A building with solar panels installed on the spandrels

Abstract

To develop a technique for installing solar cells in areas other daylighting openings such as windows on a wall surface of a building in the building employing a glass curtain wall.SOLUTION: In a building with a glass curtain wall installed on an exterior wall, a solar cell module is installed in an interior space of a spandrel.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a solar power generation technology that utilizes the wall surfaces of buildings. [Background technology]

[0002] As a measure against global warming, there is a need to promote the use of renewable energy, and there is also a need to make buildings more energy efficient. There have been several proposals to install solar cells on the rooftops or walls of buildings. The present applicant has also made some proposals, as shown in the following patent documents.

[0003] As shown in Patent Document 1 (Japanese Patent No. 6905936), proposals have been made to apply solar power generation to buildings, such as a method of installing solar cell modules in which adjacent solar cell modules are arranged side by side in a substantially vertical direction with overlapping portions between them. The present inventors have also proposed using glass in buildings for solar cells, as shown in Patent Document 2 (WO2018 / 056286). Patent Document 3 (JP Patent Publication No. 2000-64555) proposes a structure for attaching solar cells to a wall surface, in which detachable solar cell mounting plate support means of different sizes are attached to the exterior wall of a building, and the solar cell mounting plates are supported at an angle at a specified distance from the exterior wall, making it possible to easily replace damaged solar cells and maintain a certain level of power generation capacity, and by attaching the solar cells at an angle to the wall surface, they can efficiently receive sunlight. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6905936 [Patent Document 2] WO2018 / 056286 publication [Patent Document 3] Japanese Patent Application Laid-Open No. 2000-64555 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to develop a technology for installing solar cells in areas other than windows and other lighting openings on the wall of a building that uses a glass curtain wall. [Means for solving the problem]

[0006] 1. A building with a glass curtain wall installed on the exterior wall, characterized by the installation of solar cell modules in the interior space of the spandrels. 2. The building described in 1., characterized in that an infrared-transmitting film is installed on the glass surface side of the spandrel section, and a solar cell module with high power generation efficiency in the near-infrared range is installed. 3. The building described in 2., characterized in that the solar cell modules are installed at an angle. 4. A building as described in 2. or 3., characterized in that a reflector that reflects sunlight toward the solar cell module is installed within the spandrel. 5. The building described in 4., characterized in that the solar cell modules are arranged in multiple tiers, one above the other, and a reflector is provided above each tier to reflect solar radiation toward that tier. Maintenance can be improved by laminating metal plates such as aluminum plates. [Effects of the Invention]

[0007] 1. In buildings that use glass curtain walls, solar cells can be installed inside the wall by utilizing the internal space of the spandrels, which are the areas of the building walls other than windows and other openings for lighting. Since the solar cell modules are provided within the spandrels, the solar cell modules are not exposed, and a building equipped with solar cells can be provided without affecting the exterior appearance. The present invention allows solar cell modules to be retrofitted using the spandrels of existing buildings, thereby improving the building's power generation capacity. 2. Furthermore, by installing solar reflectors around the solar cell module facing the solar cell module, the utilization efficiency of sunlight entering the spandrel can be increased, thereby increasing power generation efficiency. 3. Furthermore, by using glass or a film attached to the glass that has low transmittance in the visible light range and high transmittance in the near-infrared range for the openings in the spandrel section, and by using solar cell modules that have high power generation efficiency when exposed to sunlight in the near-infrared range, the solar cell modules cannot be seen from outside, and power can be generated without affecting the appearance. The depth of the spandrel can be used to install solar cell modules at an angle, which can increase the amount of power generated compared to installing them vertically on the wall. 4. By utilizing the space inside the spandrel, the solar cell modules can be divided and installed in several stages, allowing them to be installed at an even greater incline, further improving power generation efficiency. 5. This invention maximizes annual power generation by effectively utilizing solar radiation through the installation angle of the solar cell module and the installation of reflectors, and also ensures freedom in the exterior design of the building by using near-infrared-transmitting glass or film. [Brief explanation of the drawings]

[0008] [Figure 1] A diagram showing a building with solar modules installed in the interior space of the spandrels. [Figure 2] 1 shows a spandrel on which a solar cell module is installed. [Figure 3] A diagram showing examples 1 and 2 of a solar cell module and a reflector. [Figure 4] Figures showing examples 3 and 4 of a solar cell module and a reflector. [Figure 5] FIG. 5 shows Example 5 of a solar cell module and a reflector. [Figure 6] FIG. 10 is a diagram showing an example in which a near-infrared transmitting film is installed on a spandrel. [Figure 7] A diagram showing an example of installing side reflectors on spandrels and the reflected light. [Figure 8] An example of installing an upper reflector on a spandrel and a diagram showing the reflected light. [Figure 9] An example of a central reflector installed on a spandrel and a diagram showing the reflected light. [Figure 10] A diagram showing an example of a lower part with solar modules installed on spandrels. [Figure 11] 10A and 10B are diagrams showing an example of a process for installing solar cell modules on spandrels. [Figure 12] A diagram showing the wavelength relationship for solar power generation (a) and the wavelength characteristics transmitted by a near-infrared (NIR) transmitting film (b). DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Figure 1 shows a building with solar cell modules installed in the internal space of the spandrel. (a) shows a cross section of the spandrel with solar cell modules installed. (b) shows the spandrel portion of the glass curtain wall building where the solar cell modules are installed. This figure is used for general explanation, and the glass curtain wall buildings to which the present invention can be applied are not limited to this. A building 10 equipped with a glass curtain wall 6 generally has mullions 34 arranged vertically in parallel, with glass 5 installed on one side. The building basically has an upper story 91 separated by an upper slab and a lower story 92 separated by a lower slab, and the exterior surface of the story is formed by openings 93 for letting light into the living area and spandrels 1 that form the exterior wall of the ceiling recess. The spandrel 1 consists of a mullion 34 protruding from the skeleton 42 of the building 10, with glass 5 at its tip. Generally, there is space between the mullions on both sides, the glass, and the wall surface of the skeleton. The size of the spandrel depends on the design specifications of the building, but is, for example, about 1 to 3 m wide, 1 to 2 m high, and 10 to 30 cm deep. In the present invention, a solar cell module 3 is installed in the internal space 2 of this spandrel 1 to make effective use of it. In the figure (a), a solar cell module 3 is installed with a PV width D that is shorter than the inter-mullion spacing L between the mullions 53 formed by the left and right mullions 34, 34. This building is assumed to face south, and an example of an arrangement is shown in which a margin is provided in the area shaded by the mullions and receiving less sunlight. In addition, in the example shown, insulation material 43 is provided on the far side of the spandrel, a measure to reduce the heat load inside the building, but this is not directly related to solar power generation. Based on the solar cell module installation shown in Figure 1(a), several embodiments are proposed below.

[0010] Figure 2 shows the spandrel on which the solar cell modules are installed. In Figure 2, reflectors 44 and 46 are provided in the upper and left and right margins where the solar cell modules 3 are less likely to be exposed to sunlight. In addition, the solar cell modules 3 are arranged with their top edges facing backward and their bottom edges facing forward, tilting upward. This is designed to allow sunlight entering the spandrel to be effectively irradiated onto the solar cell modules. Side reflectors 45 are installed at an angle in the blank spaces between the solar cell module 3 and the left and right mullions 34. An upper reflector 46 is installed at an angle above the solar cell module 3. As shown in (b), the solar cell module 3 is also arranged with the upper part facing the back and the lower part facing forward, tilting upward. In the example shown, the side reflectors 45, 45 on both sides are identical, but this can be adjusted to improve reflective efficiency depending on the solar radiation conditions, such as the orientation of the building.

[0011] Furthermore, in this embodiment, a near-infrared transmitting film 52 is provided on the inside of the glass 5. The near-infrared transmitting film transmits near-infrared light to be used as energy by the solar cell and reflects visible light, so the installation of the solar cell module does not change the exterior appearance of the building. Therefore, by using a near-infrared transmitting film, the impact of the installation of the solar cell module on the exterior appearance can be reduced, ensuring freedom in exterior design.

[0012] 3 to 5 show five main installation examples of solar cell modules. Figure 3 shows (a) the type without a reflector (Type A), (b) the type with a reflector (Type B), Figure 4 shows (a) the reflector + tilted PV type (Type C), (b) the multiple installation type (Type D), and Figure 5 shows the full-surface PV installation type (Type E). In each figure, a cross-sectional view is shown at the top and a vertical cross-sectional view at the bottom. Note that "PV" is sometimes an abbreviation for "solar cell module." In all cases, a near-infrared transmitting film is applied to the glass surface, just like in Figure 2.

[0013] The type without a reflector (Type A) shown in Fig. 3(a) is installed on the spandrel 1 with margins on the left, right, and top of the solar cell module 3. The solar cell module 3 is also installed vertically. The reflector-mounted type (type B) shown in Fig. 3(b) has side reflectors 45, 45 on the left and right sides of the solar cell module 3 and an upper reflector 46 on the top, mounted on the spandrel 1. The solar cell module 3 is also mounted vertically.

[0014] The reflector + tilted PV type (C type) shown in Figure 4(a) has side reflectors 45, 45 on the left and right sides of the solar cell module 3 and an upper reflector 46 on the top, installed on the spandrel 1. The solar cell module 3 is tilted at an inclination angle θ with the top facing back and the bottom facing forward. The multiple installation type (D type) shown in Figure 4(b) has side reflectors 45, 45 on the left and right sides of the solar cell module 3. The solar cell module 3 is divided into three sections and arranged at an angle in three stages, with reflectors provided between the divided solar cell modules. The reflectors are, from top to bottom, an upper reflector 46, and the middle reflector is a central reflector 47. The angle of inclination θ of the divided solar cell modules 3 is smaller, which can increase the solar light utilization efficiency.

[0015] In the full-surface PV installation type shown in Figure 5, the solar cell modules are installed close to the glass surface, filling the spandrel.

[0016] Table 1 shows the estimated power generation amounts when types A to D are installed facing south. The amount of electricity generated varies depending on the type, but you can make an appropriate selection taking into account the building constraints and the specifications of the solar cell module. [Table 1]

[0017] Figure 6 shows an example of installing a near-infrared transmitting film on a spandrel. The near-infrared transmitting film 52 is installed on the inner surface of the glass 5. The near-infrared transmitting film is installed in the form of a film or sheet. It can be installed independently or attached to the glass surface. Alternatively, glass that has been given near-infrared transmittance can be used when building a new building. Near-infrared transmitting film suppresses the transmission of visible light (VL) and transmits a large amount of near-infrared rays (NIR). It reflects visible light and makes the solar cell modules installed inside invisible, so there is no impact on the exterior (it is difficult to see inside the spandrels). Even if solar power generation functions are added to exterior walls, there are fewer restrictions on the design of the architectural exterior (architectural facade), making it possible to create buildings with excellent design.

[0018] Near-infrared rays are electromagnetic waves with wavelengths of approximately 0.8 to 2.5 μm, mid-infrared rays are electromagnetic waves with wavelengths of approximately 2.5 to 4 μm, and the wavelength of electromagnetic waves equivalent to visible light is approximately 0.4 to 0.8 μm. The near-infrared transmitting film of the present invention has the light transmission property of transmitting a large amount of wavelengths in the range of about 0.8 to 2.5 μm (800 to 2500 nm) and suppressing (including reflecting) the transmission of wavelengths less than 0.8 μm. Note that the film may transmit some visible light, and the transmittance in the visible light range may be wavelength-selective or the transmittance over the entire visible light range may be adjusted, and it is not necessary to strictly classify the film by the wavelength of electromagnetic waves.

[0019] The near-infrared transmitting film can be constructed by depositing the near-infrared (NIR) transmitting film onto the glass, sealing it with laminated glass, or making it into a film. If planning to install it at the time of new construction, it is also possible to impart near-infrared transmitting properties to the glass. The following materials are used to make near-infrared transmitting films: Near-infrared (NIR) transparent films can be made from NIR-transmitting materials such as silicon (Si), calcium fluoride (CaF2), magnesium fluoride (MgF2), synthetic quartz (FS), germanium (Ge), N-BK7, potassium bromide (KBr), sapphire, sodium chloride (NaCl), zinc selenide (ZnSe), and zinc sulfide (ZnS), and can be produced by depositing these compounds onto glass or film.

[0020] 7 to 10 show (a) the structure for attaching the solar cell module and reflector shown in FIGS. 3 and 4, and (b) the state of sunlight. FIG. 7 shows an example of a structure in which a side reflector is installed, and shows a side reflector 45 installed on the right side of the spandrel modeled after the C type in FIG. 4(a). A base 71 made of C-shaped light iron or the like is erected on the back side of the side end of the solar cell module 3, and a rear jig 72a is fixed to this base 71 using connecting means 79a such as bolts and nuts. Meanwhile, a front jig 72b is installed on the front end side of the mullion 34 using sash 54. The shapes of the rear jig 72a and front jig 72b are curved to match the arrangement of the side reflectors 45, which are arranged diagonally. The rear jig 72a and front jig 72b are made of elongated material and are installed in multiple numbers along the sides of the side reflectors 45, and the side reflectors 45 can be fixed using connecting means 79b, 79c such as bolts and nuts. A near-infrared transmitting film 52 is installed on the inner surface of the glass 5. The near-infrared transmitting film suppresses the transmission of visible light and transmits a large amount of near-infrared light. The near-infrared transmitting film 52 can be attached to the glass 5, or the near-infrared transmitting film 52 can be made into a sheet-like independent film with a film frame 55. The installation of the near-infrared transmitting film is the same as that shown in Figures 8 to 10. For example, when building a new building, it is possible to use glass 5 with near-infrared transmitting film 52 already attached. When installing solar cell modules 3 during renovations, a freestanding type attached to a film frame is suitable, taking into consideration the need to work at height and the technology required for attachment.

[0021] The arrows indicate the state of solar radiation, with the visible light VL portion of sunlight SL being reflected to the outer surface by the near-infrared transmitting film 52, and the near-infrared NIR being transmitted and reflected obliquely by the side reflector 45, entering the solar module 3 and contributing to power generation. The applicant has disclosed the near-infrared transmitting film and the solar cell suitable for near-infrared light in Japanese Patent Application No. 2021-047389.

[0022] FIG. 8 shows an example of a structure in which an upper reflector is installed, in which an upper reflector 46 is installed above the spandrel modeled after the C-type in FIG. 4(a). A C-shaped light steel base 71 or the like is erected on the back side of the solar cell module 3 and fixed to the upper sash 51 via a jig. The upper part of the solar cell module 3 is fastened to an upper PV jig 72c attached to the base 71. An upper reflector 46 is attached to a V-shaped upper jig 72d attached to the upper sash 51. The arrows indicate the solar radiation conditions, with sunlight SL reflected to the outer surface by the near-infrared transmitting film 52 as visible light VL, and near-infrared light NIR passing through and reflected obliquely by the upper reflector 46 before entering the solar module 3 and contributing to power generation.

[0023] Figure 9 shows an example of a structure in which a central reflector and central solar cell are installed in the middle of the spandrel. This is an example of an installation structure in which the reflector and solar cell are divided into parts and folded back on the spandrel, modeled after Type D in Figure 4(b). A base 71 made of C-shaped light iron or the like is erected on the back side of the solar cell module 3, and an intermediate jig 72e with a support plate 72f attached from the middle to the front end is extended forward, the upper part of the support plate 72f supports the lower end of the solar cell, and a middle reflector 47 is attached below. The arrows indicate the state of solar radiation. From the upper sunlight SL1, visible light VL1 is reflected to the outer surface by the near-infrared transmitting film 52, and near-infrared light NIR1 is transmitted and enters the solar cell 3-1, contributing to power generation. From the lower sunlight SL2, visible light VL2 is reflected to the outer surface by the near-infrared transmitting film 52, and near-infrared light NIR2 is transmitted and reflected obliquely by the central reflector 47, entering the lower solar cell 3-2, contributing to power generation. The solar cell can use the directly incident NIR1 and the reflected and incident NIR2 for power generation. Furthermore, by dividing it into several stages, the installation angle can be adjusted.

[0024] Figure 10 shows an example of a structure for installing the lower end of a solar cell module, showing the lower part of a spandrel modeled after the C-type in Figure 4(a). The lower end of a C-shaped light iron or similar substrate 71 is fixed to the lower sash 54 with bolts or the like on the rear side of the solar cell module 3. The lower end of the solar cell module 3 is supported by a lower PV jig 72g attached to the front part of the lower sash 54. The arrows indicate the state of sunlight, with sunlight SL being reflected by the near-infrared transmitting film 52 as visible light VL to the outside, and near-infrared light NIR being transmitted and entering the solar module 3, contributing to power generation.

[0025] As shown in FIGS. 7 to 10, a solar cell module and a reflector can be installed within the spandrel using a base 71 provided at the back and various jigs 72 on this base and sash 54.

[0026] Figure 11 shows the construction process for installing solar cell modules on the spandrels of an existing glass curtain wall building. The spandrel opening will be 2m long, 3m wide and 20cm deep. It will be a C-type as shown in Figure 4(a), with reflectors installed on the top and both sides. The solar cell module will be 1m long and 2m wide. The near-infrared transmitting film will be roughly the same size as the glass, but will be adjusted according to the structure of the sash to which it will be attached. Furthermore, by selecting existing solar cells of a size that can be housed in the spandrel, it will be easier to procure the equipment and perform the installation work. The first step is to remove the glass from the building's spandrels. The second step is to install the base and various jigs inside the spandrel. The third step is to install the solar cell module and reflector. In the fourth step, a near-infrared transmitting film is installed. The fifth step is to reinstall the glass.

[0027] About solar cell modules The relationship between wavelength and solar power generation is shown in Figure 12. (a) shows that amorphous silicon solar cells use visible light to generate power, while crystalline silicon solar cells have a high utilization rate of near-infrared light. Since crystalline silicon solar cells have a high solar power generation conversion rate, it is advantageous to use crystalline silicon solar cells in the present invention. An example of the wavelength characteristics of a near-infrared (NIR) transmitting film is shown in Figure 12(b). As shown here, it is possible to use a near-infrared transmitting film that transmits light in the near-infrared wavelength range of 800 nm (0.8 μm) or more, but does not transmit light in the visible light range of less than approximately 800 nm (0.8 μm). In the present invention, it is effective to use a solar cell module in combination that has power generation characteristics suitable for near-infrared rays. [Explanation of symbols]

[0028] 1 Spandrel (SD) 2. Interior space 3. Photovoltaic modules (PV) 32 tilted solar module 33-segment solar cell module 34 Mullion 35 PV slots 42 Body 43 Insulation 44 Reflector 45 Side reflector 46 Upper reflector 47 Central reflector 48 Margins 5. Glass 51 Upper sash 52 Near-infrared transmitting film 53 mullion room 54 Sash 55 Film Frame 6. Glass curtain wall 71 Base 72 Jig 79 Joining means 9 Exterior Wall 91 Upper Floors 92 Lower Floor 93 Opening 10 Building L mullion spacing D PV (solar cell) width d SD depth SDH Spandrel Height PVD solar module width PVH solar cell module height SL Sunlight (solar radiation, sunlight) VL visible light NIR Near Infrared θ Tilt angle

Claims

1. A building with a glass curtain wall installed on its exterior wall, characterized in that solar cell modules with high power generation efficiency in the near-infrared range are installed in the internal space of the spandrels, and an infrared-transmitting film is installed on the glass surface side of the spandrels, and the infrared-transmitting film is a film formed by vapor-depositing a compound selected from the group consisting of silicon (Si), calcium fluoride (CaF2), magnesium fluoride (MgF2), synthetic quartz (FS), germanium (Ge), N-BK7, potassium bromide (KBr), sapphire, sodium chloride (NaCl), zinc selenide (ZnSe), and zinc sulfide (ZnS), which are materials that transmit near-infrared rays, onto glass or a film.

2. 2. The building according to claim 1, wherein the solar cell modules are installed at an angle.

3. 3. The building according to claim 1, wherein a reflector for reflecting sunlight toward the solar cell module is provided within the spandrel.

4. 4. The building according to claim 3, wherein the solar cell modules are arranged in a plurality of vertical stages, and a reflector is provided above each stage to reflect solar radiation toward that stage.

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