JP6104141B2 - Recycling method of solar cell module - Google Patents

Description

  The present invention relates to a method for separating a back surface protective material from a glass plate and utilizing the glass plate for recycling in a solar cell module in which a back surface protective material is bonded to a glass plate protecting a solar cell element.

  In recent years, installation of solar cells has been promoted in various places such as public facilities, business sites, and general households due to environmental concerns and policy. Since the solar cell uses clean energy called sunlight, it is effective in reducing the load on the environment. For example, in Japan, the “Purchase Measures for Renewable Energy Electricity Procurement by Electric Power Companies” enforced in July 2012 (the so-called Renewable Energy Law) implemented a total purchase system, The purchase of power generated by modules for 20 years has led to the explosive spread of solar power generation systems.

  More specifically, in Japan, due to the enforcement of the full volume purchase system, the certification for business equipment in 2012 alone was 13 GW (52 million when converted to a 250W module). Some of these solar cell modules installed in 2012 are expected to be removed simultaneously when the purchase system ends 20 years after the enforcement of the Renewable Energy Law.

  Various materials such as a solar cell element that realizes photoelectric conversion, a glass plate (cover glass) that protects the solar cell element, a filler that bonds each member, and a silver circuit line for energization are used for the solar cell module. ing. For this reason, it is important to reuse the resources contained in the removed solar cell module as much as possible. Therefore, it is required to establish a low-cost and efficient solar cell module recycling method.

  In this regard, Patent Document 1 discloses a technique for dismantling and recycling a solar cell module with an emphasis on a solar cell element recovery method. Patent Document 2 discloses a technique for separating a back surface protection material from a glass plate in a solar cell module in which a back surface protection material is bonded to a glass plate as a method for recycling waste glass.

JP 2007-180063 A JP 2011-173099 A

  In the solar cell module, a back surface protective material is bonded to the back surface of the glass plate via a filler such as EVA (ethylene-vinyl acetate) or PVB (polyvinyl butyral). Even if the outer frame of the solar cell module is disassembled, it is not easy to recycle the cover glass as it is, so that the technique of Patent Document 1 cannot be utilized / applied to the recycling of the cover glass. Further, in the method of Patent Document 2, since the cover glass and the filler are pulverized without being separated, costs and man-hours for separation are required in the manufacturing process of the recycled glass. Therefore, it is considered that the recycling cost becomes high and the recycling function of using recycled materials is hindered.

  This invention is made | formed in view of the above, Comprising: It aims at obtaining the recycling method of the solar cell module which can peel reliably the structure which has a filler, a solar cell element, and a back surface protection material from a cover glass. .

  In order to solve the above-described problems and achieve the object, the present invention provides a solar cell panel in which a solar cell element is sealed by filling a filler between a cover glass and a back surface protective material, and a solar cell panel A method for recycling a solar cell module comprising a frame attached to a peripheral portion, a disassembly step of removing the frame from the solar cell panel, and a cover glass from a structure including a back surface protective material, a filler, and a solar cell element And a recovery step of recovering the cover glass separated from the structure.

  ADVANTAGE OF THE INVENTION According to this invention, there exists an effect that the structure which has a filler, a solar cell element, and a back surface protection material can be peeled reliably from a cover glass.

FIG. 1 is a diagram showing an example of the structure of a solar cell module to be recycled by the solar cell module recycling method according to the present invention. FIG. 2 is a diagram illustrating processing steps of the solar cell module recycling method according to the embodiment. FIG. 3 is a diagram showing a state in which a solar cell panel is placed on a stage installed in a thermostat. FIG. 4 is a diagram showing how to install the solar cell panel in the decompression device. FIG. 5 is a diagram showing a state in which the solar cell panel is placed on the decompression device. FIG. 6 is a view showing a state in which the edge portion of the solar cell panel is mechanically chucked by the chuck of the tension device. FIG. 7 is a diagram illustrating another example of the second peeling step.

  Embodiments of a method for recycling a solar cell module according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment.
FIG. 1 is a diagram showing an example of the structure of a solar cell module to be recycled by the solar cell module recycling method according to the present invention. The solar cell module 1 includes a laminate (solar cell panel) 40 having a structure in which a cover glass 3 and a plurality of solar cell elements 4 are integrally bonded by a back surface protective material 10 and a filler 7. Each of the solar cell elements 4 is a unit cell that generates power by receiving light, and is formed using single crystal silicon or polycrystalline silicon. The end face of the solar cell panel 40 is covered with an aluminum frame 2. That is, the frame 2 is attached to the peripheral edge of the solar cell panel 40. The frame 2 and the solar cell panel 40 are sealed with a sealing material 11. For the sealing material 11, butyl rubber or the like is used.

  The electrode wire 6 attached to the electrode on the solar cell element 4 is sandwiched between the cover glass 3 and the electrode on the solar cell element 4 by the filler 7 and drawn into the terminal box 9. The electrode wire 6 drawn into the terminal box 9 is connected to the output cable 8.

  The cover glass 3 has translucency and protects the solar cell element 4 from an impact from the outside. Each of the solar cell elements 4 is connected in series by an interconnector 5 to form a so-called cell string.

  The back surface protective material 10 is a sheet that prevents moisture from entering from the outside. The back surface protective material 10 is made of, for example, a film in which a fluorine resin, PET (polyethylene terephthalate), aluminum foil, or the like is bonded. The back surface protective material 10 has a characteristic that is resistant to breakage without passing moisture. The electrode wire 6 is a strip-shaped lead wire and is made of a highly conductive metal such as copper or silver.

  The filler 7 is formed by integrally bonding the cover glass 3, the solar cell element 4, and the back surface protective material 10. The filler 7 serves as a cushioning material and as a sealing material. For example, EVA is used as the filler 7.

  As described above, the solar cell panel 40 includes the structure 50 constituted by the filler 7, the solar cell element 4, and the back surface protective material 10 and the cover glass 3.

  The solar cell module described above is an example of a solar cell module applicable to the method for recycling the solar cell module according to the embodiment of the present invention, and a solar cell panel in which the cover glass 3 and the structure 50 are combined. If it is a solar cell module which has 40, this invention is applicable. Therefore, for example, the present invention can be applied to a structure having the solar cell element 4 using amorphous silicon, a compound thin film, or the like.

  Next, an outline of a method for manufacturing a solar cell module will be described. EVA, silicon resin, and fluororesin used as the filler 7 are in a solid gel state at room temperature. Lamination of the structure 50 and the cover glass 3 is performed as follows.

  The structure 50 and the cover glass 3 are heated to 100 to 200 ° C. under reduced pressure, and the filler 7 is fluidized by heating. By being under reduced pressure, the filler 7 is defoamed and becomes free of bubbles. In the subsequent cooling step, the filler 7 is cured, whereby the structure 50 and the cover glass 3 are bonded and synthesized (laminated).

  In the filler 7, a silane coupling agent is contained. The silane coupling agent has a function of bonding the cover glass 3 that is an inorganic material and the filler 7 that is an organic material.

  Next, processing steps of the solar cell module recycling method according to the embodiment of the present invention will be described. FIG. 2 is a diagram illustrating processing steps of the solar cell module recycling method according to the embodiment. As shown in FIG. 2, the solar cell module recycling method according to the embodiment includes a decomposition step (S101), a separation step (heat softening step (S102), a first peeling step (S103), and a second peeling step (S104). )) And a recovery step (S105). The decomposition process is a pre-process, and the heat softening process, the first peeling process, the second peeling process, and the recovery process are this process.

  First, the decomposition process will be described. In the disassembling process, the frame 2, the terminal box 9 and the output cable 8 are removed from the solar cell panel 40 of the solar cell module 1 which has become unnecessary due to the end of its useful life or the depreciation of facilities, and the solar cell panel 40 The remaining sealing material 11 is removed. In this way, the solar cell panel 40 including the cover glass 3, the solar cell element 4, the filler 7, and the back surface protective material 10 is separated from the solar cell module 1. The frame 2, the output cable 8, and the terminal box 9 are reused as resources.

  Next, the heat softening process will be described. The solar cell panel 40 separated in the decomposition step is heated to soften the filler 7. That is, the adhesive layer formed at the boundary between the filler 7 and the back surface protective material 10 is softened. FIG. 3 is a diagram showing a state in which a solar cell panel is placed on a stage installed in a thermostat. In the heat softening step, the solar cell panel 40 is placed on the stage 25 installed in the thermostat 30. In this state, the heater 20 is operated and warm air is sent into the thermostatic chamber 30 by the warm air heater 31 to heat the solar cell panel 40 at a temperature of 200 to 300 ° C. for about 60 to 90 minutes. By doing so, the solar cell panel 40 which is the laminate of the structure 50 and the cover glass 3 is heated, the silane coupling bonding the cover glass 3 and the filler 7 is decomposed, and the adhesive strength is increased. descend. When the solar cell panel 40 is placed on the stage 25, the heat of the heater 20 is transferred to the structure 50 through the cover glass 3 by placing the cover glass 3 downward and the structure 50 upward. Therefore, a temperature difference between the cover glass 3 and the structure 50 is less likely to occur, and the entire solar cell panel 40 is easily heated uniformly.

  After the heating at the preset temperature and time is completed, the solar cell panel 40 is gradually cooled to room temperature, whereby the filler 7 is cured in a state where the adhesive force between the cover glass 3 and the filler 7 is reduced. In this manner, the solar cell panel 40 is annealed in the heat softening process.

  In addition, a silane coupling can be decomposed | disassembled more effectively by applying an ultrasonic wave to the solar cell panel 40 in a heat softening process.

  Next, a 1st peeling process is demonstrated. In performing a 1st peeling process, the solar cell panel 40 is mounted on a decompression device. FIG. 4 is a diagram showing how to install the solar cell panel in the decompression device. FIG. 5 is a diagram showing a state in which the solar cell panel is placed on the decompression device. When the solar cell panel 40 is placed on the decompression device 12, the cover glass 3 is disposed on the surface where the air holes 13 for vacuuming are provided. The decompression device firmly fixes the solar cell panel 40 by adsorbing the cover glass 3 constituting the solar cell panel 40 by evacuation.

  The solar cell panel 40 fixed to the decompression device 12 is heated so that the internal temperature becomes about 80 ° C. in order to make the filler 7 soft enough for decomposition. The filler 7 made of EVA has a property of becoming harder when the temperature is lowered and softer when the temperature is raised. At room temperature, the whole is hard and difficult to handle. On the other hand, if the temperature is raised too much, it becomes too soft and the filler 7 partially extends and breaks. The temperature suitable for decomposition is about 80 ° C.

  Thereafter, the edge portion on the short side of the solar cell panel 40, that is, the end portion on the short side of the solar cell panel 40 is peeled from the cover glass 3 to such an extent that the tension device 15 can be mechanically chucked. Form a grip allowance. At this time, for example, a method in which an operator manually pushes a heated thin plate-like member into the boundary between the cover glass 3 and the structure 50 is employed. In addition, a machine may perform the work of a thin plate member at the boundary between the cover glass 3 and the structure 50. Alternatively, the structure 50 at one end of the solar cell panel 40 may be peeled off from the cover glass 3 by vacuum-sucking the back surface protective material 10 and applying a tensile load. Since the adhesive layer at the boundary surface between the structure 50 and the cover glass 3 that has already been softened by heating is easily separated due to decomposition of the silane coupling, the cover glass 3 and the structure 50 are easy to separate. Can be separated.

  Next, a 2nd peeling process is demonstrated. FIG. 6 is a view showing a state in which the edge portion of the solar cell panel is mechanically chucked by the chuck of the tension device. As shown in FIG. 6, the edge portion of the solar cell panel 40 (the gripping margin 51 formed in the first peeling step) is mechanically chucked to the chuck 17 of the tension device 15. And while pulling up the chuck 17 in the direction of arrow A, the horizontal feed mechanism 18 moves the tensioning device 15 in parallel in the direction of arrow B, thereby pulling upward the portion peeled off from the cover glass 3 of the structure 50. The body 50 and the cover glass 3 are gradually peeled off. For example, the tension device 15 is moved by the horizontal feed mechanism 18 so that a tensile load is always applied to the peeling point between the structure 50 and the cover glass 3 in a direction perpendicular to the cover glass 3.

  Further, in order to shorten the process time and to peel the adhesive layer at the boundary between the cover glass 3 and the structure 50 efficiently and cleanly, the heated blade 16 is moved in parallel with the arrow C direction by the horizontal feed mechanism 19. Then, the adhesive layer is pressed against the adhesive layer at the boundary between the cover glass 3 and the structure 50, and the adhesive layer is peeled off by both the force pulled by the tension device 15 and the force pressed by the blade 16. That is, in the second peeling step, the blade 16 is used as a peeling auxiliary member. The force drawn by the tensioning device 15 and the force pushed by the blade 16 are preferably larger than the force drawn by the tensioning device 15, and the ratio of the force drawn by the tensioning device 15 and the force pushed by the blade 16 is about 6: 4. Then, it can peel efficiently.

  When the second peeling step is completed, the structure 50 and the cover glass 3 are separated. The cover glass 3 separated from the structure 50 is recovered and recycled in the recovery process.

  Conventionally, the solar cell module 1 has been crushed and discarded as it is, but according to the present embodiment, the cover glass 3 can be regenerated. Furthermore, as disclosed in Patent Document 1, there is a recycling method such as a peeling method by swelling with a liquid and pulverization of a cover glass. However, when considering the shortening of the process and the investment cost of the recycling apparatus, The form is simple (heating (decomposition of silane coupling), slow cooling (curing), heating (softening)), and the adhesive layer at the interface between the cover glass 3 and the structure 50 can be reliably peeled off. Glass material recycling can be performed efficiently.

  As described above, the solar cell module recycling method according to the embodiment is a solar cell module recycling method in which a cover glass and a solar cell element are stacked and a back surface protective material is bonded with a filler. As a process, a solar cell module disassembly process (removal of frame, terminal box, electric wiring) is provided. In addition, as the present process, a heat softening process (annealing process) for heating and softening the back surface protective material bonded to the cover glass and the solar cell element, and an edge part on the short side of the solar cell panel after the heat softening process are performed. A first peeling step for partly peeling, a heated peeling auxiliary member applied to the boundary surface between the cover glass and the filler, and the peeling auxiliary member is moved while pulling the upper side of the back surface protective material. It has the 2nd peeling process which peels the structure containing an element and a back surface protection material from a cover glass. Through these steps, the cover glass can be separated from the waste structure and recycled. Therefore, it is possible to reduce the environmental load throughout the life cycle of the solar cell module.

  In the above embodiment, in the second peeling step, the example in which the blade 16 is used as the peeling auxiliary member has been described. However, instead of the blade 16, a heating wire (for example, nichrome wire) is used as the peeling auxiliary member, and the structure 50 It is also possible to peel off the cover glass 3.

  In the above embodiment, the structure having the horizontal feed mechanism 18 is taken as an example. However, the structure 50 may be wound around a cylindrical member such as a roll. FIG. 7 is a diagram illustrating another example of the second peeling step. After fixing the part of the grip allowance 51 formed in the first peeling step to the roll 60, the structure 50 peeled from the cover glass 3 is sent by rotating the roll 60 in the arrow E direction while rotating in the arrow D direction. The structure is wound around a roll 60. Even in such a system, the structure 50 can be peeled off by pulling upward the portion of the structure 50 peeled off from the cover glass 3.

  According to the present embodiment, since the filler can be reliably removed from the cover glass, the work of separating them in the manufacturing process of the recycled glass becomes unnecessary, and the recycling cost can be reduced. Moreover, if it is uses other than the cover glass for solar cells with low quality requirements, such as transparency, the separated cover glass can also be reused (reused) as it is.

  As described above, the method for recycling the solar cell module according to the present invention is useful in that the material recycling of the glass used for the cover glass can be efficiently performed.

  DESCRIPTION OF SYMBOLS 1 Solar cell module, 2 frames, 3 cover glass, 4 solar cell element, 5 interconnector, 6 electrode wire, 7 filler, 8 output cable, 9 terminal box, 12 decompression device, 13 air hole, 15 tension device, 16 Blade, 17 Chuck, 18, 19 Horizontal feed mechanism, 20 heater, 25 stage, 30 constant temperature bath, 31 hot air heater, 40 solar cell panel, 50 structure, 51 grip allowance, 60 rolls.

Claims (5)

Recycling method of solar cell module comprising a solar cell panel in which a solar cell element is sealed by filling a filler between a cover glass and a back surface protective material, and a frame attached to a peripheral portion of the solar cell panel Because
A disassembly step of removing the frame from the solar cell panel;
A separation step of separating the cover glass without crushing it from a structure including the back surface protective material, the filler, and the solar cell element;
Possess a recovery step of recovering the cover glass separated from said structure,
The separation step includes
A heat softening step for annealing the solar cell panel separated from the solar cell module;
A first peeling step of peeling one end of the structure of the solar cell panel subjected to the annealing treatment from the cover glass;
Pulling the part of the structure peeled off from the cover glass in a direction away from the cover glass, while applying a tensile load in a direction perpendicular to the cover glass to the peeling point of the structure and the cover glass, by pushing the peeling auxiliary member which has been heated to a boundary between the cover glass and the structure, the recycling method of a solar cell module characterized by have a second separation step of separating the cover glass and the structure. 2. The method for recycling a solar cell module according to claim 1, wherein the annealing process is a process of gradually cooling to room temperature after heating at 200 to 300 ° C. for 60 to 90 minutes. Wherein in the second peeling process, the cover glass in a state of fixing the solar cell panel by suction to the pressure reducing device, according to claim 1, characterized in that separating the cover glass and the structure Recycling method for solar cell modules. The method for recycling a solar cell module according to any one of claims 1 to 3 , wherein the peeling assisting member is a heating wire that generates heat when energized. Wherein in the second separation step, the recycling method of the solar cell module according to claim 1, any one of 4, characterized in that winding the structure separated from the cover glass on the roll.

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