JPS59231358A - Solar battery hybrid heat collector - Google Patents

Abstract

PURPOSE:To reduce the heat loss from a heat collecting plate and also reduce leakage of solar light by attaching a solar battery material to both surfaces the heat collecting plate and setting the angle of incidence of light toward the battery surface due to a reflection mirror at 60 deg. or less. CONSTITUTION:Solar light 1 which permeate through a glass plate 2, and then a reflection mirror 3 (having a configuration in which an involute circle is combined with a straight line) are collected in a front solar battery 4 and a rear solar battery 5 by reflection or directly, and utilized for the solar light power generation. Since the solar batteries simultaneously generate heat, heat from the heat collecting plate 6 is cooled by a heat collecting pipe 7. Although the temperature of the reflection mirror 3 slightly rises up, when a heat-insulator 8 is set between the mirror 3 and the outer box, heat loss toward the back surface is reduced. Since a reflection mirror is installed on the back surface of the solar battery, solar light are collected on both surfaces and radiation of heat can be reduced. It is necessary for preventing the solar battery from lowering to reduce the angle of incidence toward the surface of the solar battery of light to 60 deg. or less. Therefore, only a selective absorption surface 12 is attached to the heat collecting pipe 7, and the solar battery is formed in the heat collecting plate 6.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a solar cell hybrid heat collector, and particularly to a solar cell hybrid collector for generating solar power using a reflecting mirror suitable for effectively utilizing expensive solar cells. The present invention also relates to a structure suitable for collecting heat.

[Background of the invention]

In the conventional solar cell hybrid heat collector, as shown in FIG. 1, sunlight i passes through the glass plate 2 and is reflected at reflection@3, concentrating only on the surface of the solar cell 40. Since a large proportion of heat was radiated from the heat collecting plate 6 on the back surface to the outer box through the heat insulating material 8, there was a drawback that the solar cell area was large and heat loss was also large. In FIG. 1, cooling water flows through the heat collecting pipe 7, which prevents overheating of the solar cells and also allows hot water to be supplied.

However, since the solar cells are installed only on one side of the heat collecting plate, there is a drawback that the ratio of the area of the expensive solar cells to the aperture area of the reflector becomes large. Furthermore, since the shape of this reflecting mirror is a compound parabola, its focal point is at the end of the solar cell, and the light is often concentrated locally, which may reduce the output of the solar cell.

Another major drawback is that the surface of a solar cell is covered with a glass plate or a transparent electrode, so in conventional systems, where the incident angle of light is often over 60 degrees, a lot of light is reflected from one surface.・Electric output There was a drawback that the value decreased.

FIG. 2 shows another conventional embodiment, in which a vacuum glass tube 11
The light is focused on the circular heat collecting tube 7 by the reflection @3 installed inside the
Electricity was generated using solar cells 4 formed on the surface of the heat collecting tube. - The distance between them had to be wide to prevent heat from being conducted from the heat collecting pipe to the reflecting mirror, so sunlight leaked after being reflected, resulting in low thermal efficiency. There was a drawback. In particular, in this embodiment, since the shape of the reflecting mirror is a parabola, there is no light leakage when the angle of incidence of sunlight on the opening of the reflecting mirror is 0 degrees, but as the angle of incidence increases, there is a drawback that light leaks. there were.

[Object of the Invention] An object of the present invention is to provide a solar cell hybrid heat collector in which the incident angle of light to the solar cell is small and the heat loss from the heat collecting plate is also small. Furthermore, the distance between the heat collecting plate or the solar cell and the reflecting mirror is reduced to reduce the leakage of sunlight.

[Summary of the invention]

In order to achieve the above object, the present invention has devised a method in which solar cell material is attached to both sides of a heat collecting plate and light is focused on both sides using a reflecting mirror. If the heat collector plate is used as a common substrate electrode and pn junctions are formed on both sides, approximately 1
．． They focused on the fact that six times as much electromotive force was generated. In addition, a 5-reflector is installed at the bottom of the heat collector plate, and a heat collector tube is installed above it, so that the distance between the reflector and the heat collector plate or solar cell is adjusted so that the angle of incidence of light on the battery surface is 60 degrees or less. Make it smaller.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. After sunlight 1 passes through a glass plate 2, it is reflected by a reflecting mirror 3 (shaped like an impoliid circle and a straight line) or directly focused on the front solar cells 4 and back solar cells 5 of the heat collecting plate 6. hand,
Used for solar power generation. Since the solar cells generate heat at the same time, the heat from the heat collecting plate 6 is cooled by the heat collecting tube 7. The temperature of the reflecting mirror 3 also rises a little, but if the heat insulating material 8 is installed between it and the outer box, the heat loss to the back surface will be reduced. There is also a reflective mirror on the back of the solar cell, which allows light to be focused on both sides and also reduces heat dissipation.

Figure 4 shows an enlarged view of the solar cells and heat collector plates. The heat collecting plate 6 is located at the lower part of the heat collecting tube 7, and on the front and back sides of the heat collecting plate there are transparent electrodes 10 (or glass plates) on the surface of the semiconductor material forming the solar cells, respectively. n
02, etc., and its surface is protected with a thin glass plate. The surface of the heat collecting tube 70 is formed of a light selective absorption surface, and absorbs sunlight but does not emit infrared rays. The diameter of the heat collecting tube is increased to reduce the amount of light rays with a small angle of incidence on the solar cell surface.

FIG. 5 shows the incidence angle dependence of the reflectance of the selective absorption surface around the heat collecting tube and the glass plate on the solar/cell surface. When the incident angle becomes 60 degrees or more, the reflectance of the glass plate surface suddenly increases and reaches 50 qb at 80 degrees, which has the disadvantage that the power generation efficiency of the solar cell becomes 5% or less. Even when there is no glass plate, the surface condition of the transparent electrode is similar to that of a glass plate, so the efficiency is similarly low. Therefore, the angle of incidence of light onto the solar cell surface needs to be 60 degrees or less. Taking chrome black as a typical example of a selective solar heat absorption surface, as shown in FIG. 5, the reflectance does not increase much even if the incident angle of light is 60 degrees or more. Therefore, only selective absorption surfaces were attached to the heat collecting tubes, and solar cells were formed on the heat collecting plates.

As shown in Fig. 6, the solar cell cost of the present invention is a little lower than that of the conventional one because the light collection ratio (reflector aperture width/heat collection plate perimeter) is large, which is 5 times the electrical output. The sum of the heat output and the heat output of the present invention is approximately 1.1 times that of the conventional method.The reason why the electric output is considered to be five times as valuable as the thermal output is because the heat generation efficiency is assumed to be approximately 20%. Although the electrical output is the same as before, the amount of heat collected has increased because there is less heat loss to the back side (the light collection ratio is approximately twice as high).In other words, −・Ibrid efficiency = (thermal output + Electrical output x 5)/optical input has been improved from 52 inches to 58 inches.

FIG. 7 shows an example of a method for manufacturing a double-sided solar cell of the present invention.

In order to manufacture the front solar cells 4 and the back solar cells on both sides of the heat collecting plate 6, there are gas supply ports 15 containing semiconductor material from the heat dissipation electrodes 14 on both sides of the vacuum container 130. The power sources 16 that discharge between the heat collecting plate 6 and the electrodes 14 are also symmetrical. To automatically and continuously manufacture this solar cell, a ribbon-shaped substrate is moved, and chambers for forming p-n junctions are installed on both sides of the ribbon-shaped substrate. Although this embodiment is directed to a bottle-shaped amorphous thin film solar cell, it can be similarly applied to a ribbon-shaped silicon crystal. A discharge mask 17 was installed on the heat collecting tube 7 to prevent the formation of solar cells.

FIG. 8 shows an apparatus (plan view) for continuously manufacturing semiconductors and transparent electrodes IO of an amorphous solar cell 4.5 on both sides of a substrate (stainless steel electrodes, heat collecting plate 6). Heat collecting plate 6
bS to continuously produce solar cells 4.5 on both sides of
The i material and doped materials (P, B) are deposited by discharge.

Finally, it is necessary to deposit 18n02 to add a transparent electrode.

FIG. 9 is an enlarged view of a heat collecting plate portion and a reflecting mirror as a modification of the present invention. Comparing with FIG. 4, a solar cell without a heat collecting plate is added below the heat collecting plate. The purpose of this is to reduce heat conduction from the heat collecting plate to the reflecting mirror and to prevent light from passing between the heat collecting plate and the reflecting mirror.

FIG. 10 shows another modification in which the heat collecting tube is placed between the solar cells. The upper solar cell has a heat collection plate, but the thickness of the lower heat collection plate has been made extremely thin to reduce heat conduction to the reflecting mirror.

11 and 12 show an embodiment of a vacuum glass tube type heat collector of the present invention. Conventionally, solar cells were installed on only one surface of the heat collecting plate, but in the present invention, a reflector prevents infrared rays from radiating downward, improving heat collection efficiency. The shape shown in FIG. 11 is a combination of a circle and a compound parabola, and the shape shown in FIG. 12 is a combination of a circle and a straight line. The temperature of the cooling water in the heat collecting tube 7 is approximately 50'C in the case of a silicon solar cell, but 100'C in the case of bGaAS.
It can be made close to c. The reason why the shape of the reflecting mirror is a combination of a circle and a straight line in Fig. 12 is that the impolied curve of a straight line (heat collector plate) is a circle, and adding a straight line at the end increases the aperture of the reflecting mirror (collecting plate). This is because the light ratio is large).

A light selective absorption surface is attached to the heat collecting tube, and its diameter is increased. As a result, it is possible to reduce the number of light rays with a small incident angle to the lower solar cell.

In the vacuum glass tube, there is no need to add a glass plate to the surface of the solar cell, and there is a transparent electrode (such as ITO), but in order to reduce the surface reflectance.

The larger the angle of incidence of light, the better. In order to eliminate the gap between the reflector and the heat collecting plate to prevent light leakage, add a solar cell (with a thin heat collecting plate) at the bottom as shown in Figure 9.

〔Effect of the invention〕

According to the present invention, sunlight can be focused by the reflecting mirror onto the solar cells formed on both sides of the heat collecting plate.

The ratio of the area of the solar cell to the aperture area of the reflecting mirror is approximately 1
This has the effect of reducing the manufacturing cost of solar cells by about 2/3. Furthermore, since the heat collection plate is surrounded by reflective mirrors, heat radiation loss is reduced, and heat collection efficiency is improved by approximately 1.2 times. The electrical output from the solar cells remains the same, but even though the electrical output is five times more valuable than the thermal output, the overall hybrid efficiency is about 1.1 times more effective. here.

It is defined as

An automatic method for forming solar cells on both sides of a heat collector plate can produce, for example, an amorphous thin film on both sides of a metal common electrode by glow discharge, so it can be produced continuously in large quantities, reducing manufacturing costs. .

Furthermore, we increased the diameter of the heat collecting tube and changed the shape of the reflector to a combination of an impoliid curve and a straight line.

Since it is designed so that the angle of incidence of light on the solar cell is 60 degrees or less, it has the effect of increasing the conversion efficiency of the solar cell by about 1.2 times compared to conventional solar cells.

In order to reduce the distance between the part containing the heat collecting plate and the reflector,
Since you can add only the solar cell (thin electrode),
This has the effect of preventing sunlight from leaking through the gap between the reflector and the heat collector. This improves the light collection efficiency and increases the overall hybrid efficiency by about 1.1 times.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of a conventional solar cell hybrid heat collector, FIG. 3 is a cross-sectional view of an embodiment of the present invention, FIG. 4 is an enlarged view of the heat collector plate, and FIGS. Fig. 6 is a comparison diagram of the effect with the conventional one, Fig. 7 is a sectional view of the manufacturing device, Fig. 8 is a plan view thereof, Fig. 9 and 1θ are sectional views of other embodiments, and Fig. 11 is a sectional view of the manufacturing device. The figure and FIG. 12 are cross-sectional views of the vacuum tube type embodiment. Backside solar cell, 6.
... Heat collecting plate (electrode) 7... Heat collecting tube, 8... Heat insulating material, 9... Outer box, 10... Transparent electrode, 11... Vacuum glass tube, 12... Selection Absorption surface, 13... Vacuum vessel, 14... Discharge electrode, 15... Gas supply port, 16.
...Power supply, 17...MP with discharge mass,, (JK) $6 Figure Jinshakage Semen Kasu (ml) $''f Figure

Claims (1)

[Claims] 1. In a solar heat collector consisting of a glass plate, a reflector, and a heat collecting plate, an incident angle of 6 is applied to the round solar cells formed on both sides of the heat collecting plate.
Equipped with a reflector that focuses light below 0 degrees. A solar cell hybrid heat collector characterized by generating solar power using a heat collecting plate as a common substrate for solar cells and supplying hot water using the heat from the heat collecting plate.