Construction method of solar light power generation facility and solar light power generation facility

Abstract

To provide a construction method of a solar light power generation facility which can improve power generation efficiency of a double-sided solar battery panel installed on a rooftop or a roof of a building.SOLUTION: A construction method of a solar light power generation facility includes: a step for installing a base of a frame which supports a solar battery panel of a double-sided power generation type on a building frame of a rooftop or a roof of a building; a step for forming at least a light reflection layer having a light reflection property on a whole face of a light reflection area which is wider than an installation area of the solar battery panel and which is on the building frame including the base; and a step of installing the solar battery panel along with the frame on the base after the light reflection layer is formed.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a construction method for a solar power generation facility and the solar power generation facility. [Background technology]

[0002] In recent years, bifacial solar cell panels (hereinafter referred to as "bifacial solar cell panels" or simply "panels"), in which solar cell elements (cells) are laid out on both the front and back sides of the panel surface, have become popular. In photovoltaic power generation facilities using such bifacial solar cell panels, a reflector is provided below the bifacial solar cell panel so that more sunlight is incident on the back side of the panel (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-330523 [Patent Document 2] Japanese Patent Application Publication No. 11-340491 Summary of the Invention [Problem to be solved by the invention]

[0004] In the solar power generation equipment described in the above patent documents, the size of the reflector provided below the panel is limited to the same or a smaller range than the installation space of the panel. This is because walkways and work spaces are required around the panel for panel installation, maintenance, inspection, etc. When bifacial solar panels are installed on the rooftop or roof of a building, sunlight is less likely to be blocked compared to when they are installed on the ground, and therefore improved power generation efficiency is expected. However, even when bifacial solar panels are installed on the rooftop or roof of a building, the size of the reflector provided below the panel is also limited, just as when they are installed on the ground. Therefore, further improving the power generation efficiency when bifacial solar panels are installed on the rooftop or roof of a building remains a challenge.

[0005] An object of the present disclosure is to provide a construction method for a solar power generation facility and a solar power generation facility that can further improve the power generation efficiency of a bifacial solar cell panel installed on the roof or roof of a building. [Means for solving the problem]

[0006] The construction method for solar power generation equipment according to the first disclosure includes the steps of: providing a base for a mounting frame supporting a bifacial solar panel on the roof or roof structure of a building; forming a light-reflecting layer having at least light reflectivity on the entire surface of a light-reflecting area on the structure including the base, the light-reflecting area being larger than the installation area of ​​the solar cell panel; and, after forming the light-reflecting layer, installing the solar cell panel together with the mounting frame on the base.

[0007] The solar power generation facility according to the second disclosure comprises a base for a mount that supports a bifacial solar cell panel and is installed on the roof or roof structure of a building, a light-reflecting layer that is set on the structure including the base and covers the entire light-reflecting area that is larger than the installation area of ​​the solar cell panel, a mount supported by the base, and the solar cell panel installed on the mount. [Effects of the Invention]

[0008] According to the solar power generation facility installation method and solar power generation facility disclosed herein, it is possible to further improve the power generation efficiency of bifacial solar cell panels installed on the rooftop or roof of a building. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a solar power generation facility 1. [Figure 2] FIG. 2 is a diagram illustrating the arrangement of the photovoltaic power generation units 10. [Figure 3] 2 is a schematic cross-sectional view of a light reflecting portion 20 and a body 2. FIG. [Figure 4] 10(A) to 10(D) are conceptual diagrams illustrating the procedure for forming the light reflecting portion 20 on the skeleton 2 including the base 13. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of a photovoltaic power generation facility construction method and a photovoltaic power generation facility according to one aspect of the present disclosure will be described. The drawings attached to this specification are all schematic or conceptual diagrams, and the shape, scale, aspect ratio, etc. of each part have been modified or exaggerated from the actual product for ease of understanding. Furthermore, hatching indicating cross sections of components has been omitted as appropriate in the drawings.

[0011] In this specification, the depth direction of the solar power generation facility 1 shown in Fig. 1 is defined as the X (X1-X2) direction, the left-right direction as the Y (Y1-Y2) direction, and the height direction as the Z (Z1-Z2) direction. Each component will be described using the XYZ coordinate system, based on the configuration shown in Fig. 1 in which each component is installed in the solar power generation facility 1. In this specification, "direction" may also be referred to as "side" as appropriate.

[0012] In this embodiment, an example will be described in which the solar power generation facility 1 is installed on the roof of a building. In addition, in this embodiment, a concrete slab (concrete plate) covering the roof of the building will be described as the skeleton 2. Fig. 1 is a perspective view of a solar power generation facility 1. Fig. 2 is a diagram illustrating the arrangement of a solar power generation unit 10. Fig. 3 is a schematic cross-sectional view of a light reflecting portion 20 and a frame 2. As shown in FIG. 1, the solar power generation facility 1 includes a plurality of solar power generation units 10 and a light reflecting portion 20.

[0013] The solar power generation unit 10 includes a bifacial solar cell panel 11, a mounting base 12, and a foundation 13. The foundation 13 is a structure provided on the skeleton 2 and is integrated with the skeleton 2, but in this embodiment, it will be described as a component of the solar power generation unit 10. The bifacial solar panel 11 is a power generation panel that generates electricity by photoelectrically converting sunlight. The bifacial solar panel 11 is divided into photovoltaic cells (not shown), modules 11a, and strings 11b. The module 11a is a panel formed by laying out a plurality of photovoltaic cells (not shown). The string 11b is a panel formed by connecting a plurality of modules 11a in series in the X direction. The bifacial solar panel 11 is a panel formed by connecting a plurality of strings 11b in parallel in the Y direction. The bifacial solar panel 11 has the above-described panel structure on both its front surface (Z1 side) and back surface (Z2 side). That is, the bifacial solar panel 11 has light-receiving surfaces on both its front and back surfaces. In the bifacial solar panel 11, the power generated by each module 11a is output in series in one string 11b. The power obtained from each string 11b is output in parallel. The power output from the double-sided solar cell panel 11 is sent to a power receiving and transforming facility (neither of which is shown) via a junction box and a power conditioner.

[0014] The mount 12 is a structure for supporting the bifacial solar cell panel 11. The bifacial solar cell panel 11 is fixed to the mount 12 via a support (not shown). The bifacial solar cell panel 11 is fixed to the mount 12 so as to be inclined downward from the rear side X2 to the front side X1. In the depth direction X shown in FIG. 1, the front side X1 faces south, and the rear side X2 faces north. That is, the panel surface of the bifacial solar cell panel 11 faces south where there is more solar radiation, and is inclined downward from the rear side to the front side. The inclination angle of the panel surface is approximately 20 to 30 degrees. The mount 12 can have a variety of structures, and the structure shown in FIG. 1 shows one example. The base 13 is a structure for installing the mount 12. As will be described later, the base 13 is integrated with the skeleton 2.

[0015] The light reflecting portion 20 is a portion that diffusely reflects incident sunlight and causes it to be incident on the back side of the double-sided solar cell panel 11. As shown in FIG. 2, the light reflecting portion 20 covers the entire light reflecting area A1 set on the skeleton 2, including the base 13 (not shown). The light reflecting area A1 may be the entire rooftop of the building, or may be a part of the rooftop. As shown in FIG. 2, if the area corresponding to the area of ​​the solar power generation unit 10 (double-sided solar cell panel 11) projected onto a horizontal plane is defined as the installation area A2 of the double-sided solar cell panel 11, the light reflecting area A1 in which the light reflecting portion 20 is formed is larger than the sum of all the installation areas A2.

[0016] As shown in FIG. 3, the light reflecting portion 20 includes a primer layer 21 and a light reflecting layer 22. Although FIG. 3 shows an example in which the light reflecting portion 20 is formed on the surface of the skeleton 2, the light reflecting portion 20 is also formed on the surface of the foundation 13. The primer layer 21 is a layer formed on the surface of the skeleton 2 including the foundation 13, and has the function of increasing the adhesion between the skeleton 2 and the light reflecting layer 22. For example, an epoxy resin or the like can be used as the primer layer 21. The primer layer 21 can be formed by applying a primer paint made of these materials to the surface of the skeleton 2 one or more times.

[0017] The light-reflecting layer 22 is a layer formed on the primer layer 21 and has the function of diffusely reflecting incident sunlight. For example, polyurea can be used as the light-reflecting layer 22. Polyurea is a resin compound produced by chemically reacting polyamine and isocyanate. When two liquids, polyamine and isocyanate, are mixed and applied to an object, the two liquids harden through a chemical reaction to form a coating film. A light-reflecting material is added to the polyurea. The light-reflecting material is a material that imparts light reflectivity to the light-reflecting layer 22. For example, a white pigment can be used as the light-reflecting material. When the reflectance of the light-reflecting layer 22 is to be 80 to 95%, the light-reflecting material may be added in a ratio of 20 to 50 weight percent to 100 weight percent of polyamine and isocyanate. Hereinafter, polyurea containing a light-reflecting material will also be simply referred to as "polyurea."

[0018] As shown in FIG. 2, in the solar power generation facility 1, four solar power generation units 10 are provided along the left-right direction Y and are installed in two rows in the depth direction X. In the left-right direction Y shown in FIG. 2, the right side Y1 corresponds to an eastward orientation, and the left side Y2 corresponds to a westward orientation. Therefore, in each row, the four bifacial solar cell panels 11 are installed at a distance from each other along the east-west direction. The gap s1 between adjacent bifacial solar cell panels 11 is, for example, 200 mm. By providing the gap s1 between adjacent bifacial solar cell panels 11 in the east-west direction, morning and evening sunlight can more easily penetrate under the panels, thereby increasing the amount of power generation.

[0019] Next, we will explain the construction method of the solar power generation facility 1. Figures 4(A) to 4(D) are conceptual diagrams explaining the procedure for forming the light reflecting portion 20 on the skeleton 2 including the foundation 13. First, as shown in Fig. 4(A), a foundation 13 is placed on the surface of the skeleton 2. The foundation 13 can be placed, for example, by burying adhesive anchors 14 in holes formed in the surface of the skeleton 2 and fixing the foundation 13 directly or indirectly to the adhesive anchors 14.

[0020] Next, as shown in Fig. 4(B), a primer paint is applied once or multiple times onto the skeleton 2 including the foundation 13 to form a primer layer 21. Before forming the primer layer 21, it is desirable to clean the surface of the skeleton 2 with a high-pressure washer or the like.

[0021] Next, as shown in Fig. 4(C), polyurea is applied to the surface of the primer layer 21 to form a light-reflecting layer 22. The polyurea can be applied, for example, by mixing two liquids using a spray gun and spraying the mixture onto the frame 2. After application, the polyurea hardens rapidly to form the light-reflecting layer 22. By forming the light-reflecting layer 22 on the surface of the primer layer 21, a light-reflecting portion 20 is formed on the frame 2.

[0022] Next, as shown in Fig. 4(D), the mounting base 12 and the bifacial solar panel 11 (not shown) are fixed onto the foundation 13. By carrying out the construction according to the above procedure, the solar power generation facility 1 equipped with a plurality of solar power generation units 10 can be installed on the rooftop of a building.

[0023] According to the solar power generation facility 1 and the construction method for the solar power generation facility 1 of this embodiment, for example, the following effects are achieved. The solar power generation system 1 includes a light reflecting portion 20 (light reflecting layer 22) on a framework 2 including a foundation 13. The light reflecting portion 20 covers the entire light reflecting area A1, which is larger than the installation area A2 of the bifacial solar cell panel 11. According to this configuration, the area of ​​the light reflecting portion 20 is larger than the installation area A2 of the bifacial solar cell panel 11, thereby increasing the amount of sunlight incident on the backside of the bifacial solar cell panel 11. That is, the light reflecting portion 20 is also provided in the open areas around the panels, which serve as walkways and work spaces, allowing sunlight diffused in these areas to be incident on the backside of the bifacial solar cell panel 11. Therefore, the solar power generation system 1 of this embodiment can further improve the power generation efficiency of the bifacial solar cell panel 11 compared to a configuration in which a reflector limited to the same area as or smaller than the installation area A2 of the bifacial solar cell panel 11 is installed below the panel. Furthermore, forming the light reflecting portion 20 on the entire light reflecting area A1 increases the strength of the framework 2 including the foundation 13.

[0024] In the light-reflecting portion 20 of the solar power generation facility 1, the light-reflecting layer 22 is formed from polyurea. By adding a light-reflecting material, polyurea can achieve a reflectance of 80 to 95%, allowing more sunlight to be incident on the back side of the double-sided solar cell panel 11. Furthermore, the polyurea that forms the light-reflecting layer 22 has excellent durability, light-blocking properties, and a high ultraviolet absorption rate, thereby suppressing deterioration of the light-reflecting portion 20 due to ultraviolet rays. The applicant's outdoor exposure test confirmed that the polyurea light-reflecting layer 22 turns yellow over time, but its reflectance remains almost unchanged. Furthermore, the polyurea that forms the light-reflecting layer 22 has excellent waterproofing properties, thereby preventing moisture from penetrating through the gap between the foundation 13 and the building frame 2. Additionally, polyurea has excellent heat-shielding properties, thereby suppressing temperature increases inside the building.

[0025] Because the foundation 13 of this embodiment is integrated with the skeleton 2, it can more effectively prevent moisture from entering through the gap between the foundation 13 and the skeleton 2. Furthermore, the foundation 13 integrated with the skeleton 2 is lighter than a typical laid foundation, thereby reducing the burden on the building. As such, the foundation 13 integrated with the skeleton 2 according to the present disclosure is lightweight, and therefore can be suitably installed on roofs with poor load-bearing capacity by combining it with bifacial solar cell panels, which are lighter than monofacial solar cell panels (for the same power generation capacity). Furthermore, even if the light-reflecting layer 22 needs to be repainted to maintain waterproofing, new polyurethane can be applied over the existing light-reflecting portion 20 (light-reflecting layer 22), resulting in excellent maintenance.

[0026] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications and variations, such as the modified embodiments described below, are possible, and these are also included within the technical scope of the present disclosure. Furthermore, the effects described in the embodiments are merely a list of the most preferable effects resulting from the present disclosure, and are not limited to those described in the embodiments. The above-described embodiments and the modified embodiments described below can also be used in appropriate combinations, but detailed description thereof will be omitted.

[0027] (Variations) In the embodiment, an example in which the solar power generation facility is installed on the roof of a building has been described, but the solar power generation facility 1 may also be installed on the roof of a building. The roof may be any of a flat roof, a shed roof, a gable roof, etc., as long as the solar power generation unit (double-sided solar cell panel) can be installed appropriately.

[0028] In the embodiment, an example has been described in which polyurea is used as the material for the light reflecting layer, but polyurethane, which is produced by chemically reacting polyol with isocyanate, may also be used as the material for the light reflecting layer.

[0029] In the embodiment, an example has been described in which four solar power generation units 10 are provided along the left-right direction Y and installed in two rows in the depth direction X, but the number of solar power generation units 10 installed in the left-right direction Y and the depth direction X can be appropriately selected depending on the size of the installation area, the target power generation amount, etc. The same applies to the number of strings 11b (see FIG. 1) that make up the bifacial solar panel 11 and the number of modules 11a connected to each string 11b. [Explanation of symbols]

[0030] 1. Solar power generation equipment 2 skeleton 10 solar power generation units 11. Bifacial solar panels 12 Mounting stand 13 Basics 20 Light reflecting part 21 Primer layer 22 Light reflective layer

Claims

1. A step of providing a base for a frame supporting a bifacial solar panel on the rooftop or roof structure of a building; forming a light-reflecting layer having at least light reflectivity on the entire surface of a light-reflecting area on the framework including the foundation, the light-reflecting area being larger than the installation area of ​​the solar cell panel; After forming the light reflecting layer, a step of installing the solar cell panel together with the mount on the foundation; A construction method for a solar power generation facility having the above.

2. The light-reflecting layer is a resin compound containing at least polyamine, isocyanate, and a light-reflecting material. A method for constructing a solar power generation facility according to claim 1.

3. The reflectance of the light-reflecting layer is 80 to 95%. A method for constructing a solar power generation facility according to claim 1 or 2.

4. a step of forming a primer layer that enhances adhesion with the light reflecting layer between the step of providing a base for the frame and the step of forming the light reflecting layer, A method for constructing a solar power generation facility according to claim 1 or 2.

5. A base for a frame supporting a bifacial solar panel installed on the roof or roof frame of the building; a light-reflecting layer that covers the entire surface of a light-reflecting area that is wider than the installation area of ​​the solar cell panel and is set on the framework including the foundation; a frame supported by the foundation; The solar cell panel installed on the mount; A solar power generation facility equipped with:

6. The reflectance of the light-reflecting layer is 80 to 95%. The solar power generation facility according to claim 5.

7. The solar cell panels are installed in a plurality at intervals along the east-west direction. The solar power generation facility according to claim 5 or 6.

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