Photovoltaic generator, snow-melting method therefor, power generation panel under snow accumulation, and snow-melting method therefor

Abstract

To provide a photovoltaic generator, a snow-melting method using the photovoltaic generator, a photovoltaic generation panel, and a snow-melting method using the photovoltaic generation panel which are capable of removing snow accumulated during snowfall without reducing the power generation amount due to a decrease in a light reception amount.SOLUTION: During snowfall, snow accumulates on a snow accumulation photovoltaic generation panel 120 which becomes a snow accumulation part of the photovoltaic generation panel, and a snow accumulation removal photovoltaic generation panel 110 being a snow accumulation-time power generation part connected to the snow accumulation photovoltaic generation panel 120 being the snow accumulation part that cannot generate power due to snow accumulation is turned into a state where snow during snow accumulation is removed in the photovoltaic generation panel, thereby enabling power generation.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a photovoltaic device, snow melting using a photovoltaic device, a power generation panel during snow accumulation, and a method of melting snow using a power generation panel during snow accumulation, and in particular to a photovoltaic device that melts snow accumulated on a photovoltaic panel, snow melting using a photovoltaic device, a power generation panel during snow accumulation, and a method of melting snow using a power generation panel during snow accumulation. [Background technology]

[0002] Photovoltaic power generation has been developed in which solar panels with an array of solar cells receive light irradiated from the sun and convert the light energy into electricity. In addition, solar panels that not only receive light irradiated from the sun and generate electricity, but also receive light reflected from the ground on the back side of the panel and generate electricity, thereby increasing the amount of electricity generated.

[0003] However, these solar panels have a problem that when snow accumulates on the surface of the solar panels, mainly in areas with heavy snowfall, the snow blocks sunlight, reducing the amount of power generated. For this reason, solar panels that can efficiently remove snow from the panels have been developed (for example, Patent Document 1).

[0004] FIG. 14 is a diagram showing an example of a heat exchange system including a solar cell and a solar cell heat exchanger disclosed in Patent Document 1. In FIG. As shown in FIG. 14, a heat exchange system 10 disclosed in Patent Document 1 includes a solar panel 11 and a solar cell heat exchanger 12 that covers a solar cell 11a in the solar panel 11 from the front side.

[0005] The heat exchanger 12 for solar cells is formed as a hollow plate-like rectangular box having a fluid flow passage 12c through which the fluid flows between a fluid inlet 12a through which the fluid is injected and a fluid outlet 12b through which the fluid injected from the fluid inlet 12a is discharged, and the heat exchanger 12 for solar cells is configured to transmit sunlight to the fluid flow passage 12c.

[0006] At this time, a transparent or translucent fluid is injected through the fluid inlet 12a, passes through the fluid flow passage 12c and is discharged through the fluid outlet 12b. By using a fluid with a higher temperature than the temperature of the accumulated snow, the snow that has accumulated on the surface side of the solar panel 11 can be melted and removed. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2023-36300 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, when the heat exchange system 10 disclosed in the above-mentioned Patent Document 1 is placed on top of an existing solar power generation panel, there is a problem in that the amount of power generation decreases. Specifically, the heat exchange system 10 disclosed in Patent Document 1 has a solar cell heat exchanger 12 provided to cover the front side of the solar cell 11a, which reduces the amount of light received by the solar cell 11a, i.e., reduces the amount of power generated by the solar cell 11a.

[0009] More specifically, the solar cell heat exchanger 12, which is arranged to cover the front side of the solar cell 11a, is configured to allow a fluid to pass through its interior, but not all of the incident light passes through the solar cell heat exchanger 12.

[0010] For example, it is conceivable that some of the light does not reach the solar cell 11a because the incident light hits the heat exchanger 12 for solar cells and is absorbed by the heat exchanger 12 for solar cells, the incident light is reflected by the heat exchanger 12 for solar cells, or the incident light is scattered by the heat exchanger 12 for solar cells.

[0011] Therefore, by interposing the solar cell heat exchanger 12 between the incident light and the solar cell 11a, the amount of light received by the solar cell 11a is reduced, resulting in a problem of a reduced amount of power generated by the solar cell 11a.

[0012] The present invention has been made in consideration of these points, and aims to provide a photovoltaic power generation device that can remove accumulated snow without a decrease in the amount of power generation due to a decrease in the amount of light received, a snow melting device, a power generation panel that powers snow, and a method of melting snow using a power generation panel that powers snow. [Means for solving the problem]

[0013] In order to solve the above problem, the present invention provides a photovoltaic device that melts snow that has accumulated on a photovoltaic panel, characterized in that it comprises a snow accumulation section which is the part of the photovoltaic panel where snow accumulates, and a snow accumulation power generation section connected to the snow accumulation section which becomes a part of the photovoltaic panel that can generate electricity when snow has been removed. As a result, snow accumulates on the snow-covered portion of the photovoltaic panel, and the snow-covered power generation unit connected to the snow-covered portion becomes capable of generating power as the snow on the photovoltaic panel is removed.

[0014] In addition, the present invention provides a method for melting snow using a photovoltaic device comprising a snow-accumulated portion which is a portion of a photovoltaic panel on which snow accumulates, and a power-generating-in-snow portion connected to the snow-accumulated portion which becomes a portion of the photovoltaic panel capable of generating electricity when snow is removed during snow accumulation, the method comprising the steps of: generating electricity in the power-generating-in-snow portion; and generating heat as the electricity generated by the power-generating-in-snow portion flows into the snow-accumulated portion. As a result, the snow power generation unit generates electricity, and the electricity generated by the snow power generation unit flows into the snow-covered area, causing the snow power generation unit to generate heat.

[0015] The present invention also provides a snow-induced power generation panel comprising a snow-induced power generation section connected to a snow-induced photovoltaic panel comprising a snow-accumulation section, which is the section that accumulates snow, and which becomes capable of generating electricity when snow is removed during snow accumulation.

[0016] As a result, the snow-induced power generation panel, which is composed of a snow-induced power generation section connected to a snow-induced photovoltaic power generation panel composed of a snow-accumulated section, which is the part where snow accumulates, becomes capable of generating power when the snow is removed.

[0017] In addition, the present invention provides a method for melting snow using a snow-induced power generation panel, the method comprising a snow-induced power generation section connected to a snow-induced photovoltaic panel comprising a snow-accumulated section, which is a section that accumulates snow, and which becomes capable of generating electricity when snow is removed from the snow-accumulated power generation section, the method comprising: The snow melting method is characterized by comprising a step of causing the snow photovoltaic power generation panel to generate heat by flowing electricity generated by the snow photovoltaic power generation panel to the snow photovoltaic power generation panel. As a result, the snow-covered power generation panel generates electricity, and the electricity generated by the snow-covered power generation panel flows to the snow-covered photovoltaic power generation panel, causing the snow-covered photovoltaic power generation panel to generate heat. Effect of the Invention

[0018] According to the photovoltaic power generation device, snow melting using the photovoltaic power generation device, snow-induced power generation panel, and method of melting snow using the snow-induced power generation panel of the present invention, snow accumulates on the snow-accumulated portion of the photovoltaic panel, and the snow-accumulated power generation portion connected to the snow-accumulated portion is able to generate electricity when the snow on the photovoltaic panel is removed. This has the following effects.

[0019] First, the power generation unit when snow is removed from the photovoltaic panel, and the power generation unit when snow is accumulated generates electricity. At this time, the electricity generated by the power generation unit when snow is accumulated flows to the snow-covered area, but the snow-covered area cannot generate electricity and has a high resistance. When the voltage generated by the power generation unit when snow is accumulated is applied to the snow-covered area, the snow-covered area generates heat, and the snow that has accumulated in the snow-covered area melts. As a result, the snow that has accumulated in the snow-covered area can be melted without a decrease in the amount of electricity generated. [Brief description of the drawings]

[0020] [Figure 1] 1 is a block diagram showing the concept of a photovoltaic device according to a first embodiment. [Diagram 2] 1 is a block diagram showing the concept of a photovoltaic device, illustrating an example of a snow removal photovoltaic panel provided in the photovoltaic device according to a first embodiment. FIG. [Diagram 3] This is a diagram showing the process from snow accumulation on a snow removal photovoltaic panel to the generation of heat by a single-sided photovoltaic panel. [Figure 4] A diagram showing the process from when the snow on a single-sided photovoltaic panel melts to when the snow that has accumulated on a double-sided photovoltaic panel melts. [Diagram 5] FIG. 1 is a diagram showing the flow from snow accumulation on a photovoltaic power generation device to the melting of snow on a snow removal photovoltaic power generation panel. [Figure 6] FIG. 13 is a diagram showing the flow from the state in which snow that has accumulated on the snow removal photovoltaic power generation panel has melted to the state in which snow that has accumulated on the snow accumulation photovoltaic power generation panel melts. [Figure 7] FIG. 11 is a block diagram showing the concept of a photovoltaic device according to a second embodiment. [Figure 8] FIG. 11 is a block diagram showing the concept of a photovoltaic device, illustrating an example of a snow removal photovoltaic panel provided in the photovoltaic device according to the second embodiment. [Figure 9] FIG. 1 is a diagram showing the flow from snow accumulation on a photovoltaic power generation device to the melting of snow on a snow removal photovoltaic power generation panel. [Figure 10] FIG. 13 is a diagram showing the flow from the state in which snow that has accumulated on the snow removal photovoltaic power generation panel has melted to the state in which snow that has accumulated on the snow accumulation photovoltaic power generation panel melts. [Figure 11] FIG. 11 is a block diagram showing the concept of a photovoltaic device according to a third embodiment. [Figure 12] 1 is a cross-sectional view showing a concept of an example of installation of a non-snow-covered photovoltaic power generation panel and a snow-covered photovoltaic power generation panel in a photovoltaic power generation device. [Figure 13] FIG. 13 is a block diagram showing the concept of a photovoltaic device according to a fourth embodiment. [Figure 14]FIG. 1 is a diagram showing an example of a heat exchange system including a solar cell and a solar cell heat exchanger disclosed in Patent Document 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. First Embodiment FIG. 1 is a block diagram showing the concept of a photovoltaic device according to a first embodiment.

[0022] As shown in Fig. 1, the photovoltaic device 100 is configured by connecting in parallel a snow-removal photovoltaic panel 110, which is a photovoltaic panel with a snow-removal function, and a snow-accumulation photovoltaic panel 120, which is a photovoltaic panel without a snow-removal function, i.e., where snow accumulates, by branching them with a branch cable B such as a Y-branch cable, and electricity generated by the photovoltaic device 100 is converted to AC power by a power conditioner 200 connected to the photovoltaic device 100 by a connection cable or the like, and sent to a distribution board or the like (not shown here). Also, the branch cable B does not have a backflow prevention function such as a backflow prevention diode, and is connected to allow backflow.

[0023] The photovoltaic power generation device 100 is installed, for example, on the roof of a house, factory, warehouse, etc., where there is nothing blocking sunlight, or in an open space, etc. Furthermore, the photovoltaic power generation device 100 is installed at an inclination of about 30 degrees with respect to the horizontal plane so that it is directly exposed to sunlight.

[0024] For this reason, if snow accumulates on the surface of the photovoltaic device 100 in areas with heavy snowfall, the snow blocks sunlight, resulting in a problem of reduced power generation. In view of this, the photovoltaic device 100 of this embodiment can efficiently melt accumulated snow as described below.

[0025] FIG. 2 is a block diagram showing the concept of the photovoltaic device, illustrating an example of a snow removal photovoltaic panel provided in the photovoltaic device according to the first embodiment. As shown in Figure 2, the snow removal photovoltaic panel 110 is composed of a plurality of single-sided photovoltaic panels 111 and a plurality of double-sided photovoltaic panels 112, and the single-sided photovoltaic panels 111 and the double-sided photovoltaic panels 112 are connected in series via panel connection parts 113 so that the single-sided photovoltaic panels 111 and the double-sided photovoltaic panels 112 are alternated.

[0026] In addition, the snow removal photovoltaic panel 110 is not limited to being constructed by combining a new single-sided photovoltaic panel 111 and a double-sided photovoltaic panel 112, but can also be constructed by replacing some single-sided photovoltaic panels of an existing photovoltaic device consisting only of single-sided photovoltaic panels with double-sided photovoltaic panels.

[0027] It is also possible to replace some of the existing bifacial photovoltaic panels in a photovoltaic device consisting only of bifacial photovoltaic panels with single-sided photovoltaic panels. Furthermore, it is also possible to convert some of the existing bifacial photovoltaic panels in a photovoltaic device consisting only of bifacial photovoltaic panels into single-sided photovoltaic panels by attaching a light-blocking sheet material to the backside of the bifacial photovoltaic panels.

[0028] The single-sided photovoltaic panel 111 described here is a panel in which photovoltaic cells that are irradiated with light such as sunlight and directly convert the energy of the received light into electrical energy are provided only on the surface of the single-sided photovoltaic panel 111.

[0029] Generally, single-sided photovoltaic panels are formed with a light-transmitting glass surface on the front side and a backsheet material on the back side. The backsheet material is used to protect the single-sided photovoltaic panel from heat, ultraviolet rays, moisture, etc., and is made of a multi-layer structure made of PET (Polyethyleneterephthalate) film, fluorine film, etc.

[0030] The double-sided photovoltaic panel 112 described here has photovoltaic cells on both the front and back sides, so that it can receive not only direct sunlight but also light reflected from the ground, buildings, water surfaces, snow, etc., and directly convert the energy of the received light into electrical energy.

[0031] Generally, a bifacial photovoltaic panel has a front and back surface made of light-transmitting glass, with photovoltaic cells disposed between the front and back glass surfaces.

[0032] In addition, the front surface of the single-sided photovoltaic panel 111 or double-sided photovoltaic panel 112 described here refers to the sky side of the single-sided photovoltaic panel 111 or double-sided photovoltaic panel 112 installed at an incline, and the ground side of the single-sided photovoltaic panel 111 or double-sided photovoltaic panel 112 is referred to as the back surface.

[0033] 3 is a diagram showing the flow from snow accumulation on the snow-removal photovoltaic panel to the single-sided photovoltaic panel generating heat. Note that the following description is given using one single-sided photovoltaic panel 111, double-sided photovoltaic panel 112, and panel connector 113 as an example, and omits other single-sided photovoltaic panels 111 and double-sided photovoltaic panels 112 that are connected in series, the panel connector 113, the power conditioner 200, and the connection cables connecting these. The following description is given on the assumption that the photovoltaic device 100 receives sunlight and generates electricity, and the snow-removal photovoltaic panel 110 can receive sunlight without being blocked.

[0034] FIG. 3A is a diagram showing the snow removal photovoltaic panel 110 in a non-snowy state. As shown in FIG. 3(A), in a snow removal photovoltaic panel 110 in a non-snowy state, a single-sided photovoltaic panel 111 and a double-sided photovoltaic panel 112 are connected in series via a panel connector 113.

[0035] In this case, in the single-sided photovoltaic panel 111, the photovoltaic cells arranged on the front side receive light directly from the sun and generate 100% of the power. In the double-sided photovoltaic panel 112, the photovoltaic cells arranged on the front side receive sunlight and generate 100% of the power, and the photovoltaic cells arranged on the back side receive reflected light from the ground, etc., and the back side of the double-sided photovoltaic panel 112 generates 20% of the power of the front side.

[0036] FIG. 3B is a diagram showing the snow-removing photovoltaic panel 110 in a snow-covered state. 3B, the entire surface of the snow-removal photovoltaic panel 110 is covered with snow due to snow accumulation. Note that the cross hatched lines in the figure indicate accumulated snow.

[0037] FIG. 3C is a diagram showing a state in which sunlight is irradiated onto the snow-removal photovoltaic panel 110 in a snow-covered state. As shown in FIG. 3(C), when sunlight is irradiated onto the snow-removed photovoltaic panel 110, the amount of power generated on the surface of the single-sided photovoltaic panel 111 is 0% because the sunlight is blocked by snow.

[0038] In addition, the front side of the double-sided photovoltaic panel 112 also generates 0% electricity because sunlight is blocked by snow, but as the back side receives reflected light, the back side of the double-sided photovoltaic panel 112 generates 20% of the electricity compared to the front side of the double-sided photovoltaic panel 112 when there is no snow.

[0039] As the back side of the double-sided photovoltaic panel 112 generates electricity, the snow removal photovoltaic panel 110, in which the single-sided photovoltaic panel 111 and the double-sided photovoltaic panel 112 are connected in series via the panel connection part 113, becomes a single conductor as a whole, and electricity flows from the positive side to the negative side as a whole.

[0040] FIG. 3D is a diagram showing a state in which electricity generated on the back side of the double-sided photovoltaic panel 112 flows to the snow-removal photovoltaic panel 110 in a snow-covered state, causing the single-sided photovoltaic panel 111 to generate heat. When electricity generated on the back side of the double-sided photovoltaic panel 112 flows to the snow-removal photovoltaic panel 110 that is covered in snow, electricity also flows to the adjacent single-sided photovoltaic panel 111 via the panel connection part 113.

[0041] However, the surface of the adjacent single-sided photovoltaic panel 111 is covered with snow, making it impossible for electricity to generate power and making it difficult for electricity to flow, resulting in a high resistance. When electricity generated by the back surface of the adjacent double-sided photovoltaic panel 112 flows through this surface, the temperature of the single-sided photovoltaic panel 111 rises.

[0042] When electricity becomes difficult to flow inside the single-sided photovoltaic panel 111 due to these reasons, a phenomenon known as a hot spot occurs, in which the electrical energy of the electricity is converted into thermal energy.

[0043] As the single-sided photovoltaic panel 111 generates heat due to this hot spot phenomenon, the snow that has accumulated on the surface of the single-sided photovoltaic panel 111 eventually melts and falls to the ground along the slope provided on the single-sided photovoltaic panel 111.

[0044] When the snow that has accumulated on the single-sided photovoltaic panel 111 due to the hot spot phenomenon of the single-sided photovoltaic panel 111 is removed, the electrical resistance to the single-sided photovoltaic panel 111 is reduced, and the heat that has been generated in the single-sided photovoltaic panel 111 is eventually released and the heat decreases.

[0045] Fig. 4 is a diagram showing the flow from the state where the snow melts on the single-sided photovoltaic panel to the melting of the snow that has accumulated on the double-sided photovoltaic panel. Note that Fig. 4 shows the state after the single-sided photovoltaic panel 111 generates heat in Fig. 3(D) and the accumulated snow melts, and is a continuation of Fig. 3.

[0046] As shown in FIG. 4(E), the snow that has accumulated on the single-sided photovoltaic panel 111 due to the hot spot phenomenon of the single-sided photovoltaic panel 111 shown in FIG. 3(D) has melted and been removed.

[0047] FIG. 4(F) is a diagram showing a state in which sunlight is irradiated onto the snow-removed photovoltaic panel 110 after the snow that had accumulated on the single-sided photovoltaic panel 111 has melted. As shown in Figure 4 (F), when sunlight is irradiated onto the snow-removed photovoltaic panel 110 after the snow that has accumulated on the single-sided photovoltaic panel 111 has melted, the amount of power generated on the surface of the double-sided photovoltaic panel 112 is 0% because the sunlight is blocked by the snow.

[0048] However, even if the heat generated by the power generation on the back side of the double-sided photovoltaic panel 112 or the heat generated by the adjacent single-sided photovoltaic panel 111 is transmitted via the panel connection part 113, not all of the snow that has accumulated on the double-sided photovoltaic panel 112 will melt, and the amount of power generated on the front side of the double-sided photovoltaic panel 112 will be infinitesimally smaller than the amount of power generated by the adjacent single-sided photovoltaic panel 111 via the panel connection part 113.

[0049] However, in the single-sided photovoltaic panel 111 where the accumulated snow has melted, there is no snow to block the sunlight shining on it, so the single-sided photovoltaic panel 111 generates electricity at 100% of its capacity.As a result, the snow-removal photovoltaic panel 110, in which the single-sided photovoltaic panel 111 and the double-sided photovoltaic panel 112 are connected in series via the panel connection part 113, becomes a single conductor as a whole, and electricity flows from the positive side to the negative side overall.

[0050] FIG. 4(G) is a diagram showing a state in which electricity generated by a single-sided photovoltaic panel 111 where accumulated snow has melted flows to a snow-removed photovoltaic panel 110 that is still covered in snow, causing a double-sided photovoltaic panel 112 to generate heat.

[0051] When electricity generated by the single-sided photovoltaic panel 111 from which accumulated snow has melted flows to the snow-removal photovoltaic panel 110 that is still covered in snow, electricity also flows to the adjacent double-sided photovoltaic panel 112 via the panel connection part 113.

[0052] However, since the surface of the adjacent double-sided photovoltaic panel 112 is covered with snow, the amount of electricity generated is small, making it difficult for electricity to flow and resulting in a high resistance value. As electricity generated by the surface of the adjacent single-sided photovoltaic panel 111, where the accumulated snow has melted, flows through the surface, the temperature of the double-sided photovoltaic panel 112 rises.

[0053] As a result, electricity that is no longer able to flow easily inside the double-sided photovoltaic panel 112 generates a phenomenon known as a hot spot, where the electrical energy of the electricity is converted into thermal energy.

[0054] This hot spot phenomenon causes the double-sided photovoltaic panel 112 to generate heat, causing the snow that has accumulated on the surface of the double-sided photovoltaic panel 112 to eventually melt and fall to the ground along the slope provided on the double-sided photovoltaic panel 112.

[0055] When the snow that has accumulated on the bifacial photovoltaic panel 112 due to the hot spot phenomenon of the bifacial photovoltaic panel 112 is removed, the electrical resistance to the bifacial photovoltaic panel 112 is reduced, and the heat generated in the bifacial photovoltaic panel 112 is eventually released and the heat decreases.

[0056] FIG. 4(H) is a diagram showing the snow-removing photovoltaic panel 110 in a state where the accumulated snow has melted. As shown in FIG. 4(H), the snow that had accumulated on the double-sided photovoltaic panel 112 due to the hot spot phenomenon of the double-sided photovoltaic panel 112 shown in FIG. 4(G) has melted and been removed.

[0057] As a result, the snow that has accumulated on the snow-removal photovoltaic panel 110 goes through the following processes: power generation on the back side of the double-sided photovoltaic panel 112, melting of the snow due to heat generated by the single-sided photovoltaic panel 111, power generation by the single-sided photovoltaic panel 111, and melting of the snow due to heat generated on the front side of the double-sided photovoltaic panel 112, and the snow that has accumulated on the snow-removal photovoltaic panel 110 is completely removed.

[0058] FIG. 5 is a diagram showing the flow from snow accumulation on a photovoltaic device to the melting of snow on a snow-removal photovoltaic panel. Note that the power conditioner 200 connected to the photovoltaic power generation device 100 and the connection cables connecting them are omitted here. In addition, the following description will be given assuming that the photovoltaic power generation device 100 receives sunlight to generate electricity, and that the snow removal photovoltaic power generation panel 110 can receive sunlight without being blocked.

[0059] FIG. 5(A) is a diagram showing the photovoltaic device 100 in a non-snowy state. As shown in FIG. 5(A), in the photovoltaic device 100 in a non-snowy state, the snow-removal photovoltaic panel 110 and the snow-accumulated photovoltaic panel 120 are connected in parallel via a branch cable B.

[0060] FIG. 5(B) is a diagram showing the photovoltaic device 100 in a snowy state. 5(B), the photovoltaic device 100 is in a state where the entire surfaces of the snow-removal photovoltaic panel 110 and the snow-accumulation photovoltaic panel 120 are covered with snow due to snow accumulation. Note that the crossed diagonal lines shown in the figure indicate accumulated snow.

[0061] FIG. 5(C) is a diagram showing a state in which snow that has accumulated on the snow-removal photovoltaic panel 110 has melted. As shown in Figure 5 (C), for example, if the snow removal photovoltaic panel 110 consists of a double-sided photovoltaic panel 112 and a single-sided photovoltaic panel 111, the snow that has accumulated on the snow removal photovoltaic panel 110 is completely removed through the following processes: power generation on the back side of the double-sided photovoltaic panel 112, melting of snow due to heat generated by the single-sided photovoltaic panel 111, power generation by the single-sided photovoltaic panel 111, and melting of snow due to heat generated on the front side of the double-sided photovoltaic panel 112.

[0062] In addition, the snow removal photovoltaic panel 110 can melt snow by placing a heating wire on the photovoltaic panel and heating the snow with the heating wire, or by passing warm water through the upper layer of the snow removal photovoltaic panel 110.Other means can also be used as long as they can melt the snow that has accumulated on the snow removal photovoltaic panel 110.

[0063] Fig. 6 is a diagram showing the flow from the state where snow accumulated on the snow-removal photovoltaic panel melts to the state where snow accumulated on the snow-removal photovoltaic panel melts. Fig. 6 shows the state after the snow accumulated on the snow-removal photovoltaic panel 110 in Fig. 5(C) has melted, and is a continuation of Fig. 5.

[0064] 6(D), when sunlight is irradiated onto the snow removal photovoltaic power generation panel 110, electricity generated by the snow removal photovoltaic power generation panel 110 flows to the photovoltaic power generation device 100. On the other hand, the snow removal photovoltaic power generation panel 120 does not generate electricity because of the snow accumulation.

[0065] At this time, the snow-removal photovoltaic power generation panel 110 and the snow-covered photovoltaic power generation panel 120 are connected in parallel by the branch cable B that allows reverse current, so that in the snow-covered photovoltaic power generation panel 120, which is unable to generate power due to snow accumulation, electricity flows toward the snow-removal photovoltaic power generation panel 110, through which electricity flows more easily. As a result, electricity flows from the negative side to the positive side of the snow-covered photovoltaic power generation panel 120, generating a reverse voltage in the snow-covered photovoltaic power generation panel 120.

[0066] FIG. 6E is a diagram showing a state in which the snow photovoltaic panel 120 generates heat due to a reverse voltage generated in the snow photovoltaic panel 120. As shown in FIG. When a reverse voltage occurs in the snow-covered photovoltaic panel 120, the snow-covered photovoltaic panel 120 generates heat, and the snow that has accumulated on the snow-covered photovoltaic panel 120 eventually melts and falls to the ground along the slope provided on the snow-covered photovoltaic panel 120.

[0067] FIG. 6(F) is a diagram showing the photovoltaic device 100 in a state where the accumulated snow has melted. As shown in Figure 6 (F), the snow that has accumulated on the snow-accumulated photovoltaic panel 120 has been melted and removed due to heat generated by the snow-accumulated photovoltaic panel 120 due to the reverse voltage generated by the snow-accumulated photovoltaic panel 120 shown in Figure 6 (E).

[0068] As the snow that has accumulated on the snow-covered photovoltaic panel 120 melts and is removed, the snow-covered photovoltaic panel 120 is able to generate electricity normally, and the reverse voltage that has been occurring in the snow-covered photovoltaic panel 120 eventually disappears.

[0069] As described above, in the photovoltaic power generation device 100 of this embodiment, the snow removal photovoltaic power generation panel 110 first melts the snow that has accumulated on the snow removal photovoltaic power generation panel 110, enabling the snow removal photovoltaic power generation panel 110 to generate power, and as the snow removal photovoltaic power generation panel 110 generates power, a reverse voltage is generated in the snow photovoltaic power generation panel 120 connected in parallel, and the snow photovoltaic power generation panel 120 generates heat as a result of the reverse voltage generated in the snow photovoltaic power generation panel 120, which melts the snow that has accumulated on the snow photovoltaic power generation panel 120. In this way, the snow that has accumulated on the photovoltaic power generation device 100 is completely removed.

[0070] Second Embodiment Next, a second embodiment of the present invention will be described. The photovoltaic power generation device 100 of this embodiment has almost the same configuration as that shown in the first embodiment, except for the method of connecting the snow removal photovoltaic power generation panel 110 and the snow photovoltaic power generation panel 120. Therefore, the same reference numerals are used for the components almost the same as those of the first embodiment, and the description thereof will be omitted as appropriate.

[0071] FIG. 7 is a block diagram showing the concept of a photovoltaic device according to the second embodiment. As shown in Figure 7, the photovoltaic power generation device 100 is configured by connecting a snow removal photovoltaic power generation panel 110, which is a photovoltaic power generation panel with a snow removal function, and a snow accumulation photovoltaic power generation panel 120 in a series-connected electrical circuit, with the snow removal photovoltaic power generation panel 110 on the upstream side. The electricity generated by the photovoltaic power generation device 100 is converted into AC power by a power conditioner 200 connected to the photovoltaic power generation device 100 by a connection cable or the like, and is sent to a distribution board or the like not shown here.

[0072] FIG. 8 is a block diagram showing the concept of a photovoltaic device, illustrating an example of a snow removal photovoltaic panel provided in the photovoltaic device according to the second embodiment. As shown in Figure 8, the snow removal photovoltaic panel 110 is composed of a plurality of single-sided photovoltaic panels 111 and a plurality of double-sided photovoltaic panels 112, and the single-sided photovoltaic panels 111 and the double-sided photovoltaic panels 112 are connected in series via panel connection parts 113 so that the single-sided photovoltaic panels 111 and the double-sided photovoltaic panels 112 are alternated.

[0073] As a result, the snow that has accumulated on the snow removal and accumulation photovoltaic panel 110 goes through the following processes: power generation on the back side of the double-sided photovoltaic panel 112, melting of the snow due to heat generated by the single-sided photovoltaic panel 111, power generation by the single-sided photovoltaic panel 111, and melting of the snow due to heat generated on the front side of the double-sided photovoltaic panel 112, and the snow that has accumulated on the snow removal and accumulation photovoltaic panel 110 is completely removed.

[0074] FIG. 9 is a diagram showing the flow from snow accumulation on a photovoltaic device to the melting of snow on a snow-removal photovoltaic panel. Note that the power conditioner 200 connected to the photovoltaic power generation device 100 and the connection cables connecting them are omitted here. In addition, the following description will be given assuming that the photovoltaic power generation device 100 receives sunlight to generate electricity, and that the snow removal photovoltaic power generation panel 110 can receive sunlight without being blocked.

[0075] FIG. 9(A) is a diagram showing the photovoltaic device 100 in a non-snowy state. As shown in FIG. 9(A), in the photovoltaic device 100 in a non-snowy state, a snow-removal photovoltaic panel 110 and a snow-accumulated photovoltaic panel 120 are connected in series.

[0076] FIG. 9(B) is a diagram showing the photovoltaic device 100 in a snowy state. As shown in FIG. 9(B), the photovoltaic device 100 is in a state where the entire surfaces of the snow-removal photovoltaic panel 110 and the snow-accumulation photovoltaic panel 120 are covered with snow due to accumulation of snow.

[0077] FIG. 9C is a diagram showing a state in which snow that has accumulated on the snow-removal photovoltaic panel 110 has melted. As shown in Figure 9 (C), for example, if the snow removal photovoltaic panel 110 consists of a double-sided photovoltaic panel 112 and a single-sided photovoltaic panel 111, the snow that has accumulated on the snow removal photovoltaic panel 110 is completely removed through the following processes: power generation on the back side of the double-sided photovoltaic panel 112, melting of snow due to heat generated by the single-sided photovoltaic panel 111, power generation by the single-sided photovoltaic panel 111, and melting of snow due to heat generated on the front side of the double-sided photovoltaic panel 112.

[0078] Fig. 10 is a diagram showing the flow from the state where snow accumulated on the snow-removal photovoltaic panel melts to the state where snow accumulated on the snow-removal photovoltaic panel melts. Fig. 10 shows the state after the snow accumulated on the snow-removal photovoltaic panel 110 in Fig. 9(C) has melted, and is a continuation of Fig. 9.

[0079] 10(D), when sunlight is irradiated onto the snow removal photovoltaic power generation panel 110, electricity generated by the snow removal photovoltaic power generation panel 110 flows to the photovoltaic power generation device 100. On the other hand, the snow removal photovoltaic power generation panel 120 does not generate electricity because of the snow accumulation.

[0080] At this time, the snow removal photovoltaic power generation panel 110 and the snow accumulation photovoltaic power generation panel 120 are connected in series, so that electricity generated by the snow removal photovoltaic power generation panel 110 flows to the snow removal photovoltaic power generation panel 110 in a snow-covered state.

[0081] FIG. 10E is a diagram showing a state in which the snow-covered photovoltaic panel 120 generates heat due to a hot spot phenomenon. As shown in FIG. 10(E), the snow-covered photovoltaic panel 120 connected to the downstream side of the electric circuit constituting the photovoltaic device 100 is covered with snow and is therefore unable to generate power and is therefore in a state in which electricity does not flow easily.

[0082] When electricity generated by the snow removal photovoltaic panel 110 connected in series upstream flows through the snow photovoltaic panel 120, which is in a state where electricity does not easily flow through it, the temperature of the snow photovoltaic panel 120 rises, the entire snow photovoltaic panel 120 becomes a hot spot, and this hot spot phenomenon causes the entire snow photovoltaic panel 120 to heat up.

[0083] Due to the hot spot phenomenon occurring in the snow-covered photovoltaic panel 120, the snow that has accumulated on the snow-covered photovoltaic panel 120 generates heat, and the snow that has accumulated on the snow-covered photovoltaic panel 120 eventually melts and falls to the ground along the slope provided on the snow-covered photovoltaic panel 120.

[0084] FIG. 6(F) is a diagram showing the photovoltaic device 100 in a state where the accumulated snow has melted. As shown in Figure 6 (F), the snow that has accumulated on the snow-accumulated photovoltaic panel 120 has melted and been removed due to heat generated by the snow-accumulated photovoltaic panel 120 caused by the hot spot phenomenon that has occurred in the snow-accumulated photovoltaic panel 120 shown in Figure 6 (E).

[0085] As the snow that has accumulated on the snow-covered photovoltaic panel 120 melts and is removed, the snow-covered photovoltaic panel 120 is able to generate electricity normally, and the heat that has been generated by the snow-covered photovoltaic panel 120 is eventually released and reduced.

[0086] As described above, in the photovoltaic power generation device 100 of this embodiment, the snow removal photovoltaic power generation panel 110 first melts the snow that has accumulated on the snow removal photovoltaic power generation panel 110, enabling the snow removal photovoltaic power generation panel 110 to generate power, and as the snow removal photovoltaic power generation panel 110 generates power, a hot spot phenomenon occurs in the snow photovoltaic power generation panel 120 connected in series, and the hot spot phenomenon occurs in the snow photovoltaic power generation panel 120, causing the snow photovoltaic power generation panel 120 to generate heat, which melts the snow that has accumulated on the snow photovoltaic power generation panel 120. In this way, the snow that has accumulated on the photovoltaic power generation device 100 is completely removed.

[0087] Third embodiment Next, a third embodiment of the present invention will be described. The photovoltaic power generation device 100 of this embodiment has substantially the same configuration as that shown in the first and second embodiments, except for the shape of the snow removal photovoltaic power generation panel 110. Therefore, the same reference numerals are used for substantially the same components as those of the first and second embodiments, and the description thereof will be omitted as appropriate.

[0088] FIG. 11 is a block diagram showing the concept of a photovoltaic device according to the third embodiment. As shown in Fig. 11, the photovoltaic power generation device 100 is configured by connecting in parallel a non-snow-covered photovoltaic power generation panel 130, which is a photovoltaic power generation panel installed in a state where there is no snow accumulation, and a snow-covered photovoltaic power generation panel 120, which is a photovoltaic power generation panel that does not have a snow accumulation removal function, i.e., is subject to snow accumulation, by branching them with a branch cable B such as a Y-branch cable, and electricity generated by the photovoltaic power generation device 100 is converted to AC power by a power conditioner 200 connected to the photovoltaic power generation device 100 by a connection cable or the like, and is sent to a distribution board or the like (not shown here). Also, the branch cable B does not have a backflow prevention function such as a backflow prevention diode and is connected to allow backflow.

[0089] In the photovoltaic power generation device 100 of the third embodiment, the non-snow-covered photovoltaic power generation panel 130 is installed in a state where there is no snow coverage, so that the non-snow-covered photovoltaic power generation panel 130 is always in a state where it can generate power as long as it is in an environment where it can receive light.

[0090] For this reason, in the photovoltaic power generation device 100 of this embodiment, only the snow-covered photovoltaic power generation panel 120 is covered with snow when snow accumulates, and as the non-snow-covered photovoltaic power generation panel 130 generates power, a reverse voltage is generated in the parallel-connected snow-covered photovoltaic power generation panels 120, as in the photovoltaic power generation device 100 of the first embodiment, and the snow-covered photovoltaic power generation panel 120 generates heat due to the reverse voltage generated in the snow-covered photovoltaic power generation panel 120, which melts the snow that has accumulated on the snow-covered photovoltaic power generation panel 120. As a result, the snow that has accumulated on the photovoltaic power generation device 100 is completely removed.

[0091] FIG. 12 is a cross-sectional view showing a concept of an example of installation of a non-snow-covered photovoltaic panel and a snow-covered photovoltaic panel in a photovoltaic device. FIG. 12(A) is a cross-sectional view showing an example in which the non-snow-covered photovoltaic panel 130 is installed perpendicular to the horizontal plane, and the snow-covered photovoltaic panel 120 is installed at an incline with respect to the horizontal plane.

[0092] As shown in FIG. 12(A), the non-snow-covered photovoltaic panel 130 is installed perpendicular to a horizontal plane, so that the power generating surface of the non-snow-covered photovoltaic panel 130 is oriented horizontally. Therefore, even during snowfall, snow does not accumulate on the surface of the non-snow-covered photovoltaic panel 130.

[0093] Furthermore, by making the non-snow-covered photovoltaic panel 130 a double-sided photovoltaic panel, light irradiated onto the non-snow-covered photovoltaic panel 130 can be received by both surfaces facing the horizontal plane, and electricity can be generated.

[0094] Furthermore, since the snow accumulation photovoltaic panel 120 is installed at an incline with respect to the horizontal plane, snow accumulates on the surface of the snow accumulation photovoltaic panel 120 when it snows. However, in the photovoltaic power generation device 100 of this embodiment, a reverse voltage is generated in the snow-covered photovoltaic power generation panel 120 connected in parallel as a result of the non-snow-covered photovoltaic power generation panel 130 generating power, and the snow-covered photovoltaic power generation panel 120 generates heat as a result of the reverse voltage being generated, which melts the snow that has accumulated on the snow-covered photovoltaic power generation panel 120. As a result, the snow that has accumulated on the photovoltaic power generation device 100 is completely removed.

[0095] FIG. 12(B) is a cross-sectional view showing an example in which the non-snow-covered photovoltaic panel 130 is installed on a wall surface W that extends in the vertical direction, and the snow-covered photovoltaic panel 120 is installed horizontally. As shown in Figure 12 (B), the non-snow-covered photovoltaic panel 130 is installed on a wall surface W that extends vertically, so that the power generation surface of the non-snow-covered photovoltaic panel 130 is oriented horizontally, and therefore snow does not accumulate on the surface of the non-snow-covered photovoltaic panel 130 even during snowfall.

[0096] Furthermore, since the snow accumulation photovoltaic panel 120 is installed horizontally, snow accumulates on the surface of the snow accumulation photovoltaic panel 120 during snowfall. However, in the photovoltaic power generation device 100 of this embodiment, a reverse voltage is generated in the snow-covered photovoltaic power generation panel 120 connected in parallel as a result of the non-snow-covered photovoltaic power generation panel 130 generating power, and the snow-covered photovoltaic power generation panel 120 generates heat as a result of the reverse voltage being generated, which melts the snow that has accumulated on the snow-covered photovoltaic power generation panel 120. As a result, the snow that has accumulated on the photovoltaic power generation device 100 is completely removed.

[0097] As shown in Figure 12 (B), even if the snow-covered photovoltaic panel 120 is installed horizontally, it is possible to melt accumulated snow simply by connecting the non-snow-covered photovoltaic panel 130 in parallel. Therefore, for example, if the snow-covered photovoltaic panel 120 is installed on the road surface and the snow-covered photovoltaic panel 120 receives light on the road surface, not only will the snow-covered photovoltaic panel 120 generate electricity, but it will also be able to melt the snow that has accumulated on the road surface.

[0098] [Fourth embodiment] Next, a fourth embodiment of the present invention will be described. The photovoltaic power generation device 100 of this embodiment has substantially the same configuration as that shown in the third embodiment, except for the method of connecting the non-snow-covered photovoltaic power generation panel 130 and the snow-covered photovoltaic power generation panel 120. Therefore, the same reference numerals are used for substantially the same components as those of the first to third embodiments, and the description thereof will be omitted as appropriate.

[0099] FIG. 13 is a block diagram showing the concept of a photovoltaic device according to the fourth embodiment. As shown in Figure 13, the photovoltaic power generation device 100 is configured by connecting a non-snow-covered photovoltaic power generation panel 130 and a snow-covered photovoltaic power generation panel 120 in series in an electrical circuit, with the snow-removal photovoltaic power generation panel 110 connected upstream. The electricity generated by the photovoltaic power generation device 100 is converted into AC power by a power conditioner 200 connected to the photovoltaic power generation device 100 by a connection cable or the like, and is sent to a distribution board or the like not shown here.

[0100] In the photovoltaic power generation device 100 of the fourth embodiment, the non-snow-covered photovoltaic power generation panel 130 is installed in a state where there is no snow coverage, so that the non-snow-covered photovoltaic power generation panel 130 is always in a state where it can generate power as long as it is in an environment where it can receive light.

[0101] For this reason, in the photovoltaic device 100 of this embodiment, only the snow-covered photovoltaic panel 120 is covered with snow when snow accumulates, and the non-snow-covered photovoltaic panel 130 generates power, so that the snow-covered photovoltaic panel 120, which generates heat due to the hot spot phenomenon of all the series-connected snow-covered photovoltaic panels 120, melts the snow that has accumulated on the snow-covered photovoltaic panel 120, just like the photovoltaic device 100 of the second embodiment. This allows the snow that has accumulated on the photovoltaic device 100 to be completely removed.

[0102] In the first to fourth embodiments described above, examples have been described in which the snow-removal photovoltaic panel or non-snow-accumulated photovoltaic panel and the snow-accumulated photovoltaic panel are connected separately, but snow that has accumulated on the photovoltaic device 100 can also be completely removed by connecting the snow-accumulated portion, which is the portion of the photovoltaic panel that accumulates snow, i.e., the snow-accumulated photovoltaic panel, with the snow-accumulated power-generating portion, which is the portion of the photovoltaic panel that becomes capable of generating electricity when snow has been removed, i.e., the snow-removal photovoltaic panel or non-snow-accumulated photovoltaic panel. [Explanation of symbols]

[0103] 100 Photovoltaic device 110 Snow removal photovoltaic panel 120 Snow photovoltaic panels 200 Power Conditioner B Branch Cable

Claims

1. In a photovoltaic power generation device that melts snow that has accumulated on a photovoltaic panel, A snow-covered portion of the photovoltaic panel that is a portion on which snow accumulates; a power generation unit during snow accumulation that is connected to the snow accumulation unit and that is a portion of the photovoltaic panel that is capable of generating electricity when snow is removed during snow accumulation; A photovoltaic device comprising:

2. The snowfall power generation unit is being connected in series to the electrically upstream side of the snow accumulation portion; 2. The photovoltaic device according to claim 1 .

3. The snowfall power generation unit is being connected in parallel with the snow accumulation portion; 2. The photovoltaic device according to claim 1 .

4. The parallel connection is being connected in a manner that allows reverse flow; 4. The photovoltaic device according to claim 3,

5. The snowfall power generation unit is It is a heat generating photovoltaic panel that removes snow by generating heat.

2. The photovoltaic device according to claim 1 .

6. The snowfall power generation unit is A double-sided photovoltaic panel that receives light and generates electricity on both sides, i.e., a surface on which snow accumulates and a back surface opposite the surface; The surface on which the snow accumulates is a single-sided photovoltaic panel that receives light and generates electricity. a panel connection section that connects the bifacial photovoltaic panel and the single-sided photovoltaic panel in series; 6. The photovoltaic device according to claim 5, further comprising:

7. The snowfall power generation unit is The photovoltaic panel is a non-snow-covered photovoltaic panel installed in a state where there is no snow coverage; 2. The photovoltaic device according to claim 1 .

8. The non-snow photovoltaic panel is The photovoltaic panel is installed vertically; 8. The photovoltaic device according to claim 7,

9. The snow-covered portion is The photovoltaic panel is installed on a road surface.

2. The photovoltaic device according to claim 1 .

10. A method for melting snow using a photovoltaic device including a snow-covered portion that is a portion of a photovoltaic panel that accumulates snow, and a power-generating portion during snow accumulation that is connected to the snow-covered portion and that is a portion of the photovoltaic panel that can generate electricity when snow is removed during snow accumulation, comprising: a step of generating electricity by the snowfall power generation unit; a step of causing the electricity generated by the power generation unit during snow accumulation to flow into the snow accumulation portion, thereby causing the power generation unit during snow accumulation to generate heat; A snow melting method comprising:

11. The snow accumulation photovoltaic panel is made up of a snow accumulation portion which is connected to a snow accumulation photovoltaic panel, and a snow accumulation power generation portion which becomes capable of generating electricity when snow is removed during snow accumulation.

12. A method for melting snow using a snow-induced power generation panel, comprising a snow-induced power generation part that is connected to a snow-induced power generation panel that is a part that accumulates snow and that is capable of generating electricity when snow is removed during snow accumulation, A step of generating electricity by the snowfall power generation panel; a step of causing the snow photovoltaic power generation panel to generate heat by flowing electricity generated by the snow photovoltaic power generation panel to the snow photovoltaic power generation panel; A snow melting method comprising:

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