Solar power generator, method for melting snow of the same, solar power generation panel, and method for melting snow of the same

Abstract

To provide a solar power generator, a method for melting snow by the solar power generator, a solar power generator panel, and a method for melting snow by the solar power generation panel which can provide a snow removal function at a low cost to an existing solar power generation panel and can melt snow efficiently.SOLUTION: The back surface of a dual-side solar power generation panel 120 generates power, electricity generated in the back side of the dual-side solar power generation panel 120 flows into a one-side power generation panel 110 connected via a panel connection part 130 to the dual-side solar power generation panel. Electricity generated in the back side of the dual-side solar power generation panel 120 flows into the one-side power generation panel 110 so that the one-side power generation panel 110 generates heat. Further, electricity generated in the surface of the one-side power generation panel 110 on which snow melted by heat generated from the one-side power generation panel 110 flows into the dual-side solar power generation panel 120 connected via the panel connection unit 130. Electricity generated in the surface of the one-side power generation panel 110 flows into the dual-side solar power generation panel 120 so that dual-side solar power generation panel 120 generates heat.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a photovoltaic device, a snow melting method using the photovoltaic device, a photovoltaic panel, and a snow melting method using the photovoltaic panel, and particularly to a photovoltaic device for melting snow accumulated on the photovoltaic panel, a snow melting method using the photovoltaic device, a photovoltaic panel, and a snow melting method using the photovoltaic panel.

Background Art

[0002] Conventionally, photovoltaic power generation has been developed in which sunlight irradiated from the sun is received by a photovoltaic panel in which solar cells are arranged, and the light energy is converted into electricity. In addition, not only receiving the light irradiated from the sun and generating electricity, but also a photovoltaic panel that increases the power generation amount by receiving the light reflected from the ground on the back side of the photovoltaic panel has been developed.

[0003] However, these photovoltaic panels have a problem that when snow accumulates on the surface of the photovoltaic panel, mainly in heavy snow areas, the sunlight is blocked by the snow, resulting in a decrease in the power generation amount. For this reason, a photovoltaic panel capable of efficiently removing snow on the photovoltaic panel has been developed (see, for example, Patent Documents 1 and 2).

[0004] FIG. 9 is a diagram showing an example of a heat exchange system including a solar cell and a heat exchanger for solar cells disclosed in Patent Document 1. As shown in FIG. 9, in the heat exchange system 10 disclosed in Patent Document 1, a photovoltaic panel 11 and a heat exchanger for solar cells 12 that covers the solar cell 11a in the photovoltaic panel 11 from the front side are provided.

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

[0006] At this time, the transparent or translucent fluid is injected from the fluid inlet 12a, passes through the fluid passage 12c, and is discharged from the fluid outlet 12b. By using a fluid at a temperature higher than the temperature of the accumulated snow, the snow accumulated on the surface side of the photovoltaic panel 11 can be melted and removed.

[0007] FIG. 10 is a diagram showing an example of a photovoltaic panel capable of continuing power generation even during snow accumulation disclosed in Patent Document 2. As shown in FIG. 10, the photovoltaic panel 20 disclosed in Patent Document 2 is a laminate in which a plurality of members are laminated. A heating module 23 is laminated on the upper layer of the heat insulating material layer 21 via an adhesive layer 22, a photovoltaic module 25 is laminated on the upper layer of the heating module 23 via an adhesive layer 24, and a light-transmitting support member 27 is laminated on the upper layer of the photovoltaic module 25 via an adhesive layer 26. A surface protection layer 28 is laminated on the upper layer of the light-transmitting support member 27.

[0008] Thus, the photovoltaic panel 20 disclosed in Patent Document 2 includes a photovoltaic module 25 that converts light irradiated from the sun into electric power, and a heating module 23 that converts the electric energy converted by the photovoltaic module 25 into thermal energy. The heating module 23 is disposed on the side opposite to the side where the light irradiated from the sun is irradiated to the photovoltaic module 25.

[0009] Thereby, the photovoltaic panel 20 can be heated by the heating module 23 so that the surface temperature of the photovoltaic panel 20 does not drop below the freezing point, and the snow adhering to the surface of the photovoltaic panel 20 can be melted. Therefore, power generation can be continued even during snow accumulation in winter.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0011] However, when attempting to endow an existing solar power generation panel with the snow removal function disclosed in Patent Document 1 or Patent Document 2 above, there is a problem that the introduction cost becomes high and the introduction is not easy.

[0012] Specifically, the heat exchange system 10 disclosed in Patent Document 1 is one in which a heat exchanger for solar cells 12 is installed on the upper layer of the solar power generation panel 11. Therefore, by installing the heat exchanger for solar cells 12 on the upper layer of the existing solar power generation panel, even an existing solar power generation panel can be endowed with a snow removal function.

[0013] However, when attempting to install the heat exchanger for solar cells 12 on an existing solar power generation panel, columns and the like that supported the existing solar power generation panel will have to support not only the solar power generation panel but also the heat exchanger for solar cells 12.

[0014] Therefore, in order to install the heat exchange system 10 on an existing solar power generation panel, columns and the like that support the solar power generation panel need to be reinforced to withstand the load with the addition of the heat exchanger for solar cells 12, or replaced with sturdy columns that can withstand the load with the addition of the heat exchanger for solar cells 12. For this reason, additional costs for reinforcing or replacing columns and the like are required for the introduction of the heat exchange system 10.

[0015] Also, when using the heat exchange system 10, a fluid will be passed through the inside of the heat exchanger for solar cells 12. For this reason, the inside of the heat exchanger for solar cells 12 will be in a state filled with the fluid, and the weight of the heat exchanger for solar cells 12 containing the fluid will become even heavier. Therefore, columns that support the existing solar power generation panel 11 need to be of even higher strength, and the cost will also increase.

[0016] Furthermore, in the heat exchange system 10, a tank for storing fluid, a heat exchanger for heating the fluid, a pump for circulating the fluid, etc. are also required. Not only are the installation costs of these necessary, but also the space for installing them is required. For this reason, it is not easy to introduce the heat exchange system 10 disclosed in Patent Document 1 into an existing solar power generation panel because of the high cost.

[0017] In addition, in the solar power generation panel 20 disclosed in Patent Document 2, since the heating module 23 is arranged on the side opposite to the side where the photovoltaic module 25 is irradiated with light from the sun, when trying to introduce it into an existing solar power generation panel, the solar cells included in the existing solar power generation panel need to be removed and the heating module 23 needs to be installed below it. For this reason, the working time becomes long and the introduction cost increases.

[0018] Furthermore, when removing the solar cells included in the existing solar power generation panel, if the solar cells are damaged, there is also a risk that the existing solar power generation panel has to be replaced.

[0019] Although it is also conceivable to replace the existing solar power generation panel with the solar power generation panel 20 disclosed in Patent Document 2, the cost required to discard the existing solar power generation panel is also incurred. In addition, it is not good for the environment to discard all the existing solar power generation panels that are still usable in order to provide a snow removal function.

[0020] The present invention has been made in view of such points, and an object of the present invention is to provide a photovoltaic device capable of imparting a snow removal function to an existing solar power generation panel at low cost and melting snow efficiently, a snow melting method using the photovoltaic device, a photovoltaic panel, and a snow melting method using the photovoltaic panel.

Means for Solving the Problems

[0021] In the present invention, in order to solve the above problems, in a photovoltaic device that melts snow accumulated on a photovoltaic panel, both surfaces of the surface on which snow accumulates and the back surface opposite to the surface are a double-sided photovoltaic panel that generates electricity by receiving light, the surface on which snow accumulates is a single-sided photovoltaic panel that generates electricity by receiving light, and a panel connection part that connects the double-sided photovoltaic panel and the single-sided photovoltaic panel in series are provided. A photovoltaic device is provided, characterized in that it comprises these components.

[0022] As a result, both surfaces of the surface on which snow accumulates and the back surface opposite to the surface receive light, the double-sided photovoltaic panel generates electricity, the surface on which snow accumulates receives light, the single-sided photovoltaic panel generates electricity, and the panel connection part connects the double-sided photovoltaic panel and the single-sided photovoltaic panel in series.

[0023] Further, in the present invention, in a snow melting method in a photovoltaic device comprising a double-sided photovoltaic panel that generates electricity by receiving light on both surfaces of the surface on which snow accumulates and the back surface opposite to the surface, a single-sided photovoltaic panel that generates electricity by receiving light on the surface on which snow accumulates, and a panel connection part that connects the double-sided photovoltaic panel and the single-sided photovoltaic panel in series, a step of generating electricity on the back surface of the double-sided photovoltaic panel, a step of the electricity generated on the back surface of the double-sided photovoltaic panel flowing to the single-sided photovoltaic panel connected via the panel connection part, a step of the single-sided photovoltaic panel generating heat because the electricity generated on the back surface of the double-sided photovoltaic panel flows to the single-sided photovoltaic panel, a step of the electricity generated on the surface of the single-sided photovoltaic panel on which the accumulated snow has melted due to the heat generation of the single-sided photovoltaic panel flowing to the double-sided photovoltaic panel connected via the panel connection part, and a step of the double-sided photovoltaic panel generating heat because the electricity generated on the surface of the single-sided photovoltaic panel flows to the double-sided photovoltaic panel are provided. A snow melting method is provided, characterized in that it comprises these steps.

[0024] As a result, the back surface of the bifacial photovoltaic panel generates electricity, and the electricity generated on the back surface of the bifacial photovoltaic panel flows to the monofacial photovoltaic panel connected via the panel connection part. When the electricity generated on the back surface of the bifacial photovoltaic panel flows to the monofacial photovoltaic panel, the monofacial photovoltaic panel generates heat, and the snow accumulated thereon melts due to the heat generation of the monofacial photovoltaic panel. Then, the electricity generated on the front surface of the monofacial photovoltaic panel where the snow has melted flows to the bifacial photovoltaic panel connected via the panel connection part. When the electricity generated on the front surface of the monofacial photovoltaic panel flows to the bifacial photovoltaic panel, the bifacial photovoltaic panel generates heat.

[0025] In addition, the present invention provides a photovoltaic panel comprising: a bifacial photovoltaic cell that generates electricity by receiving light on both a front surface where snow accumulates and a back surface opposite to the front surface; a monofacial photovoltaic cell that generates electricity by receiving light on the front surface where snow accumulates; and a cell connection part that connects the bifacial photovoltaic cell and the monofacial photovoltaic cell in series.

[0026] As a result, the bifacial photovoltaic cell generates electricity by receiving light on both the front surface where snow accumulates and the back surface opposite to the front surface, the monofacial photovoltaic cell generates electricity by receiving light on the front surface where snow accumulates, and the cell connection part connects the bifacial photovoltaic cell and the monofacial photovoltaic cell in series.

[0027] In addition, in the present invention, a bifacial photovoltaic cell that generates electricity by receiving light on both a surface where snow accumulates and a back surface opposite to the surface, a single-sided photovoltaic cell that generates electricity by receiving light on the surface where snow accumulates, and a cell connection portion that connects the bifacial photovoltaic cell and the single-sided photovoltaic cell in series. In a snow melting method using a photovoltaic panel, a step of generating electricity on the back surface of the bifacial photovoltaic cell, a step of the electricity generated on the back surface of the bifacial photovoltaic cell flowing to the single-sided photovoltaic cell connected via the cell connection portion, and the electricity generated on the back surface of the bifacial photovoltaic cell flowing to the single-sided photovoltaic cell to cause the single-sided photovoltaic cell to generate heat, and the electricity generated on the surface of the single-sided photovoltaic cell where the accumulated snow has melted due to the heat generation of the single-sided photovoltaic cell flowing to the bifacial photovoltaic cell connected via the cell connection portion, and a step of the electricity generated on the surface of the single-sided photovoltaic cell flowing to the bifacial photovoltaic cell to cause the bifacial photovoltaic cell to generate heat are provided. A snow melting method is provided, characterized by comprising the steps of:

[0028] As a result, electricity is generated on the back surface of the bifacial photovoltaic cell, the electricity generated on the back surface of the bifacial photovoltaic cell flows to the single-sided photovoltaic cell connected via the cell connection portion, the electricity generated on the back surface of the bifacial photovoltaic cell flows to the single-sided photovoltaic cell to cause the single-sided photovoltaic cell to generate heat, and the electricity generated on the surface of the single-sided photovoltaic cell where the accumulated snow has melted due to the heat generation of the single-sided photovoltaic cell flows to the bifacial photovoltaic cell connected via the cell connection portion, and the electricity generated on the surface of the single-sided photovoltaic cell flows to the bifacial photovoltaic cell to cause the bifacial photovoltaic cell to generate heat.

Advantages of the Invention

[0029] According to the photovoltaic device, the snow melting method using the photovoltaic device, the photovoltaic panel, and the snow melting method using the photovoltaic panel of the present invention, both a surface where snow accumulates and a back surface opposite to the surface receive light, the bifacial photovoltaic panel generates electricity, the surface where snow accumulates receives light, the single-sided photovoltaic panel generates electricity, and the bifacial photovoltaic panel and the single-sided photovoltaic panel are connected in series by the panel connection portion, so there are the following effects.

[0030] First, electricity generated on the back surface of a bifacial photovoltaic panel flows to a monofacial photovoltaic panel, applying a voltage to the monofacial photovoltaic panel. However, since the monofacial photovoltaic panel is covered with snow, it cannot generate electricity, the flow of electricity is difficult, and the resistance value is high, causing heat generation and melting of the snow accumulated on the monofacial photovoltaic panel.

[0031] Next, electricity generated on the surface of the monofacial photovoltaic panel where the accumulated snow has melted flows to the bifacial photovoltaic panel, causing the bifacial photovoltaic panel to generate heat, and thus melting the snow accumulated on the bifacial photovoltaic panel.

[0032] Therefore, by simply replacing some of the existing solar photovoltaic panels with monofacial photovoltaic panels or bifacial photovoltaic panels, a snow removal function can be imparted. For this reason, reinforcement or replacement of the support columns is not necessary, and the snow removal function can be imparted at low cost.

[0033] In addition, since new equipment such as heat exchangers and pumps is not required, the snow removal function can be imparted at low cost, and snow can be melted only by the bifacial photovoltaic panel and the monofacial photovoltaic panel, so the efficiency is good.

Brief Description of the Drawings

[0034]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0035] Hereinafter, embodiments 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 the first embodiment.

[0036] As shown in FIG. 1, the photovoltaic device 100 is configured by connecting a plurality of photovoltaic panels. The electricity generated by the photovoltaic device 100 is converted into alternating current power by a power conditioner 200 connected to the photovoltaic device 100 by a connection cable or the like, and is sent to a distribution board or the like (not shown here).

[0037] The photovoltaic device 100 is composed of a plurality of single-sided photovoltaic panels 110 and a plurality of double-sided photovoltaic panels 120. The single-sided photovoltaic panels 110 and the double-sided photovoltaic panels 120 are connected in series via a panel connection part 130 so that the single-sided photovoltaic panels 110 and the double-sided photovoltaic panels 120 alternate with each other.

[0038] The photovoltaic device 100 is installed, for example, on the roofs of houses, factories, warehouses, etc. where there is nothing to block sunlight, or on vacant lots. Also, the photovoltaic device 100 is installed at an inclination of about 30 degrees with respect to the horizontal plane so that the sun's light hits directly.

[0039] Therefore, when snow accumulates on the surface of the photovoltaic device 100 in a heavy snow area or the like, there is a problem that the amount of power generation decreases because sunlight is blocked by the snow. Thus, in the photovoltaic device 100 of the present embodiment, the snow that has accumulated efficiently can be melted as described below.

[0040] Further, the photovoltaic device 100 is not limited to being configured by combining a new single-sided photovoltaic panel 110 and a double-sided photovoltaic panel 120. Among photovoltaic devices composed only of existing single-sided photovoltaic panels, it can also be configured by replacing some of the single-sided photovoltaic panels with double-sided photovoltaic panels.

[0041] Also, among photovoltaic devices composed only of existing double-sided photovoltaic panels, it can be configured by replacing some of the double-sided photovoltaic panels with single-sided photovoltaic panels. Furthermore, among photovoltaic devices composed only of existing double-sided photovoltaic panels, it is also conceivable to convert the double-sided photovoltaic panels into single-sided photovoltaic panels by attaching a sheet material that blocks light reception to the back surfaces of some of the double-sided photovoltaic panels.

[0042] Here, the single-sided photovoltaic panel 110 described herein is one in which photovoltaic cells that receive irradiation of 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 110.

[0043] Generally, a single-sided photovoltaic panel is formed with a glass surface that transmits light on the surface, and a backsheet material is provided on the back surface. The backsheet material mentioned here is for protecting the single-sided photovoltaic panel from heat, ultraviolet rays, moisture, etc., and has a multilayer structure formed by laminating a PET (Polyethyleneterephthalate) film, a fluorine film, or the like.

[0044] Also, the double-sided photovoltaic panel 120 described here is one in which photovoltaic cells are provided not only on the surface but also on the back surface, so that it receives not only direct sunlight but also light reflected from the ground, buildings, water surfaces, snow, etc., and directly converts the energy of the received light into electrical energy.

[0045] Generally, a bifacial photovoltaic panel has a glass surface on both the front and back sides that transmits light, and a photovoltaic cell is disposed between the front glass surface and the back glass surface.

[0046] Note that, with respect to the front surface of the monofacial photovoltaic panel 110 and the bifacial photovoltaic panel 120 described herein, the upper side of the monofacial photovoltaic panel 110 and the bifacial photovoltaic panel 120 installed with an inclination is defined as the front surface, and the ground side of the monofacial photovoltaic panel 110 and the bifacial photovoltaic panel 120 is defined as the back surface for description.

[0047] FIG. 2 is a diagram showing the flow from snow accumulation on the photovoltaic device to heat generation of the monofacial photovoltaic panel. Here, description will be made by taking one monofacial photovoltaic panel 110, bifacial photovoltaic panel 120, and panel connection part 130 as examples, and other continuously connected monofacial photovoltaic panels 110, bifacial photovoltaic panels 120, panel connection parts 130, power conditioner 200, connection cables connecting these, etc. are omitted. Further, here, it is assumed that the photovoltaic device 100 receives sunlight and generates electricity, and the following description will be made on the assumption that the photovoltaic device 100 can receive sunlight without being blocked.

[0048] FIG. 2(A) is a diagram showing the photovoltaic device 100 in a non-snow-accumulation state. As shown in FIG. 2(A), in the photovoltaic device 100 in a non-snow-accumulation state, the monofacial photovoltaic panel 110 and the bifacial photovoltaic panel 120 are connected in series via the panel connection part 130.

[0049] At this time, in the monofacial photovoltaic panel 110, the photovoltaic cells arranged on the front surface receive the light directly irradiated from the sun and generate electricity with a power generation amount of 100%. Further, in the bifacial photovoltaic panel 120, the photovoltaic cells arranged on the front surface receive sunlight and generate electricity with a power generation amount of 100%, and the photovoltaic cells arranged on the back surface receive the reflected light from the ground or the like, and the back surface of the bifacial photovoltaic panel 120 generates electricity with a power generation amount of 20% with respect to the front surface.

[0050] FIG. 2(B) is a diagram showing the photovoltaic device 100 in a snow-accumulation state. As shown in FIG. 2(B), the photovoltaic device 100 is in a state where the entire surface is covered with snow due to snow accumulation. The cross-hatched lines shown in the figure indicate the snow accumulation.

[0051] FIG. 2(C) is a diagram showing a state in which the photovoltaic device 100 in a snow accumulation state is irradiated with sunlight. As shown in FIG. 2(C), when the photovoltaic device 100 in a snow accumulation state is irradiated with sunlight, on the surface of the single-sided photovoltaic panel 110, since the sunlight is blocked by the snow, the power generation amount becomes 0%.

[0052] Also, on the surface of the double-sided photovoltaic panel 120, since the sunlight is blocked by the snow, the power generation amount becomes 0%. However, since the back surface receives the reflected light, the back surface of the double-sided photovoltaic panel 120 generates electricity with a power generation amount of 20% with respect to the surface of the double-sided photovoltaic panel 120 in a non-snow accumulation state.

[0053] Since the back surface of the double-sided photovoltaic panel 120 generates electricity, the photovoltaic device 100 in which the single-sided photovoltaic panel 110 and the double-sided photovoltaic panel 120 are connected in series via the panel connection portion 130 becomes a single conductor as a whole. Therefore, electricity flows from the plus side to the minus side as a whole.

[0054] FIG. 2(D) is a diagram showing a state in which the electricity generated by the back surface of the double-sided photovoltaic panel 120 flows into the photovoltaic device 100 in a snow accumulation state and the single-sided photovoltaic panel 110 generates heat. When the electricity generated by the back surface of the double-sided photovoltaic panel 120 flows into the photovoltaic device 100 in a snow accumulation state, electricity also flows through the panel connection portion 130 to the adjacent single-sided photovoltaic panel 110.

[0055] However, since the surface of the adjacent single-sided photovoltaic panel 110 is covered with snow, it cannot generate electricity, the flow of electricity is difficult, and the resistance value is high. When the electricity generated by the back surface of the adjacent double-sided photovoltaic panel 120 flows there, the temperature of the single-sided photovoltaic panel 110 rises.

[0056] Due to these causes, the electricity that has become difficult to flow inside the single-sided photovoltaic panel 110 causes a phenomenon where the electrical energy is converted into thermal energy, that is, a phenomenon called a hot spot occurs.

[0057] Due to this hot spot phenomenon, the single-sided photovoltaic panel 110 generates heat, and the snow accumulated on the surface of the single-sided photovoltaic panel 110 will eventually melt and fall to the ground along the slope provided on the single-sided photovoltaic panel 110.

[0058] Due to the hot spot phenomenon of the single-sided photovoltaic panel 110, the snow accumulated on the single-sided photovoltaic panel 110 is removed, thereby reducing the electrical resistance to the single-sided photovoltaic panel 110, and the heat generation that has occurred in the single-sided photovoltaic panel 110 will eventually be released and the heat will decrease.

[0059] Figure 3 is a diagram showing the flow from the state where the single-sided photovoltaic panel has melted snow to the state where the snow accumulated on the double-sided photovoltaic panel has melted. Note that Figure 3 shows the state after the single-sided photovoltaic panel 110 generates heat and the accumulated snow has melted in Figure 2(D), and shows the continuation of Figure 2.

[0060] As shown in Figure 3(E), due to the hot spot phenomenon of the single-sided photovoltaic panel 110 shown in Figure 2(D), the snow accumulated on the single-sided photovoltaic panel 110 has melted and been removed.

[0061] Figure 3(F) is a diagram showing the state where sunlight is irradiated on the photovoltaic device 100 in a state where the snow accumulated on the single-sided photovoltaic panel 110 has melted. As shown in Figure 3(F), when sunlight is irradiated on the photovoltaic device 100 in a state where the snow accumulated on the single-sided photovoltaic panel 110 has melted, on the surface of the double-sided photovoltaic panel 120, since the sunlight is blocked by the snow, the power generation amount becomes 0%.

[0062] However, even if the amount of heat generated by the power generation on the back surface of the double-sided photovoltaic panel 120 or the amount of heat transmitted from the adjacent single-sided photovoltaic panel 110 generated through the panel connection portion 130 is considered, not all of the snow accumulated on the double-sided photovoltaic panel 120 will melt, and the power generation amount on the surface of the double-sided photovoltaic panel 120 for power generation is extremely smaller than the power generation amount of the adjacent single-sided photovoltaic panel 110 through the panel connection portion 130.

[0063] However, in the single-sided photovoltaic panel 110 where the accumulated snow has melted, since there is no snow blocking the irradiated sunlight, the single-sided photovoltaic panel 110 generates electricity with 100% power generation amount. By generating electricity with 100% power generation amount in the single-sided photovoltaic panel 110, in the photovoltaic power generation device 100 where the single-sided photovoltaic panel 110 and the double-sided photovoltaic panel 120 are connected in series through the panel connection portion 130, since it becomes a single conductor as a whole, electricity flows from the positive side to the negative side as a whole.

[0064] FIG. 3(G) is a diagram showing a state in which the electricity generated by the single-sided photovoltaic panel 110 where the accumulated snow has melted flows into the photovoltaic power generation device 100 in a snow-covered state and the double-sided photovoltaic panel 120 generates heat.

[0065] When the electricity generated by the single-sided photovoltaic panel 110 where the accumulated snow has melted flows into the photovoltaic power generation device 100 in a snow-covered state, electricity also flows to the adjacent double-sided photovoltaic panel 120 through the panel connection portion 130.

[0066] However, since the surface of the adjacent double-sided photovoltaic panel 120 is covered with snow and the power generation amount is small, the electricity flow is difficult and the resistance value is high. When the electricity generated on the surface of the adjacent single-sided photovoltaic panel 110 where the accumulated snow has melted flows, the temperature of the surface of the double-sided photovoltaic panel 120 rises.

[0067] Therefore, the electricity that has become difficult to flow inside the double-sided photovoltaic panel 120 causes a phenomenon in which the electrical energy by the electricity is converted into heat energy, that is, a phenomenon called a hot spot occurs.

[0068] Due to this hot spot phenomenon, the bifacial photovoltaic panel 120 generates heat, causing the snow accumulated on the surface of the bifacial photovoltaic panel 120 to eventually melt and fall to the ground along the inclined surface provided on the bifacial photovoltaic panel 120.

[0069] Due to the hot spot phenomenon of the bifacial photovoltaic panel 120, the snow accumulated on the bifacial photovoltaic panel 120 is removed, reducing the electrical resistance to the bifacial photovoltaic panel 120. The heat generation that occurred in the bifacial photovoltaic panel 120 is eventually released, and the heat decreases.

[0070] FIG. 3(H) is a diagram showing the photovoltaic device 100 in a state where the accumulated snow has melted. As shown in FIG. 3(H), due to the hot spot phenomenon of the bifacial photovoltaic panel 120 shown in FIG. 3(G), the snow accumulated on the bifacial photovoltaic panel 120 has melted and been removed.

[0071] As a result, the photovoltaic device 100 in the snow-accumulated state undergoes the processes of power generation on the back surface of the bifacial photovoltaic panel 120, melting of snow due to heat generation of the single-sided photovoltaic panel 110, power generation of the single-sided photovoltaic panel 110, and melting of snow on the surface due to heat generation of the bifacial photovoltaic panel 120. The snow accumulated on the photovoltaic device 100 is completely removed.

[0072] FIG. 4 is a diagram showing an example of connecting by changing the composition ratio of the single-sided photovoltaic panel and the bifacial photovoltaic panel constituting the photovoltaic device. As shown in FIG. 4, it is also possible to connect by changing the composition ratio of the single-sided photovoltaic panel 110 and the bifacial photovoltaic panel 120 constituting the photovoltaic device 100. However, during snow accumulation, the electricity generated on the back surface of the bifacial photovoltaic panel 120 causes the adjacent single-sided photovoltaic panel 110 to generate heat and melt the snow through the panel connection part 130. Therefore, it is preferable to connect the single-sided photovoltaic panel 110 and the bifacial photovoltaic panel 120 in series alternately through the panel connection part 130.

[0073] FIG. 5 is a diagram showing an example in which single-sided photovoltaic panels are arranged on the starting end side of the connection structure between the single-sided photovoltaic panel and the double-sided photovoltaic panel constituting the photovoltaic device, and single-sided photovoltaic panels are arranged and connected on the ending end side.

[0074] As shown in FIG. 5, on the starting end side and the ending end side of the connection structure between the single-sided photovoltaic panel 110 and the double-sided photovoltaic panel 120 constituting the photovoltaic device 100, the single-sided photovoltaic panel 110 and the double-sided photovoltaic panel can be arbitrarily set.

[0075] For example, as shown in FIG. 5, when the double-sided photovoltaic panel 120 is arranged on the starting end side, since the snow accumulated on the single-sided photovoltaic panel 110 connected to the minus side has not melted, it is difficult for electricity to flow. That is, it is considered that electrons from the minus side where electrons flow are difficult to flow to the double-sided photovoltaic panel 120 connected to the starting end side.

[0076] Also, as shown in FIG. 5, when the single-sided photovoltaic panel 110 is arranged on the ending end side, since only the power conditioner 200 (not shown here) is connected to the minus side, it is considered that it is difficult for electricity to flow. Therefore, as shown in FIG. 1, it is preferable to arrange the single-sided photovoltaic panel 110 on the starting end side which is the plus side and the double-sided photovoltaic panel 120 on the ending end side.

[0077] 〔Second Embodiment〕 Next, a second embodiment of the present invention will be described. The photovoltaic panel of this embodiment is substantially the same as the configuration shown in the first embodiment except that the constituent unit is reduced from the panel unit to the cell unit. Therefore, for the constituent parts that are substantially the same as those in the first embodiment above, the same reference numerals are attached and the description thereof is appropriately omitted.

[0078] FIG. 6 is a block diagram showing the concept of the photovoltaic panel according to the second embodiment. As shown in FIG. 6, the photovoltaic panel 300 includes a single-sided photovoltaic part 310 and a double-sided photovoltaic part 320 in one panel.

[0079] The single-sided photovoltaic power generation part 310 is the part where the photovoltaic cells are provided only on a part of the surface of the photovoltaic panel 300. Also, the double-sided photovoltaic power generation part 320 is the part of the photovoltaic panel 300 excluding the single-sided photovoltaic power generation part 310, and is the part provided not only on the front surface but also on the back surface.

[0080] The single-sided photovoltaic power generation part 310 and the double-sided photovoltaic power generation part 320 are formed by connecting a plurality of photovoltaic cells in series. The end of the photovoltaic cells constituting the single-sided photovoltaic power generation part 310 and the start of the photovoltaic cells constituting the double-sided photovoltaic power generation part 320 are connected in series via the cell connection part 330.

[0081] Thus, when snow accumulates on the surface of the photovoltaic panel 300, first, the back surface of the double-sided photovoltaic power generation part 320 receives reflected light and generates electricity. The electricity generated on the back surface of the double-sided photovoltaic power generation part 320 flows into the single-sided photovoltaic power generation part 310 within the photovoltaic panel 300.

[0082] Next, when the electricity generated on the back surface of the double-sided photovoltaic power generation part 320 flows into the single-sided photovoltaic power generation part 310, a hot spot phenomenon occurs in the single-sided photovoltaic power generation part 310, causing the single-sided photovoltaic power generation part 310 to heat up, and the snow accumulated on the surface of the single-sided photovoltaic power generation part 310 melts.

[0083] When the snow accumulated on the surface of the single-sided photovoltaic power generation part 310 melts, the surface of the single-sided photovoltaic power generation part 310 that receives sunlight generates electricity, and the electricity generated on the surface of the single-sided photovoltaic power generation part 310 flows into the double-sided photovoltaic power generation part 320.

[0084] When the electricity generated on the surface of the single-sided photovoltaic power generation part 310 flows into the double-sided photovoltaic power generation part 320, a hot spot phenomenon occurs in the double-sided photovoltaic power generation part 320, causing the double-sided photovoltaic power generation part 320 to heat up, and the snow accumulated on the surface of the double-sided photovoltaic power generation part 320 melts. As described above, the snow accumulated on the surfaces of all the photovoltaic panels 300 connected to the photovoltaic panel 300 melts.

[0085] Figure 7 is a diagram showing the details of the photovoltaic panel. As shown in FIG. 7, the single-sided photovoltaic power generation unit 310 is formed by connecting a plurality of single-sided photovoltaic cells 311 in series. Also, the single-sided photovoltaic power generation unit 310 can be composed of single-sided photovoltaic modules 311M in which a plurality of single-sided photovoltaic cells 311 are connected in series.

[0086] Also, the double-sided photovoltaic power generation unit 320 is formed by connecting a plurality of double-sided photovoltaic cells 321 in series. Also, the double-sided photovoltaic power generation unit 320 can be composed of double-sided photovoltaic modules 321M in which a plurality of double-sided photovoltaic cells 321 are connected in series.

[0087] At this time, the cell connection part 330 connects the single-sided photovoltaic cells 311 that make up the single-sided photovoltaic module 311M and the double-sided photovoltaic cells 321 that make up the double-sided photovoltaic module 321M in series.

[0088] FIG. 8 is a diagram showing another exemplary form of the photovoltaic panel. As shown in FIG. 8, the photovoltaic panel 300 can be composed of a plurality of single-sided photovoltaic power generation units 310 and a plurality of double-sided photovoltaic power generation units 320.

[0089] Similarly in this case, the single-sided photovoltaic power generation unit 310 can be composed of a plurality of single-sided photovoltaic modules 311M, and the double-sided photovoltaic power generation unit 320 can be composed of a plurality of double-sided photovoltaic modules 321M.

Explanation of Reference Numerals

[0090] 100 Photovoltaic power generation device 110 Single-sided photovoltaic panel 120 Double-sided photovoltaic panel 130 Panel connection part 200 Power conditioner

Claims

1. In a photovoltaic power generation device that melts snow that has accumulated on a photovoltaic panel, 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; A photovoltaic device comprising:

2. The connection structure to which the panel connection portion is connected is A structure in which at least one of the single-sided photovoltaic panels is connected among the multiple connected double-sided photovoltaic panels; 2. The photovoltaic device according to claim 1 .

3. The connection structure includes: The bifacial photovoltaic panel and the single-sided photovoltaic panel are alternately connected to each other.

3. The photovoltaic device according to claim 2 .

4. The connection structure includes: The single-sided photovoltaic panel is arranged on the starting end side; 4. The photovoltaic device according to claim 3,

5. The connection structure includes: The bifacial photovoltaic panel is arranged on the terminal side; 3. The photovoltaic device according to claim 2 .

6. A snow melting method using a photovoltaic device comprising: a bifacial photovoltaic panel that receives light and generates electricity on both a surface on which snow accumulates and a back surface opposite the above-mentioned surface; a single-sided photovoltaic panel that receives light and generates electricity on the surface on which snow accumulates; and a panel connector that connects the bifacial photovoltaic panel and the single-sided photovoltaic panel in series, generating electricity on a back surface of the bifacial photovoltaic panel; A step in which electricity generated on the back surface of the bifacial photovoltaic panel flows to the single-sided photovoltaic panel connected via the panel connection portion; a step of generating heat from the single-sided photovoltaic panel by flowing electricity generated on a back surface of the double-sided photovoltaic panel to the single-sided photovoltaic panel; a step of generating electricity on a surface of the single-sided photovoltaic panel in which accumulated snow has melted due to heat generated by the single-sided photovoltaic panel, and the electricity flows to the double-sided photovoltaic panel connected via the panel connection portion; a step of generating heat from the bifacial photovoltaic panel by flowing electricity generated on a surface of the single-sided photovoltaic panel to the bifacial photovoltaic panel; A snow melting method comprising:

7. a bifacial photovoltaic cell that receives light from both a surface on which snow accumulates and a back surface opposite the surface and generates electricity; a single-sided photovoltaic cell that generates electricity by receiving light on the surface where the snow accumulates; a cell connection section that connects the bifacial photovoltaic cell and the single-sided photovoltaic cell in series; A photovoltaic panel comprising:

8. A method for melting snow using a photovoltaic panel comprising: a bifacial photovoltaic cell that receives light from both a surface on which snow accumulates and a back surface opposite to the surface, and generates electricity; a single-sided photovoltaic cell that receives light from the surface on which snow accumulates and generates electricity; and a cell connection section that connects the bifacial photovoltaic cell and the single-sided photovoltaic cell in series, generating electricity on a back surface of the bifacial photovoltaic cell; A step in which electricity generated on the back surface of the bifacial photovoltaic cell flows to the single-sided photovoltaic cell connected via the cell connection portion; electricity generated on a back surface of the bifacial photovoltaic cell flows to the single-sided photovoltaic cell, causing the single-sided photovoltaic cell to generate heat; a step of generating electricity on the surface of the single-sided photovoltaic cell in which accumulated snow has melted due to heat generated by the single-sided photovoltaic cell, and the electricity flows to the double-sided photovoltaic cell connected via the cell connection part; a step of generating heat in the bifacial photovoltaic cell by flowing electricity generated on a surface of the single-sided photovoltaic cell to the bifacial photovoltaic cell; A snow melting method comprising:

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