Solar power generation system

Abstract

To make a pilot of an aircraft in a landing approach be less likely to be dazzled by a reflection light of sunlight.SOLUTION: A photovoltaic power generation system comprises one or more solar battery modules. Each solar battery module has a light-receiving surface, including a solar battery cell and a translucent member at the light-receiving surface side. A first virtual line is extended along a path on which an aircraft flies toward a first point between target point marks on a runway and located along a virtual vertical plane passing through runway center line marks on the runway. A virtual right circular cone has a second point on the first virtual line as a vertex and has a vertex angle of 50 degrees with a center line extended along the first virtual line. The translucent member has such a configuration that an estimation irradiance of reflection light entering retinas of eyeballs located at the second point depending on reflection of sunlight in a reflection region located in the virtual right circular cone of one or more solar battery modules, is set to be less than a critical irradiance Et calculated by an expression of Et=0.359 / ω1.77 that uses a visual angle ω in the eyeballs regarding the reflection region.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a solar power generation system. [Background technology]

[0002] There are airports where solar power generation systems are installed on the rooftops of buildings (see, for example, the description in Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Jason A. Rogers, Clifford K. Ho, Andrew Mead, Angel Millan, Melissa Beben, Gena Drechsler, "Evaluation of Glare as a Hazard for General Aviation Pilots on Final Approach", Aerospace Medicine Technical Reports, FAA Office of Aerospace Medicine Civil Aerospace Medical Institute, Report No: DOT / FAA / AM-15 / 12, July 2015. Summary of the Invention [Problem to be solved by the invention]

[0004] There is room for improvement in solar power generation systems to reduce the glare from reflected sunlight on aircraft pilots preparing to land. [Means for solving the problem]

[0005] A solar power generation system is disclosed.

[0006] ThickOne aspect of the solar power generation system includes one or more mounts and one or more solar cell modules fixed to the one or more mounts, each of which has a light-receiving surface for receiving sunlight and includes a solar cell and a translucent member protecting the solar cell from the light-receiving surface side. In the case where a first virtual line is defined as a virtual straight line extending along a flight path of an aircraft toward a first point between target point markings of a runway and positioned along a virtual vertical plane passing through a runway centerline marking of the runway, and a virtual right circular cone is defined as a virtual right circular cone having a second point on the first virtual line as its apex and forming an apex angle of 50 degrees with a centerline extending along the first virtual line, the translucent member calculates an estimated irradiance of reflected light incident on the retina of an eyeball positioned at the second point in response to reflection of the sunlight at a reflective area of ​​the one or more solar cell modules positioned within the imaginary right circular cone, using Et=0.359 / ω using a visual angle ω [rad] of the eyeball for the reflective area. 1.77 The critical irradiance Et [W / m 2 ]. The one or more solar cell modules include a first solar cell module whose light-receiving surface has irregularities. The light-receiving surface is located along a first direction that is inclined with respect to a horizontal plane and a second direction that is perpendicular to the first direction and parallel to the horizontal plane. In the first solar cell module, the light-transmitting member has, on the light-receiving surface side, a planar base surface that is aligned with each of the first direction and the second direction, and a plurality of protrusions that protrude beyond the base surface in a third direction that is perpendicular to both the first direction and the second direction. The plurality of protrusions are regularly arranged at a first pitch in the first direction and regularly arranged at a second pitch that is smaller than the first pitch in the second direction. One aspect of the solar power generation system includes one or more mounts and one or more solar cell modules fixed to the one or more mounts. Each of the one or more solar cell modules has a light-receiving surface for receiving sunlight, and includes solar cells and a translucent member that protects the solar cells from the light-receiving surface side. In the case where a first virtual line is defined as a virtual straight line extending along a flight path of an aircraft toward a first point between target point markings of a runway and positioned along a virtual vertical plane passing through a runway centerline marking of the runway, and a virtual right circular cone is defined as a virtual right circular cone having a second point on the first virtual line as its apex and forming an apex angle of 50 degrees with a centerline extending along the first virtual line, the translucent member calculates an estimated irradiance of reflected light incident on the retina of an eyeball positioned at the second point in response to reflection of the sunlight at a reflective area of ​​the one or more solar cell modules positioned within the imaginary right circular cone, using Et=0.359 / ω using a visual angle ω [rad] of the eyeball for the reflective area. 1.77 The critical irradiance Et [W / m 2 The one or more solar cell modules include a first solar cell module whose light-receiving surface has irregularities. The light-receiving surface is located along a first direction that is inclined with respect to a horizontal plane and a second direction that is perpendicular to the first direction and parallel to the horizontal plane. In the first solar cell module, the light-transmitting member has, on the light-receiving surface side, a planar base surface that is aligned with each of the first and second directions, and a plurality of convex portions that protrude beyond the base surface in a third direction that is perpendicular to both the first and second directions. The plurality of convex portions include first convex portions that extend along the first direction and have a first height in the third direction, and second convex portions that extend along the second direction and have a second height in the third direction that is smaller than the first height. One aspect of the solar power generation system includes one or more mounts and one or more solar cell modules fixed to the one or more mounts. Each of the one or more solar cell modules has a light-receiving surface for receiving sunlight, and includes solar cells and a translucent member that protects the solar cells from the light-receiving surface side. In the case where a first virtual line is defined as a virtual straight line extending along a flight path of an aircraft toward a first point between target point markings of a runway and positioned along a virtual vertical plane passing through a runway centerline marking of the runway, and a virtual right circular cone is defined as a virtual right circular cone having a second point on the first virtual line as its apex and forming an apex angle of 50 degrees with a centerline extending along the first virtual line, the translucent member calculates an estimated irradiance of reflected light incident on the retina of an eyeball positioned at the second point in response to reflection of the sunlight at a reflective area of ​​the one or more solar cell modules positioned within the imaginary right circular cone, using Et=0.359 / ω using a visual angle ω [rad] of the eyeball for the reflective area. 1.77 The critical irradiance Et [W / m 2 The one or more solar cell modules include a first solar cell module whose light-receiving surface has irregularities. The light-receiving surface is located along a first direction inclined with respect to a horizontal plane and a second direction perpendicular to the first direction and aligned with the horizontal plane. In the first solar cell module, the light-transmitting member has, on the light-receiving surface side, a planar base surface aligned with each of the first and second directions, and a plurality of convex portions protruding beyond the base surface in a third direction perpendicular to both the first and second directions. The plurality of convex portions include two or more convex portions aligned in an imaginary plane and a fourth direction aligned with the light-receiving surface. The imaginary plane is located along a second imaginary line connecting the second point and the reflective area and is located along the third direction. The two or more convex portions include a third convex portion and a fourth convex portion aligned adjacent to each other in the fourth direction. The second virtual line intersects with the fourth convex portion when passing through a central portion of the base surface that is located at the center between the third convex portion and the fourth convex portion in the fourth direction. One aspect of the solar power generation system includes one or more mounts and one or more solar cell modules fixed to the one or more mounts. Each of the one or more solar cell modules has a light-receiving surface for receiving sunlight, and includes solar cells and a translucent member that protects the solar cells from the light-receiving surface side. In the case where a first virtual line is defined as a virtual straight line extending along a flight path of an aircraft toward a first point between target point markings of a runway and positioned along a virtual vertical plane passing through a runway centerline marking of the runway, and a virtual right circular cone is defined as a virtual right circular cone having a second point on the first virtual line as its apex and forming an apex angle of 50 degrees with a centerline extending along the first virtual line, the translucent member calculates an estimated irradiance of reflected light incident on the retina of an eyeball positioned at the second point in response to reflection of the sunlight at a reflective area of ​​the one or more solar cell modules positioned within the imaginary right circular cone, using Et=0.359 / ω using a visual angle ω [rad] of the eyeball for the reflective area. 1.77 The critical irradiance Et [W / m 2 ]. The one or more solar cell modules include a first solar cell module whose light-receiving surface has an unevenness. The one or more solar cell modules include the first solar cell module and a second solar cell module whose light-receiving surface is flat. The one or more solar cell modules include a first number of solar cell modules whose light-receiving surfaces are aligned with the second virtual mirror surface, and which can produce specularly reflected light of the sunlight that intersects the first virtual line when a flat second virtual mirror surface is set for each of the one or more solar cell modules and the sun performs diurnal motion throughout the year, and a second number of solar cell modules whose light-receiving surfaces are aligned with the second virtual mirror surface, which cannot produce specularly reflected light of the sunlight that intersects the first virtual line. Each of the first number of solar cell modules is the first solar cell module, and each of the second number of solar cell modules is either the first solar cell module or the second solar cell module. [Effects of the Invention]

[0008] To prevent a pilot of an aircraft preparing to land from being dazzled by sunlight reflected by a solar power generation system. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view that schematically shows an example of the configuration of an airport solar power generation system according to the first embodiment. [Figure 2] FIG. 2 is a perspective view schematically illustrating an example of the configuration of a solar cell array. [Figure 3] FIG. 3 is a plan view showing an example of the appearance of the light-receiving surface side of a solar cell module. [Figure 4] FIG. 4 is a cross-sectional view showing an example of a virtual cross section taken along the position IV-IV of the solar cell module in FIG. [Figure 5] Figure 5 is a schematic illustration of the reflected light generated by specular reflection in response to sunlight irradiation in an airport solar power generation system entering the pilot's eyeball. [Figure 6] FIG. 6 is a schematic illustration of the reflected light generated by diffuse reflection in response to sunlight irradiation in an airport solar power generation system entering the pilot's eyeball. [Figure 7] FIG. 7 is a schematic illustration of the reflective area that reflects sunlight projected onto the retina of the pilot's eye. [Figure 8] FIG. 8 is an image diagram that schematically shows the distribution of the intensity of reflected light when perfect diffuse reflection and non-uniform diffuse reflection occur in response to sunlight irradiation in a reflective area. [Figure 9] FIG. 9 is an image diagram that schematically shows the distribution of the intensity of reflected light when perfect diffuse reflection occurs in response to sunlight irradiation in the reflective area. [Figure 10] FIG. 10 is an image diagram that schematically shows the distribution of the intensity of reflected light related to gloss when non-uniform diffuse reflection occurs in the reflective area in response to irradiation with sunlight. [Figure 11]Figure 11 is an image diagram that shows a schematic representation of the combined distribution of reflected light intensity when perfect diffuse reflection occurs in response to sunlight irradiation in a reflective area, and the combined distribution of reflected light intensity related to gloss when non-uniform diffuse reflection occurs in response to sunlight irradiation in a reflective area. [Figure 12] FIG. 12 is a plan view schematically illustrating an example of the appearance of a part of a light-transmitting member having a first form. [Figure 13] FIG. 13 is a cross-sectional view schematically illustrating an example of a virtual cross section taken along the position XIII-VIII of the light-transmitting member in FIG. [Figure 14] FIG. 14 is a cross-sectional view schematically showing an example of a virtual cross section taken along the position XIV-XIV of the light-transmitting member in FIG. [Figure 15] FIG. 15 is a plan view schematically illustrating an example of the appearance of a part of a light-transmitting member having a second form. [Figure 16] FIG. 16 is a cross-sectional view schematically showing an example of a virtual cross section taken along the position XVI-XVI of the light-transmitting member in FIG. [Figure 17] FIG. 17 is a cross-sectional view schematically showing an example of a virtual cross section taken along the position XVII-XVII of the light-transmitting member in FIG. [Figure 18] FIG. 18 is a plan view schematically illustrating an example of the appearance of a portion of a light-transmitting member having a third form. [Figure 19] FIG. 19 is a cross-sectional view schematically showing an example of a virtual cross section taken along the position XIX-XIX of the light-transmitting member in FIG. [Figure 20] FIG. 20 is a cross-sectional view schematically showing an example of a virtual cross section taken along the line XX-XX of the light-transmitting member in FIG. [Figure 21] FIG. 21 is a side view schematically showing an example of the traveling direction of specularly reflected light generated on the light receiving surface of a solar cell module in response to irradiation with sunlight during a time period when the sun's altitude is high. [Figure 22] FIG. 22 is a perspective view schematically illustrating an example of the traveling direction of specularly reflected light generated on the light receiving surface of a solar cell module in response to irradiation with sunlight during a time period when the solar altitude is low. [Figure 23]FIG. 23 is a plan view schematically illustrating an example of the appearance of a part of a light-transmitting member. [Figure 24] FIG. 24 is a cross-sectional view schematically showing an example of a virtual cross section taken along the position XXIV-XXIV of the light-transmitting member in FIG. [Figure 25] FIG. 25 is a cross-sectional view schematically showing an example of a virtual cross section taken along the position XXV-XXV of the light-transmitting member in FIG. [Figure 26] FIG. 26 is a cross-sectional view that schematically shows an example of a virtual cross section of a light-transmitting member. [Figure 27] FIG. 27 is a cross-sectional view that schematically shows an example of a virtual cross section of a light-transmitting member. [Figure 28] FIG. 28 is a perspective view schematically showing an example of the configuration of a solar cell array according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] At airports, solar power generation systems with multiple solar panels fixed to the rooftops of buildings are sometimes installed. In addition, with the relaxation of regulations to make use of the land around runways (also known as airport land), it is possible to install solar power generation systems on this airport land.

[0011] In this solar power generation system, the light-receiving surface of each solar panel may reflect sunlight. For example, the solar power generation system may reflect sunlight toward the flight path of an aircraft as it approaches the runway just before landing. In this situation, there is a risk that the pilot of the aircraft may be dazzled by the reflected sunlight, impairing his or her ability to see the instruments and control the aircraft.

[0012] For example, if a solar power generation system, which is a source of reflected light corresponding to sunlight, is located within a range of a predetermined angle from the direction of the pilot's line of sight while the pilot is in landing mode, the pilot's ability to recognize instruments and to control the aircraft may be reduced. For example, according to the description in Non-Patent Document 1, the predetermined angle may be 25 degrees.

[0013] Therefore, there is room for improvement in solar power generation systems in terms of making it less likely that pilots of aircraft preparing to land will be dazzled by reflected sunlight.

[0014] Therefore, the inventors of the present disclosure have created a technology for a solar power generation system that can make it difficult for pilots of aircraft preparing to land to be dazzled by reflected sunlight.

[0015] Various embodiments will be described below with reference to the drawings. In the drawings, parts having the same or similar configurations and functions are denoted by the same reference numerals, and redundant explanations will be omitted below. The drawings schematically illustrate various configurations, etc. FIGS. 1, 2, 22, and 28 each show the four cardinal directions of east, west, north, and south. The four cardinal directions are indicated by E, the initial letter of west, W, S, the initial letter of south, and N, the initial letter of north. FIG. 21 shows the three cardinal directions of west, north, south, and south. The three cardinal directions are indicated by W, the initial letter of west, S, the initial letter of south, and N, the initial letter of north. Each of FIGS. 2 to 4, 8 to 25, and 28 shows a right-handed XYZ coordinate system. In this XYZ coordinate system, the direction in which light-receiving surface 12s of solar cell module 12 is inclined (also referred to as the first direction) is defined as the -Y direction, the direction perpendicular to the -Y direction and along light-receiving surface 12s (also referred to as the second direction) is defined as the +X direction, and the normal direction of light-receiving surface 12s that is orthogonal to both the +X and +Y directions is defined as the +Z direction. The Z axis of the XYZ coordinate system is indicated in Figures 5, 6, 26, and 27.

[0016] Unless otherwise specified, expressions indicating relative or absolute positional relationships (e.g., "located on a line," "in one direction," "along one direction," "parallel," "orthogonal," "perpendicular," or "center") not only express that exact positional relationship, but may also express a state of relative displacement in terms of angle or distance within a range that provides tolerance or equivalent functionality. Expressions indicating an equal state (e.g., "identical," "equal," or "homogeneous") not only express a state of strict quantitative equality, but may also express a state of difference that provides tolerance or equivalent functionality, unless otherwise specified. Expressions indicating shape (e.g., "rectangular," "quadrangular," or "cylindrical") not only express that exact geometric shape, but may also express a shape with, for example, irregularities and chamfers, within a range that provides equivalent effects. The expressions "comprise," "include," or "have" one component are not exclusive expressions that exclude the presence of other components. Unless otherwise specified, the terms "above" and "below" may refer to two elements that are in contact with each other, as well as two elements that are separated from each other.

[0017] <1. Overview of the airport solar power generation system> An airport solar power generation system 100 according to a first embodiment will be described with reference to Figures 1 to 4. The airport solar power generation system 100 is a solar power generation system installed around a runway 2 within the grounds of an airport 200.

[0018] 1, the airport solar power generation system 100 includes one or more mounts 11 and one or more solar cell modules 12 fixed to the one or more mounts 11. In other words, the airport solar power generation system 100 includes a solar cell array 1 that is a part that includes the one or more mounts 11 and the one or more solar cell modules 12.

[0019] In the example of FIGS. 1 and 2 , the airport solar power generation system 100 includes multiple mounts 11 and multiple solar cell modules 12 fixed to the multiple mounts 11. More specifically, three rows of solar cell modules 12, each consisting of 21 solar cell modules 12 arranged along the east-west direction, are arranged in the north-south direction. In other words, 63 solar cell modules 12 are arranged in a matrix. The number and arrangement of the one or more mounts 11 and the one or more solar cell modules 12 are not limited to those shown in FIGS. 1 and 2 , and various numbers and arrangements are possible. For example, the number of mounts 11 constituting the airport solar power generation system 100 may be one or any number equal to or greater than two. The number of solar cell modules 12 constituting the airport solar power generation system 100 may be one or any number equal to or greater than two.

[0020] The mount 11 fixes the solar cell module 12 to the land (airport land) or a structure around the runway 2 within the grounds of the airport 200. The longitudinal direction of the runway 2 is, for example, along the east-west direction. In the example of FIGS. 1 and 2 , the mount 11 is located on the land (also called a landing strip) 7 surrounding the runway 2. In this case, the mount 11 fixes the solar cell module 12 to the landing strip 7. For example, a structure (also called a frame structure) in which columns and beams are combined is applied to the mount 11. For example, one solar cell module 12 may be fixed to one mount 11, two or more solar cell modules 12 may be fixed to one mount 11, or one solar cell module 12 may be fixed to two or more mounts 11.

[0021] 3 and 4, for example, each of one or more solar cell modules 12 has a solar cell 123c and a light-transmitting member 121 that protects this solar cell 123c from the light-receiving surface 12s side. The light-receiving surface 12s is a surface of the solar cell module 12 that receives sunlight SL0. From another perspective, for example, the surface of the solar cell module 12 that faces upward or diagonally upward is the light-receiving surface 12s.

[0022] Each solar cell module 12 includes, for example, a solar cell panel 12p and a frame 12f that reinforces the outer edge of the solar cell panel 12p.

[0023] The solar cell panel 12p has a first surface F1 constituting a light-receiving surface 12s that mainly receives light, and a second surface F2 located on the opposite side of the first surface F1. The solar cell panel 12p has, for example, in order from the first surface F1 side, a light-transmitting member 121 as a first protective layer, a first sealing layer 122, a photoelectric conversion unit 123, a second sealing layer 124, a back surface protective member 125 as a second protective layer, and a terminal box 12b.

[0024] The light-transmitting member 121 is located, for example, on the first surface F1 side of the photoelectric conversion unit 123. Here, for example, the surface of the light-transmitting member 121 opposite the photoelectric conversion unit 123 (also referred to as the first surface) constitutes the first surface F1. The light-transmitting member 121 has, for example, a role of protecting the photoelectric conversion unit 123 and a role of sealing the photoelectric conversion unit 123. The light-transmitting member 121 is, for example, translucent to light of a specific range of wavelengths. The specific range of wavelengths includes, for example, wavelengths of light that can be photoelectrically converted by the photoelectric conversion unit 123. If the specific range of wavelengths includes wavelengths of light with high irradiation intensity in sunlight SL0, the photoelectric conversion efficiency of the solar cell module 12 can be improved. For example, glass can be used as the material of the light-transmitting member 121. However, the material of the light-transmitting member 121 is not limited thereto and may be, for example, a resin such as acrylic or polycarbonate, or another light-transmitting material. The glass may be a material with high light transmittance, such as white plate glass, tempered glass, or heat-reflecting glass, with a thickness of about 2 millimeters (mm) to 5 mm. The thickness and type of glass are not limited to these, and various thicknesses and types of glass may be used.

[0025] The first sealing layer 122 is located between the light-transmitting member 121 and the photoelectric conversion unit 123. The second sealing layer 124 is located between the photoelectric conversion unit 123 and the back surface protection member 125. In other words, the first sealing layer 122 and the second sealing layer 124 are located between the light-transmitting member 121 and the back surface protection member 125 so as to cover the photoelectric conversion unit 123 and fill the space between them. The first sealing layer 122 and the second sealing layer 124 have, for example, the role of holding the photoelectric conversion unit 123 and the role of sealing the photoelectric conversion unit 123. The first sealing layer 122 is translucent to light having wavelengths within the specific range described above. The second sealing layer 124 may or may not be translucent to light having wavelengths within the specific range described above. Examples of materials for the first sealing layer 122 and the second sealing layer 124 include thermosetting resins. Examples of thermosetting resins include resins whose main component is ethylene-vinyl acetate copolymer (EVA) or polyvinyl butyral (PVB). Thermosetting resins may contain a crosslinking agent. Here, the term "main component" refers to the component whose proportion (also called content) is the largest (highest).

[0026] The photoelectric conversion unit 123 includes, for example, a plurality of solar cell (also referred to as solar cell elements) 123c, a plurality of first wiring members W1, and a plurality of second wiring members W2. In the example of FIGS. 3 and 4, the plurality of solar cell 123c are arranged two-dimensionally. More specifically, the photoelectric conversion unit 123 includes a plurality of solar cell strings S1. Although FIGS. 3 and 4 show an example in which the photoelectric conversion unit 123 includes six solar cell strings S1, this is not limiting. For example, the photoelectric conversion unit 123 may include five or fewer or seven or more solar cell strings S1. Each solar cell string S1 includes a plurality of solar cell 123c and a plurality of first wiring members W1. Although FIGS. 3 and 4 show an example in which each solar cell string S1 includes eight solar cell 123c, this is not limiting. For example, each solar cell string S1 may include seven or fewer or nine or more solar cell 123c. The multiple first wiring members W1 electrically connect, for example, adjacent solar cell cells 123c among the multiple solar cell cells 123c, respectively. The multiple second wiring members W2 electrically connect, for example, adjacent solar cell strings S1 among the multiple solar cell strings S1, respectively.

[0027] The back surface protection member 125 is located, for example, on the second surface F2 side of the photoelectric conversion unit 123. Here, for example, the surface of the back surface protection member 125 opposite the photoelectric conversion unit 123 constitutes the second surface F2. The back surface protection member 125 has, for example, a role of protecting the photoelectric conversion unit 123 and a role of sealing the photoelectric conversion unit 123. The back surface protection member 125 may be translucent to light of the specific wavelength range described above, or may not be translucent. The back surface protection member 125 may be, for example, a flexible sheet-like member (also referred to as a sheet member) or a plate-like member. The sheet member may be made of various materials, such as resin. The plate-like member may be made of various materials, such as glass or resins such as acrylic or polycarbonate.

[0028] The terminal box 12b can extract, for example, the output obtained by the photoelectric conversion unit 123 to the outside. The terminal box 12b is located, for example, on the second surface F2. The terminal box 12b can be fixed to the second surface F2 using, for example, a resin such as a silicone sealant. The terminal box 12b may be located at another location on the solar cell panel 12p. The terminal box 12b has, for example, a box body, a terminal plate, and a cable. The box body can be made of various materials such as modified polyphenylene ether resin (modified PPE resin) or polyphenylene oxide resin (PPO resin). The terminal plate is located within the box body, and a second wiring member W2 of the photoelectric conversion unit 123 is connected to the terminal plate. The cable can extract power to the outside of the box body.

[0029] The frame 12f has a function of holding the solar cell panel 12p. The frame 12f is located, for example, along the outer periphery of the solar cell panel 12p. The frame 12f includes, for example, a portion having a U-shaped cross-sectional structure that extends from a position along the first surface F1 to a position along the second surface F2 on the outer periphery of the solar cell panel 12p. The frame 12f can be made, for example, by extruding aluminum.

[0030] The runway 2 is a straight, paved road provided within the airport 200 and used by aircraft 3 for takeoff and landing. As shown in FIG. 1, the runway 2 has various markings, such as a runway centerline marking 2c and a target point marking 2a. The runway centerline marking 2c indicates the center of the runway 2 in the width direction and indicates the centerline located along the longitudinal direction. The runway centerline marking 2c is drawn as a dashed line along the centerline of the runway 2. The target point marking 2a indicates the target point (also called the landing target point) on the runway 2 where the tires of the aircraft 3 will touch down. The target point marking 2a has two parallel rectangular marks on either side of the centerline of the runway 2. In order to avoid complicating the drawing, part of the runway 2 has been omitted from FIG. 1, and various markings and lighting equipment on the runway 2 have also been omitted as appropriate.

[0031] <2. Shape of the light-transmitting member> The light-transmitting member 121 has a shape that makes it difficult for the pilot 5 of the aircraft 3 preparing to land to be dazzled by the sunlight SL0 reflected by the airport solar power generation system 100.

[0032] Here, for example, as shown in FIG. 1, a first virtual line L1 is defined as an imaginary straight line extending along a path (also referred to as a landing flight path) that an aircraft 3 takes toward runway 2 immediately before landing on the runway 2. The landing flight path is a path that an aircraft takes toward a point (also referred to as a first point) P1 between target point markers 2a on runway 2. Runway 2 is located along a horizontal plane that is perpendicular to the vertical direction. The target point markers 2a have two rectangular marks that sandwich a runway centerline marker 2c. The first point P1 is located between the two rectangular marks. The landing flight path is inclined at a predetermined angle (also referred to as a first angle) θ1 with respect to the horizontal plane. The first angle θ1 is set to 3 degrees or an angle approximately 3 degrees by the International Civil Aviation Organization (ICAO). An angle approximately 3 degrees includes, for example, an angle in the range of 2.5 degrees to 3.5 degrees. Furthermore, the first virtual line L1 is located along an imaginary vertical plane (also referred to as a virtual vertical plane) Vp1 that passes through the runway centerline marking 2c of the runway 2. The imaginary vertical plane Vp1 is an imaginary plane that passes over the runway centerline marking 2c and is perpendicular to the horizontal plane. In other words, the first virtual line L1 is located along the imaginary vertical plane Vp1 and forms an inclination angle of 3 degrees or approximately 3 degrees with respect to the runway 2, which is located along the horizontal plane. The first virtual line L1 includes a portion that extends in a straight line diagonally downward from the runway 2. In other words, the first virtual line L1 includes a portion of the landing flight path that extends in a straight line diagonally downward from the runway 2. In FIG. 1, the outer edge of an example of the imaginary vertical plane Vp1 is depicted by a dashed line.

[0033] 1, a certain point on the first imaginary line L1 is defined as the second point P2. The second point P2 may be any point on the first imaginary line L1. When the aircraft 3 is preparing to land on the runway 2, the second point P2 may indicate the position of the head of the pilot 5 of the aircraft 3. More specifically, the second point P2 may indicate the position of the eyeball 5e of the pilot 5 of the aircraft 3 preparing to land on the runway 2.

[0034] 1, for example, a virtual right circular cone Cn1 is defined as a virtual right circular cone having the second point P2 as its apex, a center line (also referred to as the axis of rotation) Lc1 extending along the first virtual line L1, and an apex angle of a predetermined angle (also referred to as the second angle) θ2. Here, the center line Lc1 is not limited to the line segment from the second point P2 to the runway 2, but also includes a portion extending in a straight line obliquely downward from the runway 2. In FIG. 1, an example of the virtual right circular cone Cn1 is depicted by a dashed line.

[0035] A right circular cone is a cone with a circular base and a centerline (axis of rotation) that connects the center of the base to the vertex and is perpendicular to the base. The apex angle of a cone is the apex angle of the isosceles triangle that is created when the right circular cone is cut by a plane that passes through the centerline (axis of rotation). This apex angle is twice the angle between the centerline (axis of rotation) and the generatrix of the right circular cone, and is also the largest angle between any two generatrix of the right circular cone.

[0036] The second angle θ2 is set to 50 degrees, for example, based on the description in the aforementioned Non-Patent Document 1. The aforementioned Non-Patent Document 1 describes, for example, that if a solar panel, which is a source of reflected light derived from sunlight, is located within a range of an angle deviation of 25 degrees from the pilot's line of sight along the aircraft's direction of travel, the pilot's ability to recognize instruments and control the aircraft may be impaired. Therefore, the imaginary right circular cone Cn1 defines a region of one or more solar cell modules 12 constituting the airport solar power generation system 100 that could be a source of reflected light derived from sunlight SL0 that could dazzle the pilot 5 of the aircraft 3 preparing to land on the runway 2. In other words, the region A1 (also referred to as the reflection region) of one or more solar cell modules 12 located within the imaginary right circular cone Cn1 could be a source of reflected light derived from sunlight SL0 that could dazzle the pilot 5 of the aircraft 3 preparing to land on the runway 2.

[0037] The reflective area A1 includes, for example, an area of ​​the light-receiving surface 12s of each of the one or more solar cell modules 12 that is located within the imaginary right circular cone Cn1. In this case, the light-receiving surface 12s may include a surface (also referred to as an upper surface) that is irradiated with sunlight SL0 and that is located along the first surface F1 of the frame 12f. The reflective area A1 may include, for example, a portion of the one or more solar cell modules 12 other than the light-receiving surface 12s. The portion other than the light-receiving surface 12s may include, for example, the interface between the light-transmitting member 121 and the first sealing layer 122, the interface between the first sealing layer 122 and the second sealing layer 124, the surface of the photoelectric conversion unit 123 facing the light-transmitting member 121, and the surface of the back surface protection member 125 facing the second sealing layer 124.

[0038] 5, in the reflective area A1 of one or more solar cell modules 12, at least a portion of the irradiated sunlight SL0 may be specularly reflected in response to irradiation of the sunlight SL0 from the sun 9. In this case, for example, light RL1 generated by specular reflection (also referred to as specularly reflected light) may be incident on the eyeball 5e of the pilot 5 of the aircraft 3 preparing to land on the runway 2.

[0039] 6, for example, in the reflective area A1 of one or more solar cell modules 12, in response to irradiation of sunlight SL0 from the sun 9, at least a portion of the irradiated sunlight SL0 may be diffusely reflected. In this case, for example, light DL1 generated by diffuse reflection (also referred to as diffusely reflected light) may be incident on the eyeball 5e of the pilot 5 of the aircraft 3 preparing to land on the runway 2.

[0040] In FIGS. 5 and 6, the reflective area A1 is conveniently depicted as an elliptical area. Also, in FIGS. 5 and 6, the optical path of sunlight SL0 is depicted by a thin, two-dot chain line. Also, in FIGS. 5 and 6, the normal 12n of the reflective area A1 is depicted by a straight, one-dot chain line. In FIG. 5, the outer edge of a first reflective area A11 in the reflective area A1 is depicted by an ellipse depicted by a one-dot chain line. The first reflective area A11 is an area in the reflective area A1 that emits specularly reflected light corresponding to sunlight SL0 toward the eyeball 5e of the pilot 5 of the aircraft 3 preparing to land on the runway 2. In other words, the first reflective area A11 can emit specularly reflected light corresponding to sunlight SL0 from the reflective area A1 toward the second point P2. Also, in FIG. 5, the optical path of specularly reflected light RL1 directed toward the eyeball 5e of the pilot 5 of the aircraft 3 preparing to land on the runway 2 is depicted by a thin, two-dot chain line. In Figure 6, the optical path of diffusely reflected light DL1 toward the eyeball 5e of the pilot 5 of the aircraft 3 preparing to land on the runway 2 is depicted by a thin two-dot chain line. In the example of Figure 5, the reflective area A1 may not be a mirror-like area (also referred to as a specular area) that produces only specular reflection, nor an area (also referred to as a perfectly diffuse reflection area) that produces only diffuse reflection. In other words, the reflective area A1 may be a reflective surface (also referred to as a non-uniform diffuse reflection surface) in which the brightness of reflected light is high in a direction that produces specular reflection (also referred to as a specular reflection direction) and decreases as the brightness of reflected light deviates from the specular reflection direction, like a typical reflective surface. In this case, the area A12 of the reflective area A1 other than the first reflective area A11 (also referred to as a second reflective area) functions as an area that can emit diffusely reflected light corresponding to sunlight SL0 toward the second point P2.

[0041] 7, the visual angle of the reflective area A1 in the eyeball 5e of the pilot 5 of the aircraft 3 preparing to land on the runway 2 is defined as ω (unit: radian (rad)). The visual angle ω is the angle formed by the reflective area A1 as a visual object projected onto the eyeball 5e of the pilot 5 as an observer. From another perspective, the visual angle ω corresponds to the angle formed by two straight lines that pass through both ends of the reflective area A1 as a visual object projected onto the retina 5e5 of the eyeball 5e of the pilot 5 of the aircraft 3 preparing to land on the runway 2 and extend to the eyeball 5.

[0042] Figure 7 shows a schematic diagram of the structure of an eyeball 5e. The eyeball 5e has a cornea 5e1, an iris 5e2, a crystalline lens 5e3, a pupil 5e4, and a retina 5e5. Figure 7 also shows the distance r from the reflective area A1 to the eyeball 5e, the focal length f of the eyeball 5e, the nodal point 5e6 of the optical path from the reflective area A1 to the retina 5e5, the width ds of the reflective area A1 as seen by the pilot 5 as an observer, the width dr of the area on the retina 5e5 onto which the reflected light from the reflective area A1 is projected, and the diameter dp of the pupil (also called the pupil diameter). The width ds is the width of the reflective area A1 projected onto a plane perpendicular to the line of sight of the pilot 5 as an observer. The width ds may be, for example, the width of the reflective area A1 when the reflective area A1 is rectangular when projected onto a plane perpendicular to the line of sight of the pilot 5 as an observer, or the width of the reflective area A1 when the reflective area A1 is circular when projected onto a plane perpendicular to the line of sight of the pilot 5 as an observer.

[0043] Here, the visual angle ω can be calculated using, for example, the width ds of the reflective area A1 as seen by the pilot 5 as an observer and the distance r from the reflective area A1 to the observer's eyeball 5e. For example, the visual angle ω can be calculated using the formula ω=2×arctan{ds / (2×r)}, which uses the width ds, the distance r, and the inverse trigonometric function arctangent. Furthermore, for example, when the distance r from the observer to the reflective area A1 is clearly larger than the width ds of the reflective area A1, which is the visual target, and the visual angle ω is small, the visual angle ω can be approximately calculated by dividing the width ds by the distance r. When the reflective area A1 is inclined with respect to the line of sight of the observer, the distance r may be the average value of the distance from the reflective area A1 to the observer's eyeball 5e, for example. The width ds of the reflective area A1 may be calculated, for example, by various calculations. For example, when the reflective area A1 is formed by two or more solar cell modules 12, the reflective area A1 may be an area that approximately includes an area located between the two or more solar cell modules 12. Furthermore, when the reflective area A1 is formed by two or more solar cell modules 12, the reflective area A1 may be an area excluding the area located between the two or more solar cell modules 12. In this case, for example, the width ds of the reflective area A1 may be calculated as the width of the area as seen by the pilot 5 after the reflective area A1 is converted into an area excluding the area located between the two or more solar cell modules 12.

[0044] Here, for example, an estimated value (also referred to as estimated irradiance) of the irradiance of reflected light incident on the retina 5e5 of the eyeball 5e located at the second point P2 in response to reflection of sunlight SL0 on the reflective area A1 is set to E1.

[0045] In this case, the light-transmitting member 121 calculates the estimated irradiance E1 as the irradiance (also called the critical irradiance) Et (unit: watts per square meter (W / m)) calculated by the formula (1) using the visual angle ω (rad) 2 )].

[0046] Et=0.359 / ω 1.77 ···(1).

[0047] The critical irradiance Et defined by equation (1) corresponds to Eq. (5), which defines the green line in Fig. 2 in Non-Patent Document 2 (Clifford K. Ho, Cheryl M. Ghanbari, Richard B. Diver, "Methodology to Assess Potential Glint and Glare Hazards From Concentrating Solar Power Plants: Analytical Models and Experimental Validation," Journal of Solar Energy Engineering, AUGUST 2011, Vol. 133 / 031021-1 to 031021-9). Non-Patent Document 2 states that if the irradiance of light incident on the retina from a light source is below the irradiance calculated by Eq. (5), pilots are less likely to experience temporary afterimages due to flashlights (also known as temporary flash blindness).

[0048] Therefore, for example, if the translucent member 121 has a configuration that makes the estimated irradiance E1 less than the critical irradiance Et calculated by equation (1), the pilot 5 of the aircraft 3 preparing to land will be less likely to be dazzled by the sunlight SL0 reflected by the airport solar power generation system 100.

[0049] <2-1. Estimated irradiance calculation and evaluation methods> The estimated irradiance E1 can be calculated by, for example, various calculation methods. Here, an example of a calculation method for the estimated irradiance E1 and an example of an evaluation method using the calculation result of the estimated irradiance E1 will be described.

[0050] For example, a method of calculating the estimated irradiance E1 can be considered, assuming that the reflective area A1 is a single surface (also called a Lambertian surface) that has irregularities and produces Lambertian diffuse reflection in response to irradiation with sunlight SL0. Lambertian diffuse reflection is a type of reflection that follows Lambert's cosine law, in which the spatial distribution of the brightness of the reflected radiation is equal in all reflection directions, regardless of the direction of incident light. Here, the light-receiving surface 12s that constitutes the reflective area A1 may be positioned along a horizontal plane or may be inclined relative to the horizontal plane. Furthermore, the inclination direction of the light-receiving surface 12s that constitutes the reflective area A1 may be appropriately set in accordance with the structures around the runway 2.

[0051] Here, the irradiance of the diffusely reflected light DL1 incident on the cornea 5e1 of the pilot 5 as an observer (also called corneal irradiance) is Ed [unit: W / m 2 The irradiance of the diffuse reflected light DL1 incident on the retina 5e5 of the eyeball 5e of the pilot 5 (also called retinal irradiance) is Er [unit: W / m 2 The retinal irradiance Er corresponds to the estimated irradiance E1. The irradiance of sunlight SL0 incident on the reflective area A1 as a diffuse reflection surface is defined as Es [unit: W / m 2 ]. The energy of all light (also called total light energy) emitted from the reflective area A1 as a diffuse reflecting surface is Pd [unit: watts (W)]. The radiance (also called diffuse radiance) of the diffuse reflected light DL1 after being reflected by the reflective area A1 as a diffuse reflecting surface is Ld [unit: watts per square meter per steradian (W / m 2 The distance from the reflective area A1 as a diffuse reflecting surface to the pilot 5 as an observer is r [unit: meters (m)]. The area of ​​the reflective area A1 as a diffuse reflecting surface (also called the reflective area area) is Ad [unit: square meters (m 2)]. The width of the reflective area A1 as seen by the pilot 5 as an observer (also called the reflective area width) is ds (unit: m). The width of the light image of the reflective area A1 projected onto the retina 5e5 of the eyeball 5e of the pilot 5 as an observer (also called the retinal projection image width) is dr (unit: m). The solid angle (also called the pupil solid angle) of the area of ​​the pupil 5e4 of the pilot 5 as an observer (also called the pupil area) based on the center of the reflective area A1 as a diffuse reflecting surface is Ω (unit: rad). The diffuse reflectance of the reflective area A1 as a diffuse reflecting surface is ρd. The irradiance of sunlight SL0 incident perpendicularly to the plane (also called solar irradiance) is E DNI [W / m 2 ]. Here, the solar irradiance E DNI to 1000W / m 2 The diameter (pupil diameter) of the pupil 5e4 of the pilot 5 as an observer is dp [unit: m]. Here, the pupil diameter dp is a constant value of 0.002 m. The area of ​​the pupil 5e4 of the pilot 5 as an observer is Ap [unit: m]. 2 ]. The light transmittance (also called the light transmittance of the ocular medium) of the path that light travels through from the anterior surface of the cornea 5e1 to the retina 5e5 in the eye 5e of the pilot 5 as an observer is called τ. This path includes the cornea 5e1, the anterior chamber, the lens 5e3, and the vitreous body. Here, the transmittance τ is a constant value of 0.5. The focal length of the eye 5e of the pilot 5 as an observer is called f [unit: m]. Here, the focal length f is a constant value of 0.017 m. The angle (also called the incident angle) that the incident direction of sunlight SL0 makes with respect to the normal 12n of the reflective area A1 as a diffuse reflecting surface is called θ [unit: degrees (°)]. The angle (also called the line of sight angle) that the pilot 5 as an observer makes with respect to the normal 12n of the reflective area A1 as a diffuse reflecting surface is called φ [unit: degrees (°)]. As described above, the visual angle of the reflective area A1 in the eyeball 5e of the pilot 5 as an observer is set to ω (unit: rad). In this case, the formulas (2-1) to (2-8) can be established.

[0052] Es=Pd / Ad (2-1) dr=f×ω (2-2) ds=r×ω (2-3) Pd=E DNI ×cosθ×Ad×ρd (2-4) Ed=Ld×Ω×Ad×cosφ / Ap (2-5) Es=Pd / Ad=πLd (2-6) Ω=Ap / r 2 (2-7) Er=Ed×{(π×dp 2 / 4) / (π×dr 2 / 4)}×τ =Ed×(dp 2 / dr 2 )×τ ···(2-8).

[0053] Here, the width ds of the reflection area A1 as seen by the pilot 5 as an observer may be the diameter derived when the reflection area A1 is assumed to be a perfect circle having an area of ​​Ad×cosφ.

[0054] By transforming equation (2-3), we obtain equation (2-9).

[0055] ω=ds / r=(1 / r)×(4×Ad×cosφ / π) 0.5 ···(2-9).

[0056] By substituting equations (2-6) and (2-7) into equation (2-5), we obtain equation (2-10).

[0057] Ed=Pd×cosφ / (π×r 2 ) ···(2-10).

[0058] By substituting equations (2-2), (2-4), (2-9), and (2-10) into equation (2-8), we obtain equation (2-11).

[0059] Er=E DNI ×cosθ×ρd×dp 2 ×τ / (4×f 2 ) ···(2-11).

[0060] The retinal irradiance Er corresponding to the estimated irradiance E1 can be calculated using equation (2-11). Here, the retinal irradiance Er is calculated based on the solar irradiance E DNI , the incident angle θ, the diffuse reflectance ρd, the pupil diameter dp, the light transmittance τ, and the focal length f. DNI By applying known values ​​to the pupil diameter dp, light transmittance τ, and focal length f, the retinal irradiance Er can be calculated using the incident angle θ and the diffuse reflectance ρd. For example, the retinal irradiance Er is calculated as the estimated irradiance E1. In this case, the estimated irradiance E1 is the retinal irradiance Er as an estimated value of the irradiance of the diffusely reflected light DL1 that is incident on the retina 5e5 of the pilot 5 after sunlight SL0 is diffusely reflected in the reflection area A1.

[0061] Furthermore, the critical irradiance Et can be calculated by substituting the visual angle ω calculated by equation (2-9) into equation (1). Here, the visual angle ω can be calculated based on the distance r, the reflective area Ad, and the line of sight angle φ.

[0062] Then, for example, if the estimated irradiance E1 is less than the critical irradiance Et, an evaluation (also referred to as a pass evaluation) is made that the light-transmitting member 121 has a form that makes it difficult for the pilot 5 of the aircraft 3 preparing to land to be dazzled by the sunlight SL0 reflected by the airport solar power generation system 100. On the other hand, for example, if the estimated irradiance E1 is equal to or greater than the critical irradiance Et, an evaluation (also referred to as a fail evaluation) is made that the light-transmitting member 121 does not have a form that makes it difficult for the pilot 5 of the aircraft 3 preparing to land to be dazzled by the sunlight SL0 reflected by the airport solar power generation system 100.

[0063] Here, the diffuse reflectance ρd in the reflection area A1 of the actually installed airport solar power generation system 100 can be measured, for example, by using a measuring device that can measure the regular reflectance ρr and the diffuse reflectance ρd separately.

[0064] <<Examples of cases where a failing evaluation will occur>> The distance r is 120 m and the reflection area Ad is 6000 m2 It is assumed that the line of sight angle φ is 45°, the incident angle θ is 45°, and the diffuse reflectance ρd is 0.7.

[0065] In this case, the visual angle ω is calculated to be 0.612 rad from equation (2-9). Then, by substituting this visual angle ω (= 0.612 rad) into equation (1), the critical irradiance Et is calculated to be 0.854 W / m 2 Furthermore, from equation (2-11), the retinal irradiance Er corresponding to the estimated irradiance E1 is calculated as 0.856 W / m 2 Therefore, the estimated irradiance E1 (= 0.856 W / m 2 ) is the critical irradiance Et (= 0.854 W / m 2 ) is exceeded. Therefore, a failing evaluation may be made. In other words, in this case, the pilot 5 of the aircraft 3 preparing to land may be dazzled by the sunlight SL0 reflected by the airport solar power generation system 100, and the pilot 5 may suffer from a temporary afterimage caused by the flash (temporary flash blindness).

[0066] <<First example of a case where a passing grade is given>> In one example of the case where the above-mentioned failing evaluation is made, it is conceivable that by reducing the diffuse reflectance ρd, the pilot 5 of the aircraft 3 preparing to land will be less likely to be dazzled by sunlight SL0 reflected by the airport solar power generation system 100. Here, for example, assume that the diffuse reflectance ρd is reduced from 0.7 to 0.6.

[0067] In this case, the visual angle ω is calculated to be 0.612 rad from equation (2-9). Then, by substituting this visual angle ω (= 0.612 rad) into equation (1), the critical irradiance Et is calculated to be 0.854 W / m 2 Furthermore, from equation (2-11), the retinal irradiance Er corresponding to the estimated irradiance E1 is calculated as 0.734 W / m 2 Therefore, the estimated irradiance E1 (= 0.734 W / m 2 ) is the critical irradiance Et (= 0.854 W / m 2) is smaller than the reflection of sunlight SL0 from the airport solar power generation system 100. Therefore, a passing evaluation can be performed. In other words, in this case, the pilot 5 of the aircraft 3 preparing to land is less likely to be dazzled by the sunlight SL0 reflected by the airport solar power generation system 100, and the pilot 5 is less likely to suffer from temporary afterimages caused by the flash (temporary flash blindness).

[0068] Here, for example, the diffuse reflectance ρd can be reduced by providing the light-transmitting member 121 with a film (also referred to as an anti-reflection film or AR film) that reduces the diffuse reflectance ρd on the surface opposite the photoelectric conversion unit 123. For example, the AR film can be formed on the surface of the light-transmitting member 121 using a coating method, a chemical treatment, a physical thin film formation method, or the like. For example, when the coating method is employed, an organic solution can be applied to the surface of a plate-like member (also referred to as a plate-like member) such as a glass plate that constitutes the light-transmitting member 121, and the organic solution can be baked, thereby realizing a configuration in which the light-transmitting member 121 has an anti-reflection film on the surface. For example, a solution containing a fluorine-based resin, or a silicon dioxide (SiO2)-based or titanium dioxide (TiO2)-based sol solution can be used as the organic solution. Furthermore, for example, when chemical treatment is employed, the surface of the glass plate for constituting the light-transmitting member 121 is treated with a chemical solution to modify the surface of the glass plate and form a layer with a refractive index lower than that of glass, thereby realizing a configuration in which the light-transmitting member 121 has an anti-reflection coating on its surface. The chemical solution may be, for example, a fluorinating agent such as hydrogen fluoride or hydrofluoric acid. More specifically, for example, an anti-reflection coating can be formed on the surface of the glass plate by contacting the surface of the heated glass plate with a fluorinating agent to form a porous structure on the surface of the glass plate. For example, when a physical thin film formation method is employed, a configuration in which the light-transmitting member 121 has an anti-reflection coating on its surface can be realized by forming a thin film of zirconium dioxide (ZrO) as an anti-reflection coating on the surface of the glass plate for constituting the light-transmitting member 121 by sputtering or the like.

[0069] <<Second example of a case where a passing grade is given>> In one example of a case where the above-mentioned failing evaluation is made, it is conceivable that by reducing the area (reflection area area) Ad of the reflection area A1 as a diffuse reflection surface, the pilot 5 of the aircraft 3 preparing to land will be less likely to be dazzled by the sunlight SL0 reflected by the airport solar power generation system 100. Here, for example, if the reflection area Ad is reduced to 6000 m 2 5000m from 2 Let us consider the case where the

[0070] In this case, the visual angle ω is calculated to be 0.559 rad from equation (2-9). Then, by substituting this visual angle ω (= 0.559 rad) into equation (1), the critical irradiance Et is calculated to be 1.004 W / m 2 Furthermore, from equation (2-11), the retinal irradiance Er corresponding to the estimated irradiance E1 is calculated as 0.856 W / m 2 Therefore, the estimated irradiance E1 (= 0.856 W / m 2 ) is the critical irradiance Et (= 1.004 W / m 2 ) is smaller than the standard deviation. Therefore, a pass rating can be given.

[0071] Here, the reduction in the reflective area Ad can be achieved, for example, by reducing the number of one or more solar cell modules 12 that make up the airport solar power generation system 100, or by moving some of the one or more solar cell modules 12 that make up the airport solar power generation system 100 outside the imaginary right circular cone Cn1.

[0072] <<Third example of a case where a passing grade is given>> In one example of the case where the above-mentioned fail evaluation is made, it is possible to consider a mode in which the pilot 5 of the aircraft 3 preparing to land may be less likely to be dazzled by the sunlight SL0 reflected by the airport solar power generation system 100 by adjusting the tilt direction and angle of the reflective area A1 as a diffuse reflective surface relative to the horizontal plane. Here, for example, consider a case in which the incident angle θ is changed from 45 degrees to 50 degrees and the line of sight angle φ is changed from 45 degrees to 50 degrees.

[0073] In this case, the visual angle ω is calculated to be 0.583 rad from equation (2-9). Then, by substituting this visual angle ω (= 0.583 rad) into equation (1), the critical irradiance Et is calculated to be 0.930 W / m 2 Furthermore, from equation (2-11), the retinal irradiance Er corresponding to the estimated irradiance E1 is calculated as 0.778 W / m 2 Therefore, the estimated irradiance E1 (= 0.778 W / m 2 ) is the critical irradiance Et (= 0.930 W / m 2 ) is smaller than the standard deviation. Therefore, a pass rating can be given.

[0074] Here, for example, the airport solar power generation system 100 may further include a control unit capable of calculating at least one of the estimated irradiance E1 and the critical irradiance Et. This control unit may be implemented by various computers capable of performing various calculations using one or more processors, such as a central processing unit (CPU). In this case, for example, the control unit may calculate at least one of the estimated irradiance E1 and the critical irradiance Et through calculations using the one or more processors. The control unit may perform a pass or fail evaluation by, for example, comparing the estimated irradiance E1 with the critical irradiance Et. Furthermore, for example, the airport solar power generation system 100 may include a drive mechanism capable of adjusting at least one of the direction and angle at which the reflective area A1 is tilted with respect to the horizontal plane. More specifically, the drive mechanism may be capable of adjusting at least one of the direction and angle at which the light-receiving surface 12s of the solar cell module 12 is tilted with respect to the horizontal plane. Various types of drive mechanisms can be used for this drive mechanism, including, for example, an electric motor, an electric jack, an electric actuator, an electric cylinder, or an electric elevator. This drive mechanism may be incorporated, for example, into a portion connecting the mount 11 and the solar cell module 12, or into some of the columns and beams of the mount 11. Here, for example, the drive mechanism may be capable of adjusting at least one of the direction and angle at which the reflective area A1 is tilted with respect to the horizontal plane in response to a command signal from the control unit. More specifically, for example, the drive mechanism may be capable of adjusting at least one of the direction and angle at which the light receiving surface 12s of the solar cell module 12 is tilted with respect to the horizontal plane in response to a command signal from the control unit.

[0075] <<Another example of how to calculate estimated irradiance>> The retinal irradiance Er does not have to be calculated as the estimated irradiance E1. For example, the estimated irradiance E1 may be a calculated value of irradiance calculated based on the retinal irradiance Er as an estimate of the irradiance of diffusely reflected light DL1 that is incident on the retina 5e5 of the pilot 5 after sunlight SL0 is diffusely reflected in the reflection area A1. Here, for example, a mode may be adopted in which the calculated value of irradiance is calculated by multiplying the retinal irradiance Er by a coefficient. For example, a safety factor may be applied as the coefficient. For example, the safety factor may be set to a value greater than 1 and equal to or less than 3.

[0076] If the reflective area A1 were a single perfect diffuse reflecting surface, as shown in Figure 8, when sunlight SL0, depicted by the thick two-dot chain line, is irradiated onto point P0 on the reflective area A1 at an incident angle θ, the brightness of the diffusely reflected light generated in the reflective area A1 would exhibit a semicircular arc-shaped distribution depicted by the one-dot chain line Lpd centered at point P0. A perfect diffuse reflecting surface is a uniform diffuse reflecting surface with a reflectance of 100%.

[0077] On the other hand, if the reflective area A1 is not a perfect diffuse reflecting surface but a typical glossy reflecting surface (also called a non-uniform diffuse reflecting surface), as shown in FIG. 8, the luminance of the reflected light generated in the reflective area A1 will be represented by the distribution depicted by the dashed line Lr with point P0 as the reference point. The distribution depicted by the dashed line Lr with point P0 as the reference point varies depending on the angle θr (also called the reflection angle) between the normal 12n and the reflected light ray. In other words, if the reflective area A1 is a typical reflective surface (a non-uniform diffuse reflecting surface), reflected light including specularly reflected light (also called regular reflected light) and diffusely reflected light is generated in response to the incidence of sunlight SL0. As a result, when the reflection angle θr is close to the incidence angle θ, the luminance of the reflected light is higher than when the reflection angle θr is not close to the incidence angle θ. Therefore, when the gaze angle φ of the pilot 5 is close to the incidence angle θ, the irradiance of the reflected light incident on the retina 5e5 of the eyeball 5e of the pilot 5 in response to the reflection of sunlight SL0 in the reflective area A1 may be high.

[0078] Therefore, for example, in order to make the calculation result of the estimated irradiance E1 closer to reality, when the gaze angle φ of the pilot 5 is close to the incident angle θ, weighting may be applied to the diffuse radiance Ld or the diffuse reflectance ρd when calculating the retinal irradiance Er using equation (2-11) or the like. More specifically, for example, the diffuse radiance Ld or the diffuse reflectance ρd may be multiplied by a weighting coefficient β. As a result, when the gaze angle φ of the pilot 5 is close to the incident angle θ, the retinal irradiance Er corresponding to the estimated irradiance E1 can be calculated so that it is high. Also, for example, when the gaze angle φ of the pilot 5 is close to the incident angle θ, the estimated irradiance E1 may be calculated by weighting the retinal irradiance Er calculated using equation (2-11) or the like. More specifically, for example, the calculated value of the irradiance as the estimated irradiance E1 may be calculated by multiplying the retinal irradiance Er by a weighting coefficient β as a coefficient.

[0079] Here, an example of a method for setting the weighting coefficient β will be described.

[0080] Let us assume that the reflective area A1 is a uniform diffuse reflecting surface. Here, the intensity of sunlight SL0 incident on the reflective area A1 from the sun 9 is Iin, the angle of incidence is θ, the diffuse reflectance in the reflective area A1 is ρd, and the intensity of reflected light generated by the reflective area A1 as a uniform diffuse reflecting surface is Id. In this case, equation (3) can be established.

[0081] Id=Iin×ρd×cosθ (3).

[0082] Here, as shown in Figure 9, when sunlight SL0, depicted by a thick dashed double-dashed line at an incident angle θ, is irradiated onto point P0 of the reflective area A1, the intensity Id of the reflected light generated in the reflective area A1 exhibits a semicircular arc-shaped distribution depicted by a dashed dotted line Lid centered at point P0, with point P0 as the reference point.

[0083] Next, let us consider a case where the reflective area A1 is a reflective surface (non-Lambertian diffuse reflecting surface) with a typical gloss. Here, let Iin be the intensity of sunlight SL0 incident on the reflective area A1 from the sun 9, and let ρr be the specular reflectance in the reflective area A1. Also, as shown in FIG. 10, let γ be the angle (also called the deviation angle) between a straight virtual line Lmr along the direction in which sunlight SL0 is specularly reflected from the reflective area A1 (the specular reflection direction) and the line of sight Los of the pilot 5 as an observer. Also, let Is be the intensity of the reflected light associated with gloss occurring near the specular reflection direction in the reflective area A1 as a non-Lambertian diffuse reflecting surface. In this case, if the Phong model is used, Equation (4) can be established.

[0084] Is=Iin×ρr×cos n γ ···(4).

[0085] Here, n is a constant that approximately represents the manner in which reflected light attenuates as the offset angle γ increases. A natural number is used for the constant n. Here, as shown in FIG. 10, when sunlight SL0, depicted by a thick two-dot chain line, is irradiated onto point P0 on the reflective area A1 at an incident angle θ, the intensity Is of the reflected light related to gloss exhibits a distribution depicted by, for example, a dashed line Lsr with point P0 as the reference point.

[0086] The constant n can be set, for example, as follows: The distribution of reflected light intensity Id shown in FIG. 9 is combined with the distribution of reflected light intensity Is shown in FIG. 10. Here, the distribution of reflected light intensity Is is added to the distribution of reflected light intensity Id, excluding the portion of the distribution of reflected light intensity Is that overlaps with the distribution of reflected light intensity Id, thereby combining the distribution of reflected light intensity Id and the distribution of reflected light intensity Is. In FIG. 11, the distribution of reflected light intensity after combining the distribution of reflected light intensity Id and the distribution of reflected light intensity Is (also referred to as the combined intensity of reflected light) is schematically depicted by the thick line Lc. Furthermore, the distribution of reflected light intensity depicted by the dashed line Lr in FIG. 8 is obtained by actual measurement (also referred to as actual measurement) using a measurement device for the reflective area A1. Then, by varying n, the constant n is set to the value at which the protruding portion in the distribution of the combined intensity of the reflected light drawn by the thick line Lc in Figure 11 is closest to the protruding portion in the portion of the distribution of the intensity of the reflected light obtained by actual measurement where the reflection angle θr is close to the incident angle θ.

[0087] Here, for example, a constant n may be set for each of two or more incidence angles θ, and the constant n for an incidence angle θ other than the two or more incidence angles θ may be calculated by interpolation or extrapolation using the constant n set for each of the two or more incidence angles θ. For example, 30 degrees and 60 degrees may be applied to the two or more incidence angles θ.

[0088] Equation (5) is calculated from equations (3) and (4).

[0089] Is / Id=(ρr×cos n γ) / (ρd×cosθ) ···(5).

[0090] Here, if the value (Is / Id) obtained by dividing Is by Id is greater than 1, a weighting coefficient β can be set according to the value (Is / Id). Here, the diffuse reflectance ρd and the specular reflectance ρr can be obtained by actual measurements using a measuring device targeting the reflective area A1. If the incident angle θ is known, a weighting coefficient β can be set according to the deviation angle γ. The deviation angle γ can be calculated using the incident angle θ and the line of sight angle φ. Since the specular reflectance ρr changes depending on the incident angle θ, the specular reflectance ρr may be changed according to the incident angle θ. Here, the specular reflectance ρr may be obtained by actual measurements for each of two or more incident angles θ, and a weighting coefficient β according to the deviation angle γ may be set for each of the two or more incident angles θ. In this case, for example, the weighting coefficient β according to the deviation angle γ for an incident angle θ other than the two or more incident angles θ may be calculated by interpolation or extrapolation using the weighting coefficient β according to the deviation angle γ for the two or more incident angles θ. Furthermore, for example, as the weighting coefficient β corresponding to the deviation angle γ for another incident angle θ that is different from the two or more incident angles θ, a weighting coefficient β corresponding to the deviation angle γ at an incident angle θ that is close to another incident angle θ among the two or more incident angles θ may be adopted.

[0091] Although a simplified calculation method has been described as an example of the method for calculating the retinal irradiance Er corresponding to the estimated irradiance E1, the method is not limited to this. For example, the retinal irradiance Er may be calculated using a calculation method that takes into account other factors such as light attenuation. For example, in the example of the method for calculating the retinal irradiance Er described above, the retinal irradiance Er may be calculated by including a calculation that takes into account the attenuation rate of light in the atmosphere, assuming that sunlight SL0 and diffusely reflected light DL1 attenuate. Furthermore, in the example of the method for calculating the retinal irradiance Er described above, equations (2-1) to (2-8) are defined on the assumption that a vector relating to the direction in which sunlight SL0 is incident on the reflective area A1 (also referred to as an incident direction vector) and the line of sight of the pilot 5 are located on a virtual plane perpendicular to the reflective area A1. However, the method is not limited to this. For example, in cases where the incident direction vector and the line of sight of the pilot 5 are not located on a single imaginary plane perpendicular to the reflection area A1, a variable for the angle between the incident direction vector and the line of sight of the pilot 5 may be introduced to calculate the retinal irradiance Er.

[0092] Note that the area through which specularly reflected light of sunlight SL0 generated in the reflection area A1 passes is not limited to an area defined by a single linear virtual line Lmr, and various calculations may be performed using a cylindrical area centered on the single linear virtual line Lmr. The cylindrical area may be set to a cylindrical area having a diameter equal to or greater than the diameter of the approximately circular image of the sun 9 seen on the light-receiving surface 12s by the observer pilot 5. Here, for example, if the light-receiving surface 12s has an embossed or other irregular surface, and the outer edge of the image of the sun 9 seen on the light-receiving surface 12s by the observer pilot 5 is unclear, the cylindrical area may be determined by calculation. In this case, for example, the cylindrical area may be set by calculation assuming that the outer edge of the image of the sun 9 seen on the light-receiving surface 12s by the observer pilot 5 is clear.

[0093] <<Other examples of methods for calculating and evaluating estimated irradiance>> For example, assuming that the reflective area A1 is a single flat virtual mirror surface (also referred to as a first virtual mirror surface), there may be a first reflective area A11 in the reflective area A1 that emits specularly reflected light corresponding to sunlight SL0 toward a second point P2. In this case, as shown in Fig. 5, the reflective area A1 can be divided into the first reflective area A11 and a second reflective area A12 other than the first reflective area A11 that emits diffusely reflected light corresponding to sunlight SL0 toward the second point P2. In this case, the light-transmitting member 121 may have a configuration in which the first estimated irradiance (also referred to as first estimated irradiance) E11 for the first reflection area A11 is set to an irradiance smaller than the first critical irradiance (also referred to as first critical irradiance) Et1, and the second estimated irradiance (also referred to as second estimated irradiance) E12 for the second reflection area A12 is set to an irradiance smaller than the second critical irradiance (also referred to as second critical irradiance) Et2. The units of the first estimated irradiance E11, the first critical irradiance Et1, the second estimated irradiance E12, and the second critical irradiance Et2 are each W / m 2 Even if this configuration is adopted, the pilot 5 of the aircraft 3 preparing to land is unlikely to be dazzled by the sunlight SL0 reflected by the airport solar power generation system 100.

[0094] Here, the first estimated irradiance E11 is an estimated value of the irradiance of specularly reflected light RL1 incident on the retina 5e5 of the eyeball 5e of the pilot 5 of the aircraft 3 preparing to land on the runway 2 in response to reflection of sunlight SL0 on the first reflection area A11. In other words, the first estimated irradiance E11 is an estimated irradiance as an estimated value of reflected light incident on the retina 5e5 of the eyeball 5e located at the second point P2 in response to reflection of sunlight SL0 on the first reflection area A11, which is a reflection area located within the imaginary right circular cone Cn1 of one or more solar cell modules 12. Here, the reflected light is the specular component of the reflected light generated on the reflection area A1. In addition, the first critical irradiance Et1 is the irradiance calculated by equation (6) using ω1 [unit: rad] as the visual angle (also referred to as the first visual angle or the first visual angle) for the first reflective area A11 in the eyeball 5e of the pilot 5 of the aircraft 3 preparing to land on the runway 2.

[0095] Et1=0.359 / ω1 1.77 ···(6).

[0096] Equation (6) is an equation obtained by substituting the first critical irradiance Et1 for the critical irradiance Et in the above-mentioned equation (1) and substituting the first visual angle ω1 for the visual angle ω. Therefore, the light-transmitting member 121 has a form that makes the first estimated irradiance E11 smaller than the first critical irradiance Et1 as the critical irradiance Et calculated by equation (1) using the visual angle ω into which the first visual angle ω1 of the eyeball 5e for the first reflection region A11 is substituted.

[0097] Furthermore, here, the second estimated irradiance E12 is an estimated value of the irradiance of diffusely reflected light DL1 incident on the retina 5e5 of the eyeball 5e of the pilot 5 of the aircraft 3 preparing to land on the runway 2 in response to reflection of sunlight SL0 on the second reflective area A12. In other words, the second estimated irradiance E12 is an estimated irradiance as an estimated value of reflected light incident on the retina 5e5 of the eyeball 5e located at the second point P2 in response to reflection of sunlight SL0 on the second reflective area A12 as a reflective area located within the imaginary right circular cone Cn1 of one or more solar cell modules 12. Here, the reflected light is the diffusely reflected light component of the reflected light generated on the reflective area A1. In addition, the second critical irradiance Et2 is the irradiance calculated by equation (7) using ω2 [unit: rad] as the visual angle (also referred to as the second visual angle or second visual angle) for the second reflective area A12 in the eyeball 5e of the pilot 5 of the aircraft 3 preparing to land on the runway 2.

[0098] Et2=0.359 / ω2 1.77 ···(7).

[0099] Equation (7) is an equation obtained by substituting the second critical irradiance Et2 for the critical irradiance Et in equation (1) above and substituting the second visual angle ω2 for the visual angle ω. Therefore, the light-transmitting member 121 has a form that makes the second estimated irradiance E12 smaller than the second critical irradiance Et2 as the critical irradiance Et calculated by equation (1) using the visual angle ω into which the second visual angle ω2 of the eyeball 5e for the second reflection region A12 is substituted.

[0100] The first estimated irradiance E11 can be calculated by, for example, various calculation methods. Here, an example of a calculation method for the first estimated irradiance E11 will be described.

[0101] The irradiance of the specularly reflected light RL1 incident on the retina 5e5 of the eyeball 5e of the pilot 5 (also called the first retinal irradiance) is Er1 [unit: W / m 2 The first retinal irradiance Er1 corresponds to the first estimated irradiance E11. The irradiance of the specularly reflected light RL1 incident on the front surface of the cornea 5e1 of the pilot 5 as an observer (also called the irradiance of the front surface of the cornea) is defined as Ec [unit: W / m 2 The specular reflectance in the first reflective area A11 is ρr. The irradiance of sunlight SL0 incident perpendicularly to the plane is E DNI [Unit: W / m 2 ]. Here, the solar irradiance E DNI to 1000W / m 2 Let dp (unit: m) be the diameter (pupil diameter) of the pupil 5e4 of the pilot 5 as an observer. Let τ be the light transmittance (light transmittance of the ocular medium) of the path along which light passes from the front surface of the cornea 5e1 to the retina 5e5 in the eyeball 5e of the pilot 5 as an observer. Here, the transmittance τ is a constant value of 0.5. Let f (unit: m) be the focal length in the eyeball 5e of the pilot 5 as an observer. Here, the focal length f is a constant value of 0.017 m. Let θ (unit: degrees (°)) be the angle formed by the incident direction of sunlight SL0 with respect to the normal 12n of the first reflective area A11. Let ω1 (unit: rad) be the visual angle (also referred to as the first visual angle or first visual angle) for the first reflective area A11 in the eyeball 5e of the pilot 5 as an observer. Here, assuming that the entire image of the sun 9 is reflected on the light receiving surface 12s of one solar cell module 12 as viewed by the pilot 5 as an observer, the first visual angle ω1 is set to 0.0093 rad, which is the apparent diameter of the sun 9. The width of the optical image of the first reflection area A11 projected onto the retina 5e5 of the eyeball 5e of the pilot 5 as an observer (width of the first retinal projected image) is set to dr1 [unit: m]. In this case, equations (8-1) to (8-3) can be established.

[0102] dr1=f×ω1 (8-1) Ec=E DNI ×ρr (8-2) Er1=Ec×{(π×dp 2 / 4) / (π×dr1 2 / 4)}×τ =Ec×(dp 2 / dr1 2 )×τ ···(8-3).

[0103] Substituting equations (8-1) and (8-2) into equation (8-3) gives equation (8-4).

[0104] Er1=E DNI ×ρr×dp 2 ×τ / (f 2 ×ω1 2 ) ···(8-4).

[0105] The first retinal irradiance Er1 corresponding to the first estimated irradiance E11 can be calculated using equation (8-4). The first retinal irradiance Er1 is calculated based on the solar irradiance E DNI , can be calculated based on the specular reflectance ρr, pupil diameter dp, light transmittance τ, focal length f, and first visual angle ω1. Here, the solar irradiance E DNI By applying known values ​​to the pupil diameter dp, the light transmittance τ, the focal length f, and the first visual angle ω1, the first retinal irradiance Er1 can be calculated using the specular reflectance ρr. For example, the first retinal irradiance Er1 can be calculated as a first estimated irradiance E11. In this case, the first estimated irradiance E11 is the first retinal irradiance Er1 as an estimated value of the irradiance of specularly reflected light RL1 that is incident on the retina 5e5 of the pilot 5 in response to specular reflection of sunlight SL0 in the first reflection area A11. Note that the first estimated irradiance E11 may also be a calculated value of irradiance calculated based on the first retinal irradiance Er1. Here, for example, a mode can be adopted in which the calculated value of irradiance is calculated by multiplying the first retinal irradiance Er1 by a safety factor as a coefficient. The safety factor can be set to, for example, a value greater than 1 and equal to or less than 3.

[0106] The second estimated irradiance E12 can be calculated by various methods, for example. An example of the method for calculating the second estimated irradiance E12 will now be described.

[0107] The retinal irradiance Er (also referred to as the second retinal irradiance Er2) corresponding to the second estimated irradiance E12 can be calculated using the above-mentioned formula (2-11). Here, the second retinal irradiance Er2 is calculated by multiplying the solar irradiance E DNI , the incident angle θ, the diffuse reflectance ρd, the pupil diameter dp, the light transmittance τ, and the focal length f. DNI By applying known values ​​to the pupil diameter dp, the optical transmittance τ, and the focal length f, the second retinal irradiance Er2 can be calculated using the incident angle θ and the diffuse reflectance ρd. For example, the second retinal irradiance Er2 can be calculated as the second estimated irradiance E12. In this case, the second estimated irradiance E12 is the second retinal irradiance Er2 as an estimated value of the irradiance of the diffusely reflected light DL1 that is incident on the retina 5e5 of the pilot 5 in response to the diffuse reflection of sunlight SL0 in the second reflective area A12.

[0108] The first critical irradiance Et1 is calculated, for example, by substituting the first viewing angle ω1 (=0.0093 rad) into equation (6). The second critical irradiance Et2 is calculated, for example, by substituting the second viewing angle ω2 calculated by equation (9) into equation (7).

[0109] ω2=(1 / r)×(4×Ad2×cosφ / π) 0.5 ···(9).

[0110] Equation (9) is obtained by substituting Ad2 [unit: m ], which is the area of ​​the second reflective area A12 as a diffuse reflective surface, for the reflective area area Ad when the visual angle ω is the second visual angle ω2 in the above-mentioned equation (2-9). 2 ] is substituted into the expression.

[0111] Then, for example, if the first estimated irradiance E11 is less than the first critical irradiance Et1 and the second estimated irradiance E12 is less than the second critical irradiance Et2, a pass evaluation is performed.

[0112] Also, for example, if the first estimated irradiance E11 is equal to or greater than the first critical irradiance Et1, or if the second estimated irradiance E12 is equal to or greater than the second critical irradiance Et2, a fail evaluation is made.

[0113] Here, for an airport solar power generation system 100 that has actually been installed, the specular reflectance ρr in the first reflection area A11 and the diffuse reflectance ρd in the second reflection area A12 can be measured, for example, using a measuring device that can measure the specular reflectance ρr and the diffuse reflectance ρd separately.

[0114] Here, for example, if the first estimated irradiance E11 is equal to or greater than the first critical irradiance Et1, the first estimated irradiance E11 can become less than the first critical irradiance Et1 by reducing the specular reflectance ρr in the first reflection region A11. For example, if the light-transmitting member 121 has at least one of an anti-reflection coating and unevenness on the surface opposite the photoelectric conversion unit 123, the specular reflectance ρr of the light-receiving surface 12s constituting the first reflection region A11 can be reduced. Furthermore, if the second estimated irradiance E12 is equal to or greater than the second critical irradiance Et2, the second estimated irradiance E12 can become less than the second critical irradiance Et2 by using one or more of the following techniques: reducing the diffuse reflectance ρd in the second reflection region A12, reducing the area Ad2 of the second reflection region A12, and adjusting the tilt direction and angle of the second reflection region A12 with respect to the horizontal plane. For example, if the light-transmitting member 121 has an anti-reflection film on the surface opposite to the photoelectric conversion section 123, the diffuse reflectance ρd on the light-receiving surface 12s that constitutes the second reflection region A12 can be reduced.

[0115] For example, the estimated irradiance E1 may be calculated as the sum of the first retinal irradiance Er1 associated with the specularly reflected light component and the second retinal irradiance Er2 associated with the diffusely reflected light component (also referred to as the total irradiance). In this case, if the estimated irradiance E1 is less than the critical irradiance Et calculated by equation (1), a pass evaluation may be performed. Also, if the estimated irradiance E1 is equal to or greater than the critical irradiance Et calculated by equation (1), a fail evaluation may be performed.

[0116] Here, for example, if the estimated irradiance E1 is equal to or greater than the critical irradiance Et, the estimated irradiance E1 may become less than the critical irradiance Et due to a reduction in the specular reflectance ρr and diffuse reflectance ρd in the reflective region A1. For example, if the light-transmitting member 121 has an anti-reflection coating on the surface opposite to the photoelectric conversion unit 123, the specular reflectance ρr and diffuse reflectance ρd on the light-receiving surface 12s that constitutes the reflective region A1 may be reduced.

[0117] <2-2. Specific examples of glare reduction using light-transmitting members> An example of a configuration of the light-transmitting member 121 (also referred to as a glare-reducing configuration) that makes it difficult for the pilot 5 of the aircraft 3 preparing to land to be dazzled by sunlight SL0 reflected by the airport solar power generation system 100 is a configuration in which the first surface F1 that forms the light-receiving surface 12s has irregularities. Further, the glare-reducing configuration of the light-transmitting member 121 may include a configuration in which the light-transmitting member 121 has an anti-reflection film as a coating layer that reduces the reflectance of the light-receiving surface 12s, or a configuration in which the attitude of the light-transmitting member 121, such as the tilt direction and angle with respect to the horizontal plane, is adjusted.

[0118] In other words, the estimated irradiance E1 can be reduced by setting at least one of the unevenness of the first surface F1 constituting the light-receiving surface 12s, the reflectance of the light-receiving surface 12s, and the attitude of the light-transmissive member 121. As a result, for example, the estimated irradiance E1 can become an irradiance less than the critical irradiance Et defined by equation (1). Note that, for example, the first estimated irradiance E11 may be less than the first critical irradiance Et1 and the second estimated irradiance E12 may be less than the second critical irradiance Et2.

[0119] Here, for example, if the reflective area A1 is a non-uniform diffuse reflecting surface, if the first surface F1 constituting the light-receiving surface 12s has irregularities, the reduction in specular reflectance ρr reduces the likelihood of specular reflection from the reflective area A1 in response to irradiation with sunlight SL0. Therefore, for example, if one or more solar cell modules 12 include a solar cell module (also referred to as a first solar cell module) 12A whose light-receiving surface 12s has irregularities, the presence of the irregularities causes diffuse reflection of sunlight SL0 on the light-receiving surface 12s, making it less likely that sunlight SL0 will be specularly reflected. This makes it less likely that the estimated irradiance E1 or the first estimated irradiance E11 will increase. As a result, the pilot 5 of the aircraft 3 preparing to land is less likely to be dazzled by reflected sunlight SL0.

[0120] For example, if the light-transmitting member 121 is a glass plate (also referred to as a glass plate), the unevenness of the light-receiving surface 12s can be realized by forming unevenness on one side of the glass plate when manufacturing the glass plate. In this case, for example, when manufacturing a glass plate by passing molten glass between two water-cooled rolls arranged one above the other, if the surface of the lower of the two water-cooled rolls has a pattern formed by engraving or the like, unevenness can be formed on one side of the glass plate by transferring the pattern.

[0121] As shown in FIG. 2, the light-receiving surface 12s may be inclined relative to the horizontal plane. In this case, the light-receiving surface 12s may be positioned along a first direction, which is the direction inclined relative to the horizontal plane (also referred to as the inclination direction), and a second direction, which is perpendicular to the first direction and parallel to the horizontal plane (also referred to as the lateral direction). In the first embodiment, the first direction is the -Y direction, and the second direction is the +X direction. In the first embodiment, assuming that the airport solar power generation system 100 is installed in the Northern Hemisphere, the light-receiving surface 12s is inclined relative to the horizontal plane so as to face diagonally upward, tilting toward the south, which is the direction in which the sun 9 is median (also referred to as the median direction). In other words, the light-receiving surface 12s is inclined relative to the horizontal plane so as to be positioned lower as it moves southward. This increases the amount of sunlight SL0 incident on the light-receiving surface 12s during the diurnal motion of the sun 9, thereby improving the amount of power generated by the airport solar power generation system 100. The angle at which the light receiving surface 12s is inclined relative to the horizontal plane (also referred to as the inclination angle) is set according to, for example, the latitude at which the airport solar power generation system 100 is installed.

[0122] Here, for example, as shown in any of the sets of Figures 12 to 14, 15 to 17, and 18 to 20, the light-transmitting member 121 of the first solar cell module 12A may have a base surface B1 and multiple protrusions C1 on the light-receiving surface 12s side. The base surface B1 is a planar surface along both the first direction and the second direction. The multiple protrusions C1 are portions that protrude beyond the base surface B1 in a direction (also referred to as the third direction) perpendicular to both the first direction and the second direction. The third direction is the normal direction to the base surface B1. In the first embodiment, the third direction is the +Z direction.

[0123] For example, as shown in FIGS. 12 to 14, in the first solar cell module 12A, the light-transmitting member 121 may have a configuration (also referred to as a first configuration) in which multiple protrusions C1 are arranged in a dot pattern when the light-receiving surface 12s is viewed in plan. In the examples of FIGS. 12 to 14, the multiple protrusions C1 are arranged along the −Y direction as a first direction, and the multiple protrusions C1 are arranged along the +X direction as a second direction. In other words, the multiple protrusions C1 are arranged in a matrix pattern. From another perspective, multiple rows of multiple protrusions C1, each composed of multiple protrusions C1 arranged along the −Y direction as a first direction, are arranged in the +X direction as a second direction. The direction in which the multiple protrusions C1 arranged along the −Y direction as a first direction are arranged may form a slight angle with respect to the −Y direction as the first direction. This slight angle may be, for example, an angle greater than 0 degrees and less than 30 degrees, or an angle greater than 0 degrees and less than 20 degrees. The direction in which the multiple protrusions C1 are aligned along the +X direction as the second direction may form a slight angle with respect to the +X direction as the second direction. This slight angle may be, for example, an angle greater than 0 degrees and less than or equal to 30 degrees, or an angle greater than 0 degrees and less than or equal to 20 degrees.

[0124] 13 and 14, if the surface of the convex portion C1 constituting the light-receiving surface 12s is curved, diffuse reflection occurs on the light-receiving surface 12s in response to irradiation of sunlight SL0, making it difficult for specular reflection to occur. This makes it difficult for the estimated irradiance E1 or the first estimated irradiance E11 to increase. As a result, the pilot 5 of the aircraft 3 preparing to land is unlikely to be dazzled by reflected sunlight SL0.

[0125] For example, as shown in Figures 15 to 17, in the first solar cell module 12A, the translucent member 121 may have a form (also referred to as a second form) in which the multiple convex portions C1 include multiple first convex portions C11 and multiple second convex portions C12.

[0126] Each of the multiple first protrusions C11 is a protrusion extending along the −Y direction as a first direction. The direction in which the first protrusions C11 extend (also referred to as a first longitudinal direction) may form a slight angle with respect to the −Y direction as the first direction. This slight angle may be, for example, an angle greater than 0 degrees and less than 30 degrees, or an angle greater than 0 degrees and less than 20 degrees. Each of the multiple second protrusions C12 is a protrusion extending along the +X direction as a second direction. The direction in which the second protrusions C12 extend (also referred to as a second longitudinal direction) may form a slight angle with respect to the +X direction as the second direction. This slight angle may be, for example, an angle greater than 0 degrees and less than 30 degrees, or an angle greater than 0 degrees and less than 20 degrees.

[0127] In the examples of FIGS. 15 to 17, each of the multiple first protrusions C11 is positioned linearly along the −Y direction as a first direction. The multiple first protrusions C11 are aligned in the +X direction as a second direction. The multiple second protrusions C12 are positioned linearly along the +X direction as a second direction. The multiple second protrusions C12 are aligned in the −Y direction as a first direction. In other words, the multiple protrusions C1 are positioned in a lattice pattern. Here, the extending direction of the first protrusions C11 (first longitudinal direction) and the extending direction of the second protrusions C12 (second longitudinal direction) may or may not be orthogonal. In other words, the first longitudinal direction of the first protrusions C11 may intersect with the second longitudinal direction of the second protrusions C12. The angle formed between the first longitudinal direction of the first convex portion C11 and the second longitudinal direction of the second convex portion C12 may be, for example, an angle less than 90 degrees and greater than 60 degrees, or an angle less than 90 degrees and greater than 70 degrees.

[0128] Here, the first convex portion C11 may be formed of, for example, two or more convex portions (also referred to as first convex portions) that extend along the −Y direction as a first direction and are spaced apart from each other, and the second convex portion C12 may be formed of, for example, two or more convex portions (also referred to as second convex portions) that extend along the +X direction as a second direction and are spaced apart from each other.

[0129] Here, for example, as shown in FIGS. 16 and 17, if the surface of the convex portion C1 constituting the light receiving surface 12s is curved, diffuse reflection occurs on the light receiving surface 12s in response to irradiation of sunlight SL0, making it difficult for specular reflection to occur. This makes it difficult for the estimated irradiance E1 or the first estimated irradiance E11 to increase. As a result, the pilot 5 of the aircraft 3 preparing to land is unlikely to be dazzled by reflected sunlight SL0. Here, for example, as shown in FIG. 16, a configuration is adopted in which the surface of the first convex portion C11 constituting the light receiving surface 12s is curved in the +X direction (the second direction). For example, as shown in FIG. 17, a configuration is adopted in which the surface of the second convex portion C12 constituting the light receiving surface 12s is curved in the -Y direction (the first direction).

[0130] For example, as shown in Figures 18 to 20, in the first solar cell module 12A, the translucent member 121 may have a form (also called a third form) in which multiple convex portions C1 form multiple hexagonal patterns when the light-receiving surface 12s is viewed in plan view.

[0131] In the examples of FIGS. 18 to 20 , the multiple protrusions C1 include multiple first protrusions C11 and multiple second protrusions C12. Each of the multiple first protrusions C11 is a protrusion extending along the −Y direction as a first direction. Each of the multiple second protrusions C12 is a protrusion extending along the +X direction as a second direction. Each of the multiple second protrusions C12 extends in a slightly meandering manner along the +X direction as the second direction. The multiple second protrusions C12 are aligned in the −Y direction as the first direction. Each of the multiple first protrusions C11 is positioned linearly along the −Y direction as the first direction between two adjacent second protrusions C12. Furthermore, the multiple first protrusions C11 are aligned in the +X direction as the second direction between two adjacent second protrusions C12. In each of the plurality of sets of second protrusions C12, each set consisting of two adjacent second protrusions C12, a plurality of first protrusions C11 are arranged in the +X direction as the second direction between the two adjacent second protrusions C12. Here, two adjacent second protrusions C12 and two adjacent first protrusions C11 form a tortoiseshell pattern. In other words, the direction in which the first protrusions C11 extend (first longitudinal direction) and the direction in which the second protrusions C12 extend (second longitudinal direction) do not have to be perpendicular to each other. The second longitudinal direction of the second protrusions C12 may intersect with the first longitudinal direction of the first protrusions C11. The angle formed between the first longitudinal direction of the first protrusions C11 and the second longitudinal direction of the second protrusions C12 may be, for example, less than 90 degrees and equal to or greater than 60 degrees, or less than 90 degrees and equal to or greater than 70 degrees.

[0132] Here, the direction in which the first protrusions C11 extend (also referred to as the first longitudinal direction) may form a slight angle with respect to the −Y direction as the first direction. This slight angle may be, for example, an angle greater than 0 degrees and less than or equal to 30 degrees, or an angle greater than 0 degrees and less than or equal to 20 degrees. The direction in which the second protrusions C12 extend (also referred to as the second longitudinal direction) may form a slight angle with respect to the +X direction as the second direction. This slight angle may be, for example, an angle greater than 0 degrees and less than or equal to 30 degrees, or an angle greater than 0 degrees and less than or equal to 20 degrees.

[0133] Here, for example, as shown in FIGS. 19 and 20, if the surface of the convex portion C1 constituting the light receiving surface 12s is curved, diffuse reflection occurs on the light receiving surface 12s in response to irradiation of sunlight SL0, making it difficult for specular reflection to occur. This makes it difficult for the estimated irradiance E1 or the first estimated irradiance E11 to increase. As a result, the pilot 5 of the aircraft 3 preparing to land is unlikely to be dazzled by reflected sunlight SL0. Here, for example, as shown in FIG. 19, a configuration is adopted in which the surface of the first convex portion C11 constituting the light receiving surface 12s is curved in the +X direction, which is the second direction. For example, as shown in FIG. 20, a configuration is adopted in which the surface of the second convex portion C12 constituting the light receiving surface 12s is curved in the -Y direction, which is the first direction.

[0134] Here, for example, as shown in any of the sets of Figures 12 to 14, the set of Figures 15 to 17, and the set of Figures 18 to 20, multiple protrusions C1 may be regularly arranged at a first pitch (also referred to as the first pitch) Py1 in the -Y direction as a first direction, and may be regularly arranged at a second pitch (also referred to as the second pitch) Px1 smaller than the first pitch Py1 in the +X direction as a second direction.

[0135] In the examples of FIGS. 12 to 14, the dot-shaped convex portions C1 are regularly arranged at a first pitch Py1 in the −Y direction (first direction) and at a second pitch Px1 in the +X direction (second direction). From another perspective, in the examples of FIGS. 12 to 14, rows of the convex portions C1, each composed of the convex portions C1 arranged along the +X direction (second direction), are arranged at a first pitch Py1 in the −Y direction (first direction). Rows of the convex portions C1, each composed of the convex portions C1 arranged along the −Y direction (first direction), are arranged at a second pitch Px1 in the +X direction (second direction). The second pitch Px1 is smaller than the first pitch Py1. Here, the first pitch Py1 is set to, for example, 600 micrometers (μm) to 1100 μm. The first pitch Py1 may also be set to, for example, 700 μm to 1000 μm. The second pitch Px1 is set to, for example, 300 μm to 700 μm. The second pitch Px1 may be set to, for example, 400 μm to 600 μm. The height of the convex portion C1 is set to, for example, 15 μm to 50 μm. The height of the convex portion C1 is the length by which the convex portion C1 protrudes from the base surface B1 in the +Z direction as the third direction. The height of the convex portion C1 may be set to, for example, 20 μm to 40 μm.

[0136] In each of the examples of FIGS. 15 to 17 and the examples of FIGS. 18 to 20, the multiple second protrusions C12 are regularly arranged at a first pitch Py1 in the −Y direction as a first direction, and the multiple first protrusions C11 are regularly arranged at a second pitch Px1 in the +X direction as a second direction. The second pitch Px1 is smaller than the first pitch Py1. Here, the first pitch Py1 is set to, for example, 600 μm to 1100 μm. The first pitch Py1 may be set to, for example, 700 μm to 1000 μm. The second pitch Px1 is set to, for example, 300 μm to 700 μm. The second pitch Px1 may be set to, for example, 400 μm to 600 μm. The height of each of the first protrusions C11 and the second protrusions C12 is set to, for example, 15 μm to 50 μm. The height of the first convex portion C11 is the length by which the first convex portion C11 protrudes from the base surface B1 in the +Z direction as a third direction. The height of the second convex portion C12 is the length by which the second convex portion C12 protrudes from the base surface B1 in the +Z direction as a third direction. The heights of the first convex portion C11 and the second convex portion C12 may be set to, for example, 20 μm to 40 μm. The width (also referred to as the first line width) of the first convex portion C11 and the width (also referred to as the second line width) of the second convex portion C12 are set to, for example, 200 μm to 300 μm. The width (first line width) of the first convex portion C11 is the length in a direction perpendicular to the first longitudinal direction of the first convex portion C11 and along the XY plane. The width (second line width) of the second convex portion C12 is the length in a direction perpendicular to the second longitudinal direction of the second convex portion C12 and along the XY plane.

[0137] In the first embodiment, the light receiving surface 12s is inclined with respect to the horizontal plane so as to face diagonally upward, tilting toward the south, which is the median direction of the sun 9. The angle (also referred to as the landing angle) formed by the landing flight path of the aircraft 3 flying toward the runway 2 immediately before landing on the runway 2 with respect to the horizontal plane is 3 degrees or approximately 3 degrees. The line of sight of the pilot 5 of the aircraft 3 preparing to land is directed toward an area centered on the target point marking 2a on the runway 2. Here, the traveling direction of the reflected light of sunlight SL0 generated by the airport solar power generation system 100, which may dazzle the pilot 5 of the aircraft 3 preparing to land, is considered to be along the line of sight of the pilot 5. For this reason, it is estimated that the angle formed by the traveling direction of the reflected light of sunlight SL0, which may dazzle the pilot 5 of the aircraft 3 preparing to land, with the horizontal plane is a small angle centered around an angle of approximately 3 degrees with respect to the ground along the horizontal plane.

[0138] For example, when the sun 9 is located southward, which is the midline, around noon, the solar altitude of the sun 9 is assumed to be high. Therefore, as shown in FIG. 21 , for example, the angle between the direction of specular reflection light RL1 generated at the light-receiving surface 12s in response to irradiation of sunlight SL0 from the sun 9 at a high solar altitude and the horizontal plane is relatively large. In FIG. 21 , an example of the direction of sunlight SL0 is indicated by a two-dot chain arrow, and an example of the direction of specular reflection light RL1 is indicated by a two-dot chain arrow. In this case, the direction of reflection light RL1 significantly deviates from the line of sight of the pilot 5 of the aircraft 3 preparing for landing. Therefore, the pilot 5 of the aircraft 3 preparing for landing is unlikely to be dazzled by the light reflected at the light-receiving surface 12s in response to irradiation of sunlight SL0.

[0139] On the other hand, for example, when the sun 9 is located in the east just after sunrise or when the sun 9 is located in the west just before sunset, the solar altitude of the sun 9 is low. Therefore, as shown in FIG. 22, for example, the angle between the direction of travel of the specularly reflected light RL1 generated at the light-receiving surface 12s in response to irradiation of sunlight SL0 from the sun 9 at a low solar altitude and the horizontal plane is small. In FIG. 22, for a time just before sunset when the solar altitude is low, an example of the direction of travel of sunlight SL0 is indicated by a dash-dot arrow, and an example of the direction of travel of the specularly reflected light RL1 is indicated by a dash-dot arrow. In this case, the direction of travel of the specularly reflected light RL1 may be close to the line of sight of the pilot 5 of the aircraft 3 preparing to land. Therefore, the pilot 5 of the aircraft 3 preparing to land may be dazzled by the light reflected at the light-receiving surface 12s in response to irradiation of sunlight SL0.

[0140] Here, for example, as described above, if the second pitch Px1 is smaller than the first pitch Py1, sunlight SL0 heading toward the light-receiving surface 12s from the east or west is blocked by the multiple convex portions C1 and is less likely to be irradiated onto the base surface B1 during times when the sun's altitude is low, such as immediately after sunrise and immediately before sunset. Therefore, specular reflection of sunlight SL0 irradiated from the sun 9 onto the light-receiving surface 12s is less likely to occur. This reduces the amount of light reflected from the light-receiving surface 12s toward the pilot 5 of the aircraft 3 preparing for landing in response to the irradiation of sunlight SL0. Therefore, for example, the estimated irradiance E1 or the first estimated irradiance E11 is less likely to increase. As a result, the pilot 5 of the aircraft 3 preparing for landing is less likely to be dazzled by the reflected sunlight SL0. Furthermore, for example, if the first pitch Py1 is greater than the second pitch Px1, during times when the sun's altitude is high, sunlight SL0 heading toward the light-receiving surface 12s from the south is less likely to irradiate the convex portion C1 and more likely to irradiate the base surface B1. This makes it less likely that the amount of light irradiating the solar cell 123c in the first solar cell module 12A will decrease. As a result, the amount of power generated in the airport solar power generation system 100 can be increased. Therefore, the pilot 5 of the aircraft 3 preparing to land is less likely to be dazzled by reflected sunlight SL0, and an airport solar power generation system 100 that can increase the amount of power generated can be realized.

[0141] 15 to 17, for example, as shown in FIGS. 23 to 25, the height H1 (also referred to as the first height) of the first convex portion C11 may be greater than the height H2 (also referred to as the second height) of the second convex portion C12 in the +Z direction as the third direction. The first height H1 is the length by which the first convex portion C11 protrudes from the base surface B1 in the +Z direction as the third direction. The second height H2 is the length by which the second convex portion C12 protrudes from the base surface B1 in the +Z direction as the third direction. In other words, for example, the multiple convex portions C1 may include first convex portions C11 extending along the −Y direction as the first direction and having a first height H1 in the +Z direction as the third direction, and second convex portions C12 extending along the +X direction as the second direction and having a second height H2 smaller than the first height H1 in the +Z direction as the third direction.

[0142] With this configuration, for example, during times when the sun's altitude is low, such as immediately after sunrise or immediately before sunset, sunlight SL0 heading toward the light-receiving surface 12s from the east or west is blocked by the multiple first convex portions C11 and is less likely to irradiate the base surface B1. Therefore, specular reflection of sunlight SL0 irradiated from the sun 9 onto the light-receiving surface 12s is less likely to occur on the light-receiving surface 12s. This reduces the amount of light reflected from the light-receiving surface 12s toward the pilot 5 of the aircraft 3 preparing for landing in response to the sunlight SL0. As a result, for example, the estimated irradiance E1 or the first estimated irradiance E11 is less likely to increase. Therefore, the pilot 5 of the aircraft 3 preparing for landing is less likely to be dazzled by the reflected sunlight SL0. Furthermore, during times when the sun's altitude is high, sunlight SL0 heading toward the light-receiving surface 12s from the south is less likely to irradiate either the first convex portions C11 or the second convex portions C12, and is more likely to irradiate the base surface B1. This makes it difficult for the amount of light irradiated on the solar cell 123c in the first solar cell module 12A to decrease, for example, which can increase the amount of power generated in the airport solar power generation system 100. Therefore, the pilot 5 of the aircraft 3 preparing to land is unlikely to be dazzled by reflected sunlight SL0, and an airport solar power generation system 100 that can increase the amount of power generated can be realized.

[0143] 18 to 20, for example, the height (first height) of the first convex portion C11 may be greater than the height (second height) of the second convex portion C12 in the +Z direction as the third direction. In this case as well, an airport solar power generation system 100 can be realized in which the pilot 5 of the aircraft 3 preparing to land is less likely to be dazzled by reflected light of sunlight SL0, and the amount of power generation can be improved.

[0144] Furthermore, for example, the arrangement and height of the multiple convex portions C1 may be adjusted so that sunlight SL0 heading toward the light receiving surface 12s from the east or west side is blocked by the multiple convex portions C1 and is less likely to be irradiated onto the base surface B1.

[0145] For example, as shown in FIG. 26, a virtual line connecting the second point P2 and the reflective area A1 is defined as a second virtual line L2. A virtual plane extending along the second virtual line L2 and the +Z direction (the third direction) is defined as a virtual plane Vp2. Here, for example, assume that the multiple convex portions C1 include two or more convex portions C1 aligned in a direction D4 (also referred to as a fourth direction) along the virtual plane Vp2 and the light receiving surface 12s. In FIG. 26, the fourth direction D4 is indicated by an arrow pointing to the right. Here, the two or more convex portions C1 may be, for example, the first convex portion C11 described above. For example, two convex portions C1 aligned adjacent to each other in the fourth direction D4 among the two or more convex portions C1 are defined as a third convex portion C1a (also referred to as a third convex portion) and a fourth convex portion C1b (also referred to as a fourth convex portion). In other words, the two or more convex portions C1 include a third convex portion C1a and a fourth convex portion C1b. Furthermore, for example, a portion of the base surface B1 located at the center between the third convex portion C1a and the fourth convex portion C1b in the fourth direction D4 is defined as a central portion Pc1. Furthermore, for example, a virtual straight line that is symmetrical to the second virtual line L2 with respect to a normal line N1 of the base surface B1 at the central portion Pc1 is defined as a third virtual line L3. The normal line N1 may be the same as the normal line 12n of the reflective area A1. It is assumed that the third virtual line L3 is located along the incident direction of sunlight SL0 onto the reflective area A1.

[0146] Here, for example, as shown in FIG. 26, when the second virtual line L2 passes through the central portion Pc1, it may intersect with the fourth convex portion C1b. In this case, even if light is specularly reflected from the base surface B1 toward the pilot 5 of the aircraft 3 preparing to land at the central portion Pc1 and at a portion of the base surface B1 closer to the fourth convex portion C1b than the central portion Pc1, this specularly reflected light may be irradiated onto the fourth convex portion C1b. Therefore, for example, on the light-receiving surface 12s, specular reflection light toward the pilot 5 of the aircraft 3 preparing to land is unlikely to occur at the base surface B1 in response to irradiation of sunlight SL0 onto the light-receiving surface 12s. This makes it unlikely that the amount of light reflected from the light-receiving surface 12s toward the pilot 5 of the aircraft 3 preparing to land in response to irradiation of sunlight SL0 will increase. As a result, for example, the estimated irradiance E1 or the first estimated irradiance E11 is unlikely to increase. Therefore, the pilot 5 of the aircraft 3 preparing to land is less likely to be dazzled by the reflected light of sunlight SL0.

[0147] Here, for example, as shown in Figure 27, if the pitch (also called the third pitch) at which two or more convex portions C1 are arranged in the fourth direction D4 is Pt1, the height of the fourth convex portion C1b based on the base surface B1 is H1b, and the angle (also called the specular reflection angle) formed between the normal N1 to the base surface B1 and the second virtual line L2 is θ3, then the relational expression (10) may be satisfied.

[0148] Pt1 ≤ 2 × H1b × tanθ3 ··· (10).

[0149] 26, for example, the third virtual line L3 may intersect with the third convex portion C1a when passing through the central portion Pc1. In this case, for example, sunlight SL0 directed toward the central portion Pc1 and the portion of the base surface B1 closer to the third convex portion C1a than the central portion Pc1 may be irradiated onto the third convex portion C1a. Therefore, for example, on the light-receiving surface 12s, specular reflection light directed toward the pilot 5 of the aircraft 3 preparing for landing is unlikely to occur at the base surface B1 in response to the illumination of sunlight SL0 onto the light-receiving surface 12s. This makes it unlikely that the amount of light reflected from the light-receiving surface 12s toward the pilot 5 of the aircraft 3 preparing for landing in response to the illumination of sunlight SL0 increases. As a result, for example, the estimated irradiance E1 or the first estimated irradiance E11 is unlikely to increase. Therefore, the pilot 5 of the aircraft 3 preparing for landing is unlikely to be dazzled by the reflected sunlight SL0.

[0150] Here, for example, as shown in FIG. 27, when the height of the third convex portion C1a relative to the base surface B1 is H1a and the angle (incident angle) formed between the normal N1 of the base surface B1 and the third virtual line L3 is θ3, the relational expression of formula (11) using the pitch (third pitch) Pt1 at which two or more convex portions C1 are arranged in the fourth direction D4 may be satisfied.

[0151] Pt1 ≤ 2 × H1a × tanθ3 ··· (11).

[0152] Here, for example, the height H1a of the third convex portion C1a and the height H1b of the fourth convex portion C1b may be the same, or the height H1a of the third convex portion C1a may be greater than the height H1b of the fourth convex portion C1b. The heights of two or more convex portions C1 lined up in the fourth direction D4 may be the same, or may be greater than or equal to the height H1b.

[0153] Here, for example, when the height H1b is 350 μm and the incident angle θ3 is 70 degrees, the relational expression of formula (10) is satisfied if the third pitch Pt1 is 1923 μm or less. Furthermore, when the height H1a is 350 μm and the incident angle θ3 is 70 degrees, the relational expression of formula (11) is satisfied if the third pitch Pt1 is 1923 μm or less. Here, for example, when the height H1b is 50 μm and the incident angle θ3 is 80 degrees, the relational expression of formula (10) is satisfied if the third pitch Pt1 is 567 μm or less. Furthermore, when the height H1a is 50 μm and the incident angle θ3 is 80 degrees, the relational expression of formula (11) is satisfied if the third pitch Pt1 is 567 μm or less.

[0154] <2-3. Summary of the First Embodiment> In the airport solar power generation system 100 according to the first embodiment, for example, the translucent member 121 has a configuration that reduces the estimated irradiance E1 of reflected light incident on the retina 5e5 of the eyeball 5e located at the second point P2 in response to reflection of sunlight SL0 in the reflective area A1 to less than the critical irradiance Et. The reflective area A1 is a region located within an imaginary right circular cone Cn1 of one or more solar cell modules 12. The imaginary right circular cone Cn1 has its apex at the second point P2 on the first imaginary line L1 and forms a 50-degree apex angle with a center line Lc1 extending along the first imaginary line L1. The first imaginary line L1 extends along the landing flight path of the aircraft flying toward the first point P1 between the target point markers 2a on the runway 2, and is located along an imaginary vertical plane Vp1 that passes through the runway centerline markers 2c on the runway 2. The critical irradiance Et is Et = 0.359 / ω using the visual angle ω [rad] in the eyeball 5e for the reflection area A1. 1.77 [W / m 2 This makes it difficult for the pilot 5 of the aircraft 3 preparing to land to be dazzled by the sunlight SL0 reflected by the airport solar power generation system 100.

[0155] <3. Other embodiments> The present disclosure is not limited to the first embodiment described above, and various modifications and improvements can be made without departing from the gist of the present disclosure.

[0156] In the first embodiment, for example, as shown in Fig. 28, one or more solar cell modules 12 in the solar cell array 1 may include a first solar cell module 12A whose light-receiving surface 12s has an uneven surface, and a solar cell module (also referred to as a second solar cell module) 12B whose light-receiving surface 12s is flat. The second solar cell module 12B and the first solar cell module 12A are different solar cell modules. In Fig. 28, the light-receiving surface 12s of the first solar cell module 12A is hatched with a sandy pattern, and the light-receiving surface 12s of the second solar cell module 12B is hatched with diagonal lines slanting upward to the left.

[0157] Here, for example, assume that a flat virtual mirror surface (also referred to as a second virtual mirror surface) 12m is set along the light-receiving surface 12s for each of one or more solar cell modules 12, and the sun 9 moves diurnally throughout the year. In this case, the one or more solar cell modules 12 may include a first number of solar cell modules 12 and a second number of solar cell modules 12. The first number and the second number may each represent a number of one or more. Each of the first number of solar cell modules 12 has a light-receiving surface 12s along a second virtual mirror surface 12m (also referred to as a secondA virtual mirror surface 12m1) that can generate specularly reflected light of sunlight SL0 that intersects with the first virtual line L1. Each of the second number of solar cell modules 12 has a light-receiving surface 12s along a second virtual mirror surface 12m (also referred to as a secondB virtual mirror surface 12m2) that cannot generate specularly reflected light of sunlight SL0 that intersects with the first virtual line L1. A configuration may be adopted in which each of the first number of solar cell modules 12 is a first solar cell module 12A, and each of the second number of solar cell modules 12 is either a first solar cell module 12A or a second solar cell module 12B.

[0158] In other words, the solar cell module 12 having the light-receiving surface 12s in a position and attitude that allows it to irradiate specularly reflected light toward the landing flight path along which the aircraft 3 flies toward the runway 2 immediately before landing on the runway 2 in response to irradiation with sunlight SL0 may be the first solar cell module 12A. Also, the solar cell module 12 having the light-receiving surface 12s that is not in a position and attitude that allows it to irradiate specularly reflected light toward the landing flight path along which the aircraft 3 flies toward the runway 2 immediately before landing on the runway 2 in response to irradiation with sunlight SL0 may be the first solar cell module 12A or the second solar cell module 12B.

[0159] With this configuration, for example, in the airport solar power generation system 100, the presence of the first solar cell module 12A reduces the likelihood of specular reflection of sunlight SL0 toward the retina 5e5 of the eyeball 5e of the pilot 5 of the aircraft 3 preparing for landing. This reduces the energy density of the luminous flux of sunlight SL0 toward the retina 5e5 of the eyeball 5e of the pilot 5 of the aircraft 3 preparing for landing. This reduces the likelihood of an increase in the estimated irradiance E1 or the first estimated irradiance E11. As a result, the pilot 5 of the aircraft 3 preparing for landing is less likely to be dazzled by the reflected sunlight SL0. Furthermore, the second solar cell module 12B has a light-receiving surface 12s that is smooth, which reduces the likelihood of sand, dust, mud, and other particles contained in rainwater adhering to the light-receiving surface 12s compared to the first solar cell module 12A. This reduces the likelihood of the light-receiving surface 12s becoming soiled, reducing the amount of power generated by the airport solar power generation system 100. Therefore, the pilot 5 of the aircraft 3 preparing to land is less likely to be dazzled by reflected sunlight SL0, and an airport solar power generation system 100 can be realized that can improve the amount of power generation.

[0160] Here, for example, a simulation using a virtual three-dimensional space model can be used to determine whether the first solar cell module 12A or the second solar cell module 12B should be applied to each solar cell module 12. Specifically, a flat, virtual, mirror-like light-receiving surface (also referred to as a virtual light-receiving surface) is set to indicate the area where the light-receiving surface 12s of the solar cell module 12 being simulated is planned to be disposed. A first virtual line L1 is also set, extending along the landing flight path of the aircraft 3 flying toward the runway 2 immediately before landing on the runway 2. A three-dimensional area (also referred to as a specular reflection light passing area) through which specular reflection light generated on the virtual light-receiving surface in response to irradiation of sunlight SL0 from the sun 9, which undergoes diurnal motion throughout the year, passes is mapped. If the first virtual line L1 intersects with at least a portion of the mapped specular reflection light passing area, it can be determined that the first solar cell module 12A should be applied to the solar cell module 12 being simulated. On the other hand, if the first virtual line L1 does not intersect at all with the mapped specular reflection light passing area, it can be determined that the first solar cell module 12A or the second solar cell module 12B should be applied as the solar cell module 12 to be simulated.

[0161] Here, for example, the first solar cell module 12A may be applied to one or more solar cell modules 12 having at least a portion of their light-receiving surfaces 12s included in the imaginary right circular cone Cn1 among the multiple solar cell modules 12 that make up the airport solar power generation system 100. Also, for example, either the first solar cell module 12A or the second solar cell module 12B may be applied to a solar cell module 12 having at least a portion of its light-receiving surface 12s that is not included in the imaginary right circular cone Cn1 among the multiple solar cell modules 12 that make up the airport solar power generation system 100.

[0162] In the first embodiment, for example, when second sealing layer 124 is translucent, the portion of back surface protection member 125 on the light-receiving surface 12s side may be colored black. This can reduce the amount of reflected light that occurs in solar cell module 12 in response to irradiation with sunlight SL0.

[0163] In the first embodiment, for example, the translucent member 121 may be a glass plate having irregularities, with anti-reflection coating and embossing applied to each of the surface opposite the photoelectric conversion unit 123 (first surface) and the surface on the photoelectric conversion unit 123 side (also called the second surface).

[0164] In the first embodiment, for example, the number of the first wiring members W1 electrically connecting adjacent solar cell 123c among the plurality of solar cell 123c may be 4 to 15, etc.

[0165] In the first embodiment, for example, the plurality of solar battery cells 123c may include a plurality of solar battery cells each having a substantially rectangular shape formed by dividing a solar battery cell having a substantially square shape.

[0166] In the first embodiment, for example, the light-transmitting member 121 may be a film-like member. In this case, for example, a plate-like member may be used as the back surface protection member 125 to maintain the rigidity of the solar cell module 12. The plate-like back surface protection member 125 may be made of glass or a resin such as acrylic or polycarbonate. The film-like light-transmitting member 121 may be made of a weather-resistant resin. Weather resistance refers to the property of being resistant to deformation, discoloration, degradation, and other changes in quality when used outdoors. Here, weather-resistant resins include, for example, fluorinated ethylene propylene copolymers (FEP), ethylene-tetrafluoroethylene copolymers (ETFE), and ethylene-chlorotrifluoroethylene copolymers (ECTFE). Here, for example, the light-transmitting member 121 may be made of two or more layers of weather-resistant resin. In this case, the fluorine-based resin used in the light-transmitting member 121 may be, for example, two or more types of resin. Therefore, for example, a conceivable embodiment is one in which the fluorine-based resin used in the light-transmitting member 121 includes at least one resin selected from FEP, ETFE, and ECTFE. The thickness of the light-transmitting member 121 may be, for example, approximately 0.05 mm to 0.5 mm.

[0167] In the first embodiment, for example, if the airport solar power generation system 100 is installed in the southern hemisphere, the light-receiving surface 12s may be inclined with respect to the horizontal plane so that it faces diagonally upward in the north direction, which is the median direction of the sun 9. In other words, the light-receiving surface 12s may be inclined with respect to the horizontal plane so that it is positioned lower the further north it goes.

[0168] In the first embodiment, for example, the longitudinal direction of the runway 2 may extend in a direction that forms a certain angle with the east-west direction. This certain angle may be, for example, an angle greater than 0 degrees and less than 45 degrees, or an angle greater than 0 degrees and less than 20 degrees.

[0169] In the first embodiment, for example, the light receiving surface 12s does not have to be inclined with respect to the horizontal plane. In this case, the −Y direction as the first direction may be a direction along the north-south direction, and the +X direction as the second direction may be a direction along the east-west direction.

[0170] In the first embodiment, the estimated irradiance E1 is calculated by calculation, but this is not limiting. The estimated irradiance E1 may be, for example, an illuminance actually measured using a measuring device in the cockpit of the aircraft 3 (also referred to as an actual measured illuminance), or may be calculated based on this actual measured illuminance. Furthermore, the actual measured illuminance may be obtained by measurement using a measuring device mounted on an unmanned aerial vehicle such as a drone.

[0171] In the first embodiment, the shape and arrangement of the unevenness on the first surface F1 of the light-transmitting member 121 of the first solar cell module 12A are not limited to those described above. Various shapes and arrangements may be applied to the shape and arrangement of the unevenness on the first surface F1 of the light-transmitting member 121 of the first solar cell module 12A. For example, a glass plate (also called patterned glass or matte glass) having an uneven pattern formed on the first surface F1 may be applied to the light-transmitting member 121 of the first solar cell module 12A.

[0172] In the first embodiment, for example, the eyeball 5e located at the second point P2 and the retina 5e5 of the eyeball 5e may be a viewpoint in the cockpit of the aircraft 3 located at the second point P2. The viewpoint in the cockpit may be, for example, a position from which an object including the target point marker 2a and the reflective area A1 is viewed in the aircraft 3 in landing preparations. Here, the viewpoint in the cockpit may be specified by, for example, the position of the eyeball 5e, the position of the cockpit, the position of the cockpit seat, or the position of the head of the pilot 5. For the position of the eyeball 5e, a predetermined position of the eyeball 5e (also referred to as a first predetermined position), such as the approximate center of the retina 5e5 of the eyeball 5e or the approximate center of the eyeball 5e, may be applied. For the position of the cockpit, a predetermined position of the cockpit (also referred to as a second predetermined position), such as the approximate center of the cockpit, may be applied. For the position of the cockpit, a predetermined position of the cockpit (also referred to as a third predetermined position), such as the approximate center of the headrest of the cockpit, may be applied. For example, if there are multiple cockpits in the cockpit, the cockpit position may be a predetermined position (third predetermined position) of the cockpit that is normally used by the pilot 5 or the captain (also referred to as the main pilot) who pilots the aircraft 3, or a predetermined position for the multiple cockpits (also referred to as the fourth predetermined position), such as an approximate center position between the multiple cockpits. The head position of the pilot 5 may be a predetermined position (fifth predetermined position) of the head of the pilot 5, such as an approximate center position between the heads of the pilots 5. For example, if there are multiple pilots 5 in the cockpit, the head position of the pilot 5 may be a predetermined position (fifth predetermined position) of the head of the main pilot among the multiple pilots 5, or a predetermined position (sixth predetermined position) of the heads of the multiple pilots, such as an approximate center position between the heads of the multiple pilots. Here, for example, an estimated value of the irradiance of reflected light incident on the viewpoint in the cockpit of the aircraft 3 located at the second point P2 in response to reflection of sunlight SL0 on the reflection area A1 is applied to the estimated irradiance E1. For example, the critical irradiance Et is calculated by the formula (1) using the visual angle ω for the reflective area A1 at the viewpoint in the cockpit. In this case, the visual angle ω may be, for example, the angle formed by two straight lines that pass through both ends of the reflective area A1 and extend to the viewpoint in the cockpit.For example, if the translucent member 121 has a form that makes the estimated irradiance E1 smaller than the critical irradiance Et, the pilot 5 of the aircraft 3 preparing to land will be less likely to be dazzled by the sunlight SL0 reflected by the airport solar power generation system 100.

[0173] Although the solar power generation system has been described in detail above, the above description is merely an example in all respects, and this disclosure is not limited thereto. Furthermore, the various examples described above can be combined and applied as long as they are not mutually contradictory. It is understood that countless examples not illustrated can be envisioned without departing from the scope of this disclosure.

[0174] This disclosure includes the following:

[0175] In one embodiment, (1) a solar power generation system includes one or more mounts and one or more solar cell modules fixed to the one or more mounts, each of the one or more solar cell modules having a light-receiving surface for receiving sunlight, and including a solar cell and a light-transmitting member protecting the solar cell from the light-receiving surface side, and extending along a flight path of an aircraft toward a first point between target point markings of a runway, and positioned along an imaginary vertical plane passing through a runway centerline marking of the runway. In the case where a first virtual line is an imaginary straight line passing through the first virtual line and a second point on the first virtual line is an imaginary right circular cone having a vertex at a second point on the first virtual line and forming an apex angle of 50 degrees with a center line extending along the first virtual line, the light-transmitting member calculates an estimated irradiance of reflected light incident on the retina of the eyeball located at the second point in response to reflection of the sunlight at a reflective area of ​​the one or more solar cell modules located within the imaginary right circular cone, using Et=0.359 / ω2 where ω2 is the visual angle of the eyeball for the reflective area. 1.77 The critical irradiance Et [W / m 2 ] has a form that makes it smaller than.

[0176] (2) In the solar power generation system of (1) above, the estimated irradiance may include an estimated value of the irradiance of diffusely reflected light that is incident on the retina after the sunlight is diffusely reflected in the reflective area, or a calculated value of the irradiance calculated based on the estimated value.

[0177] (3) In the solar power generation system of (2) above, the calculated value may be calculated by multiplying the estimated value by a coefficient.

[0178] (4) In the solar power generation system of (1) above, assuming that the reflective area is a flat first virtual mirror surface, a first reflective area exists in the reflective area, which emits specularly reflected light in response to irradiation of sunlight toward the second point, and the reflective area can be divided into the first reflective area and a second reflective area other than the first reflective area, which emits diffusely reflected light in response to irradiation of sunlight toward the second point, the translucent member calculates a first estimated irradiance of the specularly reflected light incident on the retina in response to reflection of sunlight in the first reflective area by Et1=0.359 / ω1 using a first visual angle ω1 [rad] of the eyeball for the first reflective area. 1.77 The first critical irradiance Et1 [W / m 2 ], and a second estimated irradiance of the diffusely reflected light incident on the retina in response to the diffuse reflection of the sunlight in the second reflective area is calculated by Et2=0.359 / ω2 using a second visual angle ω2 [rad] of the eyeball for the second reflective area. 1.77 The second critical irradiance Et2 [W / m 2 ] may have a form in which the size is smaller than [ ].

[0179] (5) In the solar power generation system of any one of (1) to (4) above, the one or more solar cell modules may include a first solar cell module whose light-receiving surface has irregularities.

[0180] (6) In the solar power generation system of (5) above, the light receiving surface is located along a first direction inclined with respect to a horizontal plane and a second direction perpendicular to the first direction and along the horizontal plane, and in the first solar cell module, the translucent member may have, on the light receiving surface side, a planar base surface along each of the first direction and the second direction, and a plurality of convex portions protruding beyond the base surface in a third direction perpendicular to both the first direction and the second direction.

[0181] (7) In the solar power generation system of (6) above, the plurality of convex portions may be regularly arranged at a first pitch in the first direction and regularly arranged at a second pitch smaller than the first pitch in the second direction.

[0182] (8) In the solar power generation system of (6) or (7) above, the plurality of convex portions may include a first convex portion extending along the first direction and having a first height in the third direction, and a second convex portion extending along the second direction and having a second height in the third direction that is smaller than the first height.

[0183] (9) In any one of the solar power generation systems (6) to (8) above, the plurality of convex portions may include two or more convex portions arranged in a virtual plane and a fourth direction along the light receiving surface, the virtual plane being located along a second virtual line connecting the second point and the reflective area and being located along the third direction, the two or more convex portions including a third convex portion and a fourth convex portion arranged adjacent to each other in the fourth direction, and the second virtual line may intersect with the fourth convex portion when passing through a central portion of the base surface located in the middle between the third convex portion and the fourth convex portion in the fourth direction.

[0184] (10) In the solar power generation system of (9) above, the pitch Pt1 at which the two or more convex portions are arranged in the fourth direction, the height H1b of the fourth convex portion based on the base surface, and the angle θ3 formed between the normal to the base surface and the second virtual line may satisfy the relational expression Pt1≦2×H1b×tan θ3.

[0185] (11) In any one of the solar power generation systems (5) to (10) above, the one or more solar cell modules include the first solar cell module and a second solar cell module having a flat light-receiving surface, and the one or more solar cell modules include a first number of solar cell modules each having the light-receiving surface aligned with the second virtual mirror surface that can produce specularly reflected light of the sunlight that intersects the first virtual line when a flat second virtual mirror surface is set for each of the one or more solar cell modules and the sun performs diurnal motion throughout the year, and a second number of solar cell modules each having the light-receiving surface aligned with the second virtual mirror surface that cannot produce specularly reflected light of the sunlight that intersects the first virtual line, and each of the first number of solar cell modules may be the first solar cell module, and each of the second number of solar cell modules may be the first solar cell module or the second solar cell module.

[0186] In one embodiment, (12) a solar power generation system includes one or more mounts and one or more solar cell modules fixed to the one or more mounts, each of the one or more solar cell modules having a light-receiving surface for receiving sunlight, and including a solar cell and a light-transmitting member protecting the solar cell from the light-receiving surface side, and extending along a path along which an aircraft flies toward a first point between target point markings of a runway and positioned along an imaginary vertical plane passing through a runway centerline marking of the runway. is defined as a first virtual line, and a virtual right circular cone having a second point on the first virtual line as its apex and forming an apex angle of 50 degrees with a center line extending along the first virtual line is defined as a virtual right circular cone, the translucent member calculates an estimated irradiance of reflected light incident on a viewpoint in the cockpit of the aircraft located at the second point in response to reflection of the sunlight at a reflective area of ​​the one or more solar cell modules located within the virtual right circular cone, using a visual angle ω [rad] at the viewpoint for the reflective area, as Et=0.359 / ω 1.77 The critical irradiance Et [W / m 2 ] has a form that makes it smaller than. [Explanation of symbols]

[0187] 1 Solar array 11 Mounting stand 12 Solar cell modules 12A 1st solar cell module 12B Second solar cell module 100 Airport solar power generation system (solar power generation system) 121 Translucent material 123c solar cell 12m second virtual mirror 12n,N1 normal 12s light receiving surface 2 runways 2a Target point marker 2c Runway centerline marking 3 aircraft 5 Pilot 5e eyeball 5e5 retina 9 sun A1 reflective area A11 1st reflection area A12 2nd reflective area B1 basal plane C1 Convex part C11 First convex part C12 Second convex part C1a Third convex part C1b 4th convex part Cn1 Virtual right circular cone D4 4th direction DL1 Diffuse E1 Estimated irradiance E11 First estimated irradiance E12 Second estimated irradiance Er retinal irradiance Er1 First retinal irradiance Er2 Second retinal irradiance Et critical irradiance Et1 1st critical irradiance Et2 2nd critical irradiance L1 First virtual line L2 Second virtual line L3 Third virtual line Lc1 center line P1 1st point P2 2nd point Pc1 center part Pt1 3rd pitch Px1 2nd pitch Py1 1st pitch RL1 Specular reflection light SL0 solar light Vp1 Virtual vertical plane Vp2 virtual plane

Claims

1. one or more cradles; one or more solar cell modules fixed to the one or more mounts; Each of the one or more solar cell modules has a light-receiving surface for receiving sunlight, and includes a solar cell and a light-transmitting member that protects the solar cell from the light-receiving surface side, When a first virtual line is defined as an imaginary straight line that extends along a flight path of an aircraft toward a first point between target point markings on a runway and is located along an imaginary vertical plane that passes through a runway centerline marking on the runway, and when a virtual right circular cone is defined as an imaginary right circular cone that has a second point on the first virtual line as its apex and forms an apex angle of 50 degrees with a centerline that extends along the first virtual line, The light-transmitting member calculates an estimated irradiance of reflected light incident on the retina of the eyeball located at the second point in response to reflection of the sunlight at a reflective area of ​​the one or more solar cell modules located within the imaginary right circular cone, using Et=0.359 / ω where ω [rad] is the visual angle of the eyeball for the reflective area. １．７７ The critical irradiance Et [W / m ２ ], the one or more solar cell modules include a first solar cell module having an uneven light-receiving surface; the light receiving surface is located along a first direction inclined with respect to a horizontal plane and a second direction perpendicular to the first direction and along the horizontal plane, In the first solar cell module, the light-transmitting member has, on the light-receiving surface side, a planar base surface along each of the first direction and the second direction, and a plurality of convex portions protruding beyond the base surface in a third direction perpendicular to both the first direction and the second direction; A solar power generation system, wherein the plurality of protrusions are regularly arranged at a first pitch in the first direction and at a second pitch smaller than the first pitch in the second direction.

2. one or more cradles; one or more solar cell modules fixed to the one or more mounts; Each of the one or more solar cell modules has a light-receiving surface for receiving sunlight, and includes a solar cell and a light-transmitting member that protects the solar cell from the light-receiving surface side, When a first virtual line is defined as an imaginary straight line that extends along a flight path of an aircraft toward a first point between target point markings on a runway and is located along an imaginary vertical plane that passes through a runway centerline marking on the runway, and when a virtual right circular cone is defined as an imaginary right circular cone that has a second point on the first virtual line as its apex and forms an apex angle of 50 degrees with a centerline that extends along the first virtual line, The light-transmitting member calculates an estimated irradiance of reflected light incident on the retina of the eyeball located at the second point in response to reflection of the sunlight at a reflective area of ​​the one or more solar cell modules located within the imaginary right circular cone, using Et=0.359 / ω where ω [rad] is the visual angle of the eyeball for the reflective area. １．７７ The critical irradiance Et [W / m ２ ], the one or more solar cell modules include a first solar cell module having an uneven light-receiving surface; the light receiving surface is located along a first direction inclined with respect to a horizontal plane and a second direction perpendicular to the first direction and along the horizontal plane, In the first solar cell module, the light-transmitting member has, on the light-receiving surface side, a planar base surface along each of the first direction and the second direction, and a plurality of convex portions protruding beyond the base surface in a third direction perpendicular to both the first direction and the second direction; a solar power generation system, wherein the plurality of protrusions include first protrusions extending along the first direction and having a first height in the third direction, and second protrusions extending along the second direction and having a second height in the third direction that is smaller than the first height.

3. one or more cradles; one or more solar cell modules fixed to the one or more mounts; Each of the one or more solar cell modules has a light-receiving surface for receiving sunlight, and includes a solar cell and a light-transmitting member that protects the solar cell from the light-receiving surface side, When a first virtual line is defined as an imaginary straight line that extends along a flight path of an aircraft toward a first point between target point markings on a runway and is located along an imaginary vertical plane that passes through a runway centerline marking on the runway, and when a virtual right circular cone is defined as an imaginary right circular cone that has a second point on the first virtual line as its apex and forms an apex angle of 50 degrees with a centerline that extends along the first virtual line, The light-transmitting member calculates an estimated irradiance of reflected light incident on the retina of the eyeball located at the second point in response to reflection of the sunlight at a reflective area of ​​the one or more solar cell modules located within the imaginary right circular cone, using Et=0.359 / ω where ω [rad] is the visual angle of the eyeball for the reflective area. １．７７ The critical irradiance Et [W / m ２ ], the one or more solar cell modules include a first solar cell module having an uneven light-receiving surface; the light receiving surface is located along a first direction inclined with respect to a horizontal plane and a second direction perpendicular to the first direction and along the horizontal plane, In the first solar cell module, the light-transmitting member has, on the light-receiving surface side, a planar base surface along each of the first direction and the second direction, and a plurality of convex portions protruding beyond the base surface in a third direction perpendicular to both the first direction and the second direction; the plurality of protrusions include two or more protrusions aligned in a fourth direction along an imaginary plane and the light receiving surface, the virtual plane is located along a second virtual line connecting the second point and the reflective area and along the third direction; the two or more protrusions include a third protrusion and a fourth protrusion that are arranged adjacent to each other in the fourth direction, A solar power generation system, wherein the second virtual line intersects with the fourth convex portion when passing through a central portion of the base surface that is located in the center between the third convex portion and the fourth convex portion in the fourth direction.

4. The solar power generation system according to claim 3, a pitch Pt1 at which the two or more convex portions are arranged in the fourth direction, a height H1b of the fourth convex portion relative to the base surface, and an angle θ3 formed between a normal to the base surface and the second virtual line satisfy the relational expression Pt1≦2×H1b×tan θ3.

5. one or more cradles; one or more solar cell modules fixed to the one or more mounts; Each of the one or more solar cell modules has a light-receiving surface for receiving sunlight, and includes a solar cell and a light-transmitting member that protects the solar cell from the light-receiving surface side, When a first virtual line is defined as an imaginary straight line that extends along a flight path of an aircraft toward a first point between target point markings on a runway and is located along an imaginary vertical plane that passes through a runway centerline marking on the runway, and when a virtual right circular cone is defined as an imaginary right circular cone that has a second point on the first virtual line as its apex and forms an apex angle of 50 degrees with a centerline that extends along the first virtual line, The light-transmitting member calculates an estimated irradiance of reflected light incident on the retina of the eyeball located at the second point in response to reflection of the sunlight at a reflective area of ​​the one or more solar cell modules located within the imaginary right circular cone, using Et=0.359 / ω where ω [rad] is the visual angle of the eyeball for the reflective area. １．７７ The critical irradiance Et [W / m ２ ], the one or more solar cell modules include a first solar cell module having an uneven light-receiving surface; the one or more solar cell modules include the first solar cell module and a second solar cell module having a flat light-receiving surface; the one or more solar cell modules include: a first number of solar cell modules each having the light-receiving surface aligned with the second virtual mirror surface, which is a flat second virtual mirror surface that is set along the light-receiving surface for each of the one or more solar cell modules, and which can generate specularly reflected light of the sunlight that intersects the first virtual line when the sun performs diurnal motion throughout the year; and a second number of solar cell modules each having the light-receiving surface aligned with the second virtual mirror surface that cannot generate specularly reflected light of the sunlight that intersects the first virtual line, A solar power generation system, wherein each of the first number of solar cell modules is the first solar cell module, and each of the second number of solar cell modules is the first solar cell module or the second solar cell module.

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