Recycling method and recycling device

Abstract

This recycling method comprises: a step (S1) for preparing a panel comprising a cover glass and a sealing layer that adheres to the cover glass; and a step (S2) for heating the panel with light. At least a part of the wavelength range of the light, at least a part of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is included in a wavelength range in which the transmittance of the sealing layer is lower than the transmittance of the cover glass.

Description

Recycling method and recycling device

[0001] The present invention relates to a method and apparatus for recycling panels such as photovoltaic conversion panels.

[0002] Solar power generation is attracting attention as a renewable energy source. It is expected that many solar cell modules will be installed in the future. As a result, technology for recycling used solar cell modules is also attracting attention.

[0003] A recycling technology for used solar cell modules is disclosed in the following Patent Document 1. In the recycling method described in Patent Document 1, the interface between the cover glass and the sealing layer is heated to a predetermined temperature range, and the sealing layer is peeled off from the interface of the cover glass while the interface is maintained at the predetermined temperature range. Heating the interface between the cover glass and the sealing layer is performed to weaken the adhesion force.

[0004] International Publication No. 2019-203026

[0005] In Patent Document 1, a lamp-type heating device is cited as one of heating devices for heating the vicinity of the interface between the cover glass and the sealing layer. When peeling the sealing layer from the interface of the cover glass, it is preferable to effectively heat the vicinity of the interface between the cover glass and the sealing layer. Therefore, a recycling method and a recycling device that can effectively heat the vicinity of the interface between the cover glass and the sealing layer are desired.

[0006] A recycling method according to one aspect includes the steps of preparing a panel including a cover glass and a sealing layer in close contact with the cover glass, and heating the panel with light, wherein at least a portion of a wavelength range of the light, at least a portion of a wavelength range having an intensity of 80% or more of a peak intensity of the light, or the peak wavelength of the light is within a wavelength range in which the transmittance of the sealing layer is lower than that of the cover glass.

[0007] According to one aspect, a recycling device for a module includes a cover glass and a sealing layer in close contact with the cover glass. The recycling device includes a heating light source capable of emitting light. At least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is within a wavelength range in which the transmittance of the sealing layer is lower than the transmittance of the cover glass.

[0008] FIG. 1 is a schematic cross-sectional view of a photovoltaic conversion module according to an embodiment. FIG. 2 is a flowchart of a recycling method according to an embodiment. FIG. 3 is a schematic cross-sectional view of a panel according to an embodiment. FIG. 4 is a schematic diagram illustrating a heating step. FIG. 5 is a graph showing the wavelength dependence of the transmittance of a cover glass and the transmittance of an EVA (first sealing layer). FIG. 6 is a graph showing the wavelength dependence of the ratio of the transmittance of an EVA (first sealing layer) to the transmittance of the cover glass. FIG. 7 is a graph showing the wavelength dependence of the transmittance of a cover glass and the transmittance of a PE (first sealing layer). FIG. 8 is a graph showing the wavelength dependence of the ratio of the transmittance of a PE (first sealing layer) to the transmittance of the cover glass. FIG. 9 is a diagram showing an example of the light absorption characteristics of materials constituting the first sealing layer. FIG. 10 is a diagram showing an example of the wavelength distribution of light emitted from a heating light source. FIG. 11 is a schematic diagram illustrating one situation of the separation step. FIG. 12 is a schematic diagram illustrating a situation subsequent to FIG. 11. FIG. 13 is a schematic diagram showing the configuration of a recycling device according to one embodiment.

[0009] Hereinafter, embodiments will be described with reference to the drawings. In the following drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and the ratios of the dimensions may differ from those of the actual parts.

[0010] An example of the configuration of a photovoltaic conversion module that can be recycled will be described below. Fig. 1 is a schematic cross-sectional view of a photovoltaic conversion module according to an embodiment.

[0011] The photovoltaic conversion module 10 may include a photovoltaic conversion panel 20 and a frame 30 that surrounds the outer edge of the photovoltaic conversion panel 20. A junction box and an output cable (not shown) that serve as power outlets may be attached to the rear surface of the photovoltaic conversion module 10.

[0012] A sealing material 40 may be provided between the photoelectric conversion panel 20 and the frame 30. The material constituting the sealing material 40 is not particularly limited, but examples thereof include resin materials such as polyethylene resin, fluorine resin, polystyrene resin, polyolefin resin, silicone resin, and butyl rubber.

[0013] The photoelectric conversion panel 20 may include a photoelectric conversion element 21, a rear protective layer 22, a cover glass 23, a first sealing layer 24, and a second sealing layer 25. The cover glass 23 may be, for example, a transparent or translucent glass layer. The glass layer may be, for example, tempered glass.

[0014] The first sealing layer 24 is disposed between the photoelectric conversion element 21 and the cover glass 23. Examples of materials that can be used to form the first sealing layer 24 include ethylene vinyl acetate resin, polyethylene resin, fluorine resin, polystyrene resin, polyolefin resin, silicone resin, and butyl rubber.

[0015] The second sealing layer 25 is provided between the photoelectric conversion element 21 and the back-side protective layer 22. The material constituting the second sealing layer 25 is not particularly limited, but examples thereof include ethylene vinyl acetate resin, polyethylene resin, fluorine resin, polystyrene resin, polyolefin resin, silicone resin, and butyl rubber.

[0016] The first sealing layer 24 and the second sealing layer 25 may be configured as completely separate layers. Alternatively, the first sealing layer 24 and the second sealing layer 25 may be configured as an integral layer. For example, the first sealing layer 24 may be connected to the second sealing layer 25 at the edge of the photovoltaic panel 20. In this case, the first sealing layer 24 may be provided in a manner that makes it indistinguishable from the second sealing layer 25.

[0017] The rear protective layer 22 is a protective layer that covers the rear surface of the photovoltaic conversion panel 20. The rear protective layer 22 is provided on the rear surface of the second sealing layer 25. The rear protective layer 22 may be made of, for example, a glass substrate, a resin sheet, or a metal sheet. The material constituting the resin sheet may include, for example, PET resin, PVF (polyvinyl fluoride) resin, PVDF (polyvinylidene fluoride) resin, nylon resin, polyamide resin, or a combination thereof.

[0018] The photoelectric conversion element 21 is an element that converts light energy into electrical energy and vice versa. The photoelectric conversion element 21 may have any configuration that allows for the conversion of light energy into electrical energy and vice versa. Examples of such elements include crystalline photoelectric conversion elements and thin-film CIS-type photoelectric conversion elements. For example, many crystalline photoelectric conversion elements have a structure using semiconductor silicon as a substrate. Specifically, a crystalline silicon-based photoelectric conversion element may have multiple battery cell units made of a silicon substrate. The photoelectric conversion element 21 may have a pair of electrode layers and a photoelectric conversion layer (light absorption layer) sandwiched between the pair of electrode layers.

[0019] Next, a recycling method according to the present embodiment will be described with reference to FIGS. 2 to 12. FIG. 2 is a flowchart of the recycling method according to one embodiment. FIG. 3 is a schematic cross-sectional view of a panel according to one embodiment. FIG. 4 is a schematic diagram illustrating a heating step. FIG. 5 is a graph showing the wavelength dependence of the transmittance of the cover glass and the transmittance of EVA (first sealing layer). FIG. 6 is a graph showing the wavelength dependence of the ratio of the transmittance of EVA (first sealing layer) to the transmittance of the cover glass. FIG. 7 is a graph showing the wavelength dependence of the transmittance of the cover glass and the transmittance of PE (first sealing layer). FIG. 8 is a graph showing the wavelength dependence of the ratio of the transmittance of PE (first sealing layer) to the transmittance of the cover glass. FIG. 9 is a diagram showing an example of the light absorption characteristics of materials constituting the first sealing layer. FIG. 10 is a diagram showing an example of the wavelength distribution of light emitted from a heating light source. FIG. 11 is a schematic diagram illustrating one situation of the separation step. FIG. 12 is a schematic diagram illustrating a situation subsequent to FIG. 11.

[0020] The recycling method according to this embodiment includes a step of preparing a panel (step S1), a step of heating (step S2), and a step of separating (step S3). As shown in Fig. 3, the prepared panel 20a may include a cover glass 23 and a first sealing layer 24 that is in close contact with the cover glass 23. The panel 20a may be, for example, a panel that has been used for its intended purpose.

[0021] Preferably, the panel 20a may be a photovoltaic conversion panel 20 removed from the above-described photovoltaic conversion module 10. In this way, the recycling method of this embodiment is suitably applied to the recycling of photovoltaic conversion panels.

[0022] To remove the photovoltaic conversion panel 20 from the photovoltaic conversion module 10, first, the frame 30 is removed from the photovoltaic conversion module 10. At this time, a junction box (not shown) and the like may also be removed from the photovoltaic conversion module 10.

[0023] Furthermore, if necessary, the rear protective layer 22 may be separated from the photovoltaic conversion panel 20. When the rear protective layer 22 is made of a resin or metal sheet, the rear protective layer 22 may be separated from the photovoltaic conversion panel 20 before carrying out the steps described below. In this case, the rear protective layer 22 can be recycled in its sheet form. Note that the following steps may be carried out without separating the rear protective layer 22.

[0024] By performing the above step S1, a panel 20a to be recycled is prepared from the photovoltaic conversion module 10 (see also FIG. 3).

[0025] Next, in the heating step (step S2), the panel 20a is heated by light. Specifically, the panel 20a is heated by light emitted from the heating light source 110 (see FIG. 4). The light is preferably applied to the panel 20a through the cover glass 23 from the side of the cover glass 23 opposite the first sealing layer 24.

[0026] When light is applied to the panel 20a from the surface of the cover glass 23 opposite the first sealing layer 24, the heating light source 110 can be installed on the side of the cover glass 23 opposite the first sealing layer 24 (see FIG. 4 ). In this case, the heating light source 110 can be installed on the opposite side of the cover glass 23 and the first sealing layer 24 from the separation unit 122 used in the separation step (step S3) described below, specifically, the tip of the separation unit 122 that abuts against the side surface of the panel 20a. Therefore, the process can proceed directly from the heating step S2 to the separation step S3, or the separation step S3 can be performed while the heating step S2 is being continued.

[0027] The heating step (step S2) includes heating the panel 20a to a predetermined temperature range. Here, the predetermined temperature range may be, for example, 40°C or higher and 170°C or lower, preferably 70°C or higher and 140°C or lower. This effectively reduces the adhesion of the first sealing layer 24 to the cover glass 23. However, the predetermined temperature range is not limited to the above range as long as the adhesion of the first sealing layer 24 can be reduced. The reduced adhesion of the first sealing layer 24 makes it easier to separate the first sealing layer 24 from the cover glass 23 in the separation step (step S3) described below.

[0028] 5 is a graph showing the wavelength dependence of the transmittance of the cover glass 23 and the transmittance of EVA (first sealing layer 24). The transmittance shown in FIG. 5 was measured for a panel using ethylene-vinyl acetate resin (EVA) as the first sealing layer 24.

[0029] The wavelength dependence of the transmittance of cover glass 23 shown in Fig. 5 was measured by irradiating light having various wavelengths onto cover glass 23 alone. The wavelength dependence of the transmittance of first sealing layer 24 shown in Fig. 5 was measured by irradiating light having various wavelengths onto the first sealing layer.

[0030] 6 is a graph showing the wavelength dependency of the ratio of the transmittance of EVA (first sealing layer 24) to the transmittance of the cover glass 23. The vertical axis represents the ratio of the transmittance of EVA (first sealing layer 24) to the transmittance of the cover glass 23. The horizontal axis represents the wavelength.

[0031] 7 is a graph showing the wavelength dependence of the transmittance of the cover glass 23 and the transmittance of PE (first sealing layer 24). The transmittance shown in FIG. 7 was measured for a panel using polyethylene resin (PE) as the first sealing layer 24.

[0032] The wavelength dependence of the transmittance of cover glass 23 shown in Figure 7 was measured by irradiating light having various wavelengths onto cover glass 23 alone. The wavelength dependence of the transmittance of PE (first sealing layer 24) shown in Figure 7 was measured by irradiating light having various wavelengths onto the first sealing layer.

[0033] 8 is a graph showing the wavelength dependence of the ratio of the transmittance of PE (first sealing layer 24) to the transmittance of cover glass 23. The vertical axis represents the ratio of the transmittance of PE (first sealing layer 24) to the transmittance of cover glass 23. The horizontal axis represents wavelength.

[0034] FIG. 9 is a diagram showing an example of the light absorption characteristics of the material constituting the first sealing layer 24. The vertical axis of FIG. 9 represents the light absorptance of the first sealing layer 24. The horizontal axis represents wavelength. FIG. 9 shows the light absorptance of the first sealing layer 24 made of ethylene-vinyl acetate resin (EVA) and the light absorptance of the first sealing layer 24 made of polyethylene resin (PE). Comparing FIG. 5 with FIG. 9 and comparing FIG. 7 with FIG. 9, it can be seen that the light absorptance of the first sealing layer 24 peaks at wavelengths where the transmittance of the first sealing layer 24 is low. Theoretically, if the transmittance of a given material is low, it is believed that the absorptance of that material is high. The results shown in FIG. 9 are believed to reflect this theory.

[0035] 10 is a diagram showing an example of the wavelength distribution of light emitted from the heating light source 110. The vertical axis of Fig. 10 represents the intensity of light emitted from the heating light source 110, and the horizontal axis represents the wavelength of light emitted from the heating light source 110.

[0036] 5, 7, and 9 show that the transmittance and absorptance of ethylene-vinyl acetate resin (EVA) and polyethylene resin (PE) show almost the same trends. Furthermore, it is expected that almost the same results as the measurement results shown in FIGS. 5, 7, and 9 will be obtained for panels made of materials typically used in photovoltaic conversion panels 20.

[0037] In the heating step (step S2), at least a portion of the wavelength range W1 of the light emitted from the heating light source 110 is included in the wavelength range R1 in which the transmittance of the first sealing layer 24 is lower than the transmittance of the cover glass 23. In other words, the wavelength range W1 of the light at least partially overlaps with the wavelength range R1 shown in FIGS.

[0038] 5 to 8 corresponds to a wavelength range in which the light transmittance through the cover glass 23 is relatively high and the light transmittance through the first sealing layer 24 is relatively low. Therefore, it is considered that at least a portion of the wavelength range W1 of the light emitted from the heating light source 110 (the portion overlapping with the wavelength range R1) is sufficiently transmitted through the cover glass 23 and sufficiently absorbed by the first sealing layer 24. This allows the vicinity of the interface between the cover glass 23 and the first sealing layer 24 to be effectively heated.

[0039] Preferably, at least a part of wavelength range W2 having an intensity of 80% or more of the peak intensity of the light emitted from heating light source 110 is included in wavelength range R1 in which the transmittance of first sealing layer 24 is lower than the transmittance of cover glass 23. This allows a relatively high-intensity portion of the light emitted from heating light source 110 to be sufficiently transmitted through cover glass 23 and absorbed by first sealing layer 24. Therefore, the vicinity of the interface between cover glass 23 and first sealing layer 24 can be heated more effectively.

[0040] More preferably, the peak wavelength W3 of the light emitted from the heating light source 110 is included in the wavelength range R1 in which the transmittance of the first sealing layer 24 is lower than the transmittance of the cover glass 23. This allows a more intense portion of the light emitted from the heating light source to be sufficiently transmitted through the cover glass 23 and absorbed by the first sealing layer 24. Therefore, the vicinity of the interface between the cover glass 23 and the first sealing layer 24 can be heated more effectively.

[0041] Furthermore, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably a peak wavelength W3 of the light, is preferably included in a wavelength range R2 in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.9 or less. In wavelength range R2, the transmittance of the first sealing layer 24 is lower than the transmittance of the cover glass 23. Therefore, a larger amount of light transmitted through the cover glass 23 can be absorbed by the first sealing layer 24. Therefore, the first sealing layer 24, specifically the vicinity of the interface between the cover glass 23 and the first sealing layer 24, can be heated more effectively.

[0042] Furthermore, it is preferable that at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably the peak wavelength W3 of the light, is included within a wavelength range in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.01 or more and 0.9 or less.

[0043] Furthermore, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably a peak wavelength W3 of the light, may be included within a wavelength range in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.05 or more and 0.9 or less. Furthermore, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably a peak wavelength W3 of the light, may be included within a wavelength range in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.1 or more and 0.9 or less. Furthermore, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, more preferably the peak wavelength W3 of the light, may be included within a wavelength range in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.2 or more and 0.9 or less.

[0044] Furthermore, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably the peak wavelength W3 of the light, is preferably included in a wavelength range R3 in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.7 or less. In wavelength range R3, the transmittance of the first sealing layer 24 is even lower than the transmittance of the cover glass 23. Therefore, a larger amount of light transmitted through the cover glass 23 can be absorbed by the first sealing layer 24. Therefore, the first sealing layer 24, specifically the vicinity of the interface between the cover glass 23 and the first sealing layer 24, can be heated more effectively.

[0045] Furthermore, it is preferable that at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably the peak wavelength W3 of the light, is included within a wavelength range in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.01 or more and 0.7 or less.

[0046] Furthermore, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably a peak wavelength W3 of the light, may be included within a wavelength range in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.05 or more and 0.7 or less. Furthermore, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably a peak wavelength W3 of the light, may be included within a wavelength range in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.1 or more and 0.7 or less. Furthermore, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably the peak wavelength W3 of the light may be included within a wavelength range in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.2 or more and 0.7 or less.

[0047] Furthermore, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably the peak wavelength W3 of the light, is preferably included in a wavelength range R4 in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.6 or less. In wavelength range R4, the transmittance of the first sealing layer 24 is even lower than the transmittance of the cover glass 23. Therefore, a larger amount of light transmitted through the cover glass 23 can be absorbed by the first sealing layer 24. Therefore, the first sealing layer 24, specifically the vicinity of the interface between the cover glass 23 and the first sealing layer 24, can be heated more effectively.

[0048] Furthermore, it is preferable that at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably the peak wavelength W3 of the light, is included within a wavelength range in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.01 or more and 0.6 or less.

[0049] Furthermore, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably a peak wavelength W3 of the light, may be included within a wavelength range in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.05 or more and 0.6 or less. Furthermore, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably a peak wavelength W3 of the light, may be included within a wavelength range in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.1 or more and 0.6 or less. Furthermore, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably the peak wavelength W3 of the light may be included within a wavelength range in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.2 or more and 0.6 or less.

[0050] Furthermore, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably the peak wavelength W3 of the light, is preferably included in a wavelength range R5 in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.5 or less. In wavelength range R5, the transmittance of the first sealing layer 24 is even lower than the transmittance of the cover glass 23. Therefore, a larger amount of light transmitted through the cover glass 23 can be absorbed by the first sealing layer 24. Therefore, the first sealing layer 24, specifically the vicinity of the interface between the cover glass 23 and the first sealing layer 24, can be heated more effectively.

[0051] Furthermore, it is preferable that at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably the peak wavelength W3 of the light, is included within a wavelength range in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.01 or more and 0.5 or less.

[0052] Furthermore, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably a peak wavelength W3 of the light, may be included within a wavelength range in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.05 or more and 0.5 or less. Furthermore, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably a peak wavelength W3 of the light, may be included within a wavelength range in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.1 or more and 0.5 or less. Furthermore, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably the peak wavelength W3 of the light may be included within a wavelength range in which the ratio of the transmittance of the first sealing layer 24 to the transmittance of the cover glass 23 is 0.2 or more and 0.5 or less.

[0053] In addition to the above conditions regarding the wavelength distribution of light, it is preferable that at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength W3 of the light be included within a wavelength range R1 in which the transmittance of the first sealing layer 24 is lower than that of the cover glass 23 and within a wavelength range Rc1 in which the transmittance of the cover glass 23 is 70% or more. This makes it possible to maximize the amount of light that can reach the first sealing layer 24.

[0054] In addition to the above-described conditions regarding the wavelength distribution of light, it is preferable that at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength W3 of the light be included within the wavelength range R1 in which the transmittance of the first sealing layer 24 is lower than the transmittance of the cover glass 23 and within the wavelength range Rc2 in which the transmittance of the cover glass 23 is 80% or more. This makes it possible to further increase the amount of light that can reach the first sealing layer 24.

[0055] In addition to the above-mentioned conditions regarding the wavelength distribution of light, it is preferable that at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably a peak wavelength W3 of the light, be included in a wavelength range in which the transmittance of the first sealing layer 24 is less than 80%. This makes it easier for a portion of the light that has transmitted through the cover glass 23 to be absorbed by the first sealing layer 24. Therefore, the vicinity of the interface between the cover glass 23 and the first sealing layer 24 can be heated more effectively.

[0056] In addition to the above-mentioned conditions regarding the wavelength distribution of light, it is preferable that at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably a peak wavelength W3 of the light, be included in a wavelength range in which the transmittance of the first sealing layer 24 is 70% or less. This allows most of the light transmitted through the cover glass 23 to be absorbed by the first sealing layer 24. Therefore, the vicinity of the interface between the cover glass 23 and the first sealing layer 24 can be heated more effectively.

[0057] In addition to the above-mentioned conditions regarding the wavelength distribution of light, it is preferable that at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably a peak wavelength W3 of the light, be included in a wavelength range in which the transmittance of the first sealing layer 24 is 50% or less. This allows more of the light transmitted through the cover glass 23 to be absorbed by the first sealing layer 24. Therefore, the vicinity of the interface between the cover glass 23 and the first sealing layer 24 can be heated more effectively.

[0058] In addition to the above-described conditions regarding the wavelength distribution of light, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, preferably at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, and more preferably a peak wavelength W3 of the light, may be included in a wavelength range in which the transmittance of the first sealing layer 24 is 40% or less. This allows more of the light transmitted through the cover glass 23 to be absorbed by the first sealing layer 24. Therefore, the vicinity of the interface between the cover glass 23 and the first sealing layer 24 can be heated more effectively.

[0059] As described above, it is preferable that the light emitted from the heating light source 110 has a wavelength that is sufficiently transmitted through the cover glass 23 and that belongs to a wavelength range that can be absorbed by the first sealing layer 24. From this perspective, it is clear from the graphs shown in Figures 5 to 8 that the light emitted from the heating light source 110 preferably has the following wavelength distribution:

[0060] In a specific example, when first sealing layer 24 is made of EVA, wavelength range R1 is approximately 1030 nm to 2700 nm, and wavelength range R2 is approximately 1680 nm to 2570 nm. When first sealing layer 24 is made of PE, wavelength range R1 is approximately the entire range including the range of 300 nm to 2700 nm, and wavelength range R2 is approximately 2580 nm or less.

[0061] From this perspective, at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength W3 of the light may be within the range of, for example, 1000 nm to 2700 nm, 1100 nm to 2700 nm, or 1400 nm to 2600 nm, more preferably 1600 nm to 2600 nm, and even more preferably 1680 nm to 2570 nm. Even in this case, the vicinity of the interface between the cover glass 23 and the first sealing layer 24 can be heated more effectively.

[0062] 5 to 9 show that the wavelengths at which the transmittance of the first sealing layer 24 drops significantly, i.e., the peaks of light absorptance, are located roughly in the ranges of 1700 nm to 2000 nm and 2200 nm to 2600 nm. Therefore, it is preferable that at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, at least a portion of the wavelength range W2 having an intensity that is 80% or more of the peak intensity of the light, or the peak wavelength W3 of the light be included in at least one of the ranges of 1700 nm to 2000 nm and 2200 nm to 2600 nm.

[0063] From a similar viewpoint, it is more preferable that at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength W3 of the light be included in at least one of the ranges of 1700 nm to 1800 nm and the ranges of 2250 nm to 2500 nm. Note that the numerical values ​​of the wavelength ranges given in this paragraph are close to the above-mentioned wavelength ranges R3 and R4 for EVA and PE.

[0064] Furthermore, it is more preferable that at least a portion of the wavelength range W1 of the light emitted from the heating light source 110, at least a portion of the wavelength range W2 having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength W3 of the light is included in the range of 2250 nm to 2500 nm. Note that the wavelength range of 2250 nm to 2500 nm corresponds to the range in which the transmittance drops significantly for both EVA and PE. Note that the numerical values ​​of the wavelength ranges given in this paragraph are close to the wavelength range R5 described above for EVA and PE.

[0065] Next, in a separation step (step S3), first sealing layer 24 is separated from cover glass 23 (see FIGS. 11 and 12 ). This separation step is performed during or after heating panel 20 a. As described above, the reduced adhesion of first sealing layer 24 makes it easy to separate first sealing layer 24 from cover glass 23.

[0066] Separation of first sealing layer 24 from cover glass 23 is preferably performed while maintaining a predetermined temperature range near the interface between cover glass 23 and first sealing layer 24. Here, the predetermined temperature range may be, for example, 40°C or higher and 170°C or lower, preferably 70°C or higher and 140°C or lower.

[0067] In addition, by performing a step of effectively heating the interface between the cover glass 23 and the first sealing layer 24 and then separating them, it is also possible to reduce the amount of material that makes up the first sealing layer 24 remaining on the cover glass 23.

[0068] There are no particular limitations on the type of force that may be applied to separate first sealing layer 24 from cover glass 23. Therefore, separation unit 122 for separating first sealing layer 24 from cover glass 23 may have any configuration. In the embodiment shown in Figures 11 and 12, separation unit 122 has a tip that can abut against a side surface of panel 20a.

[0069] 11 and 12 , a force is applied from the side of panel 20a to first sealing layer 24 and / or a member on the opposite side of cover glass 23 with respect to first sealing layer 24. Here, the member on the opposite side of cover glass 23 with respect to first sealing layer 24 may be, for example, photoelectric conversion element 21. Separation unit 122 applies a force from the side of panel 20a to first sealing layer 24 and / or a member on the opposite side of cover glass 23 with respect to first sealing layer 24, thereby separating first sealing layer 24 from cover glass 23.

[0070] According to the separation unit 122, since no load is applied to the cover glass 23, the first sealing layer 24 can be separated from the cover glass 23 without shattering the cover glass 23. Furthermore, since the separation step is performed in a state in which the adhesion of the first sealing layer 24 is reduced, it is also possible to reduce the amount of material constituting the first sealing layer 24 remaining on the cover glass 23. Therefore, it is possible to effectively recycle the glass material constituting the cover glass 23.

[0071] Next, the recycling device according to this embodiment will be described with reference to Fig. 13. Fig. 13 is a schematic diagram showing the configuration of the recycling device according to one embodiment.

[0072] The recycling device 100 according to this embodiment is a recycling device for a panel 20a including a cover glass 23 and a first sealing layer 24 that is in close contact with the cover glass 23. Preferably, the recycling device may be a device for recycling a photovoltaic conversion panel 20.

[0073] The recycling apparatus 100 may include a heating light source 110, a separation unit 122, and a stage 126. The heating light source 110 is a light source capable of emitting light for heating an object.

[0074] Heating light source 110 is used to heat panel 20a, as described in heating step S2 of the recycling method above. The wavelength distribution of the intensity of light emitted from heating light source 110 has been described above, and therefore will not be described here.

[0075] As described above, the separation unit 122 may have any configuration as long as it can separate the first sealing layer 24 from the cover glass 23. In one example, the separation unit 122 may have a tip that can abut against a side surface of the panel 20 a held on the stage 126.

[0076] The heating light source 110 may be provided below the stage 126. In this case, the panel 20a may be held on the stage 126 with the cover glass 23 side of the panel 20a facing downward. This allows the heating light source 110 to emit light from the cover glass 23 side toward the panel 20a while the panel 20a is held on the stage 126.

[0077] Furthermore, if the heating light source 110 is provided below the stage 126 and the separation unit 122 is provided above the stage 126, the process can be easily transitioned from the heating step S2 to the separation step S3. Alternatively, the heating step S2 and the separation step S3 can be performed simultaneously.

[0078] In the above embodiment, the present invention has been described mainly by taking as an example the photoelectric conversion panel 20 having the cover glass 23 and the first sealing layer 24. It should be noted that the present invention is not limited to this embodiment and can be applied to any panel having a cover glass and a sealing layer.

[0079] As described above, the contents of the present invention have been disclosed through the embodiments, but the descriptions and drawings that form part of this disclosure should not be understood to limit the present invention. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure. Therefore, the technical scope of the present invention is defined only by the inventive features of the claims that can be reasonably understood from the above description.

[0080] This application claims priority based on Japanese Patent Application No. 2024-014534, filed on February 2, 2024, the entire contents of which are incorporated herein by reference.

Claims

1. A recycling method comprising the steps of: preparing a panel comprising a cover glass and a sealing layer in close contact with the cover glass; and heating the panel with light, wherein at least a portion of the wavelength range of the light, at least a portion of a wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is included in a wavelength range in which the transmittance of the sealing layer is lower than the transmittance of the cover glass.

2. The recycling method according to claim 1, wherein at least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is included within a wavelength range in which the ratio of the transmittance of the sealing layer to the transmittance of the cover glass is 0.9 or less.

3. The recycling method according to claim 1 or 2, wherein at least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is included within a wavelength range in which the ratio of the transmittance of the sealing layer to the transmittance of the cover glass is 0.7 or less.

4. The recycling method according to any one of claims 1 to 3, wherein at least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is included within a wavelength range in which the ratio of the transmittance of the sealing layer to the transmittance of the cover glass is 0.6 or less.

5. A recycling method described in any one of claims 1 to 4, wherein at least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is within the range of 1000 nm or more and 2700 nm or less.

6. A recycling method described in any one of claims 1 to 5, wherein at least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is within the range of 1100 nm or more and 2700 nm or less.

7. A recycling method described in any one of claims 1 to 6, wherein at least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is within the range of 1600 nm or more and 2600 nm or less.

8. A recycling method according to any one of claims 1 to 7, wherein at least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is included in at least one of the ranges of 1700 nm or more and 2000 nm or less and the ranges of 2200 nm or more and 2600 nm or less.

9. A recycling method according to any one of claims 1 to 8, wherein at least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is included in at least one of the ranges of 1700 nm or more and 1800 nm or less and the ranges of 2250 nm or more and 2500 nm or less.

10. The recycling method of any one of claims 1 to 9, wherein the heating step includes heating the panel to a predetermined temperature range.

11. The recycling method according to claim 10, wherein the predetermined temperature range is 40°C or higher and 170°C or lower.

12. The recycling method according to any one of claims 1 to 11, wherein the light is applied to the panel from the side of the cover glass opposite the sealing layer.

13. The recycling method according to any one of claims 1 to 12, comprising the step of separating the sealing layer from the cover glass.

14. A recycling device for a panel comprising a cover glass and a sealing layer in close contact with the cover glass, the recycling device comprising a heating light source capable of emitting light, wherein at least a portion of the wavelength range of the light, at least a portion of a wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is included in a wavelength range in which the transmittance of the sealing layer is lower than the transmittance of the cover glass.

15. The recycling device of claim 14, wherein at least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is included within a wavelength range in which the ratio of the transmittance of the sealing layer to the transmittance of the cover glass is 0.9 or less.

16. The recycling device of claim 14 or 15, wherein at least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is included in a wavelength range in which the ratio of the transmittance of the sealing layer to the transmittance of the cover glass is 0.7 or less.

17. A recycling device according to any one of claims 14 to 16, wherein at least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is included within a wavelength range in which the ratio of the transmittance of the sealing layer to the transmittance of the cover glass is 0.6 or less.

18. A recycling device described in any one of claims 14 to 17, wherein at least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is within the range of 1000 nm or more and 2700 nm or less.

19. A recycling device described in any one of claims 14 to 18, wherein at least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is within the range of 1100 nm or more and 2700 nm or less.

20. A recycling device described in any one of claims 14 to 19, wherein at least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is within the range of 1600 nm or more and 2600 nm or less.

21. A recycling device described in any one of claims 14 to 20, wherein at least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is included in at least one of the ranges of 1700 nm or more and 2000 nm or less and the ranges of 2200 nm or more and 2600 nm or less.

22. A recycling device described in any one of claims 14 to 21, wherein at least a portion of the wavelength range of the light, at least a portion of the wavelength range having an intensity of 80% or more of the peak intensity of the light, or the peak wavelength of the light is included in at least one of the ranges of 1700 nm or more and 1800 nm or less and the ranges of 2250 nm or more and 2500 nm or less.

23. The recycling device according to any one of claims 14 to 22, comprising a separation unit for separating the sealing layer from the cover glass.

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