JP2525189B2 - Photovoltaic power generation method and device for effectively utilizing sunlight - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to improvement of a solar power generation method and a device thereof, and more specifically, not only highly efficiently converts sunlight into electric energy, but also more efficiently heats it. The present invention relates to a recoverable solar power generation method and a device thereof.

[Background of the Invention] There is a solar cell as a technology for converting solar energy into electric energy, and recently, a technology for improving photoelectric conversion efficiency of the solar cell has been actively developed. The technology to generate electricity with high efficiency has hardly been developed, and it is the current situation that it is not yet at a satisfactory stage.

As is well known, there are various types of solar cells, and not only the manufacturing cost, the photoelectric conversion efficiency, the shape and the appearance, etc., but also the spectral sensitivity characteristics (bandgap) thereof are different.

As described above, attempts have been made to convert sunlight into electric energy comprehensively and efficiently by using a plurality of solar cells having different band gaps in combination.

That is, for example, a tandem type amorphous solar cell in which amorphous solar cells having different band gaps are stacked in multiple layers or a tandem type solar cell in which an amorphous solar cell is installed on a crystalline type solar cell has been conventionally considered. However, since sunlight is converted into electric energy in a plurality of processes while keeping its wavelength, there is a disadvantage that the selection range of the solar cells installed in multiple layers is limited.

As a result of intensive studies to eliminate such inconvenience,
The present inventors previously proposed a technique in Japanese Patent Application No. 61-150109, in which sunlight is wavelength-selected and the sunlight is comprehensively and efficiently converted into electric energy.

[Object of the Invention] The present invention further improves the high-efficiency electric energy conversion technology, which has been previously proposed by itself, achieves a comprehensive effective utilization of sunlight, and is a practical and energy-saving type photovoltaic power generation method and its method. Intended to provide the device.

[Structure of the Invention] In the solar power generation method according to the present invention, the fluorescence emitted from the fluorescent dye contained in the condensing part is made incident on the solar cell on at least one end face of the condensing part, and the condensing part is formed. In the photovoltaic power generation method of wavelength-selecting sunlight incident on and converting it into electric energy, the condensing part is formed of a transparent container, and the container contains a heat medium in which a fluorescent dye is dissolved. Characterized by heat recovery.

Further, the photovoltaic power generation device according to the present invention suitable for carrying out the method of the present invention is a solar light in which the fluorescent dye contained in the light condensing part is incident on at least one end face of the light condensing part for wavelength selection. In a photovoltaic power generation device provided with a solar cell that absorbs and radiates fluorescence emitted into electric energy, the condensing part is a transparent container containing a heat medium capable of dissolving a fluorescent dye and recovering heat. Is characterized by.

[Operation of the Invention] The present invention efficiently selects a wavelength using a transparent container containing a heat medium capable of recovering heat and containing a fluorescent dye, and efficiently uses a solar cell suitable for each wavelength band. Solar energy, in particular sunlight, is converted into electrical energy and efficient heat recovery is performed to achieve comprehensive effective utilization of sunlight.

[Specific Configuration of the Invention] In the present invention, the transparent container is a rectangular glass or plastic transparent (including semi-transparent) container, and contains a heat medium in which a fluorescent dye is dissolved. Therefore, when sunlight is applied to the transparent container, in addition to reflected light, it absorbs light in a certain wavelength band and emits light in different wavelength bands (the wavelength band of light absorbed / emitted differs depending on the fluorescent dye). ). Further, the heat energy of the sun can be absorbed by the presence of the heat medium.

Examples of fluorescent dyes include daylight fluorescent dyes and pigment dyes, and those soluble in a heat medium are used. Preferred fluorescent dyes include, for example, CI49005, CI46040, C.
I.45170, CI45350, CI45380 and the like.

As the heat medium, for example, esters such as ethyl acetate, alcohols such as methanol and ethanol, and other water and the like are used, and one preferable in relation to the fluorescent dye is selected and used.

In the present invention, when red or orange, for example, is used as the fluorescent dye, as shown in FIG. 3, the yellow-red part of incident sunlight (white light) is reflected [reflection component (1)], and Since the absorbed incident energy of ultraviolet to blue-violet is converted into yellow-red luminescence and emitted or reflected [fluorescent component (2)], yellow-red [(3) component = (1) + where both are superposed and shining. (2)].

In the transparent container of the present invention, the light emitted or reflected from the fluorescent dye (the total component (3) of the reflected light (1) and the fluorescence) is substantially totally reflected and condensed on the end face of the container. In this way, without using a special optical system (lens or reflecting mirror),
Light of a certain wavelength is focused on the end face of the container. Such wavelength selection can be determined depending on the fluorescent dye used.

In the present invention, the wavelength selection can be performed according to the band gap of the solar cell used for the end surface of the transparent container.

The solar cell used in the present invention may be of any type. That is, amorphous (non-crystalline),
It may be any of crystal type, so-called compound semiconductor type, and other types.

Further, the solar cell of the present invention may be of either dry type or wet type, and the dry type silicon solar cell may be any of single crystal, polycrystal (ingot and ribbon) and amorphous, and compound semiconductor (organic and inorganic) solar cells. Batteries are also acceptable. In the case of a wet type, a compound semiconductor solar cell and the like can be mentioned. Also, chemical cells that work by the action of light such as photovoltaic cells that work by exciting dyes (eg, photogalvanic cells, dye-sensitized cells, etc.), solar cells made of organic thin films, or metal thin films and tunnel diodes are used. A combined plasmon solar cell may be used.

For the solar cell preferably used in the present invention, see “Chemicals and Industry”, No. 37, published by the Chemical Society of Japan, October 1, 1984.
Vol. 10, pp. 671-678, "Chemical problems of solar cells" and "Chemical cells working by the action of light", and JP-A-59-4
No. 179, No. 59-47777, No. 59-96722, etc. can be referred to.

In the present invention, the means for recovering the heat energy absorbed in the heat medium is not particularly limited, and may be, for example, a heat exchanger (liquid-
A liquid type) or the like can be used, and it is also preferable to perform heat exchange by natural circulation using convection of the liquid in the transparent container in consideration of energy saving.

Hereinafter, a photovoltaic power generation device for carrying out the method of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a perspective view showing an example of a solar power generation device,
FIG. 2 is a schematic side view of the above.

In FIGS. 1 and 2, reference numeral 1 denotes a rectangular transparent plastic container, and the transparent container 1 contains a heat medium 3 in which a fluorescent dye 2 is dissolved. Reference numeral 4 is a first solar cell provided on the sunlight incident surface (upper surface) of the transparent container 1, and 5 is the transparent container 1.
2 is a second solar cell provided on one end surface of the transparent solar cell, and 6 is a third solar cell provided on the lower end of the transparent container 1. Reference numeral 7 is a reflective film provided on the surface of the transparent container 1 on which the solar cell is not provided.

In this embodiment, for example, an amorphous solar cell is used as the first solar cell 4, a crystalline solar cell is used as the second solar cell 5, and a compound semiconductor solar cell is used as the third solar cell 6. It is preferable to use a solar cell having a gap in terms of efficient conversion of sunlight into electric energy.

That is, in the case of the present embodiment, for example, an amorphous solar cell 4 is installed on the transparent container 1 to convert solar energy on the short wavelength side into electric energy. Next, sunlight (mainly medium wavelength band) that has passed through the amorphous solar cell 4 is applied to the transparent container 1 to be absorbed and emitted by the fluorescent dye 2 to shift the medium wavelength band to a longer wavelength band, which is installed on the end face. The crystalline solar cell 5 is applied and converted into electric energy. On the other hand, the sunlight (mainly in the long wavelength band) transmitted through the transparent container 1 is converted into electric energy by the compound semiconductor solar cell 6 installed under the transparent container 1.

In this way, the solar energy is wavelength-selected by the three-step process, and the solar energy including various wavelength bands is efficiently converted into electric energy by the three types of solar cells having the optimum spectral sensitivity characteristics for each wavelength band. That is, it is converted into electric power.

In FIGS. 1 and 2, 8 is a heat exchanger having a multi-tube 8A, 9 is a cold water inlet, and 10 is a hot water outlet. Reference numeral 11 is a pipe that connects the upper outlet 1A of the transparent container 1 and the inlet of the heat exchanger 8, and a pump 12 in the middle of the pipe 11 (a strainer (not shown) is preferably provided on the suction side) Is provided. Reference numeral 13 is a pipe that connects the outlet of the heat exchanger 8 and the lower inlet 1B of the transparent container 1.

The heat exchanger 8 may be provided in the vicinity of the transparent container 1 (including the contact), but may be provided in a remote place (for example, a place on the ground where maintenance is easy). The type of the heat exchanger 8 is not limited to the above, and various known types can be used.

Various types of energy utilization forms of sunlight in the present invention are conceivable, and the main types are exemplified below.

The first solar cell 4, the second solar cell 5, and the third solar cell 6 are provided to use the wavelength-selected light for electricity. In addition to this, a heat exchanger is provided to recover the light in all wavelength ranges. Type to be used First solar cell 4 and second solar cell 5 are provided, heat exchanging means is provided at a portion of the third solar cell, light in the short wave and medium wave regions is used for electricity, and light in the long wave region is recovered. Type used for (1st
Providing heat exchange means at the solar cell or the second solar cell,
Short-wave and mid-wave light may be used for heat recovery), type that omits the third solar cell and adds the use of daylight Thermal energy of sunlight (from total solar energy to solar cells) (Energy obtained by subtracting the energy consumed by
The temperature of the heat medium that has absorbed the temperature of the upper part of the container rises first, and the temperature of the heat medium in the lower part gradually rises, and the temperature of the lower heat carrier also rises, unless the transparent container 1 is powered by stirring or the like. Temperature rises. Therefore, after the temperature has risen as a whole, the heat medium may be drawn out from any part of the container 1, but at a stage where heat conduction is not sufficiently downward, as shown in the figure, the pump 12 is discharged from the upper outlet 1A of the container. It is preferable to draw out the heat medium by using. The heat medium is heat-exchanged in the heat exchanger 8 to heat cold water to warm water. This heat exchange (supply of heat medium by operation of pump, supply of cold water, etc.) may be performed continuously, or may be performed in a batch system. The warm water may be stored by any suitable method. A known heat storage method (for example, underground heat storage method) may be used.

In the above embodiment, the pump is used, but the connecting pipe
By making the inside of the heat exchanger 11 and the heat exchanger 8 a closed system and providing the heat exchanger at a position higher than the liquid level in the transparent container, the heat medium that has absorbed heat in the transparent container has a low density, so It does not necessarily require a pump as it can be moved and heat exchanged. The upper surface in the container is preferably inclined so that the heat medium can be easily moved to the heat exchanger.

Incidentally, in the above embodiment, when the heat medium in the container may be replaced, the head difference is taken between the liquid level of the heat medium in the transparent container and the position of the heat exchanger, and the pump is omitted. For example, the heat exchange can be performed only by adjusting the flow rate to an appropriate value with a valve or a cock. The heat medium discharged from the heat exchanger is received in a suitable container and either used (including a case where it is reused after reprocessing) or discarded (preferably treated and discarded).

Further, in the above embodiment, it is also preferable to provide the heat transfer pipe 14 for absorbing the heat generation energy of the solar cell. It is preferable that the pipe 14 is attached more efficiently and the number of pipes 14 is designed more efficiently.

The sunlight incident on the light condensing unit or the first solar cell of the present invention may be direct sunlight, scattered light, or convergent light.

It is also preferable to apply a technique (for example, clear overlay) for improving the durability (weather resistance) of the fluorescent dye.

The transparent container of the present invention may be used in combination with the fluorescent light condensing plate described in Japanese Patent Application No. 61-150109.

[Effects of the Invention] According to the present invention, sunlight is wavelength-selected by a combination of a unique transparent container and a solar cell, the sunlight can be efficiently and comprehensively converted into electric energy, and the heat energy of the sunlight is absorbed. As a result, it is possible to provide a practical and energy-saving solar power generation method and its device by comprehensively utilizing sunlight effectively.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an example of a photovoltaic device, FIG. 2 is a schematic side view of the same, and FIG. 3 is a wavelength when red and orange are used as fluorescent dyes. It is a graph showing the reflectance. 1: Transparent container 2: Fluorescent dye 3: Heat medium 4: First solar cell 5: Second solar cell 6: Third solar cell 7: Reflective film 8: Heat exchanger

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Claims (2)

(57) [Claims] 1. At least one end face of the light collecting part, the fluorescence emitted from the fluorescent dye contained in the light collecting part is made incident on the solar cell, and the sunlight incident on the light collecting part is wavelength-selected to generate electricity. In the solar power generation method of converting into energy, the condensing part is formed of a transparent container, the container contains a heat medium in which a fluorescent dye is dissolved, and heat is recovered from the heat medium. Power generation method. 2. A solar cell for converting the fluorescence emitted by absorbing the sunlight incident on the fluorescent dye contained in the condensing section into electric energy on at least one end surface of the condensing section for wavelength selection. In the solar power generation device, the condensing unit is a transparent container containing a heat medium capable of recovering heat and having a fluorescent dye dissolved therein.