METHOD FOR PROCESSING A PHOTOVOLTAIC MODULE FOR REMOVING CONNECTING TAPES

Description

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 contains photovoltaic cells designed to convert solar energy into electrical energy.

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

[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 rear face; A second layer, called the intermediate layer; this intermediate layer contains 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 the captured light rays to pass through;

[0005] Several solutions have already been considered for recycling photovoltaic modules. One method involves crushing the entire module and then subjecting it to various mechanical, thermal, and / or chemical treatments to separate the materials that make up its composition, such as glass, silver, copper, silicon, etc. 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 involves removing each layer of the module and separating it by cutting it with an abrasive wire. Each removed layer can then be processed separately to recover the materials of interest. This method has some drawbacks. It requires several separate processing stations, first for cutting and then for grinding each removed layer.

[0007] Patent application EP3352227A1 and patent application US2018 / 133720A1 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 multiple strings of photovoltaic cells. Within each string, the cells are connected 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 strings, these tapes typically extending near the edges of the photovoltaic module.

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

[0011] The aim of the invention is therefore to provide a solution to prevent the interconnecting ribbons used to connect cell strings from interfering 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 process 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 process comprising: A step of locating the interconnect ribbon inside the intermediate layer, A step of determining a work area to be machined, said work area being delimited to include the interconnect ribbon and exclude any photovoltaic cell, A machining step localized on said work area only.

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

[0014] According to another particularity, the machining step is implemented 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 band set in motion around an axis perpendicular to a direction along which said interconnecting band is deployed.

[0016] According to another particular embodiment, the machining tool is a sanding band set in motion around an axis parallel to a direction along which the interconnecting tape 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 peculiarity, the determined work area is defined by a rectangle surrounding in two dimensions said interconnection ribbon.

[0020] According to another particularity, the work 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, the system comprising a processing unit and means for analyzing the intermediate layer configured to generate data for the processing unit, the processing unit being configured to locate the interconnecting ribbon within the intermediate layer from the received data, the processing unit being configured to determine a work area to be machined, said work area being delimited to include the interconnecting ribbon and exclude any photovoltaic cell,the system comprising machining means controlled by the processing unit for machining said work area only.

[0022] said system comprising: Means of locating the interconnect ribbon within the intermediate layer, Means of determining a work area to be machined, said work area being delimited to include the interconnect ribbon and exclude any photovoltaic cell, Machining means located on said work area only.

[0023] According to one particular feature, the machining means include a machining tool formed by a sanding tool.

[0024] According to another particularity, 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.

[0025] 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.

[0026] According to another particular embodiment, the machining tool is formed of a sanding band set in motion around an axis parallel to a direction along which the interconnecting band is deployed.

[0027] According to a particular embodiment, the analysis means include means for optical capture of the intermediate layer.

[0028] According to another particular embodiment, the analysis means include means for capturing images using a camera oriented towards the intermediate layer.

[0029] According to another peculiarity, the determined work area is defined by a rectangle surrounding in two dimensions said interconnection ribbon.

[0030] According to another particularity, the work area has a third dimension, corresponding to the machining depth. Brief description of the figures

[0031] Other features and advantages will appear in the detailed description that follows, in conjunction with the attached drawings, in which: THE Figures 1A and 1B represent, respectively in perspective and in cross-section, the structure of a photovoltaic module; The figure 1C illustrates, through a transparent view, the structure of the intermediate layer of the photovoltaic module; The Figures 2A And 2B illustrate the principle of implementation of the invention, according to two distinct embodiments; 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 light rays and the rear face corresponds to the face opposite 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 the Figure 1A , to the figure 1B and to the figure 1C As is known, a photovoltaic module consists of several superimposed layers assembled together: A first layer, called the back layer 1 (commonly called the "backsheet"), forming a first protective element on the rear face; this back layer is usually made of a polymer-type material in one or more layers (see below); A second layer, called the intermediate layer 2, sandwiched 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 casing 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 on top and the front face is on the bottom.

[0036] For readability reasons on the Figure 1A In the attached diagram, 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 350µm), the intermediate layer 2 may have a thickness of up to 1mm and the front layer 3 may have a thickness of about 3 to 4mm.

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

[0038] This back layer 1 may consist of one or more distinct strata (not shown on the Figure 1AIt may include a first layer located furthest back, made of a fluoropolymer, and a second layer positioned in front of this first layer and composed of a non-fluoropolymer. A third layer (not shown) made of a fluoropolymer may also be integrated in front of the second layer, in contact with the intermediate layer. If the rear layer consists of a single layer, this layer is composed of a non-fluoropolymer.

[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 (poly(ethylene terephthalate)), polyamide or other.

[0041] In the intermediate layer 2, the encapsulation layer 21 is typically 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 by hot lamination, so that the back layer 1 and the front layer 3 adhere to the encapsulation layer material, thus forming a single-piece stack.

[0042] With reference to the figure 1CIn the intermediate layer 2, the photovoltaic cells 20 are connected to each other in series / parallel, forming several strings of cells. Within each string, electrical connection elements link the photovoltaic cells together. Furthermore, electrical interconnecting ribbons 23, for example made of copper, connect the strings together and ensure electrical connections between the strings of photovoltaic cells.

[0043] For the rest of the description, we consider that the photovoltaic module classically has a 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 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 back layer 1 treatment can be carried out beforehand using different options. One option may consist of taking a sample from a photovoltaic module in order to characterize it, 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, sanding, the invention consists of first removing the interconnecting ribbons 23, which make the electrical connections between the strings of photovoltaic cells. As illustrated by the figure 1C , these interconnection 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 execution of the various steps of the process. The system may also include: An analysis station responsible for locating the interconnecting ribbons 23 in the intermediate layer 2; At least one machining station P_1, P_2 adapted to the implementation of the invention;

[0049] 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.

[0050] With reference to the figure 2A and to the figure 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 attached figures).

[0051] For the purposes of this invention, it is assumed that the photovoltaic module has undergone an initial 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.

[0052] A first step E10 consists of locating the interconnecting ribbons 23 present in the intermediate layer 2. This location can be achieved using various capture methods. These may be 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 more contrasted image.

[0053] By way of example, the analysis of the back side of 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 one or more images of the surface of the photovoltaic module M using a camera.

[0054] The processing unit is configured, for example, to locate the presence of the interconnecting ribbons 23 based on data obtained using the capture methods employed. The processing unit can thus analyze the optical data acquired by the probe or the images captured by the camera. Any other capture solution could be used.

[0055] As illustrated by the Figures 2A And 2B , this E10 localization step of the interconnection ribbons is common to both embodiments.

[0056] Once the interconnecting ribbons 23 have been located, in a second step E20, the processing unit is configured to define a work area Z1 on which machining treatment can be carried out.

[0057] This work area Z1 is delimited to include at least one interconnecting ribbon 23 and exclude the photovoltaic cells 20. This work area Z1 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 Z1 can 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 and Z2.

[0058] Once the work area Z1 is delimited, the processing unit records the parameters related to this area.

[0059] Without limitation, given the arrangement of the interconnecting strips 23, the work area Z1 has an elongated shape in the transverse direction. It can also be defined in three dimensions, including the machining depth. It should be noted that the machining depth of the intermediate layer 2 (corresponding to the thickness of the intermediate layer when it is machined to its full thickness) can be predetermined by any known means. The machining depth is advantageously chosen to be less than or equal to the thickness of the intermediate layer 2.

[0060] The processing unit then generates the machining parameters P_U to be used to machine said delimited work area Z1 (in length, width and possibly depth).

[0061] Depending on the type of machining planned, the size of the Z1 work zone may differ. As illustrated by the Figures 2A And 2BThis step of determining each work zone is common to both implementation methods.

[0062] During a third step E30, E300, the processing unit controls the machining of the work area Z1, respecting the determined machining parameters.

[0063] 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).

[0064] Advantageously, machining is carried out on a machining station P_1, P_2 using a machining tool O_1, O_2. The machining tool O_1, O_2 is advantageously a sanding tool. In this case, a sanding belt is moved against the intermediate layer 2 of the photovoltaic module M to remove material. During sanding, chips and powder are collected, composed of the material forming the encapsulation casing and pieces of interconnecting tape 23.

[0065] In the first embodiment according to step E30 ( figure 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 Z1 along the positioning direction of the interconnecting ribbons (along Y).

[0066] The sanding belt advantageously has a reduced width so as not to machine outside the working area Z1. In this first mode, the belt can be arranged to machine the entire working area Z1, over the entire width (Y) of the photovoltaic module M and over a strip along its length from the edge of the module to a boundary marking the limit between the working area Z1 and an area including the photovoltaic cells 20.

[0067] At step E40, we thus obtain the photovoltaic module from which the back layer 1 and at least a part 24 of the intermediate layer 2 have been removed, this part corresponding to that which initially integrated 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.

[0068] In the second embodiment according to step E300 ( figure 2BThe 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 strips 23. In this embodiment, the machining tool O_2 thus machines the work area Z1 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 layer 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 Z1 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 along the length (along X) of the working area Z1 in a single pass.

[0069] At step E400, we thus obtain the photovoltaic module from which the back 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.

[0070] 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.

[0071] It should be noted that machining the work area could be carried out 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 travel.

[0072] The invention thus makes it possible to pre-machine the intermediate layer 2, in order to remove the interconnecting ribbons, which could disrupt the machining of the rest of the intermediate layer.

[0073] 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

1. Method for processing a photovoltaic module (M), said photovoltaic module comprising what is referred to as an intermediate layer (2), this intermediate layer comprising an encapsulating envelope (21) in which photovoltaic cells (20) and at least one interconnect ribbon (23) are placed, said photovoltaic cells being arranged in several chains, the chains being connected to one another with the aid of said interconnect ribbon (23), said method being characterized in that it comprises: - a step of locating the interconnect ribbon (23) inside the intermediate layer (2), - a step of determining a working zone (Z1) to be machined, said working zone (Z1) being delimited so as to include the interconnect ribbon (23) and exclude any photovoltaic cell (20), - a step of machining located only on said working zone (Z1).

2. Method according to Claim 1, characterized in that the machining step is implemented by sanding.

3. Method according to Claim 1 or 2, characterized in that the machining step is implemented by bringing a machining tool (O_1, O_2) opposite the determined working zone 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_1) is a sanding belt moved about an axis perpendicular to a direction (Y) in which said interconnect ribbon (23) is deployed.

5. Method according to Claim 3, characterized in that the machining tool (O_2) is a sanding belt moved about an axis parallel to a direction (Y) in which the interconnect ribbon (23) is deployed.

6. Method according to any of Claims 1 to 5, characterized in that the step of locating the interconnect ribbon is implemented by optical capture of the intermediate layer (2).

7. Method according to any of Claims 1 to 5, characterized in that the step of locating the interconnect ribbon is implemented by capture of images with the aid of a camera oriented towards the intermediate layer (2).

8. Method according to any of Claims 1 to 7, characterized in that the determined working zone (Z1) is defined by a rectangle surrounding said interconnect ribbon (23) in two dimensions.

9. Method according to Claim 8, characterized in that the working zone (Z1) has a third dimension, corresponding to the machining depth.

10. System for processing a photovoltaic module (M), said photovoltaic module comprising what is referred to as an intermediate layer (2), this intermediate layer comprising an encapsulating envelope (21) in which photovoltaic cells (20) and at least one interconnect ribbon (23) are placed, said photovoltaic cells being arranged in several chains, the chains being connected to one another with the aid of said interconnect ribbon (23), said system comprising a processing unit and means for analyzing the intermediate layer (2) which are configured to generate data for the processing unit, characterized in that: - the processing unit is configured to locate the interconnect ribbon (23) inside the intermediate layer (2) on the basis of the received data, - the processing unit is configured to determine a working zone (Z1) to be machined, said working zone (Z1) being delimited so as to include the interconnect ribbon (23) and exclude any photovoltaic cell (20), - the system comprises machining means controlled by the processing unit to machine only said working zone (Z1).

11. System according to Claim 10, characterized in that the machining means comprise a machining tool (O_1, O_2) formed by 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 working zone 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_1) is formed by a sanding belt moved about an axis perpendicular to a direction (Y) in which said interconnect ribbon (23) is deployed.

14. System according to Claim 12, characterized in that the machining tool (O_2) is formed by a sanding belt moved about an axis parallel to a direction (Y) in which the interconnect ribbon (23) is deployed.

15. System according to Claim 15, characterized in that the analysis means comprise means for optically capturing the intermediate layer (2).

16. System according to Claim 15, characterized in that the analysis means comprise means for capturing images with the aid of a camera oriented towards the intermediate layer (2).

17. System according to any of Claims 10 to 16, characterized in that the determined working zone (Z1) is defined by a rectangle surrounding said interconnect ribbon (23) in two dimensions.

18. System according to Claim 17, characterized in that the working zone (Z1) has a third dimension, corresponding to the machining depth.