WO2023038100A1

WO2023038100A1 - Environmental power generation device and environmental power generation system

Info

Publication number: WO2023038100A1
Application number: PCT/JP2022/033828
Authority: WO
Inventors: 博史後藤; 稔坂田; 拓夫安田; ラーシュマティアスアンダーソン; 誠司岡田; 貴宏中村
Original assignee: 株式会社Ｇｃｅインスティチュート
Priority date: 2021-09-10
Filing date: 2022-09-09
Publication date: 2023-03-16

Abstract

[Problem] To provide an environmental power generation device and an environmental power generation system which make it possible to increase the power generation amount of a thermoelectric element. [Solution] Provided is an environmental power generation device 7 which converts light energy and thermal energy into electrical energy, wherein the device comprises: a solar battery panel 6 that converts the light energy into the electrical energy; and a thermoelectric element 1 which, when the thermal energy is converted into the electrical energy, does not require a temperature difference between electrodes. The solar battery panel 6 includes a plurality of solar battery cells 61, a support unit 62 that is provided on a rear surface 61a side of the plurality of solar battery cell 61, and an insulation unit 63 that is in contact with the support unit 62. The thermoelectric element 61 includes a pair of electrodes 11, 12 having different work functions, respectively, and an intermediate unit 14 provided between the pair of electrodes 11, 12, and is arranged in contact with the solar battery panel 6.

Description

Energy harvesting device and energy harvesting system

The present invention relates to an energy harvesting device and an energy harvesting system that convert light energy and thermal energy into electrical energy.

For example, a solar panel in Patent Document 1 has been proposed as a power generation device that uses a combination of solar cells and thermoelectric elements.

Patent Document 1 discloses a honeycomb core sandwiched between a first skin material and a second skin material, a plurality of solar cells provided on a surface of the first skin material opposite to the honeycomb core, and the second skin material. a plurality of thermoelectric conversion elements arranged dispersedly with gaps on the surface of the skin material opposite to the honeycomb core; A photovoltaic panel is disclosed comprising a heat sink provided.

WO2018/230031

Here, when solar cells are used, the solar cell panel tends to become hot. Therefore, when using the thermoelectric element that requires the heat sink disclosed in Patent Document 1, it may be difficult to maintain the temperature difference required for power generation by the thermoelectric element due to the temperature rise around the solar cell panel and the heat sink. . As a result, there is a concern that the amount of power generated by the thermoelectric element will decrease.

SUMMARY OF THE INVENTION Accordingly, the present invention has been devised in view of the problems described above, and its object is to provide an energy harvesting device and an energy harvesting system capable of increasing the amount of power generated by a thermoelectric element. to do.

An energy harvesting device according to a first aspect of the invention is an energy harvesting device that converts light energy and thermal energy into electrical energy, and includes a solar cell panel that converts light energy into electrical energy, and a solar cell panel that converts thermal energy into electrical energy. , and a thermoelectric element that does not require a temperature difference between electrodes, and the solar cell panel includes a plurality of solar cells, a support provided on the back side of the plurality of solar cells, and the support and an insulating portion in contact with the solar cell panel, wherein the thermoelectric element includes a pair of electrodes having different work functions, and an intermediate portion provided between the pair of electrodes, the thermoelectric element being the solar cell panel It is characterized by being provided in contact with.

An energy harvesting device according to a second aspect of the invention is characterized in that, in the first aspect of the invention, the energy harvesting device further comprises a thermally conductive portion in contact with the support portion and the thermoelectric element, and the insulating portion covers the thermally conductive portion and the thermoelectric element. do.

An energy harvesting device according to a third aspect is the energy harvesting device according to the first aspect or the second aspect, wherein the insulating portion includes a sealant filled between the solar cell and the supporting portion, and the thermoelectric element is , provided between the solar cell and the support, and covered with the sealant.

An energy harvesting device according to a fourth invention is the energy harvesting device according to the third invention, characterized in that the area of the solar cell is larger than the area of the thermoelectric element when viewed from the direction from the solar cell toward the support section. do.

An energy harvesting device according to a fifth invention is the energy harvesting device according to the first invention or the second invention, wherein the insulating section includes a heat storage section provided on the back side of the supporting section, and the thermoelectric element includes the supporting section and the It is characterized by being provided in contact with the heat storage section.

An energy harvesting device according to a sixth aspect is the energy harvesting device according to the fifth aspect, wherein the heat storage unit includes a first heat storage unit and a second heat storage unit having different heat storage properties, and the thermoelectric element is in contact with the first heat storage unit. , a first element separated from the second heat storage section, and a second element in contact with the second heat storage section and separated from the first heat storage section.

An energy harvesting system according to a seventh aspect of the invention is an energy harvesting system using the energy harvesting device of the third or fourth aspect of the invention, comprising: and an evaluation unit that evaluates the temperature of the photovoltaic cell based on the measurement result.

An energy harvesting system according to an eighth invention is an energy harvesting system using the energy harvesting device according to any one of the first invention to the sixth invention, comprising: a power measuring unit for measuring power of the thermoelectric element; an estimating unit for estimating electric power generated from the photovoltaic cell based on a measurement result of the measuring unit.

According to the first to sixth inventions, the thermoelectric element includes a pair of electrodes with different work functions. That is, even when there is no temperature difference between the electrodes, thermal energy can be converted into electrical energy. Therefore, there is no need to provide a heat dissipation mechanism such as a heat dissipation plate. Also, the thermoelectric element is provided in contact with the solar cell panel. Therefore, the heat that contributes to the power generation of the thermoelectric element is directly transferred from the solar panel in addition to the transfer accompanying the temperature rise around the solar panel. These make it possible to increase the amount of power generated by the thermoelectric element.

In particular, according to the second invention, the heat conducting part is in contact with the support part and the thermoelectric element, and the insulating part covers the heat conducting part and the thermoelectric element. Therefore, the heat generated from the supporting portion is easily transferred to the thermoelectric element via the heat conducting portion. Also, the heat transferred to the thermoelectric element is less likely to be released to the outside. By these, it becomes possible to further increase the amount of power generation.

In particular, according to the third invention, the insulating portion includes a sealant filled between the solar cell and the support portion, and the thermoelectric element is provided between the solar cell and the support portion. , covered with an encapsulant. Therefore, the heat generated from the photovoltaic cell as well as the supporting portion can be easily transferred to the thermoelectric element. This makes it possible to further increase the power generation amount.

In particular, according to the fourth invention, the area of the solar cell is larger than the area of the thermoelectric element when viewed from the direction from the solar cell toward the support. For this reason, light such as sunlight that has passed between the plurality of solar cells can be reflected by the supporting portion so that the solar cells can be easily irradiated. This makes it possible to suppress a decrease in the amount of power generated by the solar cell panel due to the installation of the thermoelectric elements.

In particular, according to the fifth invention, the insulating section includes the heat storage section provided on the back side of the support section, and the thermoelectric element is provided between the support section and the heat storage section in contact therewith. Therefore, heat can be easily transferred to the thermoelectric elements via the heat storage unit even in a time zone when sunlight is not irradiated. This makes it possible to extend the power generation possible time of the entire energy harvesting device.

In particular, according to the sixth invention, the heat storage section includes a first heat storage section and a second heat storage section having different heat storage properties, and the thermoelectric element is in contact with the first heat storage section and separated from the second heat storage section. and a second element that is in contact with the second heat storage unit and separated from the first heat storage unit. Therefore, it is possible to set a different power generation possible time for each element. This makes it possible to further extend the power generation possible time of the entire energy harvesting device.

In particular, according to the seventh invention, the evaluation unit evaluates the temperature of the photovoltaic cell based on the measurement result of the measurement unit. For this reason, the thermoelectric element can be used not only for power generation but also as a sensor for determining whether or not heat is generated due to malfunction of the solar battery cell. This makes it possible to increase the amount of power generated by the energy harvesting device as a whole and to increase safety.

In particular, according to the eighth invention, the energy harvesting device, the power measuring unit for measuring the power of the thermoelectric element, and the estimating unit for estimating the power generated from the photovoltaic cell based on the measurement result of the power measuring unit. Prepare. Therefore, it is possible to easily estimate the variation in the amount of power generation due to the temperature of the solar cell panel. This makes it possible to further increase the amount of power generated by the energy harvesting device as a whole.

FIG. 1 is a schematic diagram showing an example of an energy harvesting system according to the first embodiment. FIG. 2 is a schematic perspective view showing an example of the energy harvesting device in the first embodiment. FIG. 3 is a schematic cross-sectional view showing an example of the energy harvesting device in the first embodiment. FIG. 4 is a schematic cross-sectional view showing an example of the energy harvesting device in the first embodiment. FIG. 5 is a diagram showing an example of the relationship between temperature and power for a solar cell panel and thermoelectric elements. FIG. 6 is a schematic cross-sectional view showing an example of the intermediate portion. FIG. 7A is a schematic cross-sectional view showing a first modified example of the thermoelectric element in the first embodiment, and FIG. 7B is a schematic cross-sectional view showing a second modified example of the thermoelectric element in the first embodiment. It is a diagram. FIG. 8(a) is a schematic cross-sectional view showing a third modification of the thermoelectric element in the first embodiment, and FIG. 8(b) is a schematic diagram showing an example of an intermediate portion of the thermoelectric element in FIG. 8(a). It is a sectional view. FIG. 9 is a schematic cross-sectional view showing an example of the energy harvesting device in the second embodiment. FIG. 10 is a schematic cross-sectional view showing an example of an energy harvesting device according to the third embodiment. FIG. 11 is a schematic cross-sectional view showing an example of an energy harvesting device according to the fourth embodiment. FIG. 12 is a schematic cross-sectional view showing an example of an energy harvesting device according to the fifth embodiment. FIG. 13 is a schematic cross-sectional view showing an example of an energy harvesting device according to the sixth embodiment. FIG. 14(a) is a schematic cross-sectional view showing an example of an energy harvesting device according to the seventh embodiment, and FIG. 14(b) shows a first modified example of the insulating portion of the energy harvesting device according to the seventh embodiment. FIG. 14C is a schematic cross-sectional view showing a second modification of the insulating portion of the energy harvesting device according to the seventh embodiment.

An example of an energy harvesting device and an energy harvesting system as an embodiment of the present invention will be described below with reference to the drawings. In each figure, the height direction in which each electrode is stacked is defined as a first direction Z, and one planar direction that intersects, for example, is orthogonal to the first direction Z is defined as a second direction X. A third direction Y is another planar direction that intersects, for example, is orthogonal to each of the directions X. As shown in FIG. Also, the configuration in each drawing is schematically described for explanation, and for example, the size of each configuration and the comparison of the size of each configuration may differ from those in the drawings.

(First embodiment: energy harvesting device 7, energy harvesting system 700)
FIG. 1 is a schematic diagram showing an example of an energy harvesting system 700 according to the first embodiment. FIG. 2 is a schematic perspective view showing an example of the energy harvesting device 7 in the first embodiment. FIG. 3 is a schematic cross-sectional view showing an example of the energy harvesting device 7 in the first embodiment. FIG. 4 is an enlarged view of the dashed frame A in FIG.

As shown in FIG. 1 , the energy harvesting system 700 includes an energy harvesting device 7 , a measuring section 71 and an information processing device 75 . The energy harvesting device 7 converts light energy and thermal energy into electrical energy. The energy harvesting device 7 includes a solar cell panel 6 that converts light energy into electrical energy, and a thermoelectric element 1 that does not require a temperature difference between electrodes when converting thermal energy into electrical energy.

<Energy Harvester 7>
The energy harvesting device 7 is installed, for example, in the site of the power generation facility, or installed on the ground or on the roof of a building. The energy harvesting device 7 is connected to an information processing device 75 and the like, which will be described later. The energy harvesting device 7 is connected to known devices such as a power conditioner (PCS: Power Conditioning System), a battery, etc., for example, via wiring (not shown). The energy harvesting device 7 outputs power to a load via a power conditioner or the like. A load indicates an electrical device, for example. The load is driven using, for example, the energy harvesting device 7 as a primary or auxiliary power source.

<Solar panel 6>
The solar cell panel 6 converts, for example, light energy such as sunlight and indoor light into electric energy. For example, as shown in FIG. 3, the solar battery panel 6 includes a plurality of solar battery cells 61, a support portion 62 provided on the back surface 61a side of the plurality of solar battery cells 61, and an insulating portion 63 in contact with the support portion 62. ,including. The solar cell panel 6 may include a known structure such as a protective glass (not shown), a frame, or the like. Here, the surface of the solar cell panel 6 on which light such as sunlight is irradiated is defined as the front surface, and the surface opposite to the front surface is defined as the rear surface (that is, the rear surface 62a of the support portion 62).

<Solar battery cell 61>
The solar cell 61 is an element that absorbs light energy such as sunlight and converts it into electrical energy. A semiconductor such as silicon is used for the solar cell 61 . The plurality of photovoltaic cells 61 are spaced apart from each other, for example, along the surface that absorbs light energy. For example, the area of the solar cell 61 is larger than the area of the thermoelectric element 1 when viewed in the direction from the solar cell 61 toward the support portion 62 .

<Support portion 62>
The support portion 62 is a back sheet provided on the back surface 61 a side of the solar cell 61 . The support part 62 not only reflects light energy, but also protects the solar battery cell 61 from high heat of sunlight, ultraviolet rays, wind and rain. As the support portion 62, for example, a known back sheet such as a plastic material is used.

<Insulator 63>
The insulating portion 63 has insulating properties. The insulating portion 63 includes, for example, a sealant 64 provided between the solar cell 61 and the support portion 62 . As the sealing agent 64, a known sealing material such as EVA (ethylene-vinyl acetate copolymer resin) is used.

<Thermoelectric element 1>
For example, as shown in FIG. 4, the thermoelectric element 1 includes a pair of electrodes (first electrode 11 and second electrode 12) having different work functions, and an intermediate portion 14 provided between the pair of

electrodes

11 and 12. ,including. The thermoelectric element 1 may comprise at least one of the first substrate 15 and the second substrate 16, for example. Thermoelectric element 1 is provided in contact with solar cell panel 6 . The thermoelectric element 1 converts, for example, thermal energy absorbed by the solar cell panel 6 into electrical energy to generate current. The thermoelectric element 1 is connected to the solar cell panel 6 via wiring (not shown), for example, in a parallel circuit. The thermoelectric element 1 may be connected to the solar cell panel 6 via wiring (not shown), for example, in a series circuit.

The thermoelectric element 1 is provided inside the solar panel 6 . The thermoelectric element 1 is provided, for example, between the solar battery cell 61 and the support portion 62 and covered with a sealant 64 . In the thermoelectric element 1, for example, the surface opposite to the surface of the first substrate 15 facing the first electrode 11 constitutes the first main surface 10a, and the surface of the second substrate 16 facing the second electrode 12 is the first main surface 10a. The opposite surface constitutes the second major surface 10b. The thermoelectric element 1 is provided, for example, with the first principal surface 10a in contact with the surface 62b of the support portion 62 and with the second principal surface 10b spaced apart from the back surface 61a of the solar cell 61 . Although illustration is omitted, the thermoelectric element 1 has, for example, the first main surface 10a provided in contact with the surface 62b of the support portion 62 and the second main surface 10b provided in contact with the back surface 61a of the solar cell 61. may

The thermoelectric element 1 is provided with the first main surface 10 a and the second main surface 10 b along the back surface 61 a of the solar cell 61 . At this time, the contact area between the thermoelectric element 1 and the solar cell 61 can be increased. As a result, the amount of heat transferred from the solar cell 61 to the thermoelectric element 1 increases, and the amount of power generated by the thermoelectric element 1 can be increased. Although illustration is omitted, the thermoelectric element 1 may be provided such that the first main surface 10 a and the second main surface 10 b are perpendicular to the back surface 61 a of the solar cell 61 . At this time, the heat transferred from the solar cell 61 to the

electrodes

11 and 12 increases compared to when either the first electrode 11 or the second electrode 12 is separated from the solar cell 61 . This makes it possible to increase the amount of power generated by the thermoelectric element 1 .

<Measurement unit 71>
The measurement unit 71 has a power measurement unit 72 and a power generation amount measurement unit 73 .

<Power measurement unit 72>
The power measurement unit 72 measures the power of the thermoelectric element 1 . The power measuring unit 72 uses a well-known one that measures power.

<Power generation amount measurement unit 73>
The power generation amount measurement unit 73 measures the power generation amount of the thermoelectric element 1 . A well-known unit for measuring the amount of power generation is used as the power generation amount measuring unit 73 .

<Information processing device 75>
The information processing device 75 is installed, for example, in a power plant and functions as a control unit within the power plant. For example, a personal computer or the like is used as the information processing device 75 . The information processing device 75 includes an estimation unit 76 and an evaluation unit 77 . The information processing device 75 may further include an input/output unit for inputting/outputting various types of information and a storage unit for storing various types of information.

FIG. 5 is a diagram showing an example of the relationship between temperature and power for the solar cell panel 6 and the thermoelectric element 1. FIG. As shown in FIG. 5, the solar panel 6 tends to decrease the power generated from the solar panel 6 as the temperature of the solar panel 6 increases. Also, the thermoelectric element 1 exhibits a tendency that the electric power generated from the thermoelectric element 1 increases as the temperature of the thermoelectric element 1 increases. For example, the information processing device 75 may store in advance the relationship between temperature and power for the solar panel 6 and the thermoelectric element 1 .

The information processing device 75 may store, for example, the relationship between the amount of power generated by the thermoelectric element 1 and the temperature of the solar battery cell 61 in advance. The information processing device 75 may store, for example, the relationship between the power of the thermoelectric element 1 and the temperature of the solar battery cell 61 in advance.

<Estimating unit 76>
The estimating unit 76 refers to the relationship between the temperature and power of the solar panel 6 and the thermoelectric element 1 stored in the information processing device 75, for example, and based on the measurement result of the power measuring unit 72, the power generated from the solar cell 61 Estimate the power to be applied. That is, it is possible to easily estimate the tendency of the electric power to change depending on the temperature of the solar cell panel 6 . For this reason, it is possible to detect in advance that excessive power will be generated from the solar panel 6 due to, for example, a decrease in the outside temperature, and control of the solar panel 6 can be performed. This makes it possible to further increase the amount of power generated by the energy harvesting device 7 as a whole.

<Evaluation unit 77>
The evaluation unit 77 refers to the relationship between the power of the thermoelectric element 1 and the temperature of the solar cell 61 stored in the information processing device 75, for example, and calculates the temperature of the solar cell 61 based on the measurement result of the power measurement unit 72. evaluate. The evaluation unit 77 refers to the relationship between the power generation amount of the thermoelectric element 1 and the temperature of the solar cell 61 stored in the information processing device 75, for example, and based on the measurement result of the power generation amount measurement unit 73, the temperature of the solar cell 61. Evaluate the temperature.

Details of each configuration will be described below.
<Thermoelectric element 1>
FIG. 6 is a schematic cross-sectional view showing an example of the intermediate portion 14. As shown in FIG. The first electrode 11 and the second electrode 12 are provided facing each other. The first electrode 11 and the second electrode 12 have different work functions. The intermediate portion 14 is provided in a space 140 including a gap G between the first electrode 11 and the second electrode 12, as shown in FIG. 6, for example.

The intermediate portion 14 includes nanoparticles 141 and a solid insulating layer 142 . The nanoparticles 141 are fixed in the insulating layer 142 in a dispersed state. In this case, movement of the nanoparticles 141 in the gap G is suppressed. Therefore, it is possible to prevent the nanoparticles 141 from unevenly distributing toward one of the

electrodes

11 and 12 over time and decrease the amount of electron movement. This makes it possible to stabilize the power generation amount.

The intermediate portion 14 is provided on the first electrode 11 . Also, the second electrode 12 is provided on the insulating layer 142 . Here, in the thermoelectric element 1 that does not require a temperature difference between the electrodes when converting thermal energy into electrical energy, by suppressing variations in the gap G on the surfaces along the second direction X and the third direction Y, , the amount of power generation can be increased. In this regard, when a liquid such as a solvent is used as the intermediate portion, it is necessary to provide a support portion or the like for maintaining the gap G. However, there has been a concern that the gap G may vary greatly with the formation of the supporting portion and the like. On the other hand, in the thermoelectric element 1 according to the present embodiment, the second electrode 12 is provided on the insulating layer 142, so there is no need to provide a support portion or the like for maintaining the gap G, and the formation of the support portion or the like is unnecessary. Gaps variations due to precision can be eliminated. This makes it possible to increase the amount of power generation.

<First Electrode 11, Second Electrode 12>
The first electrode 11 and the second electrode 12 are spaced apart in the first direction Z, as shown in FIG. 4, for example. Each of the

electrodes

11 and 12 may extend in the second direction X and the third direction Y, for example, and may be provided in plurality. For example, one second electrode 12 may be provided facing the plurality of first electrodes 11 at different positions. Also, for example, one first electrode 11 may be provided facing the plurality of second electrodes 12 at different positions.

A conductive material is used as the material of the first electrode 11 and the second electrode 12 . As materials for the first electrode 11 and the second electrode 12, for example, materials having different work functions are used. The same material may be used for the

electrodes

11 and 12, and in this case, the

electrodes

11 and 12 may have different work functions.

As the material of the

electrodes

11 and 12, for example, a metal conductor made of a single element such as iron, aluminum, or copper is used, or an alloy metal conductor made of, for example, two or more elements may be used. A non-metallic conductor, for example, may be used as the material of the

electrodes

11 and 12 . Examples of nonmetallic conductors include silicon (Si: for example, p-type Si or n-type Si) and carbon-based materials such as graphene.

The thickness of the first electrode 11 and the second electrode 12 along the first direction Z is, for example, 4 nm or more and 1 μm or less. The thickness of the first electrode 11 and the second electrode 12 along the first direction Z may be, for example, 4 nm or more and 50 nm or less.

A gap G that indicates the distance between the first electrode 11 and the second electrode 12 can be arbitrarily set by changing the thickness of the insulating layer 142 . For example, by narrowing the gap G, the electric field generated between the

electrodes

11 and 12 can be increased, so that the amount of power generated by the thermoelectric element 1 can be increased. Also, by narrowing the gap G, for example, the thickness of the thermoelectric element 1 along the first direction Z can be reduced.

The gap G is a finite value of 500 μm or less, for example. The gap G is, for example, 10 nm or more and 1 μm or less. For example, if the gap G is 200 nm or less, variations in the gap G on the surfaces along the second direction X and the third direction Y may lead to a decrease in the power generation amount. Also, if the gap G is larger than 1 μm, the electric field generated between the

electrodes

11 and 12 may weaken. For these reasons, the gap G is preferably larger than 200 nm and 1 μm or less.

<Intermediate part 14>
The intermediate portion 14 extends in a plane along the second direction X and the third direction Y. As shown in FIG. The intermediate portion 14 is provided within a space 140 formed between the

electrodes

11 , 12 . The intermediate portion 14 may be in contact with the main surfaces of the

electrodes

11 and 12 facing each other, and may also be in contact with the side surfaces of the

electrodes

11 and 12, for example.

The nanoparticles 141 may be dispersed in the insulating layer 142 and partially exposed from the insulating layer 142, for example. The particle diameter of the nanoparticles 141 is smaller than the gap G, for example. The particle diameter of the nanoparticles 141 is set to a finite value of 1/5 or less of the gap G, for example. When the particle diameter of the nanoparticles 141 is set to ⅕ or less of the gap G, it becomes easier to form the intermediate portion 14 containing the nanoparticles 141 within the space 140 . Thereby, when the thermoelectric element 1 is produced, workability can be improved.

Here, "nanoparticles" refer to those containing multiple particles. The nanoparticles 141 include particles having a particle diameter of, for example, 2 nm or more and 100 nm or less. The nanoparticles 141 may include, for example, particles having a median diameter (median diameter: D50) of 3 nm or more and 150 nm or less, or particles having an average particle diameter of 3 nm or more and 150 nm or less. good. The median diameter or average particle diameter can be measured, for example, by using a particle size distribution analyzer. As the particle size distribution measuring instrument, for example, a particle size distribution measuring instrument using a dynamic light scattering method (eg, Zetasizer Ultra manufactured by Malvern Panalytical, etc.) may be used.

The nanoparticles 141 include, for example, conductors, and any material is used depending on the application. The nanoparticles 141 may contain one type of material, or may contain a plurality of materials depending on the application. The value of the work function of the nanoparticles 141 is, for example, between the value of the work function of the first electrode 11 and the value of the work function of the second electrode 12, and for example, the value of the work function of the first electrode 11. , and the value of the work function of the second electrode 12, and is optional.

Examples of materials for the nanoparticles 141 may include metal. As the nanoparticles 141, for example, in addition to particles containing one type of material such as gold or silver, particles of an alloy containing two or more types of materials may be used. At least one conductive material other than gold and silver can be selected as the material of the nanoparticles 141 .

Nanoparticles 141 include, for example, metal oxides. Examples of nanoparticles 141 containing metal oxides include zirconia (ZrO ₂ ), titania (TiO ₂ ), silica (SiO ₂ ), alumina (Al ₂ O ₃ ), iron oxides (Fe ₂ O ₃ , Fe ₂ O ₅ ). , copper oxide (CuO), zinc _{oxide (ZnO), yttria (Y2O3), niobium oxide (Nb2O5} ₎ _, _molybdenum _oxide ( _MoO3 ), indium oxide ( _In2O3 ), tin oxide (SnO ₂ ), tantalum oxide ( _Ta2O5 ), tungsten oxide ( _WO3 ), lead oxide ( _PbO ), bismuth oxide ( _Bi2O3 ), ceria ( _CeO2 ₎ , antimony oxide ( _Sb2O5 , Sb2 ₎ _. A metal oxide of at least one element selected from the group consisting of metals and Si, such as O ₃ ), is used.

The nanoparticles 141 contain, for example, a dielectric. A known material, for example, is used as the nanoparticles 141 containing a dielectric.

The nanoparticles 141 may include, for example, metal oxides other than magnetic substances. For example, if the nanoparticles 141 contain a metal oxide exhibiting a magnetic substance, the movement of the nanoparticles 141 can be restricted by the magnetic field generated due to the environment in which the thermoelectric element 1 is installed. Therefore, the nanoparticles 141 contain a metal oxide other than a magnetic material, so that it is possible to suppress the decrease in the power generation amount over time without being affected by the magnetic field caused by the external environment.

The nanoparticles 141 include, for example, a coating 141a on the surface. The thickness of the coating 141a is, for example, a finite value of 20 nm or less. By providing such a film 141a on the surfaces of the nanoparticles 141, aggregation can be suppressed when the nanoparticles are dispersed in the insulating layer 142, for example. Further, for example, electrons can move between the first electrode 11 and the nanoparticles 141, between the plurality of nanoparticles 141, and between the second electrode 12 and the nanoparticles 141 using hopping conduction or the like. It is possible to improve the quality.

A material having, for example, a thiol group or a disulfide group is used as the coating 141a. Alkanethiol such as dodecanethiol is used as the material having a thiol group. As a material having a disulfide group, for example, an alkane disulfide or the like is used.

The insulating layer 142 is provided between the

electrodes

11 and 12 and is in contact with the

electrodes

11 and 12, for example. The thickness of the insulating layer 142 is, for example, a finite value of 500 μm or less. The thickness of the insulating layer 142 affects the value and variation of the gap G described above. Therefore, for example, when the thickness of the insulating layer 142 is 200 nm or less, variations in the gap G in the planes along the second direction X and the third direction Y may lead to a decrease in the power generation amount. Also, if the thickness of the insulating layer 142 is greater than 1 μm, the electric field generated between the

electrodes

11 and 12 may weaken. For these reasons, the thickness of the insulating layer 142 is preferably greater than 200 nm and equal to or less than 1 μm.

The insulating layer 142 may contain, for example, one type of material, or may contain a plurality of materials depending on the application. The insulating layer 142 may include a plurality of layers containing different materials, for example, and may include a structure in which each layer is laminated. When the insulating layer 142 includes multiple layers, for example, nanoparticles 141 containing different materials may be dispersed in each layer.

The insulating layer 142 has insulating properties. The material used for the insulating layer 142 is arbitrary as long as it is an insulating material that can fix the nanoparticles 141 in a dispersed state, but an organic polymer compound is preferable. When the insulating layer 142 contains an organic polymer compound, the insulating layer 142 can be formed flexibly, so that the thermoelectric element 1 can be formed in a shape such as curved or bent depending on the application.

Examples of organic polymer compounds include polyimides, polyamides, polyesters, polycarbonates, poly(meth)acrylates, radically polymerizable photo- or thermosetting resins, photo-cationically polymerizable photo- or thermosetting resins, epoxy resins, and acrylonitrile components. can be used, such as copolymers containing

Note that an inorganic material may be used as the insulating layer 142, for example. Examples of inorganic substances include porous inorganic substances such as zeolite and diatomaceous earth, as well as cage-like molecules.

<First Substrate 15, Second Substrate 16>
The first substrate 15 and the second substrate 16 are spaced apart in the first direction Z with the

electrodes

11 and 12 and the intermediate portion 14 interposed therebetween, as shown in FIG. 4, for example. The first substrate 15 is, for example, in contact with the first electrode 11 and separated from the second electrode 12 . The first substrate 15 fixes the first electrode 11 . The second substrate 16 is in contact with the second electrode 12 and separated from the first electrode 11 . A second substrate 16 fixes the second electrode 12 .

The thickness of each of the

substrates

15 and 16 along the first direction Z is, for example, 3 μm or more and 2 mm or less. The thickness of each

substrate

15, 16 can be set arbitrarily. The shape of each of the

substrates

15 and 16 may be, for example, square, rectangular, or disk-like, and can be arbitrarily set according to the application.

As the

substrates

15 and 16, for example, plate-shaped members having insulation properties can be used, and known members such as silicon, quartz, and Pyrex (registered trademark) can be used. For each of the

substrates

15 and 16, for example, a film-like member may be used, and for example, a known film-like member such as PET (polyethylene terephthalate), PC (polycarbonate), polyimide, or the like may be used.

For the

substrates

15 and 16, for example, a member having conductivity can be used, such as iron, aluminum, copper, or an alloy of aluminum and copper. As the

substrates

15 and 16, for example, a member such as a conductive polymer may be used in addition to a conductive semiconductor such as Si or GaN. If conductive members are used for the

substrates

15 and 16, wiring for connecting to the

electrodes

11 and 12 becomes unnecessary.

Note that the thermoelectric element 1 may include only the first substrate 15 as shown in FIG. 7(a), or may include only the second substrate 16, for example. Further, as shown in FIG. 7B, the thermoelectric element 1 has a laminated structure in which a plurality of the first electrodes 11, the intermediate portions 14, and the second electrodes 12 are laminated in this order without the

respective substrates

15 and 16. (e.g. 1a, 1b, 1c, etc.), for example, a laminated structure comprising at least one of the

substrates

15, 16 may be indicated.

<Support portion 13>
The thermoelectric element 1 may further have a support portion 13 as shown in FIG. 8, for example. The support portion 13 is provided in contact between a first substrate 15 and a second substrate 16, which are a pair of substrates, or between a first electrode 11 and a second electrode 12, which are a pair of electrodes. For example, the support portion 13 is in contact with the first electrode 11 and the second electrode 12 in the second direction X, but may be separated from the first electrode 11 and the second electrode 12 .

A material having insulating properties can be selected as the material for the support portion 13 . Examples of insulating materials include silicon, silicon oxide films, glass such as quartz, and insulating resins. In addition to the above, the supporting portion 13 may be, for example, a flexible film, and may be made of PET (polyethylene terephthalate), PC (polycarbonate), polyimide, or the like.

The middle part 14 of the thermoelectric element 1 may contain the solvent 143 instead of the insulating layer 142, for example. In this case, nanoparticles 141 are dispersed in the solvent. The intermediate portion 14 is obtained, for example, by filling the space 140 with a solvent 143 in which nanoparticles 141 are dispersed.

For the solvent 143, for example, a liquid with a boiling point of 60°C or higher can be used. Therefore, vaporization of the solvent 143 can be suppressed even when the thermoelectric element 1 is used in an environment of room temperature (for example, 15° C. to 35° C.) or higher. As a result, deterioration of the thermoelectric element 1 due to evaporation of the solvent 143 can be suppressed. At least one of an organic solvent and water can be selected as an example of the liquid. Examples of organic solvents include methanol, ethanol, toluene, xylene, tetradecane, alkanethiols, and the like. It should be noted that the solvent 143 is preferably a liquid having a high electrical resistance value and an insulating property.

<Example of operation of thermoelectric element 1>
For example, when thermal energy is applied to the thermoelectric element 1, electrons move between the first electrode 11 and the second electrode 12, converting the thermal energy into electrical energy. The amount of electrons that move between the first electrode 11 and the second electrode 12 depends on thermal energy and on the difference between the work function of the second electrode 12 and the work function of the first electrode 11 .

The amount of electrons moving between the first electrode 11 and the second electrode 12 is increased by, for example, increasing the work function difference between the first electrode 11 and the second electrode 12 and decreasing the gap G. be able to. For example, the amount of electrical energy generated by the thermoelectric element 1 can be increased by considering at least one of increasing the work function difference and decreasing the gap G. In addition, by providing the nanoparticles 141 between the

electrodes

11 and 12, the amount of electrons moving between the

electrodes

11 and 12 can be increased, which can lead to an increase in the amount of current. .

　The "work function" indicates the minimum energy required to extract electrons in a solid into a vacuum. The work function is measured using, for example, ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS), or Auger electron spectroscopy (AES). can be done.

According to this embodiment, the thermoelectric element 1 includes a pair of

electrodes

11 and 12 having different work functions. That is, even when there is no temperature difference between the electrodes, thermal energy can be converted into electrical energy. Therefore, there is no need to provide a heat dissipation mechanism such as a heat dissipation plate. Also, the thermoelectric element 1 is provided in contact with the solar cell panel 6 . Therefore, the heat that contributes to the power generation of the thermoelectric element 1 is directly transmitted from the solar cell panel 6 in addition to the heat that accompanies the temperature rise around the solar cell panel. As a result, the amount of power generated by the thermoelectric element 1 can be increased.

According to the present embodiment, the insulating portion 63 includes the sealant 64 filled between the solar cell 61 and the support portion 62 , and the thermoelectric element 1 is formed between the solar cell 61 and the support portion 62 . and covered with a sealant 64 . Therefore, the heat generated from the photovoltaic cells 61 in addition to the support portions 62 can be easily transferred to the thermoelectric elements 1 . This makes it possible to further increase the power generation amount.

According to this embodiment, the area of the solar battery cell 61 is larger than the area of the thermoelectric element 1 when viewed from the direction from the solar battery cell 61 toward the support portion 62 . Therefore, light such as sunlight that has passed between the plurality of photovoltaic cells 61 can be reflected by the support portion 62 to facilitate irradiation of the photovoltaic cells 61 . This makes it possible to suppress a decrease in the amount of power generated by the solar cell panel 6 due to the installation of the thermoelectric elements 1 .

According to this embodiment, the energy harvesting device 7, the power measuring unit 72 that measures the power of the thermoelectric element 1, and the estimating unit that estimates the power generated from the photovoltaic cell 61 based on the measurement result of the power measuring unit 72. 76 and. Therefore, it is possible to easily estimate variations in the amount of power generated due to the temperature of the solar cell panel 6 . This makes it possible to further increase the amount of power generated by the energy harvesting device 7 as a whole.

Here, when it becomes difficult for the current to flow due to a defect in the solar cell 61, the solar cell 61 may locally generate heat and be damaged. In this regard, according to the present embodiment, the evaluation unit 77 evaluates the temperature of the photovoltaic cell 61 based on the measurement result of the measurement unit 71 . Therefore, the thermoelectric element 1 can be used not only for power generation but also as a sensor for determining whether or not heat is generated due to a failure of the solar battery cell 61 . As a result, it is possible to increase the amount of power generated by the energy harvesting device 7 as a whole and to increase safety.

(Second Embodiment: Energy Harvesting Device 7, Energy Harvesting System 700)
Next, another embodiment will be described. Detailed descriptions of configurations similar to those of the above-described embodiment are omitted below. FIG. 9 is a schematic cross-sectional view showing an example of the energy harvesting device 7 in the second embodiment. In the energy harvesting device 7 according to the second embodiment, the thermoelectric element 1 is provided inside the solar panel 6 . The thermoelectric element 1 is provided, for example, between the solar battery cell 61 and the support portion 62 and covered with a sealant 64 . The thermoelectric element 1 is provided, for example, with the first principal surface 10a spaced from the surface 62b of the support portion 62 and the second principal surface 10b in contact with the back surface 61a of the solar cell 61 . For example, a plurality of thermoelectric elements 1 are provided in one solar cell 61 with a gap therebetween.

In particular, according to this embodiment, one solar cell 61 is provided with a plurality of thermoelectric elements 1 . Therefore, when the thermoelectric element 1 is used as a sensor for determining whether or not heat is generated due to the failure of the solar battery cell 61, the location of the failure of the solar battery cell 61 can be grasped in detail. This makes it possible to further improve safety.

In particular, according to this embodiment, the thermoelectric elements 1 are provided in contact with the solar cells 61 . Therefore, when the thermoelectric element 1 is used as a sensor for determining whether or not heat is generated due to the failure of the solar battery cell 61, the occurrence of the failure of the solar battery cell 61 can be detected with higher accuracy. This makes it possible to further improve safety.

(Third Embodiment: Energy Harvesting Device 7, Energy Harvesting System 700)
FIG. 10 is a schematic cross-sectional view showing an example of the energy harvesting device 7 in the third embodiment. In the energy harvesting device 7 according to the third embodiment, the thermoelectric element 1 is provided outside the solar panel 6 . The thermoelectric element 1 is provided so that the second main surface 10b is in contact with the back surface 62a of the support portion 62 of the solar cell panel 6, for example. The thermoelectric element 1 is provided in contact between the support portion 62 and a heat storage portion 65 which will be described later.

The insulating portion 63 includes a heat storage portion 65 provided on the back surface 62 a side of the support portion 62 . The heat storage part 65 has heat storage properties. The heat storage unit 65 has, for example, a sensible heat storage material that utilizes the specific heat of a substance (amount of heat required to raise the temperature of a substance by a unit temperature).

For example, when the heat storage section 65 has a sensible heat storage material, the specific heat of the heat storage section 65 is higher than the specific heat of each of the

substrates

15 and 16 . Therefore, the heat accumulated in the heat storage section 65 can be easily transferred to the

electrodes

11 and 12 of the thermoelectric element 1 . Also, for example, the specific heat of the heat storage portion 65 is higher than the specific heat of the support portion 62 . Therefore, heat can be accumulated in the heat storage portion 65 for a longer period of time than in the support portion 62 .

For example, airgel, bricks, etc. are used as sensible heat storage materials. Airgel has nano-sized porosity smaller than the mean free path of air molecules, and is made of silica, carbon, alumina, or the like. As the sensible heat storage material, for example, a material exhibiting a specific heat higher than that of glass (for example, 0.67 J/g·K at 10 to 50° C.) is used. As for the value of specific heat, in addition to referring to literature values, measurement results according to JIS K 7123 may be used.

The heat storage section 65 may have a latent heat storage material that utilizes transition heat (latent heat) associated with phase change or transition of substances, for example. As the latent heat storage material, a known material such as water, sodium chloride, etc. that utilizes phase conversion is used. The heat storage unit may have, for example, a chemical heat storage material that utilizes endothermic heat generated during a chemical reaction. As the chemical heat storage material, for example, a known material is used.

According to this embodiment, the thermoelectric element 1 includes a pair of

electrodes

11 and 12 having different work functions. That is, even when there is no temperature difference between the electrodes, thermal energy can be converted into electrical energy. Therefore, there is no need to provide a heat dissipation mechanism such as a heat dissipation plate. Also, the thermoelectric element 1 is provided in contact with the rear surface 62 a of the support portion 62 of the solar panel 6 . Therefore, heat transferred to the thermoelectric element 1 is transferred from the solar cell panel 6 . As a result, the amount of power generated by the thermoelectric element 1 can be increased.

According to the present embodiment, the insulating portion 63 includes the heat storage portion 65 provided on the back surface 62 a side of the support portion 62 , and the thermoelectric element 1 is provided between the support portion 62 and the heat storage portion 65 in contact therewith. . Therefore, heat can be easily transferred to the thermoelectric element 1 via the heat storage unit 65 even in a time zone when sunlight is not irradiated. This makes it possible to extend the power generation possible time of the energy harvesting device 7 as a whole.

According to this embodiment, the heat storage section 65 has a sensible heat storage material. Therefore, the temperature range during use can be widened compared to the latent heat storage material. This makes it possible to realize energy harvesting suitable for various uses.

(Fourth Embodiment: Energy Harvesting Device 7, Energy Harvesting System 700)
FIG. 11 is a schematic cross-sectional view showing an example of the energy harvesting device 7 in the third embodiment. In the energy harvesting device 7 according to the fourth embodiment, the thermoelectric element 1 is provided outside the solar panel 6 . The thermoelectric element 1 is provided so that the second main surface 10b is in contact with the back surface 62a of the support portion 62 of the solar cell panel 6, for example.

The insulating portion 63 includes a heat storage portion 65 provided on the back surface 62 a side of the support portion 62 . The heat storage unit 65 includes a first heat storage unit 651 and a second heat storage unit 652 having different heat storage properties.

The thermoelectric element 1 is provided in contact between the support portion 62 and the heat storage portion 65 . The thermoelectric elements 1 include a first element 1-1 in contact with the first heat storage section 651 and separated from the second heat storage section 652, and a second element 1-1 in contact with the second heat storage section 652 and separated from the first heat storage section 651. 2 and

In particular, according to the present embodiment, the heat storage unit 65 includes the first heat storage unit 651 and the second heat storage unit 652, which have different heat storage properties, and the thermoelectric element 1 is in contact with the first heat storage unit 651 and the second heat storage unit 651. A first element 1-1 separated from the portion 652 and a second element 1-2 in contact with the second heat storage portion 652 and separated from the first heat storage portion 651 are included. Therefore, it is possible to set a different power generation possible time for each element. This makes it possible to further extend the power generation possible time of the energy harvesting device 7 as a whole.

Although illustration is omitted, the heat storage unit 65 may include three or more heat storage units. For example, the heat storage unit 65 may include a first heat storage unit 651, a second heat storage unit 652, and a third heat storage unit having different heat storage properties. At this time, the thermoelectric element 1 is provided in contact between the support portion 62 and the heat storage portion 65 . The thermoelectric element 1 is in contact with the first heat storage unit 651 and separated from the second heat storage unit 652 and the third heat storage unit. A second element 1-2 separated from the heat storage unit and a third element in contact with the third heat storage unit and separated from the first heat storage unit 651 and the second heat storage unit 652 may be included. Even in this case, a different power generation possible time can be set for each element. This makes it possible to further extend the power generation possible time of the energy harvesting device 7 as a whole.

(Fifth Embodiment: Energy Harvesting Device 7, Energy Harvesting System 700)
FIG. 12 is a schematic cross-sectional view showing an example of the energy harvesting device 7 in the fifth embodiment. In the energy harvesting device 7 according to the fifth embodiment, the thermoelectric element 1 is provided outside the solar panel 6 . The thermoelectric element 1 is provided with the first electrode 11 and the second electrode 12 perpendicular to the back surface 62 a of the support portion 62 .

The first element 1-1 is provided between the pair of first heat storage units 651 and in contact therewith. The second element 1-2 is provided in contact between the pair of second heat storage portions 652. As shown in FIG.

In particular, according to this embodiment, the first electrode 11 and the second electrode 12 are provided perpendicular to the back surface 62 a of the support portion 62 . In this case, the

heat accumulators

651 and 652 can be provided in contact with the support 62 in addition to the thermoelectric element 1, and the amount of heat accumulated in the

heat accumulators

651 and 652 can be increased. This makes it possible to increase the amount of power generated by the thermoelectric element 1 using the heat storage unit 65 .

(Sixth embodiment: energy harvesting device 7, energy harvesting system 700)
FIG. 13 is a schematic cross-sectional view showing an example of the energy harvesting device 7 in the sixth embodiment. The energy harvesting device 7 according to the sixth embodiment further includes a heat conducting section 20 .

The thermoelectric element 1 is provided inside the solar panel 6 . The thermoelectric element 1 is provided, for example, between the solar battery cell 61 and the support portion 62 and covered with a sealant 64 . The thermoelectric element 1 is provided, for example, with the first principal surface 10 a in contact with the surface 62 b of the support portion 62 and with the second principal surface 10 b spaced apart from the solar cell 61 .

The heat conducting part 20 is in contact with the supporting part 62 and the thermoelectric element 1 . The thermally conductive portion 20 has a higher thermal conductivity than the insulating portion 63, for example. The heat conducting portion 20 is provided, for example, between the solar cell 61 and the supporting portion 62 and covered with a sealant 64 .

Here, the heat transferred from the support portion 62 to the thermoelectric element 1 includes heat transferred via the heat conduction portion 20 in addition to the heat transferred directly from the support portion 62 . Therefore, the contact area between the heat conducting portion 20 and the thermoelectric element 1 affects the amount of heat transferred to the thermoelectric element 1 . Therefore, in order to increase the amount of power generated by the thermoelectric element 1, it is desirable that the contact area between the heat conducting portion 20 and the thermoelectric element 1 is large. For example, when the length of the heat conducting portion 20 is equal to or longer than the length of the thermoelectric element 1 along the third direction Y, compared to the case where the length of the heat conducting portion 20 is less than the length of the thermoelectric element 1, Large contact area. As a result, the amount of heat transferred to the thermoelectric element 1 can be increased, and the amount of power generated by the thermoelectric element 1 can be increased.

The thermal conductivity of the heat conducting portion 20 may be higher than the thermal conductivity of the

substrates

15 and 16. For example, if the material of the

substrates

15 and 16 is stainless steel (SUS), the heat conduction portion 20 may be made of copper having a higher thermal conductivity than the

substrates

15 and 16. , 16, a material having relatively higher thermal conductivity than that of 16 may be used. This makes it difficult for the heat transferred from the solar cell panel 6 to the thermoelectric element 1 to be released to the outside, and the amount of power generated by the thermoelectric element 1 can be increased.

It should be noted that the thermal conductivity of the heat conductive portion 20 may be higher than that of the support portion 13 so that the heat transferred from the solar cell panel 6 to the thermoelectric element 1 is less likely to be released to the outside. Also, the thermal conductivity of the thermally conductive portion 20 may be higher than that of at least one of the pair of the first electrode 11 and the second electrode 12 .

The heat conducting part 20 has electrical conductivity and is made of, for example, a metal material. In addition, the heat conducting portion 20 is not limited to a metal material, and may be made of any material as long as it has a high electrical conductivity. Specifically, the material with high conductivity preferably has a thermal conductivity of 10 W/(m·k) or more as measured according to ASTM E1530. The material having high conductivity may be, for example, a metal material such as gold, silver, copper, or aluminum, and is preferably made of copper or aluminum.

The insulating portion 63 includes a sealant 64 provided between the solar cell 61 and the support portion 62 . A sealant 64 covers the heat conducting portion 20 and the thermoelectric elements 1 .

In particular, according to the present embodiment, the heat conducting portion 20 is in contact with the supporting portion 62 and the thermoelectric element 1, and the insulating portion 63 covers the heat conducting portion 20 and the thermoelectric element 1. Therefore, heat generated from the support portion 62 is easily transferred to the thermoelectric element 1 via the heat conduction portion 20 . Also, the heat transferred to the thermoelectric element 1 is less likely to be released to the outside. By these, it becomes possible to further increase the amount of power generation.

(Seventh embodiment: energy harvesting device 7, energy harvesting system 700)
FIG. 14 is a schematic cross-sectional view showing an example of the energy harvesting device 7 in the seventh embodiment. The energy harvesting device 7 according to the seventh embodiment further includes a heat conducting section 20 .

The thermoelectric element 1 is provided outside the solar cell panel 6 . The thermoelectric element 1 is provided so that the second main surface 10b is in contact with the back surface 62a of the support portion 62 of the solar cell panel 6, for example.

The heat conducting part 20 is in contact with the supporting part 62 and the thermoelectric element 1 . The heat conducting portion 20 is provided in contact with the rear surface 62a of the support portion 62, for example.

The insulating portion 63 includes a sealant 64 provided between the solar cell 61 and the support portion 62 . The insulating portion 63 may include a protective portion 66 provided on the back surface 62 a side of the support portion 62 . The protection part 66 has, for example, insulating properties, and suppresses deterioration of the thermoelectric element 1 caused by the external environment. As the protective portion 66, in addition to using a known insulating material, for example, the same material as the heat storage portion 65 described above may be used.

As shown in FIG. 14( a ), the protection part 66 covers part of the heat conduction part 20 and part of the thermoelectric element 1 . The protective portion 66 covers the rear surface of the heat conductive portion 20 and the first main surface 10 a of the thermoelectric element 1 .

For example, as shown in FIG. 14(b), the protection part 66 covers the entire heat conduction part 20 and the thermoelectric element 1. In this case, a state in which heat can be easily transferred to the thermoelectric element 1 can be maintained, and deterioration over time of the thermoelectric element 1 and the heat conducting portion 20 can be suppressed.

For example, as shown in FIG. 14(c), the protective portion 66 may include a first protective portion 66a and a second protective portion 66b. The first protection part 66 a covers part of the heat conducting part 20 and part of the thermoelectric element 1 . In addition, the second protection portion 66b covers the other portion of the heat conducting portion 20 and the other portion of the thermoelectric element 1. As shown in FIG. Different materials are used for the

protection portions

66a and 66b. In this case, it is possible to arbitrarily change the degree of increase in heat transfer or increase in durability according to the application of the energy harvesting device 7 .

Although several embodiments of the invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

Reference Signs List 1: thermoelectric element 10a: first main surface 10b: second main surface 11: first electrode 12: second electrode 13: support portion 14: intermediate portion 140: space 141: nanoparticles 141a: coating 142: insulating layer 143: Solvent 15 : First substrate 16 : Second substrate 20 : Thermal conductive part 6 : Solar battery panel 61 : Solar battery cell 62 : Support part 63 : Insulating part 64 : Sealant 65 : Heat storage part 66 : Protective part 7 : Environment Power generation device 71 : Measurement unit 72 : Power measurement unit 73 : Power generation amount measurement unit 75 : Information processing device 76 : Estimation unit 77 : Evaluation unit 700 : Energy harvesting system Z : First direction X : Second direction Y : Third direction

Claims

An energy harvesting device that converts light energy and thermal energy into electrical energy,
a solar panel that converts light energy into electrical energy;
a thermoelectric element that does not require a temperature difference between electrodes when converting thermal energy into electrical energy;
with
The solar panel is
a plurality of solar cells;
a support provided on the back surface side of the plurality of solar cells;
an insulating portion in contact with the support;
including
The thermoelectric element is
a pair of electrodes each having a different work function;
an intermediate portion provided between the pair of electrodes;
including
The energy harvesting device, wherein the thermoelectric element is provided in contact with the solar panel.
further comprising a heat conducting part in contact with the support part and the thermoelectric element,
The energy harvesting device according to claim 1, wherein the insulating portion covers the heat conducting portion and the thermoelectric element.
The insulating portion includes a sealant filled between the solar cell and the support portion,
3. The energy harvesting device according to claim 1, wherein the thermoelectric element is provided between the solar battery cell and the support and is covered with the sealant.
4. The energy harvesting device according to claim 3, wherein the area of the solar cell is larger than the area of the thermoelectric element when viewed from the solar cell toward the support.
The insulating section includes a heat storage section provided on the back side of the supporting section,
3. The energy harvesting device according to claim 1, wherein the thermoelectric element is provided in contact between the support portion and the heat storage portion.
The heat storage unit includes a first heat storage unit and a second heat storage unit with different heat storage properties,
The thermoelectric element is
a first element in contact with the first heat storage unit and separated from the second heat storage unit;
a second element in contact with the second heat storage unit and separated from the first heat storage unit;
6. The energy harvesting device of claim 5, comprising:
An energy harvesting system using the energy harvesting device according to claim 3 or 4,
a measuring unit that measures the amount of power generated or electric power of the thermoelectric element;
an evaluation unit that evaluates the temperature of the solar battery cell based on the measurement result of the measurement unit;
An energy harvesting system comprising:
An energy harvesting system using the energy harvesting device according to any one of claims 1 to 6,
a power measuring unit that measures the power of the thermoelectric element;
an estimating unit that estimates the power generated from the solar cell based on the measurement result of the power measuring unit;
An energy harvesting system comprising: