Solar cell module recycling method

Abstract

To reliably and easily recover only a cover glass from a solar cell module.SOLUTION: In a solar cell module having a power generating cell layer 3 in which solar cells 2 are arranged in a row, an upper encapsulant layer 4 that encapsulates the power generating cell layer 3 from above, a lower encapsulant layer 5 that encapsulates the power generating cell layer 3 from below, a cover glass 6 laminated on the upper surface of the upper encapsulant layer 4, and a module body 11 that has a backsheet 7 laminated on the lower surface of the lower encapsulant layer 5, only the cover glass 6 and the encapsulant layer 4 laminated on one surface thereof are removed, and high-pressure water is sprayed onto the encapsulant layer 4 on one surface of the cover glass 6 to remove the encapsulant layer 4 from one surface of the cover glass 6.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for recycling solar cell modules. [Background technology]

[0002] In recent years, with the international promotion of the Sustainable Development Goals (SDGs) and the growing momentum towards a carbon-neutral society in Japan, the introduction of solar power generation systems as a renewable energy source has been attracting renewed attention.In addition, with the frequent occurrence of large-scale disasters in recent years, there is a strong demand for the construction of independent power supply systems using solar power generation systems and other technologies in the event that the power supply from major power companies is cut off.

[0003] Therefore, it is expected that power generation systems using solar cell modules will continue to expand in the future, but since the power generation efficiency of solar cell modules decreases with age, solar cell modules are usually discarded after a certain number of years and replaced with new solar cell modules. Therefore, there is an increasing need to treat discarded solar cell modules as industrial waste.

[0004] A known method for recycling solar cell modules includes, for example, a solar cell module in which a frame is attached via a sealant around a solar cell panel having a structure composed of a solar cell layer in which solar cells are arranged in a row, a filler layer that encapsulates the solar cell layer, and a back surface protective material (back sheet) laminated on the underside of the filler layer, and a cover glass adhered to the upper surface of the filler layer in the structure, and a junction box is attached to the underside of the back surface protective material (back sheet).The method includes a disassembly step for removing the frame and the junction box, a separation step (heat softening step) for heating the solar cell panel to release the adhesion between the cover glass of the solar cell panel and the structure, a first peeling step for mechanically grasping one end of the structure from the cover glass and peeling it off under reduced pressure, a second peeling step for mechanically peeling the entire structure from the cover glass using a pulling device, and a recovery step for recovering the cover glass peeled off from the structure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-110201 Summary of the Invention [Problem to be solved by the invention]

[0006] In the case of the above-mentioned solar cell module recycling method, it is necessary to carry out the above-mentioned multi-stage processing steps to obtain the cover glass, and in addition to the heating and separation device in the separation step (heating and softening step), large-scale equipment such as a pressure reducing device and a tensioning device is required.Furthermore, since it is difficult to completely separate the filler layer of the structure from the cover glass in the second peeling step, there is a problem that some of the filler remains in the recovered cover glass.

[0007] An object of the present invention is to provide a method for recycling solar cell modules that can reliably and easily recover only the cover glass from the solar cell module. [Means for solving the problem]

[0008] The present invention described in claim 1 is a method for recycling a solar cell module, characterized in that only the cover glass and the sealing material layer laminated on one surface of the cover glass that constitute the solar cell module are removed from the solar cell module, and high-pressure water is sprayed onto the sealing material layer on one surface of the cover glass to remove the sealing material layer from the one surface of the cover glass, thereby obtaining a single cover glass.

[0009] The present invention as set forth in claim 2 is characterized in that, in the solar cell module recycling method as set forth in claim 1, the cover glass is placed on the bottom and the encapsulant layer is placed on the top, and high-pressure water is sprayed from above the encapsulant layer to remove the encapsulant layer.

[0010] The present invention as set forth in claim 3 relates to the method for recycling a solar cell module as set forth in claim 1 or claim 2, characterized in that the solar cell module has a module main body including a power generation cell layer formed by arranging a large number of power generation cells in a row, an upper encapsulant layer that seals the power generation cell layer from above, a lower encapsulant layer that seals the power generation cell layer from below, a cover glass laminated on the upper surface of the upper encapsulant layer, and a back sheet laminated on the lower surface of the lower encapsulant layer, and is characterized in that a hot knife is interposed between the power generation cell layer and the upper encapsulant layer to separate the upper encapsulant layer and the cover glass from the power generation cell layer and spray high-pressure water onto the upper encapsulant layer.

[0011] The present invention as set forth in claim 4 is characterized in that, in the method for recycling a solar cell module as set forth in claim 3, a hot knife is interposed between the power generation cell layer and the upper encapsulant layer to integrally crush the power generation cell layer separated from the upper encapsulant layer, the encapsulant layer below the power generation cell layer, and the back sheet below the lower encapsulant layer, and then the crushed material is sieved to select crushed material of a predetermined particle size and the silver component contained in the crushed material is extracted.

[0012] The present invention as set forth in claim 5 is a method for recycling a solar cell module as set forth in claim 3, characterized in that the solar cell module comprises a metal frame surrounding a module body and a junction box attached to the underside of a back sheet, and after removing the junction box from the back sheet and removing the metal frame from the module body, a hot knife is interposed between the power generation cell layer and the upper encapsulant layer to separate the upper encapsulant layer and the cover glass from the power generation cell layer, and high-pressure water is sprayed onto the upper encapsulant layer. [Effects of the Invention]

[0013] The method for recycling a solar cell module according to the present invention has the exceptional effect of being able to easily obtain a single cover glass by spraying high-pressure water from a solar cell module having, for example, a module main body including a power generation cell layer in which a predetermined number of solar cells are arranged in a row, an upper sealing material layer that seals the power generation cell layer from above, a lower sealing material layer that seals the power generation cell layer from below, a cover glass laminated on the upper surface of the upper sealing material layer, and a back sheet laminated on the lower surface of the lower sealing material layer, and further including an aluminum metal frame that surrounds the module main body and a junction box attached to the lower surface of the back sheet.

[0014] Furthermore, according to the recycling method of the present invention, in which the cover glass is placed on the bottom and the sealant layer is placed on the top, and high-pressure water is sprayed from above the sealant layer to remove the sealant layer, the high-pressure water is sprayed onto the sealant layer on the cover glass while the cover glass receives the spray force of the high-pressure water and is subjected to an acceleration force due to gravity, which has the advantage that the sealant layer can be removed efficiently and easily.

[0015] In addition, according to the recycling method of the present invention, in which a hot knife is interposed between the power generation cell layer and the upper encapsulant layer to separate the upper encapsulant layer and the cover glass from the power generation cell layer and then high-pressure water is sprayed onto the upper encapsulant layer, the upper encapsulant layer and the cover glass can be easily removed from the solar cell module without the need for complicated auxiliary equipment as in the prior art.

[0016] Furthermore, according to the recycling method of the present invention, in which the power generation cell layer separated from the upper encapsulant layer, the encapsulant layer below the power generation cell layer, and the back sheet below the lower encapsulant layer are pulverized together using a hot knife, and the pulverized material is then sieved to extract the silver component contained in the pulverized material of a predetermined particle size, it becomes possible to recover the silver component contained in the solar cell simply and efficiently. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is an exploded perspective view showing the configuration of a solar cell module for carrying out a recycling method according to an embodiment. [Figure 2] 1 is a flowchart showing steps of a recycling method according to an embodiment. [Figure 3] 10A and 10B are diagrams showing the process of removing a metal frame and the like, in which (a) is a cross-sectional view of the solar cell module in a completed structure, and (b) is a cross-sectional view after removal. [Figure 4] 1A and 1B are diagrams showing a process of separating the upper sealing material layer and the power generating cell layer, in which (a) is a cross-sectional view showing the state before separation, and (b) is a cross-sectional view showing the state after separation. [Figure 5] 10A and 10B are diagrams showing a process of removing an upper sealing material layer by jetting high-pressure water, in which (a) is a cross-sectional view showing a state during the removal work, and (b) is a cross-sectional view showing a state after removal. [Figure 6] 1 is a flowchart showing the steps of processing a stack including a power generating cell layer. DETAILED DESCRIPTION OF THE INVENTION

[0018] Next, an embodiment of the present invention will be described with reference to the drawings, but the present invention is not limited to such an embodiment.

[0019] First, as shown in Figures 1 and 3(a), the configuration of a solar cell module 1 that is a target of the recycling method according to this embodiment will be described. The solar cell module 1 has a power generation cell layer 3 in which a predetermined number of solar cells 2 are arranged in a row, an upper sealing material layer 4 that seals the power generation cell layer 3 from above, a lower sealing material layer 5 that seals the power generation cell layer 3 from below, a module main body 11 that has a cover glass 6 laminated on the upper surface of the upper sealing material layer 4 and a back sheet 7 laminated on the lower surface of the lower sealing material layer 5, and the solar cell module 1 further has an aluminum metal frame 8 that surrounds the module main body 11 and a junction box 9 attached to the lower surface of the back sheet 7.

[0020] Next, as shown in FIG. 2, a method for recycling the solar cell module 1 according to the present embodiment will be described. For the completed solar cell module 1 shown in FIG. 3(a), the metal frame 8 surrounding the module body 11 and the junction box 9 attached to the underside of the back sheet 7 are removed (S2001) as shown in FIG. 3(b). Thereafter, as shown in FIG. 4(a), a hot knife 12 is interposed between the power generating cell layer 3 and the upper encapsulant layer 4 in the module body 11, and the power generating cell layer 3 is cut as shown in FIG. 4(b). The upper sealing material layer 4 and the cover glass 6 are separated from the cell layer 3 (S2002). Next, as shown in FIG. 5(a), the upper sealing material layer 4 is positioned on a roller conveyor 14 laid on a base 13 so that the cover glass 6 is placed on top of it. High-pressure water 16 is sprayed onto the upper sealing material layer 4 from a spray nozzle 15 positioned above it, thereby removing the upper sealing material layer 4 from the cover glass 6. As shown in FIG. 5(b), the cover glass 6 alone is placed on the roller conveyor 14, and the cover glass 6 alone is obtained (S2003).

[0021] As shown in FIG. 6, the laminate 17 of the power generation cell layer 3, the lower sealing material layer 5, and the backsheet 7 separated in the step (S2002) is first pulverized in a pulverizer (not shown) (S2004), and then the pulverized material is passed through a sieve (not shown) (S2005) to obtain pulverized material of a predetermined particle size, from which the silver component is extracted (S2006). [Industrial Applicability]

[0022] According to the recycling method of the present invention, solar cell modules can be efficiently processed and highly reusable cover glass can be easily obtained, and therefore the method is expected to be widely used in the field of solar cell module recycling. [Explanation of symbols]

[0023] 1. Solar cell module 2. Solar cell 3 Power generation cell layer 4 Upper encapsulant layer 5 Lower encapsulant layer 6 Coverslips 7 Back Seat 8 Metal Frame 9 Junction Box 11 Module body 12 Hot Knife

Claims

1. A method for recycling a solar cell module, comprising: removing from a solar cell module only a cover glass and a sealing material layer laminated on one surface of the cover glass that constitute the solar cell module; spraying high-pressure water onto the sealing material layer on one surface of the cover glass to remove the sealing material layer from the one surface of the cover glass, thereby obtaining a single cover glass.

2. 2. The method for recycling a solar cell module according to claim 1, wherein the cover glass is placed on the lower side and the sealant layer is placed on the upper side, and high-pressure water is sprayed from above the sealant layer to remove the sealant layer.

3. 3. The method for recycling a solar cell module according to claim 1 or 2, wherein the solar cell module comprises a module main body having a power-generating cell layer formed by arranging a large number of power-generating cells in a row, an upper encapsulating material layer that seals the power-generating cell layer from above, a lower encapsulating material layer that seals the power-generating cell layer from below, a cover glass laminated on the upper surface of the upper encapsulating material layer, and a backsheet laminated on the lower surface of the lower encapsulating material layer, and wherein a hot knife is interposed between the power-generating cell layer and the upper encapsulating material layer to separate the upper encapsulating material layer and the cover glass from the power-generating cell layer, and high-pressure water is sprayed onto the upper encapsulating material layer.

4. A hot knife is interposed between the power generation cell layer and the upper sealing material layer, and the power generation cell layer separated from the upper sealing material layer, the sealing material layer below the power generation cell layer, and the back sheet below the lower sealing material layer are crushed together, and the crushed material is sieved to obtain crushed material of a predetermined particle size, and the silver component contained in the crushed material is extracted.

5. 4. The method for recycling a solar cell module according to claim 3, wherein the solar cell module comprises a metal frame surrounding a module body and a junction box attached to the underside of a back sheet, and the junction box is removed from the back sheet and the metal frame is removed from the module body, and then a hot knife is interposed between the power generation cell layer and the upper encapsulant layer to separate the upper encapsulant layer and the cover glass from the power generation cell layer, and high-pressure water is sprayed onto the upper encapsulant layer.

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