JPH10200140A - Solar battery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar battery device wherein driving parts for tracking the sun is reduced, and the occupation area of the solar battery is reduced while a hot water of a high temperature is obtained as required. SOLUTION: Rectangular solar battery cells 10 are provided, in parallel, with a constant interval, and over them, cooling water holes 12 for cooling the solar battery cells 10 are provided. Further, a hot water hole 14 is provided where no solar battery cell 10 is provided, and the hot water flowing the hot water hole 14 is heated to the high temperature under the sun light 40, which is used as a high temperature hot water. The front surface side of solar buttery cell 10 is directly irradiated with the sun light 40, while the light reflected on a mirror 42 comes to the rear surface side of the solar battery cell. In order that the light reflected on the mirror 42 always comes in the rear surface of the solar battery cell 10, a distance (I) between the mirror 42 and the solar battery cell 10 is changed according to the sun's movement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell device, and more particularly to an improvement in a solar cell device using a double-sided electrode type solar cell.

[0002]

2. Description of the Related Art Conventionally, in order to reduce the cost of a power generation system using solar cells, a technique has been known in which sunlight is condensed using a lens to reduce the use area of expensive solar cells. . At that time, a technique of tracking the sun to improve the power generation efficiency of the solar cell device is also known.

[0003] In such a concentrating solar cell device, a cooling device is provided to prevent the temperature of the solar cell from rising and thereby reducing the power generation capacity. For example, JP-A-5-83881 discloses an example of a method for cooling a solar cell.

[0004]

However, in the above-mentioned conventional solar cell device, there is a problem that energy consumed by the tracking system is required, and the number of driving parts is large and the number of steps for maintenance is also large. In addition, in the case of the condensing type, a condensing device is required, and the temperature of the solar cell is increased by condensing, so that a cooling device having a high cooling capacity is also required. For this reason, the cost of the solar cell device is increased, and there is a problem that the effect of reducing the area of the solar cell is reduced.

In addition, the temperature of the hot water produced by the solar cell device is about 40 ° C. to 50 ° C., and even if the cost of the cooling device is increased, the temperature of the obtained hot water is low. There was also the problem of being limited.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to reduce the number of driving parts for tracking the sun, to reduce the use area of the solar cell, and to increase the temperature of the solar cell if necessary. It is to provide a solar cell device capable of obtaining hot water.

[0007]

Means for Solving the Problems In order to achieve the above object, a first aspect of the present invention is a solar cell device for efficiently generating electric power by using both sides of a solar cell, and a light receiving device of the solar cell device. A solar cell having light receiving surfaces on both sides arranged in half the area, and a mirror provided on the back side of the solar cell, and the front surface of the solar cell is directly irradiated with sunlight. In addition, the back surface is irradiated with the reflected light reflected by the mirror.

According to a second aspect of the present invention, in the solar cell device according to the first aspect of the present invention, the angle of reflection from the mirror is changed along with the operation of the sun so that the mirror always reflects the rear surface of the solar cell. It is characterized by having mirror turning means for turning.

According to a third aspect of the present invention, in the solar cell device of the first aspect, the distance between the solar cell and the mirror is changed with the operation of the sun so that the reflected light always hits the back surface of the solar cell. And a mirror up / down driving means for driving the mirror.

According to a fourth aspect, in the solar cell device according to the third aspect, a cam is used for the mirror vertical drive means,
By rotating the cam, the distance between the mirror and the solar cell is changed in accordance with the operation of the sun.

According to a fifth aspect of the present invention, in the solar cell device of the first aspect, the relative position between the solar cell and the mirror is fixed, and the solar cell always reflects on the back surface of the solar cell as the sun operates. It is characterized by having a rotation driving means for integrally rotating the solar cell and the mirror so that light enters.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1A is a plan view of a solar cell device according to the present invention, and FIG. 1B is a sectional view taken along line BB of FIG. In FIG. 1 (a), rectangular solar cells 10 are arranged in parallel at a constant interval from each other,
A cooling water system for cooling the solar cell 10 and a hot water system for producing hot water using solar heat are provided. As shown in FIG. 1B, the solar cells 10 are arranged so as to be separated from each other by the same length as their own width. Accordingly, as shown in FIG. 1A, the solar cell 10 is arranged in an area that is half the light receiving area of the solar cell device. In addition, the solar cell 10 has a configuration in which light receiving surfaces are provided on both upper and lower surfaces, and power can be generated by receiving sunlight on both surfaces.
Above the solar cell 10, a transparent plate 16 made of glass or the like having a cooling water hole 12 and a hot water hole 14 is arranged. The cooling water hole 12 and the hot water hole 14
As shown in (a), it has the same width as the solar cell 10 and is arranged in parallel with the solar cell 10.

As shown in FIG. 1A, the cooling water system includes a cooling water supply header 18 for supplying cooling water to the cooling water holes 12, and a cooling water outlet header for collecting the cooling water from the cooling water holes 12. 20, a cooling water tank 22, a radiator 24 for radiating the temperature collected by the cooling water and reducing the temperature of the cooling water, and a cooling water pump 26 for circulating the cooling water. When the amount of water in the cooling water system is insufficient, cooling water is supplied from the cooling water supply tower 28 into the system.

On the other hand, the hot water system includes a hot water supply header 30 for supplying hot water to the hot water holes 14, a hot water outlet header 32 for collecting hot water coming out of the hot water holes 14, a hot water tank 34 for storing hot water, and a circulation of hot water. And a hot water pump 36. The hot water tank 34 is provided with a faucet 38 for taking out hot water. Further, when hot water is insufficient in the hot water system, cooling water is supplied from the cooling water tank 22.

With the above configuration, the solar cell 1
Cooling water having a low temperature is supplied from a cooling water system to the cooling water holes 12 for cooling the solar cell 10, so that the cooling of the solar battery cells 10 can be sufficiently ensured. In addition, by making the hot water system a separate system from the cooling water system, the temperature of the hot water can be set higher than the cooling water, and high-temperature hot water that is useful as hot water can be obtained. In the present embodiment,
It is not necessary to constantly circulate the cooling water, and the cooling water may be circulated by the cooling water pump 26 only when the temperature of the solar battery cell 10 becomes higher than a predetermined value. Thereby, the driving energy of the cooling water pump 26 can be saved. As described above, two water circulation systems can be used because the photovoltaic cells 10 are installed in half the light receiving area of the photovoltaic device. This is because the other half needs to be cooled with cooling water.

In FIG. 1B, the solar cell 10 has light-receiving surfaces on both sides as described above, and the front surface is directly irradiated with sunlight 40 via the transparent plate 16.
On the other hand, a mirror 42 is provided on the rear surface side of the solar cell 10, and the sunlight 40 is reflected by the mirror 42 and irradiates the light receiving surface on the rear surface side of the solar cell 10. As the incident angle θ of the sunlight 40 changes with time with the operation of the sun, the refraction angle when passing through the transparent plate 16 changes according to the change of the incident angle θ. The angle also changes. However, description will be made here ignoring the influence of the refractive index. In the present embodiment, the distance 1 of the mirror 42 from the solar cell 10 is changed, and the reflected light from the mirror 42 is always applied to the back surface of the solar cell 10 in accordance with the change in the reflection angle of the sunlight 40 on the mirror 42. Is controlled to hit.

FIG. 2 shows the solar cell 10 of the mirror 42.
An example of a mirror up / down driving means for controlling a distance 1 from the mirror is shown. In FIG. 2, the mirror 42 is disposed on a cam 44, and the cam 44 is mounted on a shaft 48 rotated by a motor 46. Therefore, when the incident angle of the sunlight 40 changes with the operation of the sun, the cam 44 is rotated by the motor 46 to change the distance 1 of the mirror 42 from the solar cell 10. An example of a cam 44 used in FIG. 2 is shown in FIG. Cam 44
The diameter from the axis 48 is determined for each hour of the day. This corresponds to the fact that the incident angle θ of the sunlight 40 changes with time. Note that the mirror up / down driving means for moving the mirror 42 up and down is not necessarily limited to the one using a cam, and any structure capable of performing the up / down movement of the mirror 42 can be adopted.

In this embodiment, the sunlight 40
Is reflected by the mirror 42 and is incident on the solar battery cell 10 and is not condensed by a lens or the like. Therefore, the temperature rise of the solar battery cell 10 is uniform at each part of the cell, and only one side of the cell is exposed. The range is about twice as large as that in the case of irradiating the sun with the sunlight 40. For this reason, the cooling system described above does not need to be a device having a large cooling capacity. Therefore, the apparatus cost can be reduced accordingly.

FIG. 10 shows the measurement results of the amount of power generation when the solar cell device according to this embodiment described above is used. In FIG. 10, the horizontal axis represents time, and the vertical axis represents the amount of power generated by the solar cell device. In FIG.
a is the power generation amount when the reflectance of the mirror 42 is 100%, and b is the power generation amount when the reflectance is 70%. Also,
c is the amount of power generated when power is generated only on one surface side of the solar cell 10 when the mirror 42 is not provided. Reflectance is 1
In both cases of 00% and 70%, the amount of power generation is greatly increased as compared to c in which power is generated only on one side of the solar cell 10. In particular, the reflectance of the mirror 42 is set to 10
In the case of 0%, the amount of power generation is about twice as much as the power generation on one side shown by c. As a result, in the present embodiment, even if the area of the solar cell 10 is reduced by half, it is understood that the same amount of power generation as when the entire light receiving surface of the solar cell device is a solar cell can be obtained. In addition, in a and b shown in FIG. 10, the amount of power generation is reduced between 11:00 and 13:00 because the sunlight 40 enters the mirror 42 at an angle of about 90 °. This is because it is difficult to make the light reflected by 42 incident on the back surface side of solar cell 10.

The method of causing the sunlight 40 reflected by the mirror 42 to always enter the back surface of the solar cell 10 with the operation of the sun is not limited to the above example. For example, a configuration in which the mirror 42 is divided into corresponding portions each having the same width as each of the solar cells 10 and each of the divided mirrors 42 is rotated in accordance with the operation of the sun by mirror rotation means (not shown). It may be. According to this configuration, the reflection angle from the mirror 42 is changed with the operation of the sun, and the reflected light can always be applied to the back surface of the solar cell 10.

As shown in FIG. 1 (b), the solar cell 10 is bonded to a transparent plate 16 such as glass. FIGS. 4 (a) and 4 (b) show examples of this bonding method. It is. In FIG. 4A, first, the transparent plate 16 and the solar cell 10
And a transparent film 50 such as an ethylene vinyl acetate (EVA) film. Next, the transparent film 50 is similarly stacked from the outside of the solar cell 10. These are integrally attached to the transparent plate 16, and the solar cell 10 is fixed to the transparent plate 16. FIG.
In (b), there is no transparent film 50 between the transparent plate 16 and the solar cell 10, and the transparent film 50 exists only outside the solar cell 10. The solar cell 10 is attached and fixed to the transparent plate 16 by the transparent film 50.

FIGS. 5 (a), 5 (b) and 5 (c) show an example of a method for cooling the solar battery cell 10. FIG. In FIG. 5A, the solar cell 10 is fixed to the transparent plate 16 by a method as shown in FIG. 4, for example, and a cooling water hole 12 is provided at a position corresponding to the solar cell 10. ing. Further, hot water holes 14 are provided corresponding to positions where the solar battery cells 10 do not exist. In this case, FIG.
However, as described above, it is possible to set the temperatures of the cooling water and the hot water flowing through the cooling water holes 12 and the hot water holes 14 to different values. In the example shown in FIG. 1B,
The cooling water hole 12 and the warm water hole 14 are formed by hollowing out the inside of one transparent plate 16. For example, as shown in FIG. 5A, a partition 52 is formed between the two plates. The cooling water hole 12 and the hot water hole 14
May be distinguished.

FIG. 5B shows an example in which the cooling water holes 12 and the warm water holes 14 are not provided separately. Also in this example, the solar cell 10 is fixed to the transparent plate 16 by, for example, a method as shown in FIG. In this case, the transparent plate 16
The temperature level of the cooling water flowing between them is one, and the cooling water at a temperature necessary to cool the solar cell 10 is flowed. With such a configuration, there is no need to separately provide a cooling water system and a hot water system, and the configuration of the apparatus is further simplified. This is effective especially when there is no need to use hot water.

FIG. 5C shows the solar cell 10
Is shown by air cooling. Solar cell 1
0 is fixed to the transparent plate 16 by a method as shown in FIG. 4, for example, and is cooled by air from the back side of the solar cell 10. With such a configuration, the configuration of the solar cell device can be further simplified.

FIG. 6 is a plan view of another embodiment of the solar cell device according to the present invention, and FIG. 7 is a sectional view taken along line VII-VII of the embodiment shown in FIG. In FIG. 6, the solar cell 10 is provided in a half area of the upper surface of the case 54, and a transparent plate 16 is provided thereon so as to cover the entire upper surface of the case 54. Further, a mirror 42 for reflecting sunlight is provided at the bottom of the case 54. This case 54 includes a motor 56
Attached to a shaft 58 driven by
8 is rotatably fixed to stands 60 provided on both sides of the case 54.

FIG. 8 shows a case VIII-VII of the case 54.
An I sectional view is shown. As shown in FIG. 8, the solar cell 10 is provided in a half area of the upper surface of the case 54. For this reason, the front surface side of the solar cell 10 is directly irradiated with sunlight. In addition, sunlight 40 incident from the upper surface of the case 54 where the solar cells 10 are not provided is reflected by the mirror 42 and incident on the rear surface side. In this case, the width of the solar cell 10 is set to 2 W, and the solar cell 1
Assuming that the distance between 0 and the mirror 42 is 1, the relationship of tan θ = W / l is established with respect to the incident angle θ of the sunlight 40.

In this embodiment, since the solar cell 10 and the mirror 42 are fixed to the case 54, their relative positions are not changed. Therefore, when the case 54 is rotated by the motor 56, the solar cell 10 and the mirror 42 also rotate integrally. Therefore, Case 5 is associated with the operation of the sun.
4 and the mirror 4 is always
The angle of the case 54 is controlled so that the reflected light from the light source 2 hits. That is, the solar cell 10 and the mirror 42 are integrally rotated, and the control is performed such that the incident angle θ to the surface side of the solar cell 10 and the mirror 42 is always constant. As a result, the incident angle θ of the sunlight 40 on the front surface side of the solar cell 10 and the mirror 42 is always set to 0 ° as much as possible.
Can be approached. Generally, solar cell 1
Assuming that the amount of incident light to 0 is 1 when θ = 0 °, the incident light amount is cos θ when the incident angle is θ. Therefore, as the incident angle θ is closer to 0 °, the amount of light incident on the solar cell 10 can be increased. Note that the above-described motor 56, shaft 5
8. The stand 60 constitutes a rotary drive unit according to the present invention. Further, the electric power generated by the solar cell 10 is extracted to the outside by the extraction wiring 62.

FIG. 11 shows the amount of power generated by the solar cell device of the present embodiment configured as described above. The vertical axis of FIG.
The horizontal axis is the same as in FIG. In FIG. 11, d is the amount of power generation when the reflectance of the mirror 42 is 100%, and e is the amount of power generation when the reflectance of the mirror 42 is 70%. Further, the curve of FIG. 10A is also shown for reference. As can be seen from FIG. 11, the power generation amount of the solar cell device is larger than the case of FIG.
In the case of 0%, about 25% with respect to a shown in FIG.
Power generation capacity. This is, as mentioned above,
The incident angle θ of the sunlight 40 to the photovoltaic cells 10 and the mirror 42 can always be set to an angle close to 0 °, and the incident angle θ can be reduced as compared with the embodiment shown in FIG. is there. Accordingly, the amount of light incident on the solar battery cell 10 can be increased particularly in the time zone where the incident angle θ is large in FIG. 1, which contributes to the improvement of the power generation amount.

FIGS. 9A and 9B show an example of a method for cooling the solar cell 10 of the present embodiment shown in FIG. In FIG. 9A, the solar cell 10 is air-cooled. In this case, the solar cell 10 is fixed to the transparent plate 16 by a method as shown in FIG. FIG. 9B shows an example in which cooling water 66 is circulated between the transparent plate 16 and the transparent plate 64, and the solar cell 10 is directly cooled by the cooling water 66. In this case, the electrode portion of the solar cell 10 is configured so as not to be wet by the coolant due to glass welding or resin coating.

[0031]

As described above, according to the present invention,
Since both sides of the solar cell are light receiving surfaces, it is possible to obtain the same power generation amount as the conventional one with half the cell area of the conventional one. Further, since the mirror is moved up and down or the mirror and the solar cell are rotated in accordance with the operation of the sun, the number of movable parts can be reduced and the driving energy can be reduced. In addition, since a light-collecting device such as a lens is not required, the cost of the device is reduced, and the temperature rise of the solar cell is small by an amount that does not condense. Also in this respect, the cost of the apparatus can be reduced.

Further, since the area of the solar battery cell is reduced to half, the remaining half of the area of the solar battery device can be used for heat collection, and hot water having a higher temperature than before can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view and a cross-sectional view of one embodiment of a solar cell device according to the present invention.

FIG. 2 is a diagram illustrating an example of a mirror driving unit used in the embodiment illustrated in FIG. 1;

FIG. 3 is a diagram showing an example of a cam used for the mirror driving unit shown in FIG.

FIG. 4 is a view showing a method for fixing the solar battery cells to the transparent plate used in the embodiment shown in FIG.

FIG. 5 is a diagram showing an example of a method for cooling a solar cell used in the embodiment shown in FIG.

FIG. 6 is a plan view showing another embodiment of the solar cell device according to the present invention.

FIG. 7 is a sectional view of the embodiment shown in FIG. 6;

FIG. 8 is another cross-sectional view of the embodiment shown in FIG.

FIG. 9 is a diagram illustrating a method of cooling a solar cell used in the embodiment illustrated in FIG. 6;

FIG. 10 is a graph showing a power generation amount of the solar cell device of the embodiment shown in FIG.

FIG. 11 is a graph showing a power generation amount of the solar cell device of another embodiment shown in FIG.

[Explanation of symbols]

10 solar cells, 12 cooling water holes, 14 hot water holes,
16 transparent plate, 18 cooling water supply header, 20 cooling water outlet header, 22 cooling water tank, 24 radiator, 2
6 cooling water pump, 28 cooling water supply water tower, 30 hot water supply header, 32 hot water outlet header, 34 hot water tank, 36 hot water pump, 38 faucet, 40 sunlight, 4
2 mirror, 44 cam, 46 motor, 48 axes, 5
0 Transparent film, 52 partitions, 54 cases, 56
Motor, 58 axes, 60 stands, 62 extraction wiring, 64 transparent plate, 66 cooling water.

Claims (5)

[Claims] 1. A solar cell device for efficiently generating electric power by using both sides of a solar cell, wherein the solar cells have light receiving surfaces on both sides arranged in half the light receiving area of the solar cell device. And a mirror provided on the back surface side of the solar cell, wherein the front surface of the solar cell is directly irradiated with sunlight, and the back surface is irradiated with light reflected by the mirror. A solar cell device characterized by the following. 2. The solar cell device according to claim 1,
A solar cell device comprising: mirror turning means for changing the angle of reflection from the mirror with the operation of the sun and turning the mirror so that reflected light always hits the back surface of the solar cell. 3. The solar cell device according to claim 1,
A solar cell, comprising: mirror vertical driving means for driving the mirror such that the distance between the solar cell and the mirror is changed with the operation of the sun so that reflected light always hits the back surface of the solar cell. apparatus. 4. The solar cell device according to claim 3,
A solar cell device, wherein a cam is used as the mirror vertical drive unit, and the distance between the mirror and the solar cell is changed with the operation of the sun by rotating the cam. 5. The solar cell device according to claim 1, wherein
The relative position between the solar cell and the mirror is fixed, and the solar cell and the mirror are integrally rotated so that the reflected light always enters the back surface of the solar cell with the operation of the sun. A solar cell device comprising a rotation driving unit for causing the solar cell device to rotate.