Solar cell units and solar cell systems

Abstract

It suppresses malfunctions caused by water. [Solution] The solar cell unit 10 is a solar cell unit 10 placed on the road surface and comprises a solar cell module 12 and a base portion 30 that supports the solar cell module 12. The base portion 30 includes a first recess S1 formed on its surface into which the solar cell module 12 is inserted, a second recess S2 formed in a part of the bottom surface of the first recess S1 into which the terminal box 28 of the solar cell module 12 is inserted, and a sealing portion SE formed around the entire circumference of the inner wall of the first recess S1 that seals the inner wall of the first recess S1 and the side surface 12C of the solar cell module 12.

Description

[Technical Field]

[0001] This invention relates to a solar cell unit and a solar cell system. [Background technology]

[0002] A technology has been proposed that involves placing solar cell modules on the road surface to generate electricity from solar energy irradiated onto the road surface. For example, Patent Document 1 describes embedding a pavement structure equipped with solar panels and a protective layer within the pavement. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2018-145611 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] By placing solar panels on the road surface in this way, the panels are more likely to be exposed to water, especially during rainy weather, thus increasing the risk of water-induced failure. Therefore, measures to suppress water-related failures are required.

[0005] The present invention aims to provide a solar cell unit and solar cell system capable of suppressing failures caused by water. [Means for solving the problem]

[0006] The solar cell unit according to this disclosure is a solar cell unit arranged on a road surface and comprises a solar cell module and a base portion that supports the solar cell module, wherein the base portion includes a first recess formed on its surface into which the solar cell module is inserted, a second recess formed in a part of the bottom surface of the first recess into which the terminal box of the solar cell module is inserted, and a sealing portion formed around the entire circumference of the inner wall of the first recess to seal the inner wall of the first recess and the side surface of the solar cell module.

[0007] The solar cell system according to this disclosure is a solar cell system having a first solar cell unit, a second solar cell unit, and a third solar cell unit, wherein the first solar cell unit is arranged adjacent to the second solar cell unit and the third solar cell unit, and the first solar cell unit, the second solar cell unit, and the third solar cell unit each have a first cable and a second cable as cables, wherein the first cable of the first solar cell unit is pulled into the cover portion of the second solar cell unit from the exit hole and connected to the second cable of the second solar cell unit, and the second cable of the first solar cell unit is connected to the first cable of the third solar cell unit which is pulled into the cover portion within the cover portion. [Effects of the Invention]

[0008] According to the present invention, water-related malfunctions can be suppressed. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram of a solar cell unit according to this embodiment. [Figure 2] Figure 2 is a schematic diagram of a solar cell module. [Figure 3] Figure 3 is a schematic diagram of the base. [Figure 4] Figure 4 is a schematic diagram of the base. [Figure 5]Figure 5 is a schematic diagram of the cover section. [Figure 6] Figure 6 is a schematic diagram of the cover section. [Figure 7] Figure 7 is a schematic diagram of a solar cell unit according to this embodiment. [Figure 8] Figure 8 is a schematic diagram of a solar cell unit according to this embodiment. [Figure 9] Figure 9 is a schematic diagram showing an example of a solar cell system. [Figure 10] Figure 10 is a schematic diagram showing another example of a solar cell unit. [Figure 11] Figure 11 is a schematic diagram showing another example of a solar cell unit. [Modes for carrying out the invention]

[0010] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. However, the present invention is not limited to these embodiments, and if there are multiple embodiments, they may be constructed by combining these embodiments. Numerical values ​​are rounded to the nearest whole number.

[0011] (Solar cell unit) Figure 1 is a schematic diagram of a solar cell unit according to this embodiment. As shown in Figure 1, the solar cell unit 10 according to this embodiment has a solar cell module 12 and a pavement body 14 that supports the solar cell module 12. The solar cell unit 10 is a device that is placed on a road surface such as a road and generates electricity when exposed to sunlight. For example, the solar cell unit 10 is embedded in a recess formed in the road surface, thereby forming part of the road surface. The solar cell unit 10 has a structure in which the solar cell module 12 is disposed on the pavement 14 (bottom 32 described later). When the direction in which the pavement 14 (bottom 32 described later) and the solar cell module 12 are laminated is defined as the Z direction, one direction along the Z direction is defined as the Z1 direction, and the direction opposite to the Z1 direction is defined as the Z2 direction, the solar cell unit 10 has the pavement 14 (bottom 32 described later) and the solar cell module 12 overlapping in this order toward the Z1 direction. Hereinafter, one direction orthogonal to the Z direction is defined as the X direction, and the direction orthogonal to the Z direction and the X direction is defined as the Y direction.

[0012] (Solar cell module) FIG. 2 is a schematic diagram of the solar cell module. In the solar cell module 12, the surface 12A which is the surface on the Z1 direction side serves as the light receiving surface, and the surface 12B which is the surface on the Z2 direction side serves as the back surface on the side opposite to the light receiving surface. Further, the side surface of the solar cell module 12 connecting the surface 12A and the surface 12B is hereinafter referred to as the side surface 12C. The solar cell module 12 is a photovoltaic module having solar cells 26. The solar cells 26 are arranged such that the surface 26A which is the light receiving surface faces the Z1 direction and the surface 26B on the side opposite to the surface 26A faces the Z2 direction. The solar cells 26 generate electricity when light such as sunlight is irradiated on the surface 26A (light receiving surface). The solar cells 26 may be solar cells of any system capable of generating electricity when irradiated with light. For example, as the solar cells 26, any material such as single crystal silicon, polycrystalline silicon, amorphous silicon, microcrystalline silicon, perovskite crystal, compound semiconductor, organic semiconductor, etc. can be used. Further, as the structure of the solar cells 26, a structure such as a multi-junction type (tandem type) or a quantum dot type may be used. The solar cell module 12 may have one solar cell 26 or may have a plurality of solar cells 26. When the solar cell module 12 has a plurality of solar cells 26, it is preferable that the respective solar cells 26 are connected in series while being arranged in a direction orthogonal to the Z direction (for example, the X direction or the Y direction). That is, it is preferable that the respective solar cells 26 are arranged so as not to overlap each other when viewed from the Z direction.

[0013] As shown in FIG. 2, in the present embodiment, the solar cell module 12 includes a glass plate 20, a glass plate 22, an intermediate layer 24, a solar cell 26, and a terminal box 28. In the solar cell module 12, the glass plate 20, the intermediate layer 24, and the glass plate 22 are laminated in this order toward the Z2 direction. The glass plate 20 and the glass plate 22 are fixed (adhered) to each other via the intermediate layer 24. The solar cell 26 is provided inside the intermediate layer 24. The solar cell 26 is arranged inside the intermediate layer 24 such that the surface 26A faces the Z1 direction and the surface 26B faces the Z2 direction. The terminal box 28 is provided on the surface on the Z2 direction side of the glass plate 22 (that is, the surface 12B of the solar cell module 12).

[0014] (Glass plate) The thickness of the glass plate 20 is preferably 1 mm or more and 70 mm or less, more preferably 10 mm or more and 70 mm or less, and still more preferably 30 mm or more and 70 mm or less. By setting the thickness within this range, breakage due to the application of a load can be suppressed. Note that the thickness of the glass plate 20 refers to the distance in the Z direction between the surface on the Z1 direction side and the surface on the Z2 direction side of the glass plate 20.

[0015] The glass plate 20 preferably has an average transmittance of 90% or more, more preferably 95% or more, and still more preferably 98% or more with respect to light in a wavelength range of 380 nm or more and 780 nm or less. By setting the transmittance within this range, visible light can be appropriately transmitted and the solar cell 26 can be appropriately irradiated with light. The average transmittance here refers to the average value of the transmittance for each wavelength of light within that wavelength range (in this case, 380 nm to 780 nm). Transmittance, for example, refers to external transmittance and can be measured using a spectrophotometer (Hitachi High-Technologies Corporation: U-4100).

[0016] The Young's modulus of the glass plate 20 is preferably 50 GPa or more and 80 GPa or less, more preferably 55 GPa or more and 75 GPa or less, and even more preferably 60 GPa or more and 70 GPa or less. Having a Young's modulus within this range helps to suppress breakage due to applied load. The Young's modulus of the glass plate 20 can be measured based on ultrasonic wave propagation using an OLYMPUS 38DL PLUS.

[0017] The material of the glass plate 20 may be arbitrary, but for example, it may be soda-lime silicate glass, quartz glass, crystal glass, alkali-free glass, aluminosilicate glass, borosilicate glass, or barium borosilicate glass.

[0018] The glass plate 20 may be laminated glass. Laminated glass has a structure in which an interlayer film, such as resin, is interposed between a pair of glass plates and bonded together. Because the glass plate 20 is laminated glass, breakage due to applied load can be reduced.

[0019] The glass plate 22 may have the same properties as the glass plate 20. That is, for example, the thickness, transmittance, Young's modulus, and material of the glass plate 22 may be the same as those of the glass plate 20 described above. However, the glass plate 22 is not limited to having the same properties as the glass plate 20. For example, the glass plate 22 does not have to transmit visible light, and its average transmittance for light in the wavelength range of 380 nm to 780 nm may be lower than that of the glass plate 20.

[0020] (Middle class) The intermediate layer 24 is an adhesive layer that bonds the glass plate 20 and the glass plate 22. The material of the intermediate layer 24 is arbitrary, but for example, polyvinyl butyral (PVB) modified material, ethylene-vinyl acetate copolymer (EVA) material, urethane resin material, polyvinyl chloride resin material, etc. can be used.

[0021] (terminal box) The terminal box 28 is fixed to the Z2-direction surface of the glass plate 22 (i.e., the surface 12B of the solar cell module 12). The terminal box 28 is a housing that houses a portion of the cable 28B connected to the solar cell 26. The cable 28B is a conductive wire that conducts current from the solar cell 26 and is drawn out from inside the terminal box 28 to the outside of the terminal box 28. The end of the cable 28B opposite to the side connected to the solar cell 26 is provided with a connector that can be connected to, for example, another cable 28B or other devices. In this embodiment, the solar cell module 12 has two cables 28B, one for the positive electrode and one for the negative electrode.

[0022] As described above, the solar cell module 12 according to this embodiment is a laminated glass having a glass plate 20 and a glass plate 22, and has a structure in which a solar cell 26 is located inside an intermediate layer 24 between the glass plate 20 and the glass plate 22. However, the structure of the solar cell module 12 is not limited to this, and may be any structure having a solar cell 26.

[0023] (Pavement) The paving body 14 is a member that supports the surface 12B (back surface) of the solar cell module 12. As shown in Figure 1, the paving body 14 has a base portion 30 that supports the solar cell module 12. Preferably, in addition to the base portion 30, the paving body 14 also has a cover portion 40 that covers the cable 19B connected to the terminal box 28. In this embodiment, the base portion 30 and the cover portion 40 are separate components, and the cover portion 40 can be removed from the base portion 30. However, it is not limited to this, and the base portion 30 and the cover portion 40 may be an integrated component.

[0024] (Base) Figures 3 and 4 are schematic diagrams of the base portion. Figure 3 is a perspective view of the base portion 30, and Figure 4 is a top view of the base portion 30. As shown in Figures 3 and 4, the base portion 30 includes a bottom portion 32 and a side wall portion 34. In this embodiment, the bottom portion 32 and the side wall portion 34 are a single integrated member.

[0025] The bottom portion 32 is the part that constitutes the bottom surface of the pavement body 14 on the Z2 direction side. That is, in this embodiment, the Z2 direction surface 32B of the bottom portion 32 becomes the Z2 direction surface 30B of the base portion 30. In the example of Figure 2, the bottom portion 32 is a rectangular plate-shaped member when viewed from the Z direction. However, the shape of the bottom portion 32 is not limited to a rectangle when viewed from the Z direction, and may be arbitrary.

[0026] The side wall portion 34 protrudes in the Z1 direction from the Z1-direction surface 32A of the bottom portion 32. The side wall portion 34 is provided on the surface 32A of the bottom portion 32, extending over the entire length of the outer peripheral edge of the surface 32A. That is, in this embodiment, the side wall portion 34 is provided over the entire length of the outer peripheral edge that constitutes all four sides of the rectangular surface 32A when viewed from the Z direction. In this embodiment, the Z1-direction surface 34A of the side wall portion 34 becomes the Z1-direction surface 30A of the base portion 30. In this embodiment, the space enclosed by the Z1-direction surface 32A of the bottom portion 32 and the inner surface 34B of the side wall portion 34 forms the first recess S1. The inner surface 34B is the radially inner surface of the side wall portion 34. Here, radial direction refers to the radial direction when the central axis is the axis along the Z direction passing through the center of the bottom portion 32 as viewed from the Z direction, and this is the same hereafter unless otherwise specified. The first recess S1 can also be described as a recess that is recessed in the Z2 direction from the surface 30A of the base portion 30 (surface 34A of the side wall portion 34). The solar cell module 12 is inserted into the first recess S1.

[0027] A second recess S2 is formed on the surface 32A of the bottom portion 32 (the bottom surface of the first recess S1), which is recessed in the Z2 direction. The second recess S2 is formed in a part of the surface 32A and can be described as a recess that is recessed further in the Z2 direction than the surface 32A. In other words, a surface 32C is formed radially inward from the outer edge of the surface 32A and is located on the Z2 side of the surface 32A, and a side surface 32D is formed connecting the surface 32C and the surface 32A. The space enclosed by the side surface 32D and the surface 32C can be described as the second recess S2. The terminal box 28 of the solar cell module 12 is inserted into the second recess S2.

[0028] Furthermore, it is preferable that a communication hole 34D is formed in the base portion 30 that connects the side surface 32D of the bottom portion 32 (the inner surface of the second recess S2) and the outer surface 34C of the side wall portion 34 (the radially outer surface of the side wall portion 34). In this embodiment, the communication hole 34D is formed in the side wall portion 34 on one side in the X direction (the right side in Figure 4), and penetrates from the outer surface 34C of the side wall portion 34 on one side in the X direction to the side surface 32D of the bottom portion 32 on one side in the X direction. That is, the communication hole 34D connects the second recess S2 to the space on one side in the X direction beyond the side wall portion 34 on one side in the X direction (the cable arrangement space S3 described later). In this embodiment, two communication holes 34D are formed side by side in the Y direction, but the number and direction in which the communication holes 34D are arranged are not limited to this and may be arbitrary. The shape of the communication hole 34D may also be arbitrary. Furthermore, in the example shown in Figure 4, the side surface 32D of the bottom portion 32 in the X direction and the inner surface 34B of the side wall portion 34 in the X direction are formed on the same plane. However, it is not limited to this, and the side surface 32D of the bottom portion 32 in the X direction may be recessed on one side in the X direction or protrude on the other side in the X direction compared to the inner surface 34B of the side wall portion 34 in the X direction.

[0029] Furthermore, it is preferable that the base portion 30 includes a projection 36 that protrudes from the side surface of the base portion 30. In the example shown in Figures 3 and 4, the projection 36 protrudes from one side of the base portion 30 in the X direction (the right side in this example) toward the other side in the X direction. It is preferable that the surface 36A of the projection 36 on the Z1 direction side is located on the Z2 direction side of the surface 32A of the bottom portion 32, and is also preferable that it is located on the Z2 direction side of the communication hole 34D. In this embodiment, the space enclosed by the side surface of the base portion 30 in the X direction (the outer surface 34C of the side wall portion 34 in the X direction) and the surface 36A of the protruding portion 36 in the Z1 direction forms the cable arrangement space S3. The cable arrangement space S3 can be said to be formed at a position adjacent to the first recess S1 (on one side in the X direction in this example) via the side wall portion 34, and can also be said to be formed at a position adjacent to the second recess S2 (on one side in the X direction in this example) via the side wall portion 34.

[0030] The base portion 30 may be made of any material, for example, concrete.

[0031] (Cover section) Figures 5 and 6 are schematic diagrams of the cover portion. Figure 5 is a perspective view of the cover portion 40, and Figure 6 is a top view of the cover portion 40. The cover portion 40 is a cover that covers the cable arrangement space S3. The cover portion 40 may have any shape that is capable of covering the cable arrangement space S3. For example, in this embodiment, the cover portion 40 has a top surface portion 40A and a side wall portion 40B, and the internal space SP surrounded by the top surface portion 40A and the side wall portion 40B is in communication with the outside from the area not surrounded by the top surface portion 40A and the side wall portion 40B. In this embodiment, the top surface portion 40A and the side wall portion 40B are a single integrated member.

[0032] The upper surface portion 40A is the part that constitutes the Z1 direction side of the cover portion 40. The other end face of the upper surface portion 40A in the X direction (left side in the example of Figure 5) is described as the end face 40Aa. In the examples of Figures 5 and 6, the upper surface portion 40A is a rectangular plate-shaped member when viewed from the Z direction. However, the shape of the upper surface portion 40A is not limited to a rectangle when viewed from the Z direction and may be arbitrary.

[0033] The side wall portion 40B protrudes in the Z2 direction from the surface 40Ab of the upper surface portion 40A on the Z2 direction side. The side wall portion 40B is provided on the surface 40Ab of the upper surface portion 40A, extending over a portion of the entire outer edge of the surface 40Ab. In this embodiment, the side wall portion 40B includes a side wall portion 40B1 protruding from the outer edge of one side of the surface 40Ab in the X direction (right side in the example of Figures 5 and 6), a side wall portion 40B2 protruding from the outer edge of one side of the surface 40Ab in the Y direction (front side of the paper in the example of Figures 5 and 6), and a side wall portion 40B3 protruding from the outer edge of one side of the surface 40Ab in the Y direction (back side of the paper in the example of Figures 5 and 6). In this embodiment, the side wall portion 40B is not provided on the other side of the surface 40Ab in the X direction (left side in the example of Figures 5 and 6). In this example, the space SP enclosed by the top surface 40A and the side walls 40B1, 40B2, and 40B3 is open on the other side in the X direction and on the Z2 direction (the other side in the X direction and on the Z2 direction are in communication with the outside). Hereinafter, the end face of the side wall portion 40B on the Z2 direction side will be referred to as end face 40Ba, and the end face of the other side of the side wall portion 40B in the X direction (left side in the example of Figure 5) will be referred to as end face 40Bb. In this embodiment, the side wall portion 40B includes side wall portions 40B1, 40B2, and 40B3. Therefore, the end faces of the side wall portions 40B1, 40B2, and 40B3 on the Z2 direction side are end face 40Ba, and the end faces of the other side of the side wall portions 40B2 and 40B3 in the X direction (left side in the example of Figure 5) are end face 40Bb.

[0034] Furthermore, it is preferable that the cover portion 40 has an exit hole 42 that connects the space SP with the space outside the space SP. In this embodiment, the exit hole 42 penetrates from the inner surface of the side wall portion 40B (the surface on the space SP side) to the outer surface of the side wall portion 40B (the surface opposite to the space SP). In this embodiment, the exit hole 42 is formed in the side wall portion 40B2 and the side wall portion 40B3.

[0035] The cover portion 40 may be made of any material, for example, the same material as the base portion 30.

[0036] (Solar cell unit) Next, the structure of the solar cell unit 10 in the state where the solar cell module 12 is placed on the pavement 14 will be described. Figures 7 and 8 are schematic diagrams of the solar cell unit according to this embodiment. Figure 7 is a front view of the solar cell unit, and Figure 8 is a top view of the solar cell unit.

[0037] As shown in Figure 7, in the solar cell unit 10, the solar cell module 12 is positioned in the first recess S1 of the base portion 30 with the surface 12A of the solar cell module 12 facing in the Z1 direction. In the solar cell unit 10, it is preferable that the surface 12A (light-receiving surface) of the solar cell module 12 facing in the Z1 direction is exposed. However, a member that can transmit sunlight may be provided on the surface 12A. In this embodiment, it is preferable that the solar cell module 12 is fixed in the first recess S1 with the surface 12B of the solar cell module 12 in contact with the surface 32A of the base portion 30.

[0038] The side surface 12C of the solar cell module 12 and the inner surface 34B of the base portion 30 are sealed over the entire circumferential direction (entire circumference). In other words, the inner surface 34B of the base portion 30 is provided with a sealing portion SE that seals the side surface 12C of the solar cell module 12 and the inner surface 34B of the base portion 30 over the entire circumferential direction (entire circumference). Here, sealing means that the space between the side surface 12C of the solar cell module 12 and the inner surface 34B of the base portion 30 is kept free of gaps by the sealing portion SE. The sealing portion SE seals the side surface 12C of the solar cell module 12 and the inner surface 34B of the base portion 30, suppressing the intrusion of water from the surface 12A side of the solar cell module 12 into the first recess S1. Here, the circumferential direction refers to the circumferential direction when the axis along the Z-direction passing through the center of the bottom portion 32 as viewed from the Z-direction is taken as the central axis, and the same applies hereafter unless otherwise specified. The sealing portion SE may be any material, for example, an elastic member or adhesive provided around the entire circumference of the inner surface 34B of the base portion 30. Alternatively, for example, the sealing portion SE may be formed by the contact between the side surface 12C of the solar cell module 12 and the inner surface 34B of the base portion 30 over its entire circumference. In this case, the contact points between the side surface 12C of the solar cell module 12 and the inner surface 34B of the base portion 30 constitute the sealing portion SE.

[0039] As shown in Figure 7, the terminal box 28 of the solar cell module 12 is housed in the second recess S2 of the base portion 30. Preferably, the surface 28A of the terminal box 28 on the Z2 direction side is located on the Z1 direction side of the bottom surface of the second recess S2 (surface 32C of the base portion 30), but it is not limited to this, and the surface 28A of the terminal box 28 and the bottom surface of the second recess S2 may be in contact. Furthermore, preferably, the terminal box 28 is not in contact with the inner surface of the second recess S2 (side surface 32D of the base portion 30) in directions perpendicular to the Z direction (X direction and Y direction), and is away from the inner surface of the second recess S2, but it is not limited to this, and it may be in contact with the inner surface of the second recess S2. Furthermore, a desiccant that absorbs moisture in the second recess S2 may be placed inside the second recess S2. Any material may be used as the desiccant.

[0040] As described above, the base portion 30 has a communication hole 34D that connects the second recess S2 and the cable arrangement space S3. The cable 28B drawn out from the terminal box 28 located in the second recess S2 is passed through the communication hole 34D and drawn out into the cable arrangement space S3. In other words, the cable 28B is arranged from inside the second recess S2, through the communication hole 34D, and into the cable arrangement space S3. In this embodiment, one cable 28B is drawn out into the cable arrangement space S3 from one communication hole 34D, and the other cable 28B is drawn out into the cable arrangement space S3 from the other communication hole 34D. However, both cables 28B may be drawn out into the cable arrangement space S3 from one communication hole 34D. Also, the communication hole 34D may be closed when the cable 28B is passed through it. For example, the communication hole 34D may be closed by filling it with a filler material while the cable 28B is passed through it.

[0041] Furthermore, as shown in Figures 7 and 8, in the solar cell unit 10, the cover portion 40 is positioned to cover the cable arrangement space S3 of the base portion 30. Specifically, the cover portion 40 is positioned on the surface 36A of the protruding portion 36 of the base portion 30, and the space enclosed by the inner surface of the cover portion 40, the outer surface 34C of the base portion 30, and the surface 36A of the base portion 30, in other words, the space SP inside the cover portion 40, forms the cable arrangement space S3. In this embodiment, the cover portion 40 is positioned such that the outer surface 34C of the base portion 30 and the end faces 40Aa and 40Bb of the cover portion 40 face each other, and the surface 36A of the base portion 30 and the end face 40Ba of the cover portion 40 face each other. By positioning the cover portion 40 in this way, the cable arrangement space S3 through which the cable 28B is passed is covered.

[0042] It is preferable that the opposing points between the base portion 30 and the cover portion 40 (in this example, the space between the outer surface 34C of the base portion 30 and the end faces 40Aa and 40Bb of the cover portion 40, and the space between the surface 36A of the base portion 30 and the end face 40Ba of the cover portion 40) are sealed. That is, it is preferable that the opposing points between the base portion 30 and the cover portion 40 are provided with a cover sealing portion that seals the opposing points. Here, sealing may mean that the opposing points between the base portion 30 and the cover portion 40 are kept free of gaps by the cover sealing portion. The cover sealing portion seals the opposing points between the base portion 30 and the cover portion 40, thereby preventing water from entering the cable arrangement space S3 from between the base portion 30 and the cover portion 40. The cover sealing portion may be any material, for example, an elastic member or adhesive provided at the opposing points between the base portion 30 and the cover portion 40. Alternatively, for example, the cover sealing portion may be formed by the contact between the opposing points between the base portion 30 and the cover portion 40. In this case, the opposing points (contact points) between the base portion 30 and the cover portion 40 constitute the cover sealing portion.

[0043] The cover portion 40 is preferably detachably fixed to the base portion 30 while covering the cable arrangement space S3. The cover portion 40 is preferably fixed to the base portion 30 while the opposing portions of the base portion 30 and the cover portion 40 are sealed. The method of fixing the cover portion 40 to the base portion 30 is arbitrary. For example, a fitting structure may be formed at the contact points between the cover portion 40 and the base portion 30, and the cover portion 40 may be fixed by the fitting structure.

[0044] The cover portion 40 has an exit hole 42 that connects the cable arrangement space S3 (space SP) to the outside of the cable arrangement space S3. The cable 28B that is pulled into the cable arrangement space S3 is pulled out through the exit hole 42 to the outside of the pavement 14 (outside the cable arrangement space S3). In other words, the cable 28B is arranged from the second recess S2, through the communication hole 34D, the cable arrangement space S3, and the exit hole 42, to the outside of the pavement 14. In this embodiment, one cable 28B is pulled into the cable arrangement space S3 from one exit hole 42, and the other cable 28B is pulled into the cable arrangement space S3 from the other exit hole 42. The exit hole 42 may be closed while the cable 28B is passed through it. For example, the exit hole 42 may be closed by filling the exit hole 42 with a filler material while the cable 28B is passed through it.

[0045] In the process of leading the cable 28B to the outside of the pavement 14, for example, before attaching the cover portion 40 to the base portion 30, the solar cell module 12 is inserted into the first recess S1 while the terminal box 28 is housed in the second recess S2, and the cable 28B is pulled out from the communication hole 34D of the second recess S2. Then, the cable 28B is passed through the pull-out hole 42 and the cover portion 40 is attached so as to cover the cable arrangement space S3. In this way, the cable 28B can be led to the outside of the pavement 14 while the cable arrangement space S3 is covered with the cover portion 40.

[0046] In this configuration, the solar cell unit 10 is placed on the road surface and is therefore prone to frequent exposure to water, such as during rain. For example, if the side surface 12C of the solar cell module 12 is exposed to water, the layers of the solar cell module 12 may peel off. Also, if the terminal box 28 or cable 28B is exposed to water, the electrical system of the solar cell module 12 may malfunction. In contrast, the solar cell unit 10 according to this embodiment inserts the solar cell module 12 into the first recess S1 of the base portion 30, sealing the side surface 12C of the solar cell module 12 and the inner wall (inner surface 34B) of the first recess S1 around its entire circumference. This prevents the side surface 12C of the solar cell module 12 from being exposed to water. Furthermore, since the solar cell unit 10 according to this embodiment houses the terminal box 28 in the second recess S2 formed within the first recess S1, exposure of the terminal box 28 and cable 28B to water is also prevented. Thus, according to this embodiment, water-related malfunctions can be effectively suppressed. Furthermore, in this embodiment, the cable 28B is pulled out from the second recess S2 into the cable arrangement space S3, while the cable arrangement space S3 is covered with the cover portion 40. Therefore, the cable 28B pulled out from the second recess S2 to connect to other devices or other solar cell units 10 can also be prevented from being exposed to water by the cover portion 40.

[0047] (Solar cell system) Next, a solar cell system 1 in which multiple solar cell units 10 are connected will be described. Figure 9 is a schematic diagram showing an example of a solar cell system. For example, the solar cell system 1 can be embedded in a recess formed in the road surface, thereby forming part of the road surface. In the following description, a solar cell system 1 including three solar cell units 10A, 10B, and 10C will be described, but the number of solar cell units 10 included in the solar cell system 1 is not limited to three; it may be two, four or more, or any number of units.

[0048] In solar cell system 1, solar cell unit 10A is positioned adjacent to solar cell units 10B and 10C. More specifically, solar cell unit 10B is adjacent to solar cell unit 10A on the other side in the Y direction (downward in the example of Figure 9), and solar cell unit 10C is adjacent to solar cell unit 10A on one side in the Y direction (upward in the example of Figure 9).

[0049] In this embodiment, the other side of the cover portion 40 of solar cell unit 10A in the Y direction (downward in the example of Figure 9) and the one side of the cover portion 40 of solar cell unit 10B in the Y direction (upward in the example of Figure 9) face each other. Furthermore, the exit hole 42 formed on the other side of the solar cell unit 10A in the Y direction and the exit hole 42 formed on the one side of the solar cell unit 10B in the Y direction are in communication. Hereinafter, the other side of the cover portion 40 of solar cell unit 10A in the Y direction and the one side of the cover portion 40 of solar cell unit 10B in the Y direction will be referred to as the opposing surfaces of solar cell units 10A and 10B.

[0050] It is preferable that the opposing surfaces of the solar cell units 10A and 10B are fixed in a state where the lead holes 42 formed on the opposing surfaces are in communication with each other, and the area around the lead holes 42 is sealed. In other words, it is preferable that the opposing surfaces of the solar cell units 10A and 10B are provided with a sealing portion that seals the area around the lead holes 42. Here, sealing may refer to the state in which there are no gaps around the lead holes 42 on the opposing surfaces of the solar cell units 10A and 10B due to the sealing portion. The sealing portion seals the area around the lead holes 42 and suppresses the intrusion of water from the opposing surfaces of the solar cell units 10A and 10B into the cable arrangement space S3. The sealing portion may be any material, for example, an elastic member or adhesive provided on the opposing surfaces of the solar cell units 10A and 10B. Alternatively, for example, the sealing portion may be formed by the contact between the opposing surfaces of the solar cell units 10A and 10B. In this case, the opposing surfaces (contact surfaces) of the solar cell units 10A and 10B constitute the sealing portion.

[0051] In this embodiment, one cable 28B1 (first cable) of solar cell unit 10A is connected to the other cable 28BB (second cable) of solar cell unit 10B. Cables 28B1 and 28BB are connected, for example, via a connector at the end of cable 28B1 and a connector at the end of cable 28BB. More specifically, the cable 28B1 of solar cell unit 10A is pulled out from inside the cover portion 40 of solar cell unit 10A (cable arrangement space S3) through the exit hole 42 of solar cell unit 10A (the other exit hole 42 in the Y direction in the example of Figure 9), and is pulled into the cover portion 40 of solar cell unit 10B (cable arrangement space S3) through the exit hole 42 of solar cell unit 10B (the one exit hole 42 in the Y direction in the example of Figure 9). Inside the cover portion 40 of solar cell unit 10B, the cable 28B1 of solar cell unit 10A is connected to the cable 28BB of solar cell unit 10B.

[0052] In this embodiment, the solar cell unit 10A and the solar cell unit 10C are such that one side of the cover portion 40 of the solar cell unit 10A in the Y direction (upward in the example of Figure 9) faces the other side of the cover portion 40 of the solar cell unit 10C in the Y direction (downward in the example of Figure 9). Furthermore, the exit hole 42 formed on one side of the solar cell unit 10A in the Y direction and the exit hole 42 formed on the other side of the cover portion 40 of the solar cell unit 10C in the Y direction are in communication. Hereinafter, the one side of the cover portion 40 of the solar cell unit 10A in the Y direction and the other side of the cover portion 40 of the solar cell unit 10C in the Y direction will be referred to as the opposing surfaces of the solar cell units 10A and 10C.

[0053] It is preferable that the opposing surfaces of the solar cell units 10A and 10C are fixed in a state where the lead holes 42 formed on the opposing surfaces are in communication with each other, and the area around the lead holes 42 is sealed. In other words, it is preferable that the opposing surfaces of the solar cell units 10A and 10C are provided with a sealing portion that seals the area around the lead holes 42. Here, sealing may refer to the state in which there are no gaps around the lead holes 42 on the opposing surfaces of the solar cell units 10A and 10C due to the sealing portion. The sealing portion seals the area around the lead holes 42 and suppresses the intrusion of water from the opposing surfaces of the solar cell units 10A and 10C into the cable arrangement space S3. The sealing portion may be any material, for example, an elastic member or adhesive provided on the opposing surfaces of the solar cell units 10A and 10C. Alternatively, for example, the sealing portion may be formed by the contact between the opposing surfaces of the solar cell units 10A and 10C. In this case, the opposing surfaces (contact surfaces) of the solar cell units 10A and 10C constitute the sealing portion.

[0054] In this embodiment, the other cable 28B2 (second cable) of the solar cell unit 10A is connected to one cable 28BC (first cable) of the solar cell unit 10C. Cables 28B2 and 28BC are connected, for example, via a connector at the end of cable 28B2 and a connector at the end of cable 28BC. More specifically, the cable 28BC of the solar cell unit 10C is pulled out from inside the cover portion 40 of the solar cell unit 10C (cable arrangement space S3) through the exit hole 42 of the solar cell unit 10C (the other exit hole 42 in the Y direction in the example of Figure 9), and is pulled into the cover portion 40 of the solar cell unit 10A (cable arrangement space S3) through the exit hole 42 of the solar cell unit 10A (the one exit hole 42 in the Y direction in the example of Figure 9). Inside the cover portion 40 of the solar cell unit 10A, the cable 28BC of the solar cell unit 10C is connected to the cable 28B2 of the solar cell unit 10A.

[0055] Thus, in this embodiment, the cables 28B of adjacent solar cell units 10 are routed and connected within the cover portion 40 (cable arrangement space S3) of either solar cell unit 10. As a result, even when the cables 28B of two solar cell units 10 are connected, the cables 28B are housed within the cover portion 40, thereby preventing them from being exposed to water.

[0056] (Other examples of solar cell units) Next, other structural examples of the solar cell unit 10 according to this embodiment will be described. Figures 10 and 11 are schematic diagrams showing other examples of the solar cell unit. These examples can be combined as appropriate.

[0057] As shown in Figure 10, the pull-out hole 42 may be formed in a groove shape extending to the end face 40Ba on the Z2 direction side of the side wall portion 40B of the cover portion 40. That is, the pull-out hole 42 may be open on the Z2 direction side. By forming the exit holes 42 in a groove shape in this way, it becomes possible to connect the cables 28B of adjacent solar cell units 10 and then cover them with the cover portion 40, thereby facilitating the connection work of the cables 28B of the solar cell units 10.

[0058] For example, as shown in Figure 11, the solar cell module 12 may have a protective layer 29 on the Z1-direction surface 20A of the glass plate 20. The protective layer 29 becomes the layer on the Z1-direction side of the solar cell module 12, and the Z1-direction surface 29A of the protective layer 29 becomes the surface 12A of the solar cell module 12.

[0059] The protective layer 29 has a plurality of particles 29B protruding in the Z1 direction on the surface 29A. The particle size of the particles 29B is preferably 0.01 mm to 5 mm, more preferably 0.02 mm to 2 mm, more preferably 0.03 mm to 1 mm, more preferably 0.04 mm to 1 mm, and more preferably 0.05 mm to 1 mm. By setting the particle size of the particles 29B within this range, an appropriate sliding resistance value can be obtained, and the shedding of the particles 29B is suppressed, resulting in sufficient durability. The particle size here refers to the equivalent diameter of a circle, where the area of ​​the particle in a plan view is measured using a surface image of a cover glass obtained with an optical microscope or the like, and the diameter of a circle with the same area is defined as the particle size. Furthermore, "the particle size is 0.01 mm or more and 5 mm or less" means that the number of particles with a particle size of 0.01 mm or more and 5 mm or less is 70% or more, preferably 80% or more, and more preferably 90% or more of the total number of particles. Particle 29B preferably contains particles with a particle size range of 0.1 mm to 5 mm, more preferably contains particles with a particle size range of 0.2 mm to 5 mm, and even more preferably contains particles with a particle size range of 0.3 mm to 2 mm.

[0060] The shape of particle 29B is not particularly limited and can be polygonal, plate-shaped, rod-shaped, or irregularly shaped. From the viewpoint of obtaining an appropriate sliding resistance value, an irregular shape with sharp corners is preferred over a smooth shape such as a sphere. For example, if particle 29B is a crystalline oxide particle such as SiO2, Al2O3, or ZrO2, irregularly shaped particles obtained by crushing the oxide crystals can be used. For example, if particle 2 is a glass particle, irregularly shaped particles obtained by crushing glass can be used.

[0061] Some particles 29B may protrude, but there may also be particles 29B that are completely embedded in the protective layer 29. On the surface 29A of the protective layer 29, the density of protruding particles 29B is 1 particle / cm² relative to the area of ​​the surface 29A. 2 Preferably, it should be 5 pieces / cm 2 It is more preferable that the number be greater than or equal to 10 pieces / cm 2It is even more preferable that the above conditions are met. Also, 1 × 10 5 pieces / cm 2 The following is preferable: On the surface 29A of the protective layer 29, it is preferable that the total ratio of the planar area of ​​the particles 29B to the area of ​​the surface 29A is 1% or more and 80% or less. The lower limit is more preferably 10%, and even more preferably 20%.

[0062] Particle 29B may be composed of any material, but crystalline particles, glass particles, ceramic particles, etc., can be used. From the viewpoint of the required skid resistance value and durability as a road surface, crystalline particles are preferred. Examples of crystalline particles include crystalline oxide particles such as SiO2, Al2O3, and ZrO2. Furthermore, the particles 29B may be glass particles, from the viewpoint of affinity with the protective layer 29 and the glass plate 20. The composition of the glass particles (referred to as the third glass) is preferably different from the composition of the glass frit of the protective layer 29 (referred to as the second glass), which will be described later. It is more preferable that the strain point of the third glass is 30°C or more higher than the softening point of the second glass.

[0063] The protective layer 29 may be composed of any material, but it is preferably a fired product of glass frit. The composition of the glass frit (referred to as the second glass) is preferably different from the composition of the glass plate 20 (referred to as the first glass), and the strain point of the first glass is preferably 20°C or more higher than the softening point of the second glass, more preferably 30°C or more higher, and even more preferably 50°C or more higher. Examples of glass frit include soda-lime silicate glass, borosilicate glass, alkali-free glass, and quartz glass.

[0064] The protective layer 29 preferably contains air bubbles. In the protective layer 29, it is preferable that the size of the air bubbles is less than or equal to the thickness of the protective layer 29. The number of air bubbles contained in the protective layer 29 is 100 / mm². 3 It is even more preferable that the above conditions are met. Also, 1 × 10 10 pieces / mm 3The following are preferred. The number of bubbles was counted as follows. First, polishing was performed until the thickness of the protective layer 29 reached about 15 μm. This thickness allows all bubbles present in the thickness direction to be confirmed when observed with an optical microscope. Next, optical microscope observation was carried out, and bubbles with a diameter of 0.5 μm or more in the visual field were identified and counted by image processing. The number of bubbles thus obtained was divided by the binder layer thickness and the visual field area to convert it to the number of bubbles per mm 3 At this time, since the number of bubbles varies depending on the location, measurements were taken at three arbitrary locations and an average value was obtained.

[0065] The layer thickness of the protective layer 29 is preferably 0.02 mm or more and 5 mm or less, more preferably 0.03 mm or more and 5 mm, still more preferably 0.05 mm or more and 5 mm or less, and even more preferably 0.1 m or more and 5 mm. For the protective layer 29, it is preferable that the thickness of the peripheral portion of the particle 29B is thicker than the portion away from the particle 29B. That is, for example, it is preferable that a bulge of the protective layer 29 is formed around the particle 29B. [[ID=lo]]

[0066] In the above description, the structure was such that the protective layer 29 was provided on the glass plate 20 and the particle 29B protruded from the protective layer 29, but it is not limited thereto, and a structure without the protective layer 29 may be used. That is, a structure in which the particle 29B protrudes from the surface 20A of the glass plate 20 may be used.

[0067] (Effect) As described above, the solar cell unit 10 according to the first aspect of this disclosure is placed on the road surface and comprises a solar cell module 12 and a base portion 30 that supports the solar cell module 12. The base portion 30 includes a first recess S1 formed on the surface 30A into which the solar cell module 12 is inserted, a second recess S2 formed in a part of the bottom surface (surface 32A) of the first recess S1 into which the terminal box 28 of the solar cell module 12 is inserted, and a sealing portion SE formed around the entire circumference of the inner wall (inner surface 34B) of the first recess S1 to seal the inner wall of the first recess S1 and the side surface 12C of the solar cell module 12. According to this disclosure, the sealing portion SE can prevent the side surface 12C of the solar cell module 12 from being exposed to water. Furthermore, according to this disclosure, since the terminal box 28 is housed in the second recess S2 formed in the first recess S1, the terminal box 28 and the cable 28B can also be prevented from being exposed to water. Therefore, according to this disclosure, water-related malfunctions can be effectively suppressed.

[0068] A solar cell unit 10 according to a second aspect of this disclosure is a solar cell unit 10 according to a first aspect, wherein the base portion 30 preferably has a cable arrangement space S3 formed at a position adjacent to the first recess S1 via an inner wall (inner surface 34B), and a communication hole 34D that connects the space inside the second recess S2 with the cable arrangement space S3. The cable 28B connected to the terminal box 28 is preferably arranged from the communication hole 34D across the cable arrangement space S3. According to this disclosure, by placing the terminal box 28 inside the second recess S2 and pulling out the cable 28B from the communication hole 34D, it is possible to pull out the cable 28B to the outside for connection to other devices while suppressing failure due to water.

[0069] A solar cell unit 10 according to a third aspect of this disclosure is preferably a solar cell unit 10 according to a second aspect, further comprising a cover portion 40 that covers the cable arrangement space S3. By providing the cover portion 40, the cable 28B that is brought out to the outside can be covered with the cover portion 40, thereby effectively suppressing failure due to water.

[0070] A solar cell unit 10 according to a fourth aspect of this disclosure is preferably a solar cell unit 10 according to a third aspect, further comprising a cover sealing portion that seals the opposing portions of the cover portion 40 and the base portion 30. This suppresses water from entering the cable arrangement space S3 from between the cover portion 40 and the base portion 30, thereby effectively suppressing water-related failures.

[0071] The solar cell unit 10 according to the fifth aspect of this disclosure is the solar cell unit 10 according to the fourth aspect, wherein the cover portion 40 and the base portion 30 are preferably fixed in a state where their opposing portions are sealed. This prevents water from entering the cable arrangement space S3 from between the cover portion 40 and the base portion 30, thereby effectively suppressing water-related failures.

[0072] A solar cell unit 10 according to the sixth aspect of this disclosure is a solar cell unit 10 according to any of the third to fifth aspects, wherein the cover portion 40 preferably has an exit hole 42 for pulling out the cable 28B from the cable arrangement space S3. This allows the cable 28B to be pulled out from the cable arrangement space S3 and properly connected to other devices while suppressing water-related failures.

[0073] The solar cell unit 10 according to the seventh aspect of this disclosure is a solar cell unit 10 according to any of the first to sixth aspects, wherein a desiccant is preferably provided in the second recess S2. This removes moisture from the second recess S2, thereby more effectively suppressing water-related failures.

[0074] The solar cell unit 10 according to the eighth aspect of this disclosure is a solar cell unit 10 according to any of the first to seventh aspects, wherein the solar cell module 12 preferably has a solar cell 26 and a glass plate 20 disposed on the surface 26A of the solar cell 26. By providing the glass plate 20 in this way, the solar cell 26 can be protected and damage due to load can be appropriately suppressed.

[0075] The solar cell system 1 according to the ninth aspect of this disclosure preferably has a solar cell unit 10A (first solar cell unit), a solar cell unit 10B (second solar cell unit), and a solar cell unit 10C (third solar cell unit), which are solar cell units 10 described in the sixth aspect. The solar cell unit 10A is arranged adjacent to the solar cell units 10B and 10C, and it is preferable that the solar cell units 10A, 10B, and 10C have a first cable and a second cable as cable 28B. The first cable (cable 28B1) of the solar cell unit 10A is pulled into the cover portion 40 of the solar cell unit 10B from the exit hole 42 and connected to the second cable (cable 28BB) of the solar cell unit 10B, and the second cable (cable 28B2) of the solar cell unit 10A is connected within the cover portion 40 to the first cable (cable 28BC) of the solar cell unit 10C, which is pulled into the cover portion 40. According to this disclosure, even when the cables 28B between the solar cell units 10 are connected, the cables 28B are housed inside the cover portion 40, thereby preventing them from being exposed to water.

[0076] The solar cell system 1 according to the tenth aspect of this disclosure is the solar cell system 1 according to the ninth aspect, wherein the surface on which the lead-out holes 42 are formed in the cover portion 40 of the solar cell unit 10A and the surface on which the lead-out holes 42 are formed in the cover portion 40 of the solar cell unit 10B are fixed in a state in which the lead-out holes 42 are in communication with each other and the area around the lead-out holes 42 is sealed. This prevents water from entering from the opposing surfaces of the cover portions 40 and effectively suppresses water-related failures.

[0077] Although embodiments of the present invention have been described above, the embodiments are not limited to those described herein. Furthermore, the aforementioned components include those that can be easily conceived by those skilled in the art, those that are substantially the same, and those that fall within the so-called equivalent range. Moreover, the aforementioned components can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the embodiments described above. [Explanation of Symbols]

[0078] 10 Solar cell units 12 solar modules 14. Pavement 26 solar cells 28 Terminal box 30 Base 40 Cover section S1 First recess S2 Second recess S3 Cable placement space SE sealing part

Claims

1. A solar cell unit placed on the road surface, Solar cell modules and It has a base portion that supports the solar cell module, The base portion is, A first recess formed on the surface into which the solar cell module is inserted, A second recess is formed in a portion of the bottom surface of the first recess, into which the terminal box of the solar cell module is inserted, A sealing portion is formed around the entire circumference of the inner wall of the first recess to seal the inner wall of the first recess and the side surface of the solar cell module, including, Solar cell unit.

2. The base portion is, A cable arrangement space formed adjacent to the first recess via the inner wall, A communication hole that connects the internal space of the second recess with the cable arrangement space, A structure has been formed, The cable connected to the terminal box is arranged from the communication hole through the cable arrangement space. The solar cell unit according to claim 1.

3. The solar cell unit according to claim 2, further comprising a cover portion that covers the cable arrangement space.

4. The solar cell unit according to claim 3, further comprising a cover sealing portion that seals the opposing portions of the cover portion and the base portion.

5. The solar cell unit according to claim 4, wherein the cover portion and the base portion are fixed together with the opposing portions sealed.

6. The solar cell unit according to any one of claims 3 to 5, wherein the cover portion has an outlet hole for pulling out the cable from the cable arrangement space.

7. The solar cell unit according to any one of claims 1 to 5, wherein a desiccant is provided in the second recess.

8. The solar cell module comprises a solar cell and a glass plate disposed on the surface of the solar cell, according to any one of claims 1 to 5.

9. A solar cell system having a first solar cell unit, a second solar cell unit, and a third solar cell unit, which are solar cell units according to claim 6, The first solar cell unit is arranged adjacent to the second solar cell unit and the third solar cell unit. The first solar cell unit, the second solar cell unit, and the third solar cell unit each have a first cable and a second cable as the cables, The first cable of the first solar cell unit is pulled through the exit hole into the cover portion of the second solar cell unit and connected to the second cable of the second solar cell unit. A solar cell system in which the second cable of the first solar cell unit is connected to the first cable of the third solar cell unit, which is pulled into the cover portion, within the cover portion.

10. The solar cell system according to claim 9, wherein the surface of the cover portion of the first solar cell unit on which the lead-out holes are formed and the surface of the cover portion of the second solar cell unit on which the lead-out holes are formed are fixed together such that the lead-out holes are in communication with each other and the area around the lead-out holes is sealed.

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