (lower side in the figure) among the ends of the reflection surface 3 A plane having an outer peripheral portion 104 as a line of intersection between the light and the reflection surface 3 is an opening surface.
In other words, the opening plane is the plane that forms the space with the largest volume in the space surrounded by the reflection surface in all other parts than the plane.

An embodiment of the present invention relating to a concentrating solar power generation device using the above-described photoelectric conversion device will be described with reference to FIG. FIG. 1A shows a concentrating photovoltaic power generation device in which a spherical photoelectric conversion device 1 and a reflecting surface 3 are combined to form a condensing device 7, and FIG. 1B shows a rectangular parallelepiped photoelectric conversion device 1.
A concentrating photovoltaic power generation device which is a condensing device 7 by combining the light-reflecting surface 3 with the light-reflecting surface 3 is shown. By combining the photoelectric conversion device 1 and the reflection surface 3 in this manner, the incident light 16 is reflected by the reflection surface 3 and enters the photoelectric conversion device 1 as shown in FIG. The reflection surface 3 forms a reflection surface 3 by rotating a straight line 6 about a rotation axis 8 as shown in FIG. The photoelectric conversion device 1 is installed inside the reflection surface 3 so as to be in contact with the light collecting device on the upper surface and the inclined surface. This makes incident light 1
6 is reflected by the reflection surface 3 and enters the photoelectric conversion device 1. By providing the reflecting surface 3 in this manner, when the incident angle of the incident light 16 is large, or when the incident light 16 is
Light that does not directly enter the photoelectric conversion device 1 when the light enters the end of 0 can be collected on the photoelectric conversion device 1 by reflection. Further, by filling the inside of the reflecting surface 2 with a medium having a higher refractive index than air, the incident light 16 is bent by refraction on the light collecting device surface 10, so that the incident angle can be substantially reduced. Further, when light is repeatedly reflected on the reflecting surface 3 and hits the light collecting device surface 10, depending on the angle, the light is totally reflected on the light collecting device surface 10 and is again reflected on the light collecting device 7.
The optical efficiency is increased because it is confined inside. In this shape, the light incident surface side (upper part) of the reflection surface 3 described above.
Is defined as an opening plane.

In such a shape of the reflecting surface of the condensing reflector of the concentrating solar power generation device, when the reflecting surface is cut out by an arbitrary surface including the rotation axis, both sides of the axis of this cross section are cut off. In the shape of each side, the point on the opening surface side of any two points on the side is located farther from the rotation axis, that is, outside, than the other point.

In this structure, the straight line 6 and the light collector surface 5
When the incident angle of the most inclined light of the sunlight to be condensed is θ _in , and the refractive index inside the light condensing device 7 is n, the light reflected by the reflecting surface 3 is mainly the light condensing device. conditions for total internal reflection strikes the surface 10 is θ> {arcsin (1 / n ) + arcsin (sin (θ in) / n)} is a / 2. Assuming that θ _in = 23.5 degrees and n = 1.5, θ> 2
8.6 degrees.

Assuming that the condensing magnification is (projected area of the concentrating solar power generation device on the horizontal plane) / (projected area of the photoelectric conversion device 1 on the horizontal plane), the condensing magnification in this case is about 12 times. .

Next, the case where the curve 6 is rotated to form the reflection surface 3 and the photoelectric conversion device 1 is combined with the reflection surface 3 will be described with reference to FIG. 3A is a bird's-eye view of the rotating body, FIG. 3B is a top view, FIG. 3C is a side view, and FIG.
FIG. 2 shows a front view, and FIG.

In the light collecting device 7, the reflecting surface 3 composed of a rotating body of a curve 6 is used in order to make the light reflected by the reflecting surface 3 more efficiently enter the photoelectric conversion device 1. As a result, when the light is reflected by the reflecting surface 3, the light incident on the end of the light-collecting device surface 10 changes its angle more greatly than the light incident on the central portion, so that the probability of being incident on the photoelectric conversion device 1 is increased. I can do it.

FIG. 5A illustrates a case where an arc is used as the curve 6 and a spherical photoelectric conversion device is used as the photoelectric conversion device 1. Considering light 16 incident on the left side of the axis of symmetry 12, when light inclined at 23.5 degrees passes through the surface 10 of the light-collecting device filled with a medium having a refractive index of 1.5, the inclination becomes 1
It will be 5.4 degrees. In order for the light of this inclination to enter the center of the right end of the photoelectric conversion device 1, the focal point 15 of the arc 6 needs to be at the center of the right end of the photoelectric conversion device 1. Since the focal length of the circle is about 0.476 of the radius, the photoelectric conversion device 1
Is 2 and the focal point 15 of the arc is located at the center of the right end of the photoelectric conversion device 1 and the arc is designed to pass through the center of the left end of the photoelectric conversion device 1, the radius of the circle becomes 2.77, Is located 1.4 above the center of the photoelectric conversion device 1 and 1.39 to the right of the symmetry axis 12. This arc-shaped photoelectric conversion device 1
By rotating an arc 6 having a height from the intersection with the center of the left end to the center of the circle on the left side around the axis of symmetry 12, incident light having an inclination of 0 to 23.5 degrees is centered on the photoelectric conversion device 1. The reflecting surface 3 can be designed to be incident. In this design, the focal length of the circle is set to about 0.476 in radius, but since the focal length of the light reflected at the end of the arc becomes short, even in the case of light inclined at 23.5 degrees or more, this arc 6 Can be used to collect light. In this description, the light tilted at 23.5 degrees has been described, but other tilts can be similarly designed.

In the above-described example, in the cross section of the curved reflecting surface formed of the rotating body, a circular flat surface having the outer end surface on the light incident surface side (upper side) of the reflecting surface 3 as an opening surface. is there. When an arc is used in this way, the inclination of the arc becomes vertical at the end of the opening. Further, even if a mirror surface perpendicular to the end of the reflection surface on the opening side is added, the optical efficiency does not decrease when the reflectance of the mirror surface is high. Therefore, in these cases, the shape of each side on both sides of the axis of the cross section is such that, at the end on the opening surface side, any two points on the side are positioned equidistant from the axis. However, at least in a portion far from the opening surface, a point on the opening surface side is located outside.

FIG. 5B illustrates a case where a rectangular parallelepiped photoelectric conversion device is used as the photoelectric conversion device 1. Also in this case, the design can be basically performed as described with reference to FIG. By setting the position of the focal point 15 of the arc below the upper end 17 on the right side surface of the photoelectric conversion device 1 having a rectangular parallelepiped shape, incident light can be efficiently collected.
The circular arc designed in this way is rotated around the axis of symmetry 12, and the reflection surface 3 is formed from the intersection of this rotating body and the side surface of the rectangular parallelepiped photoelectric conversion device 1 to a portion at the same height as the center of the circular arc. Thereby, it is possible to form a concentrating solar power generation device having high light condensing efficiency.

Further, as a modification of the above-mentioned shape of FIG. 5A, as shown in FIG.
A high light-collecting efficiency can be obtained even if the shape is located at the zenith or a shape having a focal point at an intermediate position between them, that is, a portion located on the right side of the spherical photoelectric conversion device 1 and located inside the reflection surface. Further, even if the focal point 15 is located at a position higher than the zenith part of the spherical photoelectric conversion device 1 as shown in FIG. Efficiency is obtained.

Next, a method of designing the reflecting surface 3 when a parabola is used as the curve 6 will be described with reference to FIG.

Basically, this is the same as the case where the arc described with reference to FIG. 5 is used. The parabola is expressed as y = (x ² ) / 4p in the xy plane, where p is the focal length. The curve is inclined so that the central axis 13 and the y-axis coincide with each other so that the origin 14 and the focal point 15 of the parabola pass on the central axis 13 and the focal point is located at the center of the right end of the photoelectric conversion device 1. If the parabola 6 is designed to pass through the center of the left end of the photoelectric conversion device 1, the parabola 6 is obtained. In this case, the light collector surface 1
Zero can be as high as the point where the slope of the parabola is vertical. However, in this case, the height of the light-collecting device is much higher than that of the photoelectric conversion device 1, and thus the height of the light-collecting solar power generation device is increased. If the height is high, incident light having an incident angle larger than the angle of the most inclined light that can be surely condensed by the light condensing device can hardly be condensed on the photoelectric conversion device 1. For this reason,
It is important to determine the position of the light-collecting device surface 10 so that the product of the light-collecting magnification and the optical efficiency becomes the highest.

As described above, as the first curve, an arc-shaped reflecting mirror, a parabolic reflecting mirror, and the like can be considered as typical shapes. However, in consideration of the manufacturing cost of the photoelectric conversion device, the light-condensing magnification, and the optical efficiency. It is desirable to adopt a structure that minimizes the manufacturing cost of the concentrating solar power generation device. In such a structure, it may be preferable to use a curved reflecting mirror having a curvature between them in addition to the arc reflecting mirror and the parabolic reflecting mirror. In addition, due to limitations in machining accuracy and restrictions in terms of machining cost, there may be cases in which the curvature of the uneven portion is reduced or the surface accuracy is reduced without using a curved reflecting mirror that precisely matches these curves. I can imagine. Also in these cases, it is needless to say that the manufacturing cost of the concentrator photovoltaic power generator can be reduced by making the main part of the curved reflecting mirror close to the curved shape of the above design.

Further, in the above example, the shape in which the upper half of the spherical photoelectric conversion device is installed in the reflecting mirror has been described.
The photoelectric conversion device may be installed at a higher position or a lower position than this, especially when the reflection surface shape is a shape with a high light collection magnification, the optical efficiency is higher if the photoelectric conversion device is installed on the upper side. .

As a modification of the above-mentioned reflection surface shape, FIG.
As shown in (a) and (a '), a multi-stage reflecting surface 100 having a shape in which a plurality of reflecting surfaces having different inclinations are combined, that is, having a convex portion whose cross section of the reflecting surface is a polygonal line. It is conceivable to approximate the above-mentioned reflection surface. As shown in FIGS. 29 (b) and (b ′), when formed so as to be polygonal when viewed from the top, when the cross-sectional shape is a curve, the vertical multi-stage reflecting surface has: In the case of a polygonal line, it has a polyhedral multi-stage reflecting surface or a condensing reflecting poly surface. Even with these shapes, a reflection surface with high optical efficiency can be produced.

The structure of the above concentrating photovoltaic power generation device employing a grooved reflecting surface having a groove structure in the cross section as the reflecting surface 19 will be described with reference to FIG. The groove is formed on the rotating surface of the reflecting surface 19 in the direction of the rotation axis. When the reflected light 20 reflected by the reflecting surface 3 runs along the optical axis 22 as shown in FIG. 3A, the angle 24 at which this light enters the light collector surface 10 is too large to be totally reflected. In this case, this light is
The light passes through 0 and exits the light collecting device. However, as shown in FIG. 3B, when the light is reflected by the grooved reflecting surface 19, the light is reflected along the optical axis 23 by the groove, so that the angle formed between the reflected light 21 and the light collecting device surface 10 is reduced. It becomes smaller than the case of FIG. Therefore, the light is totally reflected on the light-collecting device surface 10 and turned back inside the light-collecting device, so that the light-collecting efficiency is increased.

When a concentrating photovoltaic power generation device is formed by using a plurality of the concentrating photovoltaic power generating devices as described above, as shown in FIG. A module is formed with a constant. However, in this case, the light 29 incident on the module surface is all reflected in the same direction. This is the same as installing a mirror on the surface of the module. Depending on the angle of the sunlight, spots due to the reflected light 30 may be generated around the module, causing discomfort due to glare, and in some cases this may cause an accident. It is also possible to cause. In order to prevent the occurrence of harm caused by such reflected light, the surface of the light-collecting device surface 10 may be curved, or the surface of each light-collecting device surface 10 may be slightly inclined, and the inclination may be directed in various directions. It is conceivable to reduce the harm of reflection. As an example of this, FIG.
In the case where the lens-shaped curved surface 28 is provided on the surface of the light-collecting device as shown in (1), as the curvature of the curved surface 28 increases, the harm caused by reflection can be reduced, but the optical efficiency of the light-collecting device decreases. Further, when the irregularities become large, dust tends to be deposited on the module surface. In particular, in order to suppress a decrease in optical efficiency, it is necessary to suppress the lens thickness to 15% or less of the lens width.

The shape of the lens is shown in FIG.
(A), (b), and (c) the surface of the concentrating photovoltaic power generation device 90 having an uneven surface is rotated around the Y axis. A two-dimensional curved surface such as a cylindrical lens obtained by extending the lens in the axial direction can be considered.

The direct light component, which accounts for about 70% of the sunlight, tilts ± 23.5 degrees north-south depending on the season, centering on the slope of the vernal equinox, and mainly in the east-west direction from horizontal to mid-south in the morning and evening. Greatly change. For this reason, the light-collecting device was designed so that the light-collecting characteristics became stronger in the east-west direction, and ± 2
By designing such that only the light of 3.5 degrees can be collected, the light collection magnification can be increased. This example will be described with reference to FIG. For example, when making a curve using an arc and a parabola, by using a highly polar arc for the east-west curve along the Z-axis in FIG. 10 and using a parabola with a small curvature for the north-south curve along the X-axis. The light collection magnification can be increased as compared with the case where only an arc is used. In this case, the curvature between the east-west direction and the north-south direction is gradually changed to create a gentle reflection surface. That is, X-
The Z sectional shape is an ellipse. In such a reflecting surface, both sides of a cross section including the Y axis in FIG. 10 are symmetrical, and a cross section of the reflecting surface in the Z axis direction having the maximum value of curvature and the X direction in the X axis direction having the minimum value. Is orthogonal to the cross section of the reflection surface.

A method for forming a concentrating photovoltaic power generation module using a plurality of concentrating photovoltaic power generation devices described above will be described with reference to FIG. When the concentrating photovoltaic power generation device 35 whose shape as viewed from the top is a circle or an ellipse is combined, as shown in FIG. A space 36 that is not filled with the power generator 35 is formed. For this reason, the filling efficiency of the concentrating photovoltaic power generation device 35 in the concentrating photovoltaic module 37 decreases, and the photoelectric conversion efficiency of the concentrating photovoltaic module decreases. In order to prevent this, FIG.
As shown in FIG. 11, the concentrator photovoltaic power generator is cut off at a hexagon 34 inscribed in the outer periphery 33 of the concentrator photovoltaic power generator, and these are combined to form a concentrator photovoltaic power generator as shown in FIG. By forming the module 37, the filling efficiency can be made 100%. Further, this shape is not limited to a hexagon, and the filling efficiency can be increased by using a square or a triangle.

When the concentrator photovoltaic power generator having the above shape is used alone, it is necessary to form a reflecting mirror on a hexagonally cut side surface and use this surface as a reflecting surface. This is to prevent the light incident on this surface from being emitted to the outside of the concentrator photovoltaic power generation device, thereby reducing the optical efficiency. In this case, the hexagon on the upper side of the hexagon wall 34 is the opening surface. However, when forming a concentrating photovoltaic power generation module using a plurality of hexagonal concentrating photovoltaic power generating devices, it is not necessary to form a reflector on the cut end face of the concentrating photovoltaic power generating device. However, the light incident on this surface enters the adjacent concentrating photovoltaic power generation device and enters the photoelectric conversion device installed in the concentrating photovoltaic power generation device. Does not decrease the photoelectric conversion efficiency.
On the other hand, since light from the adjacent concentrator photovoltaic power generator enters this concentrator photovoltaic power generator, the photoelectric conversion efficiency and optical efficiency of the concentrator photovoltaic power generator are substantially hexagonal. There is no difference between those with mirrors on the side and those without mirrors. Rather, considering the reflectivity of the reflector, it is more advantageous to have no reflector. In addition, when the reflecting mirror is not formed, instead of forming individual concentrating photovoltaic power generation devices and then combining them, these aggregates can be formed as a continuous integrated photovoltaic device. Reduction can be achieved. In such a shape, as shown in FIG. 30B, a point 1 located at the innermost (lower) side of the end of the reflecting surface 3
The portion inside the reflecting surface 3 of the plane 105 including the reference numeral 06 is defined as an opening surface. Also in this case, similarly to the shape as shown in FIG. 30A, the reflection surface of the condensing reflection mirror always exists at a portion located inside (below) the opening surface.

When the concentrator photovoltaic power generation device has an elliptical shape instead of a circle as described with reference to FIG. 10, the outer periphery is not a regular hexagon but a vertical shape as shown in FIG. 12 (b), the filling efficiency of the concentrating photovoltaic power generation device in the concentrating photovoltaic power generation module can be made 100%.

FIG. 13 shows an overall view of the concentrating solar power generation module. When the outer shape of the concentrator photovoltaic module is made to be a quadrangle without unevenness, it is necessary to use a concentrator photovoltaic power generator cut in half or a quarter. In this case, the first 1/2 concentrating solar power generation device 39 and the second 1/2
In the two-concentration type photovoltaic power generation device 40, the 1/4 concentrator type photovoltaic power generation device 41, and the like, the power generation characteristics differ due to the difference in their optical characteristics and the difference in symmetry. Therefore, when extracting the power generated by these concentrator photovoltaic power generators, take measures such as connecting the concentrator photovoltaic power generators of each type or combining them in consideration of symmetry. Thereby, the power generation amount of the concentrating solar power generation module can be optimized.

Embodiment 1 FIG. 14 shows the structure of a concentrating solar power generation device and a concentrating solar power generation module according to Embodiment 1 of the present invention. FIG. 3A shows an example in which a circular rotating body is used for the reflecting surface 3.
FIG. 3A shows an example in which a linear rotating body is used for the reflection surface 3. In these concentrator photovoltaic power generation devices, the photoelectric conversion device 1 has a diameter of 2 m using single crystal silicon.
m spherical photoelectric conversion device was used. The condensing device cuts the reflecting surface consisting of an arc or a straight rotating body with a hexagonal wall,
Create a mold with a shape in which a plurality of recessed shapes for placing a spherical photoelectric conversion device are placed on the surface at the bottom,
A glass or acrylic resin having a refractive index of about 1.5 is filled therein, and after taking out from the mold, an aluminum thin film is formed on the back surface by a vacuum deposition method to form a mirror surface having a reflectance of about 95%. By doing so, it was integrally molded. An EVA transparent resin is fixed to a concave portion below the center of each reflecting surface 3 in the light collecting device using an EVA transparent resin as an adhesive so that the hemispherical portion of the photoelectric conversion device 1 enters the inside of the reflecting surface. The light-collecting photoelectric conversion module as shown in FIG. In this case, the width of the semiconductor portion in the space surrounded by the reflection surface and the opening surface is 2 mm, the height is 1 mm, and the height is half the width. The cross section taken along the line AA 'is shown in FIG. In this way, the cross sections of the large and small rotating bodies are arranged. When the size of the concentrator photovoltaic power generation device is small, it is possible to integrally mold the same filler and cover glass material inside the concentrator device. The first wiring 59 and the second wiring 60 were connected to the main concentrating photovoltaic power generation device, and connected in series or in parallel, respectively. Also, 1/2
Third wiring 61 connected to concentrating solar power generation device 40
And the fourth wiring 62 is a 1/2 concentrating solar power generation device 4
After connecting the wires to each other and connecting them in parallel, they were further connected in series or parallel to the first wiring 59 and the second wiring 60. The cross section taken along the line BB 'has a shape as shown in FIG.

Embodiment 2 FIG. 15 shows the structure of a concentrating solar power generation device and a concentrating solar power generation module according to Embodiment 2 of the present invention. The main part is the same as that of the first embodiment. However, the surface of the cover glass is formed as a lens-shaped surface 63, thereby preventing the harm caused by the reflected light. As the shape of this lens, a spherical lens shape having a height of 8% of the width of the outer periphery of the surface of the concentrator photovoltaic power generation device was adopted.

Third Embodiment FIG. 16 shows the structure of a concentrating solar power generation device and a concentrating solar power generation module according to a third embodiment of the present invention. As shown in FIG. 3A, a rotating body in which a circular arc and a parabola are formed in a cross section is used as a condensing / reflecting side surface 19, which is cut out in a vertically long hexagon. A mold with a groove was created. Example 1 using this
A concentrator photovoltaic module was created in the same manner as described above. In this concentrating solar power generation device, a spherical photoelectric conversion device having a diameter of 1 mm using polycrystalline silicon was used as the photoelectric conversion device 1.

Embodiment 4 FIG. 17 shows the structure of a concentrating solar power generation device according to Embodiment 4 of the present invention. In the concentrating solar power generation device of the present invention,
When the outer periphery of the reflection surface is a circle, it is circularly symmetric when viewed from above.
In the case of an ellipse, a plane passing through the long axis and the short axis is a plane of symmetry. Further, in the case of having a hexagonal side surface, a surface connecting the vertices and a surface connecting the midpoints of two opposing sides are symmetrical surfaces. Considering the case where the light incident on these surfaces is reflected by the mirror 64 placed on this surface as shown in FIG. 17B and the case where the light is transmitted without a mirror as it is, the reflected light 67 and the transmitted light 6
6 travels symmetrically in the opposite direction to the plane of symmetry. That is, when the concentrator photovoltaic power generation device is folded back on the symmetry plane, both the transmitted light and the reflected light pass through the same trajectory. Therefore, the trajectories through which these lights pass while repeating reflection are substantially the same. Therefore, when a mirror having a reflectance of 100% is placed, the optical efficiency is exactly the same as when there is no mirror. Therefore, mirror 6
4. If the reflectance is high and the thickness is sufficiently smaller than the width of the concentrator photovoltaic device, the optical characteristics of the concentrator photovoltaic device will be almost degraded even if there is a reflective surface on the symmetry plane. There is no. Therefore, as shown in FIG. 17C, the electrode 70 was formed of plate-like silver or aluminum having a high reflectivity, and was connected to the photoelectric conversion device 1 using solder or conductive paste to make electrical contact. As a result, the area of the electrode extracted from the photoelectric conversion device 1 can be increased, so that the power loss due to the electrode resistance can be reduced.

In the above description, examples were given in which a spherical solar cell using single crystal silicon or a spherical photoelectric conversion device using polycrystalline silicon was used as the photoelectric conversion device. However, the photoelectric conversion device used in the present invention does not need to be limited to the structure of the above-described photoelectric conversion device. As a main material of the photoelectric conversion unit, amorphous silicon, GaAs, CIS, CdTe, Needless to say, a material using InP or another compound as a raw material may be used.

In the above embodiment, FIG.
FIG. 18B shows an example in which a photoelectric conversion device is formed using a spherical or cubic semiconductor material as shown in FIG.
It is possible that the shape may be an expanded sphere as shown in FIG. 1, an octahedron as shown in FIG. 4 (d), a pyramid shape, a shape having irregularities or protrusions on the surface thereof, or a shape obtained by splitting them into two. Needless to say.

Further, the shape of the portion of the photoelectric conversion device having such a shape that protrudes outside the reflection surface does not contribute to the collection of incident light at all. For this reason, the shape of this portion may be any shape, and by arranging the electrode and the contact with the electrode in this portion, it is possible to easily connect to the external wiring.

Fifth Embodiment FIG. 19 shows the structure of a concentrating solar power generation device and a concentrating solar power generation module according to a fifth embodiment of the present invention. FIG. 3C is a cross-sectional view in the north-south direction when the concentrating solar power generation device is installed on the roof of the house. The surfaces of the northern roof 77 and the southern roof 88 are not generally perpendicular to the axis 79 inclined at the same angle as the latitude from the perpendicular 78, and are particularly greatly inclined in the northern roof. This angle 82 will be referred to as a shift angle. When the concentrator photovoltaic module is installed under such a condition having a shift angle, sunlight enters in advance from the axis 81 perpendicular to the concentrator photovoltaic module by a shift angle 82. It is desirable to design it. For this purpose, as shown in FIG. 7A, the converging type photovoltaic power generation device surface 83 is tilted by the shift angle 82 of the rotationally symmetric axis 12 of the reflecting surface 3 so that the conventional concentrating photovoltaic power generating device surface 84
The reflecting surface was cut out so as to be inclined by a deviation angle from the reflecting surface. By using a plurality of these, a concentrating solar power generation module as shown in FIG. By installing this concentrating solar power generation module on the north roof 77, the amount of power generation could be increased. Further, since the incident light is actually refracted on the surface 83 of the concentrator photovoltaic device, the refractive index of the filler inside the concentrator photovoltaic device is set to n,
Assuming that the shift angle is θ _d , the concentrating photovoltaic device surface 83 and the conventional concentrating photovoltaic device surface 84 are inclined by an angle θ that satisfies θ = arcsin (sin (θ _d ) / n). By doing so, the light collection efficiency could be further improved.

The shapes of the concentrating photovoltaic power generation device and the concentrating photovoltaic power generation module have been described above. However, these shapes describe an ideal case. Since it may be necessary to round or to secure a margin for cutting or gluing, the shape of the concentrating solar power generation device or the concentrating solar power generation module created is strictly the shape of the above invention. It seems that there is a case that does not match. However, it goes without saying that the effects of the present invention can be obtained if the structure and shape of the present invention are substantially followed.

[0045]

According to the present invention, since the area of the photoelectric conversion device used in the photovoltaic module can be reduced and the filling efficiency can be increased, the manufacturing cost of the photovoltaic module can be significantly reduced. Can be done.

[Brief description of the drawings]

FIG. 1 is a structural diagram of a concentrating solar power generation device of the present invention.

FIG. 2 is a structural diagram of a concentrating solar power generation device of the present invention.

FIG. 3 is a structural view of a concentrator photovoltaic power generation device of the present invention.

FIG. 4 is a structural diagram of a conventional solar power generation device using a spherical photoelectric conversion device.

FIG. 5 is a structural diagram of a photoelectric conversion device of the present invention.

FIG. 6 is a structural diagram of a concentrating solar power generation device of the present invention.

FIG. 7 is a structural diagram of a concentrating solar power generation device of the present invention.

FIG. 8 is a structural view of a concentrating solar power generation device of the present invention.

FIG. 9 is a structural diagram of a concentrator photovoltaic power generation device of the present invention.

FIG. 10 is a structural diagram of a concentrator photovoltaic power generation device of the present invention.

FIG. 11 is a structural diagram of a concentrating solar power generation device and a concentrating solar power generation module of the present invention.

FIG. 12 is a structural diagram of a concentrating solar power generation device and a concentrating solar power generation module of the present invention.

FIG. 13 is a structural view of a concentrating solar power generation module of the present invention.

FIG. 14 is a structural view of a concentrating solar power generation module according to the present invention.

FIG. 15 is a structural view of a concentrating solar power generation module of the present invention.

FIG. 16 is a structural diagram of a concentrating solar power generation module of the present invention.

FIG. 17 is a structural diagram of a concentrator photovoltaic power generation device of the present invention.

FIG. 18 is an explanatory diagram of the shape of the photoelectric conversion device of the present invention.

FIG. 19 is a structural diagram of a concentrating solar power generation device and a concentrating solar power generation module of the present invention.

FIG. 20 is a structural diagram of a conventional concentrating solar power generation device.

FIG. 21 is a structural diagram of a concentrator photovoltaic power generator of the present invention.

FIG. 22 is a structural view of a concentrator photovoltaic power generator of the present invention.

FIG. 23 is a structural view of a concentrating solar power generation device of the present invention.

FIG. 24 is a structural view of a concentrator photovoltaic power generator of the present invention.

[Explanation of symbols]

1: photoelectric conversion device, 2: inside reflective surface, 3: reflective surface, 4:
Aluminum support substrate, 5: light collector surface, 6: straight line or curve, 7: light collector, 8: rotation axis, 10: light collector surface,
12: symmetry axis, 13: central axis, 14: center of arc or origin of parabola, 15: focal point of arc or parabola, 16:
Incident light, 17: upper right end of the photoelectric conversion device, 19: condensing / reflecting side surface having a groove structure, 20: reflected light 1, 21: reflected light 2, 22: optical axis 1, 23: optical axis 2, 24: angle One, two
5: Angle 2, 26: First electrode, 27: Second electrode, 2
8: curved surface, 29: incident light, 30: reflected light, 31: north-south (Z-axis) direction curve, 32: east-west (X-axis) direction curve, 3
3: Concentrating photovoltaic power generation device outer periphery, 34: Hexagon wall, 35:
Concentrating solar power generation device, 36: space, 37: concentrating solar power generation module, 38: hexagonal concentrating solar power generation device, 39: first 1/2 concentrating solar power generation device , 40:
Second 1/2 concentrating solar power generation device, 41: 1/4 concentrating solar power generation device, 42: frame, 56: solder for electrode wiring, 58: cover glass, 59: first wiring, 60:
Second wiring, 61: third wiring, 62: fourth wiring, 6
3: lenticular surface, 64: mirror, 65: incident light, 6
6: transmitted light, 67: reflected light, 70: electrode, 71: external electrode, 76: south roof, 77: north roof, 78: perpendicular, 7
9: an axis inclined at the same angle as the latitude from the perpendicular, 80: the same angle as the latitude, 81: an axis perpendicular to the concentrating solar power generation module, 82: an axis inclined at the same angle as the latitude from the perpendicular and the condensing sunlight Angle (offset angle) of the axis perpendicular to the power generation module, 8
3: Concentrating photovoltaic device surface, 84: Conventional concentrating photovoltaic device surface, 85: height, 86: width, 87: depth, 88: spherical or rectangular parallelepiped, 100: multi-stage reflecting surface,
102: multi-stage reflecting surface or condensing reflecting surface, 104: outer peripheral portion of opening surface, 105: plane including opening surface, 106: point located inside the end of reflecting surface, 107: existing in space A shape projected on a plane perpendicular to the axis of the massive semiconductor material, 108: a shape projected on a plane parallel to the axis of the massive semiconductor material existing in the space, 109: width, 110: height.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Shinichi Muramatsu 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. Central Research Laboratory (72) Inventor Hiroyuki Otsuka 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo Hitachi Central Research Laboratory, Ltd.

Claims (16)

[Claims] 1. A condensing and reflecting mirror, and a photoelectric conversion device installed so that at least a part thereof is located in a space surrounded by a curved reflecting surface and an opening surface of the collecting and reflecting mirror. Having a medium with a higher refractive index than air filling the space, wherein the shape of the reflective surface is a cross section of the reflective surface cut out by any surface including an axis passing through the opening surface and the space. The relationship that the side on the opening surface side of the arbitrary two points on both sides of the axis is located at the same distance from the other axis as the point on the opening surface side and the relationship that is located outside the other point. The shape in which the axis having the relationship located at least on the outside exists, and a projection image of a portion formed of the semiconductor material of the photoelectric conversion device located in the space on a plane parallel to the axis. The maximum height in the axial direction is the minimum of the projected image on a plane perpendicular to the axis. Concentrator photovoltaic device, characterized in that it is 5 minutes 1 or more of. 2. The concentrator photovoltaic power generator according to claim 1, wherein a portion of the photoelectric conversion device made of a semiconductor material has a spherical shape. 3. The concentrator photovoltaic power generator according to claim 1, wherein the portion of the photoelectric conversion device made of a semiconductor material is a rectangular parallelepiped. 4. The concentrator photovoltaic power generation device according to claim 1, wherein sides of the cross section of the reflection surface on both sides of the axis are symmetrical, and the reflection surface has a maximum value of curvature of the side. And a cross section of the reflection surface having the minimum value is orthogonal to the cross section. 5. A concentrator photovoltaic power generation device according to claim 1, wherein said concentrator photovoltaic power generator has a cross section of said reflection surface having different lengths on both sides of said axis. apparatus. 6. The concentrator photovoltaic power generator according to claim 1, wherein said axis and said opening face are obliquely intersected. 7. The concentrator photovoltaic power generator according to claim 1, wherein said reflection surface is a rotating body, and said axis is a rotating axis of said rotating body. Light type solar power generator. 8. The concentrator photovoltaic power generation device according to claim 7, wherein a curve on one side of the rotation axis in a cross section of the rotator has a portion closest to an opening surface of the photoelectric conversion device, or A part of a parabola, drawn with a focus on a surface located on the other side of the axis of rotation of the type photoelectric conversion device,
A concentrating photovoltaic power generation device having one shape of an arc or a curve located between a part of the parabola and the arc. 9. The concentrator photovoltaic power generator according to claim 1, wherein a portion of the photoelectric conversion device that is continuous with the portion in contact with the reflection surface is a portion of the reflection mirror. A concentrating photovoltaic power generation device that protrudes outside, and an electrode is formed on the protruding portion. 10. The concentrator photovoltaic power generation device according to claim 1, wherein a V-groove is formed on the reflection surface in a length direction of the axis. Concentrating solar power generator. 11. The concentrator photovoltaic power generator according to claim 1, wherein the light incident surface of the medium is a curved surface. . 12. The concentrating photovoltaic power generation device according to claim 1, wherein the projection surface of the concentrating photovoltaic power generation device viewed from the light incident surface side is a square. Or 6
A concentrating solar power generation device having a square shape. 13. The concentrator photovoltaic power generator according to claim 1, further comprising a plate-shaped electrode provided on the opening side of the photoelectric conversion device. Concentrating solar power generator. 14. A concentrating photovoltaic power generation module comprising a plurality of concentrating photovoltaic power generation devices according to claim 1 formed into a module. 15. The concentrating solar power generation module according to claim 14, wherein the medium filled in the reflector is continuous between the plurality of concentrating solar power generation devices. Concentrating solar power module. 16. The concentrator photovoltaic module according to claim 14, wherein the light incident surfaces of the plurality of concentrator photovoltaic devices are covered with a protective plate, and the medium and the protective plate are covered by a protective plate. Is a concentrating photovoltaic module, wherein the concentrating photovoltaic modules are formed of the same material and are continuous with each other.