JP2005026515A - Photoelectric conversion system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoelectric conversion system capable of totally improving photoelectric conversion efficiency by using solar light energy at maximum as to a photoelectric conversion system for converting solar light energy into electric energy. <P>SOLUTION: The photoelectric conversion system 5 is provided with a solar battery 10, a heater 30 for generating heat by electricity outputted from the solar battery 10 and supplied to the heater 30, and a heat-electricity conversion element 40 arranged so that heat can be transmitted from the heater 30 and capable of converting heat energy generated from the heater 30 into electric energy. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photoelectric conversion system that converts solar energy into electrical energy.
[0002]
[Prior art]
In recent years, solar power generation systems using solar cells as an inexhaustible and clean alternative energy source have been developed from the viewpoint of saving energy resources on the earth and protecting the global environment. A solar power generation system is a system that converts solar energy into electrical energy. However, the photoelectric conversion efficiency of solar power generation systems using solar cells is low, and in order to spread the use of solar energy to society, it is essential to increase the efficiency of conversion from solar energy to electrical energy. .
[0003]
In order to solve this problem, a part of the solar energy that cannot be converted by the solar cell (the part that eventually becomes heat) is converted into electric energy by a thermoelectric conversion element, and the total photoelectric conversion efficiency is increased. Is being considered. Here, the thermoelectric conversion element refers to an element that converts thermal energy into electric energy.
[0004]
For example, a method is disclosed in which a thermoelectric conversion element is disposed on the back surface of a solar cell panel to recover energy that could not be photoelectrically converted (Patent Document 1).
[0005]
[Patent Document 1] JP-A-7-142750 [0006]
[Problems to be solved by the invention]
However, in the photovoltaic photoelectric conversion system as shown in Patent Document 1, solar energy is converted into electric energy through solar cells, and when solar energy is converted into electric energy by the solar cells. In addition, the thermal energy generated in the solar battery cell is converted into electrical energy by the thermoelectric conversion element, and the photoelectric conversion efficiency is totally increased.
[0007]
As described above, it is convenient if the photoelectric conversion efficiency can be increased in total using solar energy obtained from the sun.
[0008]
The present invention has been made in view of the above-described problems, and as an example of the problem, a photoelectric conversion system capable of totally increasing photoelectric conversion efficiency by utilizing solar energy to the maximum extent is provided. There is to do.
[0009]
[Means for Solving the Problems]
The present invention will be described below. In order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are appended in parentheses, but the present invention is not limited to the illustrated embodiment.
[0010]
The photoelectric conversion system (5) of the present application is arranged so as to be able to transfer heat to the solar cell (10), a heating element (30) that generates heat by being supplied with electricity output from the solar cell, And a thermoelectric conversion element (40) for converting heat energy generated from the heating element into electric energy. Moreover, the thermoelectric conversion element (70) for converting the heat energy generated from the solar cell into electric energy is provided.
[0011]
In this way, light energy obtained from the sun can be converted into electrical energy with a total increase in photoelectric conversion efficiency.
[0012]
The heating element is preferably formed to contain an oxide compound of tin and lead. Further, chlorine may be contained in the oxidized compound. In addition, the heating element preferably uses at least tin oxide, lead oxide, and lead chloride as raw materials, and a reducing agent is added to the raw materials and mixed to form a mixture, and the mixture is heated. It is good to be manufactured from the supernatant liquid obtained by cooling after that, or a precipitate.
[0013]
In this way, the heating element generates heat from a small voltage (about 3 V), and a large amount of heat energy can be obtained from a small amount of electrical energy. Further, by efficiently transmitting this thermal energy to the thermoelectric conversion element, the thermoelectric conversion element can obtain a large temperature difference between the pair of conductors. Due to this temperature difference, the thermoelectric conversion element generates electrical energy. Thereby, the photoelectric conversion efficiency can be increased in total.
[0014]
Moreover, you may provide the electrical storage body (20) which accumulate | stores the electricity output from the said solar cell, and supplies predetermined electricity to a heat generating body. The power storage unit is preferably an electric double layer capacitor.
[0015]
In this way, a predetermined voltage can be stably applied to the heating element, and the amount of heat generated by the heating element is also stabilized. Thereby, the lifetime reduction of a heat generating body and a thermoelectric conversion element can be prevented. Further, by using the electric double layer capacitor, it is possible to store electricity output from the solar cell panel and to supply predetermined electricity to the heating element. In addition, since the electric double layer capacitor performs charging / discharging without a chemical reaction, it can be charged / discharged 100,000 times or more, and can withstand long-term use even if charging / discharging is repeated. In addition, since charging and discharging are always repeated, it is possible to stably send electricity to other devices without being significantly affected by the output of the solar cell.
[0016]
Further, temperature detection means (50) for detecting the heat generation temperature of the heat generating body and power amount control means (55) for controlling the amount of power supplied to the heat generating body based on the heat generation temperature are provided. Also good.
[0017]
In this way, for example, the power storage unit can stably supply an optimal amount of electricity for the heating element to generate predetermined thermal energy.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, each embodiment of the photoelectric conversion system of the present application will be described.
[0019]
-First embodiment-
FIG. 1 is a block diagram showing an outline of the photoelectric conversion system of the present embodiment, FIG. 2 is a structural diagram of a solar cell panel, FIG. 3 is a diagram combining a heating element and a thermoelectric conversion element, and FIG. 4 is a structural diagram of a power supply box. It is.
[0020]
The photoelectric conversion system 5 of the present embodiment converts light energy obtained from the sun into electric energy, converts the electric energy into heat energy by the heating element 30, and then converts it into electric energy by the thermoelectric conversion element 40. is there.
[0021]
As shown in FIG. 1, the photoelectric conversion system 5 includes a solar cell panel 10, a power storage unit 20, a heating element 30, a thermoelectric conversion element 40, a temperature detection unit 50, and a control unit 55. .
[0022]
Moreover, the solar cell panel 10 comprises the solar cell of this invention, and the temperature detection part 50 comprises the temperature detection means of this invention. Furthermore, the control part 55 comprises the electric energy control means of this invention.
[0023]
As shown in FIG. 2, the solar cell panel 10 is formed of, for example, a silicon system such as single crystal Si, polycrystalline Si, or amorphous silicon, or a compound semiconductor system such as a single crystal compound semiconductor or a polycrystalline compound semiconductor. A plurality of solar cells 11, 11,..., 11 are mounted on a base material 12 surrounded by an aluminum frame 12 a and the surface is covered with tempered glass 13. The plurality of solar cells 11 are electrically connected to each other. Further, the solar cell panel 10 includes output terminals 14 and 14 for taking out electric power. Light energy obtained by sunlight is converted into electrical energy by the solar battery cell 11 and output to the output terminal 14 having positive and negative electrodes for power extraction. The output terminal 14 is electrically connected to an input terminal of a power storage unit 20 described later.
[0024]
Moreover, the solar cell panel 10 may be provided with a condensing unit for condensing solar energy, and transmit the light energy collected by the condensing unit to the solar cell (photoelectric conversion element). . Examples of the condensing unit include a refraction lens using a simple lens or a thin Fresnel lens, a reflection lens using a parabolic reflector, or a composite lens combining both.
[0025]
The power storage unit 20 uses an electric double layer capacitor (not shown).
[0026]
The electric double layer capacitor is smaller in terms of electric capacity than a secondary battery such as a lithium ion battery, but can be rapidly charged (about several seconds). In addition, the electric double layer capacitor accumulates charges without moving electrons due to a chemical reaction, and the terminal voltage thereof increases according to the amount of charging current. That is, in the case of complete discharge, the voltage is 0 V. Therefore, if a voltage is applied or there is a current amount, the charging mode is set. Thereby, the power storage unit 20 can store electricity output from the solar cell panel 10 and supply predetermined electricity to the heating element 30. Further, a predetermined number of electric double layer capacitors are provided according to a predetermined capacity, and each electric double layer capacitor is electrically connected. In addition, although not shown, the electric double layer capacitor includes an input terminal for inputting electricity and an output terminal for outputting stored electricity. In addition, the output terminal of the power storage unit 20 is electrically connected to the input terminal of the heating element 30.
[0027]
The heating element 30 is an element that generates heat from a voltage of about 3 V (about 3 V to 280 V), and the heat generating functional material disclosed in Japanese Patent Application No. 2003-148347 is particularly preferable. Moreover, although the shape of the heat generating body 30 in this embodiment is a rectangular shape, it may be any shape.
[0028]
Specifically, for example, a semiconductor mainly containing an oxide compound of tin (Sn) and lead (Pb) is preferable. Moreover, chlorine (Cl) may be contained therein. Further, a small amount of other metal oxides such as antimony oxide, bismuth oxide, lead oxide, gallium oxide, indium oxide and ITO may be contained as a minor component. Various metal valence oxides can be used as the metal oxide. Further, a small amount of a simple metal such as zinc, tin, antimony, bismuth, lead, gallium, or indium may be contained. Generally, a high-valence oxide gives a high resistance value, and a low-valence oxide and a metal simple substance give a low resistance value. Specifically, the heating element is a mixture of stannous oxide and stannic oxide in a ratio of 1: 1 to form a main component mixture, and a lead oxide-based substance and a lead chloride-based substance are mixed. This is dissolved in an organic solvent to form a dissolved product, and the main component mixture and the dissolved product are mixed using a reducing agent and heated to 150 ° C. to 230 ° C. to form a film. The film 31 is sandwiched (covered) by a heat conductive base material 32. The film 31 includes input terminals 33 and 33 having positive and negative electrodes for supplying electricity.
[0029]
As the heating element 30, a semiconductor electrothermal conversion material disclosed in Japanese Patent No. 2628519 can also be used.
[0030]
That is, at least one chloride selected from tin tetrachloride and antimony trichloride, lead chloride, zinc chloride, and indium chloride is dissolved in one organic solvent selected from ethyl alcohol, methyl alcohol, and acetone, The organic solution is reduced by adding one aqueous solution selected from aqueous solutions of ammonium fluoride, hydrofluoric acid, and tartaric acid, and heated to 150-250 ° C. to form a binder (Teflon (R ) Etc.) can also be used that have been formed into a film, or vapor-deposited and welded.
[0031]
The heating element 30 can be heated on one side or both sides. As shown in FIG. 3, a thermoelectric conversion element 40 is provided on the heating surface of the heating element 30. Further, the heating element 30 and the thermoelectric conversion element 40 are preferably bonded by an adhesive 45 having good thermal conductivity. Thereby, heat transfer from the heating element 30 to the thermoelectric conversion element 40 is performed smoothly. In addition, when heating both surfaces of the heat generating body 30, the thermoelectric conversion element 40 is provided in both heating surfaces.
[0032]
As the thermoelectric conversion element 40, a semiconductor element utilizing the Seebeck effect is usually used. As a substance used as the semiconductor element (thermoelectric conversion material), a bismuth-tellurium alloy, a lead-tellurium alloy, a silicon-germanium alloy, a selenium compound, an iron silicide, or the like is used.
[0033]
As shown in FIG. 3, the thermoelectric conversion element 40 includes a semiconductor element 41, thermal conductors 42 and 43 provided so as to sandwich the semiconductor element 41, and output terminals 44 and 44 having positive and negative electrodes for power extraction. I have.
[0034]
One heat conductor 42 is provided with a heating surface of the heating element 30. The other heat conductor 43 is provided with, for example, heat radiation fins 46. Moreover, the thermoelectric conversion element 40 and the radiation fin 46 are preferably bonded by an adhesive 45 having good thermal conductivity. Thereby, heat radiation from the thermoelectric conversion element 40 to the air is smoothly performed.
[0035]
In this way, one of the heat conductors 42 is heated, and the other heat conductor 43 is radiated by the radiation fins 46 and is maintained at a predetermined temperature (temperature in the air). A temperature difference can be obtained efficiently and electricity can be obtained.
[0036]
Moreover, as shown in FIG. 1, the temperature detection part 50 is provided between the heat conductors 42 of the thermoelectric conversion element 40 which contacts the heating surface of the heat generating body 30. The temperature detection unit 50 is, for example, a temperature sensor. The temperature detection unit 50 is connected to the control unit 55.
[0037]
The control unit 55 controls the amount of power supplied from the power storage unit 20 to the heating element 30 based on the temperature detected by the temperature detection unit 50. Accordingly, the power storage unit 20 can stably supply an optimal amount of electricity for the heating element 30 to generate predetermined thermal energy. Further, it is possible to prevent the thermoelectric conversion element 40 and the heating element 30 from being destroyed and shortened in life due to excessive heating.
[0038]
Further, between the opposing heat conductors 42 and 43 of the thermoelectric conversion element 40, a heat insulating material is provided around the thermoelectric conversion element 40 so that the heat generated from one heat conductor 42 does not affect the other heat conductor 43. Etc. need to be provided.
[0039]
Further, as shown in FIG. 4, the power storage unit 20, the heating element 30, the thermoelectric conversion element 40, the temperature sensor as the temperature detection unit 50, and the control unit 55 are housed in a power generation box 60, for example. The power generation box 60 may be provided independently, or may be provided on the back surface of the solar cell panel 10 or the like.
[0040]
The power generation box 60 has a box-shaped case body 60a. The case body 60a has a space inside. The case main body 60a is hermetically sealed so that dust and the like from the outside do not enter. Further, the case body 60a includes input terminals 62 and 62 having positive and negative electrodes for inputting power (photoelectric conversion by a solar cell panel), and output terminals 63 and 63 having positive and negative electrodes for taking out the power.
[0041]
In addition, an electric double layer capacitor as the power storage unit 20 is provided side by side on the bottom inside the case body 60a. The control unit 55 is a board 55a having a CPU, and the board 55a is fixed at a predetermined position inside the case body.
[0042]
Part of the case body 60a has an opening 65 having a predetermined shape. The opening 65 is provided with a heat radiating fin 46 provided in close contact with one of the heat conductors 43 of the thermoelectric conversion element 40 so as to protrude to the outside. The gap between the opening 65 and the radiating fin 46 is sealed with an adhesive or the like. Further, in the outer periphery of the thermoelectric conversion element 40, heat generated from one heat conductor 43 does not affect the other heat conductor 42 (or heat generated from the other heat conductor 42). Thus, it is covered with a heat insulating material 68 or the like. Further, the heating element 30 is provided in close contact with the other thermal conductor 42 of the thermoelectric conversion element 40.
[0043]
The output terminal 14 of the solar cell panel 10 is electrically connected to an input terminal 62 provided in the case body 60 a of the power generation box 60, and the input terminal 62 is electrically connected to the input terminal 21 of the power storage unit 20. . In addition, the output terminal 22 of the power storage unit 20 is electrically connected to the input terminal 33 of the heating element 30 via a substrate as the control unit 55. The output terminal 44 of the thermoelectric conversion element 40 is electrically connected to the output terminal 65 provided in the case main body 60a of the power generation box 60.
[0044]
-Second Embodiment-
A photoelectric conversion system according to a second embodiment of the present invention will be described with reference to FIG. 5 that are the same as those in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted.
[0045]
FIG. 5 shows the overall configuration of the photoelectric conversion system of this embodiment.
[0046]
The photoelectric conversion system 5A of the present embodiment converts the energy (heat) of the light energy obtained from the sun that cannot be converted by the solar cell into electric energy by the thermoelectric conversion element, and converts the light energy obtained from the sun into electricity. The energy is converted into energy, and the electrical energy is converted into thermal energy by the heating element 30 and then converted into electrical energy by the thermoelectric conversion element 40, so that the total photoelectric conversion efficiency is increased.
[0047]
As shown in FIG. 5, the photoelectric conversion system 5 </ b> A includes a solar cell panel 10, a power storage unit 20, a heating element 30, first and second thermoelectric conversion elements 40 and 70, a temperature detection unit 50, and a control. Part 55.
[0048]
The first thermoelectric conversion element 40 performs thermoelectric conversion of heat generated from the heating element 30.
[0049]
Moreover, the 2nd thermoelectric conversion element 70 carries out thermoelectric conversion of the energy (heat) of the part which cannot be converted with a solar cell among the optical energy obtained from the solar cell panel 10. FIG.
[0050]
The second thermoelectric conversion element 70 is provided on the back side of the solar cell panel 10. In particular, the thermoelectric conversion element disclosed in Japanese Patent Application No. 7-142750 is preferable. Specifically, the thermoelectric conversion element 70 is an organic thermoelectric conversion element, and includes a positive electrode made of graphite or a graphite-containing material, a negative electrode formed of a metal plate, and an electrolyte based on a glycol organic material. It is provided.
[0051]
Moreover, you may make it provide the 2nd thermoelectric conversion element 70 in the back side of a photovoltaic cell. In that case, it is preferable to connect the solar battery cell 11 (photoelectric conversion element) and the thermoelectric conversion element 70 as disclosed in JP-A-2003-69065.
[0052]
As described above, the photoelectric conversion system 5 of the present application is disposed so as to be able to transfer heat to the solar cell 10, the heating element 30 that generates heat by being supplied with electricity output from the solar cell 10, and the heating element 30. And a thermoelectric conversion element 40 for converting heat energy generated from the heating element 30 into electric energy. Moreover, you may make it comprise the thermoelectric conversion element 70 for converting the thermal energy which generate | occur | produces from the said solar cell 10 into an electrical energy. Further, the battery 20 may be configured to store electricity output from the solar cell 10 and supply predetermined electricity to the heating element 30. Moreover, you may make it comprise the temperature detection part 50 which detects the heat_generation | fever temperature of the heat generating body 30, and the control part 55 which controls the electric energy supplied to the heat generating body 30 based on heat_generation | fever temperature.
[0053]
Preferably, the power storage unit 20 is an electric double layer capacitor. Moreover, the heat generating body 30 is good to be formed including the oxidation compound of tin and lead. Moreover, as for the heat generating body 30, chlorine may contain the said oxidation compound. The heating element 30 is made of at least tin oxide, lead oxide, and lead chloride, and a reducing agent is added to the raw material and mixed to form a mixture. After heating the mixture, cooling is performed. It may be produced from a supernatant obtained by doing so, or a precipitate.
[0054]
In this way, the light energy obtained from the solar cell can be converted into electric energy with a total increase in photoelectric conversion efficiency.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating an outline of a photoelectric conversion system according to a first embodiment.
FIG. 2 is a structural diagram of a solar cell panel according to the first embodiment.
FIG. 3 is a diagram in which a heating element and a photoelectric conversion element are combined in the first embodiment.
FIG. 4 is a structural diagram of a power generation box according to the first embodiment.
FIG. 5 is a block diagram illustrating an outline of a photoelectric conversion system according to a second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 5 Photoelectric conversion system 10 Solar cell 20 Electric power storage body 30 Heat generating body 40 Thermoelectric conversion element 50 Temperature detection part (temperature detection means)
55 Control part (electric energy control means)

Claims (8)

Solar cells,
A heating element that is supplied with electricity output from the solar cell and generates heat;
A thermoelectric conversion element that is arranged to be able to transfer heat with the heating element, and that converts thermal energy generated from the heating element into electrical energy;
A photoelectric conversion system comprising: The photoelectric conversion system according to claim 1, further comprising a thermoelectric conversion element for converting thermal energy generated from the solar cell into electric energy. The photoelectric conversion system according to claim 1, further comprising a power storage unit that stores electricity output from the solar cell and supplies predetermined electricity to the heating element. Temperature detecting means for detecting the heating temperature of the heating element;
Power amount control means for controlling the amount of power supplied to the heating element based on the heat generation temperature;
The photoelectric conversion system according to claim 1, comprising: The photoelectric conversion system according to claim 3, wherein the power storage unit is an electric double layer capacitor. The photoelectric conversion system according to claim 1, wherein the heating element is formed to include an oxide compound of tin and lead. The photoelectric conversion system according to claim 6, wherein the heating element contains chlorine. The heating element is made of at least tin oxide, lead oxide, and lead chloride, and a reducing agent is added to and mixed with the raw material to form a mixture, and the mixture is heated and then cooled. The photoelectric conversion system according to claim 1, wherein the photoelectric conversion system is produced from a supernatant liquid or a precipitate obtained by the step.

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