Process for treating a photovoltaic module to remove interconnecting ribbons

Abstract

The invention relates to a method for processing a photovoltaic module (M), said photovoltaic module comprising, in particular, an intermediate layer (2), this intermediate layer having an encapsulation casing (21) in which photovoltaic cells (20) and at least one interconnecting ribbon (23) are placed, said photovoltaic cells being arranged in several strings, the strings being connected to each other by means of said interconnecting ribbon (23), said method comprising: A step of locating the interconnecting ribbon (23) within the intermediate layer (2), A step of determining a work area (Z1) to be machined, said work area (Z1) being delimited to include the interconnecting ribbon (23) and exclude any photovoltaic cell (20), A machining step localized on said work area (Z1) only. Figure to be published with the abbreviation: Figure 2A

Description

Title of the invention: Method for processing a photovoltaic module for removing interconnecting ribbons. Technical field of the invention

[0001] The present invention relates to a method for processing a photovoltaic module, implemented more particularly for removing the interconnecting ribbons of the photovoltaic module. State of the art

[0002] A photovoltaic module comprises photovoltaic cells designed to convert solar energy into electrical energy.

[0003] Such a photovoltaic module contains many interesting materials to recover and valorize when the module is at the end of its life or faulty.

[0004] Typically, a photovoltaic module takes the form of a panel composed of three main layers superimposed and fixed together: - A first layer, called the back layer (commonly called "backsheet"), forming a first protective element on the back face; - A second layer, called the intermediate layer; this intermediate layer includes the photovoltaic cells, the electrical connections between the cells and an encapsulation envelope arranged around the photovoltaic cells; - A third layer, called the front layer, forming a second protective element on the front face; this front layer is often made of glass or made of a transparent polymer to allow light rays to pass through;

[0005] With a view to recycling a photovoltaic module, various solutions have already been considered. One method consists of crushing the module in its entirety, then subjecting it to various mechanical, thermal and / or chemical treatments in order to separate the materials that make up its composition, such as glass, silver, copper, silicon... However, this first method is energy-intensive and not very environmentally friendly.

[0006] Patent application WO2019 / 043329A1 proposes a method for disassembling a photovoltaic module, which consists of removing each layer of the module to separate it by cutting it with an abrasive wire. Each removed layer can then be processed separately in order to recover the materials of interest. This last This method has some drawbacks. It requires several separate processing stations, first for cutting, then for grinding each removed layer.

[0007] Patent application EP3352227A1 and patent application US2018 / 133720Ald describe solutions for disassembling photovoltaic modules.

[0008] Patent application EP4159397A1 describes the removal by sanding of the first protective element located on the rear face and a selective machining of the intermediate layer, carried out by milling.

[0009] In the intermediate layer, the photovoltaic cells are electrically connected to each other to form several strings of photovoltaic cells. In each string, the cells are connected to each other using thin wires or connecting elements. The strings of photovoltaic cells are also electrically connected to each other using thicker interconnecting tapes located at the ends of the string, these tapes generally extending near the edges of the photovoltaic module.

[0010] The intermediate layer recycling process can be carried out by machining, for example using a sanding belt. The sanding belt is applied against the surface of the layer to be treated in a direction normal to that surface, while the module is moved by a conveyor in a longitudinal direction. In the case of sanding the intermediate layer, it has been observed that the interconnecting tapes are often torn off, accumulating in the vicinity of the sanding belt, which can cause damage to the sanding belt and ultimately necessitate thorough cleaning of the equipment, a process that is particularly time-consuming and costly.

[0011] The aim of the invention is therefore to provide a solution to ensure that the interconnecting ribbons used to connect the cell strings together do not interfere with the machining of the intermediate layer. The proposed solution allows for the prior removal of these interconnecting ribbons. Description of the invention

[0012] This objective is achieved by a method for processing a photovoltaic module, said photovoltaic module comprising in particular an intermediate layer, this intermediate layer having an encapsulation envelope in which photovoltaic cells and at least one interconnecting ribbon are placed, said photovoltaic cells being arranged in several strings, the strings being connected to each other by means of said interconnecting ribbon, said method comprising: - A step of locating the interconnecting ribbon inside the intermediate layer, - A step of determining a work area to be machined, said work area being delimited to include the interconnecting tape and exclude any photovoltaic cells, - A machining step localized to said work area only.

[0013] According to one particular feature, the machining step is carried out by sanding.

[0014] According to another particular feature, the machining step is carried out by bringing a machining tool opposite the determined work area along an axis perpendicular to the plane defined by the surface of the intermediate layer.

[0015] According to a particular embodiment, the machining tool is a sanding strip set in motion around an axis perpendicular to a direction along which said interconnecting strip is deployed.

[0016] According to another particular embodiment, the machining tool is a sanding strip set in motion around an axis parallel to a direction along which the interconnecting strip is deployed.

[0017] According to a particular embodiment, the interconnect ribbon localization step is implemented by optical capture of the intermediate layer.

[0018] According to another particular embodiment, the interconnect ribbon localization step is implemented by image capture using a camera oriented towards the intermediate layer.

[0019] According to another feature, the determined work area is defined by a rectangle surrounding said interconnection ribbon in two dimensions.

[0020] According to another feature, the working area has a third dimension, corresponding to the machining depth.

[0021] The invention relates to a processing system for a photovoltaic module, said photovoltaic module comprising in particular an intermediate layer, this intermediate layer having an encapsulation envelope in which photovoltaic cells and at least one interconnecting ribbon are placed, said photovoltaic cells being arranged in several strings, the strings being connected to each other by means of said interconnecting ribbon, said system comprising: - Means for locating the interconnecting ribbon within the intermediate layer, - Means of determining a work area to be machined, said work area being delimited to include the interconnecting tape and exclude any photovoltaic cell, - Machining equipment located solely within the said work area.

[0022] According to one particular feature, the machining means comprise a machining tool formed by a sanding tool.

[0023] According to another feature, the machining means are configured to bring a machining tool opposite the determined work area along an axis perpendicular to the plane defined by the surface of the intermediate layer.

[0024] According to a particular embodiment, the machining tool is formed of a sanding strip set in motion around an axis perpendicular to a direction along which said interconnecting strip is deployed.

[0025] According to another particular embodiment, the machining tool is formed of a sanding strip set in motion around an axis parallel to a direction along which the interconnecting strip is deployed.

[0026] According to a particular embodiment, the means for locating the interconnecting ribbon include means for optically capturing the intermediate layer.

[0027] According to another particular embodiment, the means for locating the interconnect ribbon include means for capturing images using a camera oriented towards the intermediate layer.

[0028] According to another feature, the determined work area is defined by a rectangle surrounding said interconnection ribbon in two dimensions.

[0029] According to another feature, the working area has a third dimension, corresponding to the machining depth. Brief description of the figures

[0030] Other features and advantages will become apparent in the detailed description that follows, given in relation to the accompanying drawings, in which: - Figures IA and IB represent, respectively in perspective and in cross-section, the structure of a photovoltaic module; - Fig. IC illustrates, by a transparent view, the structure of the intermediate layer of the photovoltaic module; - Figures 2A and 2B illustrate the principle of implementation of the invention, according to two distinct embodiments;

[0031] Detailed description of at least one embodiment

[0032] In the following description, the front face of the photovoltaic module M corresponds to a face of the module receiving the light rays and the rear face corresponds to the face opposite to the front face.

[0033] In the following description, the terms rear and front are therefore to be considered by taking an axis perpendicular to the surface of the module and oriented from its rear face to its front face.

[0034] With reference to [Fig.1A], [Fig.1B] and [Fig.1C], in a known manner, a photovoltaic module comprises several superimposed layers assembled together: - A first layer, called back layer 1 (commonly called "backsheet"), forming a first protective element on the back face; this back layer is usually made of a polymer-type material with one or more layers (see below); - A second layer, called intermediate layer 2, inserted between the back layer 1 and the front layer 3 (described below), allowing the assembly of one side of the back layer 1 and the other side of the front layer 3; this intermediate layer 2 includes the photovoltaic cells 20, the electrical connectors 22 and an encapsulation envelope 21 arranged around the photovoltaic cells; - The front layer 3, forming a second protective element on the front face; this front layer 3 is usually made of glass or a transparent polymer;

[0035] It should be noted that in the attached figures, the photovoltaic module M is shown upside down, so that its rear face is located above and the front face is located below.

[0036] For readability purposes in the attached [Fig. 1A], the different layers of the module are not shown to scale. For example, the back layer 1 may have a thickness of a few hundred µm (for example, about 350 µm), the intermediate layer 2 may have a thickness of up to 1 mm, and the front layer 3 may have a thickness of about 3 to 4 mm.

[0037] The back layer 1 can in particular provide a gas and water impermeability function, an electrical protection / insulation function and a mechanical protection function.

[0038] This back layer 1 may comprise one or more distinct layers (not shown in [Fig. 1A]). In particular, it may comprise a first layer located furthest back, made of a fluorinated polymer, and a second layer arranged in front of this first layer and composed of a non-fluorinated polymer. A third layer (not shown) made of a fluorinated polymer may also be integrated in front of the second layer, in contact with the intermediate layer. If the back layer consists of a single layer, this layer is composed of a non-fluorinated polymer.

[0039] The fluorinated polymer can be polyvinyl fluoride (PVF), for example marketed under the name TEDLAR (registered trademark) by the DuPont company (registered trademark).

[0040] The non-fluorinated polymer can be PET (ethylene poly(terephthalate)), polyamide or other.

[0041] In the intermediate layer 2, the encapsulating layer 21 is conventionally made of a polymer such as EVA (Ethylene-Vinyl Acetate), forming a material to which the back layer 1 can adhere on one side and the front layer 3 on the other, allowing the three layers to be joined together. The three layers can be joined together by hot lamination, so that the back layer 1 and the front layer 3 adhere to the encapsulating layer material, thus forming a single-piece stack.

[0042] With reference to [Fig. 1C], in the intermediate layer 2, the photovoltaic cells 20 are connected to each other in series / parallel, forming several strings of cells. In each string, electrical connecting elements allow the photovoltaic cells to be linked together. In addition, electrical interconnecting ribbons 23, for example made of copper, allow the strings to be connected to each other and provide the electrical connections between the strings of photovoltaic cells.

[0043] For the remainder of the description, the photovoltaic module is considered to have a classical rectangular shape, its length X (along a so-called longitudinal axis) being oriented along the direction of the strings of photovoltaic cells and its width Y (along a so-called transverse axis) along the orientation of the interconnecting ribbons.

[0044] The photovoltaic module M may include a frame (not shown), for example made of aluminum, arranged around the periphery of the stack to stiffen the module M. For the implementation of the invention described below, this frame, as well as the electrical junction box (not shown) generally fixed to the rear face of the module M, are first removed. The method of the invention is in fact more specifically dedicated to the treatment of the layer stack of the photovoltaic module M.

[0045] The principle of the invention applies more particularly to the treatment of the intermediate layer 2 of a photovoltaic module M. This treatment is part of a more global framework of the dismantling of a photovoltaic module, with a view to its recycling.

[0046] The treatment of the back layer 1 can be carried out beforehand according to different options. One of the options may consist of taking a sample from a photovoltaic module in order to characterize it, in order to deduce the machining parameters to be applied, these machining parameters being adapted to remove the back layer 1 from photovoltaic modules having an identical structure.

[0047] Before removing the intermediate layer 2 by machining and, for example, by sanding, the invention consists of first removing the interconnecting ribbons 23, which make the electrical connections between the chains of photovoltaic cells. As illustrated by [Fig.lC], these interconnecting ribbons 23 are often located at the edge of modules, for example along two opposite edges of the module (along Y), at the end of the chain.

[0048] The process of the invention is implemented using a system comprising a processing unit responsible for controlling the implementation of the different stages of the process.

[0049] The system may also include: - An analysis station responsible for locating the interconnection ribbons 23 in the intermediate layer 2; - At least one machining station P_1, P_2 adapted to the implementation of the invention;

[0050] The system may include conveying means, consisting of one or more conveyors, controlled to advance the photovoltaic module M during its processing according to the principle of the invention.

[0051] With reference to [Fig. 2A] and [Fig. 2B], the process of the invention is described below. Certain steps are common to both embodiments. The two embodiments differ in particular in the principle of localized machining of the intermediate layer 2 (steps E30 and E300 in the accompanying figures).

[0052] In the context of the invention, it must be assumed that the photovoltaic module has undergone a first treatment in which its back layer 1 has already been removed, for example by machining. The process of the invention is adapted to the treatment of the remaining intermediate layer 2 of the photovoltaic module.

[0053] A first step E10 consists of locating the interconnection ribbons 23 are present in the intermediate layer 2. This localization can be achieved by various capture methods. These can include optical capture methods. Since the back layer 1 has already been removed, all electrical connections between the cells are visible through the transparency. As described in patent application WO2023 / 194155A1, backlighting can also be used to obtain a higher-contrast image.

[0054] By way of non-limitation, the analysis of the rear face of the intermediate layer 2 of the photovoltaic module can be carried out: - By optical scanning using a probe, in order to scan the entire surface, or - By acquiring, using a camera, one or more images of the surface of the photovoltaic module M.

[0055] The processing unit is, for example, configured to locate the presence of the interconnecting ribbons 23 from the data obtained using the capture means employed. The processing unit can thus analyze the optical data acquired by the probe or images captured by the camera. Any other capture method could be used.

[0056] As illustrated by Figures 2A and 2B, this E10 localization step of the interconnecting ribbons is common to both embodiments.

[0057] Once the interconnecting ribbons 23 have been located, in a second step E20, the processing unit is configured to define a work area ZI on which machining treatment can be carried out.

[0058] This work area ZI is delimited so as to include at least one interconnecting ribbon 23 and to exclude the photovoltaic cells 20. This work area ZI is defined on the rear face of the intermediate layer 2. For example, it is rectangular in shape and corresponds to the area that will be machined to remove the interconnecting ribbon 23 without damaging the photovoltaic cells (or the connecting elements linking the photovoltaic cells). This work area ZI may advantageously include all the interconnecting ribbons 23 located on one side of the module. If the photovoltaic module incorporates interconnecting ribbons along its two opposite edges, the processing unit is configured to define at least two distinct work areas Z1, Z2.

[0059] Once the working area Zl has been delimited, the processing unit records the parameters related to this area.

[0060] By way of exception, given the arrangement of the interconnecting ribbons 23, the working area Zl has an elongated shape along the transverse direction. It can also be defined in three dimensions, including the machining depth.

[0061] It should be noted that the machining depth of the intermediate layer 2 (corresponding to the thickness of the intermediate layer when the intermediate layer is machined to its full thickness) can be defined beforehand by any known means. The machining depth is advantageously chosen to be less than or equal to the thickness of the intermediate layer 2.

[0062] The processing unit then generates the machining parameters P_U to be used to machine said delimited work area Zl (in length, width and possibly in depth).

[0063] Depending on the type of machining planned, the size of the working area Zl may differ.

[0064] As illustrated by Figures 2A and 2B, this step of determining each zone The working method is common to both modes of implementation.

[0065] During a third step E30, E300, the processing unit controls the machining of the work area Zl, respecting the determined machining parameters.

[0066] According to one particular feature, the machining of the work area is advantageously carried out without moving the photovoltaic module M, or possibly with a small movement of it (a few centimeters per minute).

[0067] Advantageously, the machining is carried out on a machining station P_l, P_2 using a machining tool O_l, O_2. The machining tool O_l, O_2 is advantageously a sanding tool. In this case, a sanding belt is thus driven in motion against the intermediate layer 2 of the photovoltaic module M so as to remove the material. During sanding, chips and powder are collected, composed of the material forming the encapsulating casing and pieces of interconnecting tapes 23.

[0068] In the first embodiment according to step E30 ([Fig. 2A]), the machining tool O_1 is actuated transversely with respect to the plane defined by the rear face of the intermediate layer 2 of the photovoltaic module. The sanding band of this machining tool O_1 is set in motion to machine the work area ZI along the positioning direction of the interconnecting strips (along Y).

[0069] The sanding belt advantageously has a reduced width so as not to machine outside the working area ZI. In this first mode, the belt can be arranged to machine the entire working area Zl, over the entire width (Y) of the photovoltaic module M and over a strip along its length extending from the edge of the module to a boundary marking the limit between the working area Zl and an area including the photovoltaic cells 20.

[0070] At step E40, we thus obtain the photovoltaic module from which the rear layer 1 and at least a part 24 of the intermediate layer 2 have been removed, this part corresponding to that which initially incorporated the interconnecting ribbon 23. The intermediate layer 2 can be machined on several working areas (see above) if interconnecting ribbons are present in various places, in particular along the two opposite edges of the photovoltaic module M.

[0071] In the second embodiment according to step E300 ([Fig. 2B]), the machining tool O_2 is also a sanding tool, and the roller is oriented so that its axis of rotation is parallel to the positioning direction (along Y) of the interconnecting ribbons 23. In this embodiment, the machining tool O_2 thus machines the work area Zl in a localized manner, possibly making several passes to cover the entire width of the module (along Y), but over a narrow strip in the lengthwise direction (along X), so that the encapsulation casing 21 remains present on both sides of this narrow strip. This localized machining is made possible, in particular, by the fact that the photovoltaic module remains fixed. The machining tool O_2 is brought directly opposite the work area Zl in a direction normal to the rear face of the intermediate layer. The diameter of the sanding tool can be chosen so as to allow the removal of the intermediate layer over the length (along X) of the working area ZI in a single pass.

[0072] In step E400, the photovoltaic module is thus obtained from which the rear layer 1 has been removed and on which a cavity 25 has been cut in the intermediate layer 2, this cavity corresponding to the area initially integrating the interconnecting ribbon 23. The intermediate layer 2 can also be machined over several working areas (see above) if interconnecting ribbons 23 are present in various places, in particular along the two opposite edges of the photovoltaic module.

[0073] Once the machining of the work area is complete, the removal of the remainder of the intermediate layer 2 can continue, for example by machining (as in patent application EP4159397A1) or another method.

[0074] It should be noted that it would be possible to machine the work area using another technique. Material can be removed using one or more cutting tools (milling, planing, or other). In this case, several passes may be necessary, moving the photovoltaic module, possibly varying its speed during the operation, and / or reversing its direction of movement.

[0075] The invention thus makes it possible to carry out a pre-machining of the intermediate layer 2, in order to remove the interconnecting ribbons, which could interfere with the machining of the rest of the intermediate layer.

[0076] The solution of the invention, according to the second embodiment, allows machining on a narrow strip of material, directly targeting the area including the interconnecting ribbons 23.

Claims

Demands

1. A method for processing a photovoltaic module (M), said photovoltaic module comprising an intermediate layer (2), said intermediate layer having an encapsulation envelope (21) in which photovoltaic cells (20) and at least one interconnecting ribbon (23) are placed, said photovoltaic cells being arranged in several strings, the strings being connected to each other by means of said interconnecting ribbon (23), said method being characterized in that it comprises: - A step of locating the interconnecting ribbon (23) inside the intermediate layer (2), - A step of determining a work area (Zl) to be machined, said work area (Zl) being delimited to include the interconnecting ribbon (23) and exclude any photovoltaic cell (20), - A machining step localized on said work area (Zl) only.

2. A method according to claim 1, characterized in that the machining step is carried out by sanding.

3. Method according to claim 1 or 2, characterized in that the machining step is carried out by bringing a machining tool (O_1, O_2) opposite the determined work area along an axis perpendicular to the plane defined by the surface of the intermediate layer (2).

4. Method according to claim 3, characterized in that the machining tool (O_l) is a sanding strip set in motion around an axis perpendicular to a direction (Y) along which said interconnecting strip (23) is deployed.

5. Method according to claim 3, characterized in that the machining tool (O_2) is a sanding strip set in motion around an axis parallel to a direction (Y) along which the interconnecting strip (23) is deployed.

6. A method according to any one of claims 1 to 5, characterized in that the interconnect ribbon localization step is implemented by optical capture of the intermediate layer (2).

7. A method according to any one of claims 1 to 5, characterized in that the interconnect ribbon localization step is implemented by capturing images using a camera oriented towards the intermediate layer (2).

8. A method according to any one of claims 1 to 7, characterized in that the determined working area (Zl) is defined by a rectangle surrounding in two dimensions said interconnecting ribbon (23).

9. Method according to claim 8, characterized in that the working zone (Zl) has a third dimension, corresponding to the machining depth.

10. A photovoltaic module (M) processing system, said photovoltaic module comprising an intermediate layer (2), said intermediate layer having an encapsulation envelope (21) in which photovoltaic cells (20) and at least one interconnecting ribbon (23) are placed, said photovoltaic cells being arranged in several strings, the strings being connected to each other by means of said interconnecting ribbon (23), said system being characterized in that it comprises: - Means for locating the interconnecting ribbon (23) within the intermediate layer (2), - Means for determining a work area (Zl) to be machined, said work area (Zl) being delimited to include the interconnecting ribbon (23) and exclude any photovoltaic cell (20), - Machining means located on said work area (Zl) only.

11. System according to claim 10, characterized in that the machining means comprise a machining tool (O_1, O_2) formed of a sanding tool.

12. System according to claim 10 or 11, characterized in that the machining means are configured to bring a machining tool (O_1, O_2) opposite the determined work area along an axis perpendicular to the plane defined by the surface of the intermediate layer (2).

13. System according to claim 12, characterized in that the machining tool (O_l) is formed of a sanding strip set in motion around an axis perpendicular to a direction (Y) along which said interconnecting strip (23) is deployed.

14. System according to claim 12, characterized in that the machining tool (O_2) is formed of a sanding strip set in motion around an axis parallel to a direction (Y) along which the interconnecting strip (23) is deployed.

15. System according to any one of claims 10 to 14, characterized in that the interconnect ribbon localization means comprise optical capture means for the intermediate layer (2).

16. System according to any one of claims 10 to 14, characterized in that the means for locating the interconnect ribbon comprise means for capturing images using a camera oriented towards the intermediate layer (2).

17. System according to any one of claims 10 to 16, characterized in that the determined working area (Zl) is defined by a rectangle surrounding in two dimensions said interconnecting ribbon (23).

18. System according to claim 17, characterized in that the working area (Zl) has a third dimension, corresponding to the machining depth.

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