Lightweight photovoltaic module having an integrated composite frame

Abstract

The invention especially relates to a photovoltaic module (1) comprising at least: a first layer (2); a plurality of photovoltaic cells (4); an assembly (3) encapsulating the photovoltaic cells (4): a composite structure (10) forming a frame for the photovoltaic module (1) comprising at least one central layer (11) and a composite frame (12), the rigidity of the frame (12) being greater than the rigidity of the central layer (11), the frame (12) having a Young's modulus (E12) greater than GPa at 25°C.

Description

[0001] Lightweight photovoltaic module with an integrated composite frame

[0002] DESCRIPTION

[0003] Technical field

[0004] The present invention relates to the field of photovoltaic modules, which comprise a set of photovoltaic cells electrically connected to each other, and preferably so-called "crystalline" photovoltaic cells, i.e. which are based on monocrystalline or multicrystalline silicon.

[0005] The invention can be implemented for numerous applications, in particular autonomous and / or on-board applications, being particularly concerned with applications which require the use of lightweight photovoltaic modules, in particular with a weight per unit area of ​​less than 5 kg / m 2, and of low thickness, in particular less than 5 mm. It can thus be applied in particular for buildings such as homes or industrial premises, for example for the construction of their roofs, for the design of street furniture, for example for public lighting, road signs or even the recharging of electric cars, or even be used for nomadic applications (solar mobility), in particular for integration on vehicles, such as cars, buses or boats, drones, airships, among others.

[0006] The invention thus proposes a lightweight photovoltaic module comprising a composite frame integrated into the structure of the module, as well as a method for producing such a photovoltaic module.

[0007] Prior art

[0008] A photovoltaic module is an assembly of photovoltaic cells arranged side by side between a first transparent layer forming a front face of the photovoltaic module and a second layer forming a rear face of the photovoltaic module.

[0009] The first layer forming the front face of the photovoltaic module is advantageously transparent to allow the photovoltaic cells to receive a luminous flux. It is traditionally made from a single glass plate, in particular tempered glass, with a thickness typically between 2 and 4 mm, conventionally around 3 mm.

[0010] The second layer forming the rear face of the photovoltaic module can be made from glass, metal or plastic, among others. It is often formed by a polymer structure based on an electrically insulating polymer, for example of the polyethylene terephthalate (PET) or polyamide (PA) type, which can be protected by one or more layers based on fluorinated polymers, such as polyvinyl fluoride (PVF) or polyvinylidene fluoride (PVDF), and having a thickness of around 400 pm.

[0011] The photovoltaic cells can be electrically connected to each other by front and rear electrical contact elements, called connecting conductors, and formed for example by strips of tinned copper, respectively arranged against the front faces (faces facing the front face of the photovoltaic module intended to receive a luminous flux) and rear faces (faces facing the rear face of the photovoltaic module) of each of the photovoltaic cells, or even only on the rear face for IBC type photovoltaic cells (for "Interdigitated Back Contact"). It should be noted that IBC type photovoltaic cells ("Interdigitated Back Contact") are structures for which the contacts are made on the rear face of the cell in the form of interdigitated combs. They are for example described in American patent US 4,478,879 A.

[0012] Furthermore, the photovoltaic cells, located between the first and second layers forming respectively the front and rear faces of the photovoltaic module, can be encapsulated. Conventionally, the chosen encapsulant corresponds to a polymer of the thermosetting or thermoplastic type, and can for example consist of the use of two layers (or films) of poly(ethylene-vinyl acetate) (EVA) between which the photovoltaic cells and the cell connecting conductors are arranged. Each layer of encapsulant can have a thickness of at least 0.2 mm and a Young's modulus typically between 2 and 400 MPa at room temperature. Thus, a conventional example of a photovoltaic module 1 comprising crystalline photovoltaic cells 4 is partially and schematically represented, respectively in section in Figure 1 and in exploded view in Figure 2.

[0013] As described above, the photovoltaic module 1 comprises a front face 2, generally made of transparent tempered glass with a thickness of approximately 3 mm, and a rear face 5, for example made of a polymer layer, opaque or transparent, single-layer or multi-layer, having a Young's modulus greater than 400 MPa at room temperature.

[0014] Between the front 2 and rear 5 faces of the photovoltaic module 1 are the photovoltaic cells 4, electrically connected to each other by connecting conductors 6 and immersed between two front 3a and rear 3b layers of encapsulating material, both forming an encapsulating assembly 3.

[0015] Usually, the method for producing the photovoltaic module 1 comprises a step called vacuum lamination of the different layers described above, at a temperature greater than or equal to 120°C, or even 140°C, or even 150°C, and less than or equal to 170°C, typically between 145 and 165°C, and for a duration of the lamination cycle of at least 10 minutes, or even 15 minutes.

[0016] During this lamination step, the layers of encapsulation material 3a and 3b melt and come to encompass the photovoltaic cells 4, at the same time as adhesion is created at all the interfaces between the layers, namely between the front face 2 and the front layer of encapsulation material 3a, the layer of encapsulation material 3a and the front faces 4a of the photovoltaic cells 4, the rear faces 4b of the photovoltaic cells 4 and the rear layer of encapsulation material 3b, and the rear layer of encapsulation material 3b and the rear face 5 of the photovoltaic module 1. The photovoltaic module 1 obtained is then framed, typically by means of an aluminum profile.

[0017] Such a structure has now become a standard which has significant mechanical resistance thanks to the use of a front face 2 made of thick glass and the aluminum frame, allowing it, in particular and in the majority of cases, to comply with the IEC 61215 and IEC 61730 standards. Nevertheless, such a photovoltaic module 1 according to the conventional design of the prior art has the disadvantage of having a high weight, in particular a weight per unit area greater than 10 kg / m 2 , or even 12 kg / m 2 , and is therefore not suitable for certain applications where lightness is a priority.

[0018] This high weight of the photovoltaic module 1 comes mainly from the presence of thick glass, with a thickness of approximately 3 mm, to form the front face 2, the density of the glass being in fact high, of the order of 2.5 kg / m 2 / mm thick, and the aluminum frame. To be able to withstand the stresses during manufacturing and also for safety reasons, for example due to the risk of cuts, the glass is tempered. However, the industrial infrastructure for thermal tempering is configured to process glass at least 3 mm thick. In addition, the choice of having a glass thickness of approximately 3 mm is also linked to a standardized mechanical resistance to pressure of 5.4 kPa. Ultimately, the glass alone thus represents almost 70% of the weight of the photovoltaic module 1, and more than 80% with the aluminum frame around the photovoltaic module 1.

[0019] Also, in order to achieve a significant reduction in the weight of a photovoltaic module to enable its use in new applications requiring lightness and shaping, there is first of all a need to find an alternative solution to the use of thick glass on the front face of the module. One of the problems therefore consists of replacing the glass front face with new plastic or composite materials with the primary aim of significantly reducing the surface weight, or grammage.

[0020] Thus, polymer sheets, such as polycarbonate (PC), polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), or fluorinated ethylene propylene (FEP), can represent an alternative to glass. However, when only replacing glass with such a thin polymer sheet is considered, the photovoltaic cell becomes very vulnerable to shock, mechanical loading, and differential expansion. An alternative is the use of glass fiber composite materials on the front face, replacing standard glass. The weight savings can be significantly important despite lower transparency.

[0021] The replacement of the glass on the front face of photovoltaic modules has been the subject of several patents or patent applications in the prior art. Examples of this include patent applications FR 2955 051 A1, FR 3 043 840 A1, FR 3 043 841 A1, FR 3 052 595 A1, FR 3 107990 A1, US patent application US 2005 / 0178428 A1 and international applications WO 2008 / 019229 A2 and WO 2012 / 140585 A1. Other patents or patent applications have described the use of composite materials, such as European patent application EP 2 863 443 A1, French patent application FR 3 106 698 A1, and international applications WO 2018 / 076525 A1, WO 2019 / 006764 A1 and WO 2019 / 006765 A1.

[0022] However, despite the progress made, the lightness of photovoltaic modules still needs to be improved in order to achieve a surface weight of less than 5 kg / m 2 while saving the material used by reducing the useful volume of the module.

[0023] Also, there is a need to find an alternative solution to the classic use of the aluminum frame with the aim of reducing the surface weight, or grammage, of the photovoltaic module.

[0024] Statement of the invention

[0025] The invention aims to at least partially remedy the needs mentioned above and the drawbacks relating to the achievements of the prior art.

[0026] The invention aims in particular to design an alternative solution for a photovoltaic module designed to be lightweight in order to adapt to certain applications, while having sufficient mechanical properties allowing it to be resistant to shocks and mechanical load, and in particular to the IEC 61215 and I EC 61730 standards.

[0027] It also aims to improve the lightness of the frame while making it possible to stiffen the module produced. The invention thus relates, according to one of its aspects, to a photovoltaic module obtained from a stack, formed along a vertical stacking axis, comprising at least:

[0028] - a first transparent layer forming the front face of the photovoltaic module, intended to receive a luminous flux,

[0029] - a plurality of photovoltaic cells arranged side by side and electrically connected to each other,

[0030] - an assembly encapsulating the plurality of photovoltaic cells, characterized in that it further comprises:

[0031] - a composite structure forming a frame for the photovoltaic module, comprising at least:

[0032] - a central layer,

[0033] - a composite frame, arranged at least in part, in particular completely, around the periphery of the central layer so as to surround at least in part, in particular completely, the central layer, the rigidity of the composite frame being greater than the rigidity of the central layer, the composite frame having a Young's modulus greater than 10 GPa at 25°C, the assembly encapsulating the plurality of photovoltaic cells being located at least in part, in particular completely, between said first layer and said composite structure.

[0034] The term "transparent" means that the first layer forming the front face of the photovoltaic module is at least partially transparent to visible light, allowing at least approximately 80% of this light to pass through.

[0035] In particular, the optical transparency, between 300 and 1200 nm, of the first layer forming the front face of the photovoltaic module may be greater than 80%. Similarly, the optical transparency, between 300 and 1200 nm, of the encapsulating assembly may be greater than 90%.

[0036] Furthermore, by the term "encapsulating" or "encapsulated", it is to be understood that the plurality of photovoltaic cells is arranged in a volume, for example hermetically sealed with respect to liquids, at least partly formed by at least two layers of encapsulating material(s), joined together after lamination to form the encapsulating assembly.

[0037] Indeed, initially, that is to say before any lamination operation, the encapsulating assembly is constituted by at least two layers of encapsulation material(s), called core layers, between which the plurality of photovoltaic cells is encapsulated. However, during the lamination operation of the layers, the layers of encapsulation material melt to form, after the lamination operation, only a single solidified layer (or assembly) in which the photovoltaic cells are embedded.

[0038] Furthermore, thanks to the invention, it may be possible to obtain a new type of lightweight photovoltaic module which, by using a composite frame instead of the conventional aluminum frame, can have a surface weight of less than 5 kg / m 2 , while allowing the module to be stiffened, in particular an increase in the overall bending rigidity of the module.

[0039] The photovoltaic module according to the invention may also include one or more of the following characteristics taken in isolation or in any possible technical combination.

[0040] The constituent materials of the central layer and the composite frame can advantageously be different.

[0041] Additionally, the first layer, the core layer, the composite frame and / or the optional second layer, described hereinafter, may be at least partly formed by a composite material comprising a polymer resin and fibers.

[0042] The fibers may in particular be glass, carbon, aramid and / or natural fibers, in particular hemp, flax and / or basalt, in particular in the form of fabrics, for example woven, non-woven and / or sewn, in particular in the form of one or more plies, for example between 1 and 6 plies.

[0043] The polymer resin may in particular be chosen from: polyurethane (PU), polypropylene (PP), epoxy, polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyamide (PA), a fluoropolymer, in particular polyvinyl fluoride (PVF) or polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE) and / or fluorinated ethylene propylene (FEP), among others.

[0044] The first layer may be at least partly formed by a composite material comprising glass fibers impregnated with polymer resin.

[0045] In addition, the composite frame may have a Young's modulus of between 20 GPa and 100 GPa at 25°C, or even between 80 GPa and 100 GPa at 25°C or even between 20 GPa and 50 GPa at 25°C.

[0046] The composite frame is integrated into the stack, which is thus a multi-layer stack, forming the photovoltaic module.

[0047] In an exemplary embodiment, a transverse dimension, relative to the vertical stacking axis, of the composite frame is equal to a transverse dimension of the first transparent layer forming the front face of the photovoltaic module.

[0048] In an exemplary embodiment, the transverse dimension of the composite frame is equal to a transverse dimension, relative to the vertical stacking axis, of the assembly encapsulating the plurality of photovoltaic cells.

[0049] The transverse dimension relative to the vertical stacking axis of the composite frame may advantageously be greater than the transverse dimension relative to the vertical stacking axis of the plurality of photovoltaic cells.

[0050] The stack may further comprise a second layer forming the rear face of the photovoltaic module. Said composite structure may in particular be located between the first and second layers, in particular between the second layer and the assembly formed by the plurality of photovoltaic cells and the encapsulating assembly.

[0051] Furthermore, the composite structure may comprise at least one additional layer, in particular located between the assembly formed by the central layer and the composite frame and the assembly formed by the plurality of photovoltaic cells and the encapsulating assembly.

[0052] According to a first variant, the composite frame may be a monolithic structure, in particular with a frame thickness equal to the thickness of the central layer. This monolithic structure may consist of one or more plies. According to a second variant, the composite frame may be a multi-layer structure, in particular with a frame thickness greater than the thickness of the central layer.

[0053] The composite frame may be a sandwich-type structure, comprising a main layer forming the core of the composite frame and two covering layers forming skin layers, in particular consisting of one or more plies, arranged on either side of the core so that the core is sandwiched between the two skin layers.

[0054] According to one embodiment, the core of the composite frame may be of trapezoidal section in a plane comprising the vertical axis.

[0055] The core of the composite frame may be at least partly formed by a low density structure of less than 500 kg / m 3 , for example 100 kg / m 3 , including a cellular structure such as low density foam, for example polyurethane (PU), polyvinyl chloride (PVC) and / or polyethylene terephthalate (PET), honeycomb, wood, balsa and / or cork.

[0056] The skin layers may be at least partly formed by a composite material comprising a polymer resin and fibers, in particular glass, carbon, aramid and / or natural fibers, in particular basalt, in particular in the form of fabrics, for example woven, non-woven and / or sewn, in particular in the form of one or more plies, for example between 1 and 6 plies.

[0057] One of the two skin layers can form the back face of the photovoltaic module. Thus, a part of said composite structure can define the back face of the module.

[0058] Furthermore, according to a variant, the composite frame may be a tubular type structure, comprising a composite hollow body, in particular of rectangular or square section in a plane comprising the vertical axis.

[0059] According to another variant, the composite frame may be an angle-type structure, comprising a solid composite body defining an “L” shape in section in a plane comprising the vertical axis. The internal angle formed by the “L” shape may advantageously define a housing for the second layer, the transverse dimension relative to the vertical stacking axis of the composite frame being greater than the transverse dimension relative to the vertical stacking axis of the second layer.

[0060] The composite frame in the form of a tubular or angle type structure can be monolithic or multi-layer.

[0061] In addition, at least one bonding film may be positioned between the composite frame and at least one of the first and second layers or the encapsulating assembly. In particular, the composite frame may comprise on either side thereof a bonding film to facilitate its adhesion.

[0062] The thickness of the composite frame may be greater than or equal to the thickness of the core layer.

[0063] Additionally, the transverse dimension relative to the vertical stacking axis of the plurality of photovoltaic cells may be greater than or equal to the transverse dimension relative to the vertical stacking axis of the core layer.

[0064] In a particular example, the transverse dimension of the central layer is substantially equal to the transverse dimension of the plurality of photovoltaic cells.

[0065] For example, the central layer is positioned under the plurality of photovoltaic cells. In other words, the plurality of photovoltaic cells is arranged between the first transparent layer forming the front face of the photovoltaic module and the central layer.

[0066] Furthermore, the encapsulating assembly may be formed by at least one front layer and one back layer comprising at least one polymer-type encapsulating material chosen from: acid copolymers, ionomers, poly(ethylene-vinyl acetate) (EVA), vinyl acetals, such as polyvinyl butyrals (PVB), polyurethanes, polyvinyl chlorides, polyethylenes, such as linear low-density polyethylenes, polyolefin elastomers of copolymers, copolymers of α-olefins and α-, β-ethylenic carboxylic acid esters, such as ethylene-methyl acrylate copolymers and ethylene-butyl acrylate copolymers, silicone elastomers and / or elastomers based on crosslinked thermoplastic polyolefin.

[0067] According to an exemplary embodiment, a transverse dimension of the front layer of the encapsulating assembly and a transverse dimension of the rear layer of the encapsulating assembly are substantially identical.

[0068] The encapsulating assembly may have a thickness of between 200 pm and 600 pm, in particular between 400 pm and 600 pm. In addition, the encapsulating assembly may have a Young's modulus of between 2 MPa and 400 MPa at 25°C, or even between 2 MPa and 200 MPa at 25°C.

[0069] Furthermore, the invention also relates, according to another of its aspects, to a method for producing a photovoltaic module as defined above, from a stack, formed along a vertical stacking axis, comprising:

[0070] - a first transparent layer forming the front face of the photovoltaic module, intended to receive a luminous flux,

[0071] - a plurality of photovoltaic cells arranged side by side and electrically connected to each other,

[0072] - an assembly encapsulating the plurality of photovoltaic cells,

[0073] - a composite structure forming a frame for the photovoltaic module, comprising at least:

[0074] - a central layer,

[0075] - a composite frame, arranged at least in part all around the periphery of the central layer so as to at least in part surround the central layer, the rigidity of the composite frame being greater than the rigidity of the central layer, the composite frame having a Young's modulus greater than 10 GPa at 25°C, the assembly encapsulating the plurality of photovoltaic cells being located at least in part between said first layer and said composite structure, the method comprising the step of manufacturing the photovoltaic module by a process of lamination, infusion, resin transfer molding (or RTM for "Resin Transfer Molding" in English) and / or consolidation of prepregs, so that the composite frame is integrated inside the photovoltaic module, in particular between the first and second layers.

[0076] The manufacturing step may include a hot and vacuum lamination step carried out at a temperature greater than or equal to 120°C, or even 140°C, or even 150°C, and less than or equal to 170°C, or even 180°C, typically between 130°C and 180°C, or even between 145°C and 165°C, and for a lamination cycle duration of at least 5 minutes, or even 10 minutes, or even 15 minutes, in particular between 5 and 20 minutes.

[0077] The photovoltaic module and the production method according to the invention may include any of the characteristics previously stated, taken in isolation or in any technically possible combination with other characteristics.

[0078] Brief description of the drawings

[0079] The invention may be better understood by reading the detailed description which follows, non-limiting examples of its implementation, as well as by examining the schematic and partial figures of the attached drawing, in which:

[0080] - figure 1 represents, in section, a classic example of a photovoltaic module comprising crystalline photovoltaic cells,

[0081] - figure 2 represents, in exploded view, the photovoltaic module of figure 1, and

[0082] - figures 3 to 9 illustrate, in section, different examples of embodiments of photovoltaic modules in accordance with the invention.

[0083] Throughout these figures, like references may designate identical or similar elements.

[0084] Furthermore, the different parts represented in the figures are not necessarily shown on a uniform scale, in order to make the figures more readable.

[0085] Detailed description of the invention

[0086] Figures 1 and 2 have already been described in the section relating to the state of the prior art. Figures 3 to 9 illustrate different distinct embodiments of photovoltaic modules 1 in accordance with the invention.

[0087] It is considered here that the photovoltaic cells 4, interconnected by soldered tinned copper strips, similar to those shown in figures 1 and 2, are “crystalline” cells, that is to say that they comprise mono or multicrysta II in silicon, and that they have a thickness of between 1 and 250 pm.

[0088] Furthermore, the transverse dimensions considered here can be widths and / or lengths.

[0089] Of course, these choices are in no way limiting.

[0090] In order to describe the different configurations envisaged, we first refer to figure 3 which illustrates, in section, a first example of embodiment of a photovoltaic module 1 in accordance with the invention.

[0091] It should be noted that Figure 3 corresponds to a view of the photovoltaic module 1 before the manufacturing step, in particular lamination, of the method according to the invention. Once this step has been carried out, in particular by lamination ensuring hot and vacuum pressing, the different layers are in reality in contact with each other, and in particular interpenetrated with each other.

[0092] The photovoltaic module 1, or more precisely the stack intended to form the photovoltaic module 1 and produced along a vertical stacking axis X, thus comprises a first layer 2 forming the front face of the photovoltaic module 1 and intended to receive a luminous flux, a plurality of photovoltaic cells 4 arranged side by side and electrically connected to each other, and an assembly 3 encapsulating the plurality of photovoltaic cells 4. In addition, in the exemplary embodiments of FIGS. 3, 4, 7, 8 and 9, the stack comprises a second layer 5 forming the rear face of the photovoltaic module 1. In the exemplary embodiments of FIGS. 5 and 6, the rear face of the photovoltaic module 1 is formed by a skin layer 16 of the composite structure 10, described below.

[0093] In accordance with the invention, and in a manner common to the examples of figures 3 to 9, a composite structure 10 is present to form a frame for the photovoltaic module 1, and more particularly the frame of the photovoltaic module, replacing the aluminum frame usually used in conventional photovoltaic modules.

[0094] This composite structure 10 comprises a central layer 11 and a composite frame 12, arranged at least in part all around the periphery P of the central layer 11 so as to at least in part surround the central layer 11.

[0095] The composite frame 12 thus encloses the central part of the photovoltaic module 1, stiffening the assembly.

[0096] Also, the composite frame 12 has a rigidity greater than the rigidity of the central layer 11, and in particular a Young's modulus E12 greater than 10 GPa at 25°C, for example between 20 GPa and 100 GPa at 25°C, or even between 80 GPa and 100 GPa at 25°C or even between 20 GPa and 50 GPa at 25°C.

[0097] In addition, the transverse dimension di2 relative to the vertical stacking axis X of the composite frame 12 is greater than the transverse dimension d4 relative to the vertical stacking axis X of the plurality of photovoltaic cells 4.

[0098] In the examples of figures 3, 4, 7, 8 and 9, this composite structure 10 is located between the first 2 and second 5 layers, and more particularly between the second layer 5 and the assembly formed by the plurality of photovoltaic cells 4 and the encapsulating assembly 3. In the examples of figures 5 and 6, the composite structure 10 is located on the rear face such that the assembly formed by the plurality of photovoltaic cells 4 and the encapsulating assembly 3 is between the composite structure 10 and the first layer 2.

[0099] In the example of Figure 3, the transverse dimensions d2 of the first layer 2, dsa of the front layer 3a of the encapsulant 3, dsb of the rear layer 3b of the encapsulant 3, dio of the composite structure 10 and ds of the second layer 5 are substantially identical, while the transverse dimensions d4 of the plurality of photovoltaic cells 4 and of the central layer 11 are smaller but also substantially identical.

[0100] Furthermore, the first layer 2, forming the front face, comprises glass fibers impregnated with polymer resin. It is thus in the form of a transparent composite layer based on glass fiber fabrics impregnated with transparent and impact-resistant polymer resin, and in particular in the form of a single ply.

[0101] The second layer 5, forming the rear face, may also comprise glass fibers impregnated with polymer resin. It may therefore be of the same nature as the first layer 2. This possibility is particularly interesting for obtaining bifacial modules with bifacial cells where transparency is required on the front and rear faces.

[0102] More generally, the second layer 5, forming the rear face, may be at least partly formed by a composite material comprising a polymer resin and fibers, in particular glass, carbon, aramid and / or natural fibers, in particular hemp, flax and / or basalt, in particular in the form of fabrics, for example woven, non-woven and / or sewn, in particular in the form of one or more plies, for example between 1 and 6 plies, and preferably 4 plies. Preferably, the second layer 5 may comprise one or more basalt fiber fabrics, in particular one or more plies. The basalt fibers have a grammage of the order of 300 to 600 g / m 2 .

[0103] The central layer 11 and the composite frame 12 are at least partly formed by a composite material comprising a polymer resin and fibers, in particular glass, carbon, aramid and / or natural fibers, in particular hemp, flax and / or basalt, in particular in the form of fabrics, for example woven, non-woven and / or sewn, in particular in the form of one or more plies, for example between 1 and 6 plies.

[0104] Advantageously, the materials constituting the central layer 11 and the frame 12 are different.

[0105] The polymer resin, used to impregnate the fibers, both for the first layer 2, the central layer 11, the composite frame 12 and / or the optional second layer 5, can be chosen from: polyurethane (PU), polypropylene (PP), epoxy, polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyamide (PA), a fluoropolymer, in particular polyvinyl fluoride (PVF) or polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE) and / or fluorinated ethylene propylene (FEP).

[0106] Pre-impregnation may take place before shaping of the photovoltaic module 1, for example by lamination, or impregnation may take place during assembly, for example by injection of polymer resin during assembly.

[0107] Preferably, in all the embodiments of Figures 3 to 9, the central layer 11 comprises one or more fabrics with linen fibers, in particular two plies of fabric. These fibers have a weight of the order of 200 to 400 g / m 2 .

[0108] Furthermore, in the examples of Figures 3 and 4, the composite frame 12 is monolithic, formed from one or more plies of fibers. It is for example made of one or more fabrics with basalt, glass or carbon fibers, in particular one ply or several plies.

[0109] In addition, in the example of Figure 4, the composite structure 10 comprises an additional layer 13, located between the assembly formed by the central layer 11 and the composite frame 12 and the assembly formed by the plurality of photovoltaic cells 4 and the encapsulating assembly 3. This additional layer 13 is for example made of a composite material comprising a polymer resin and one or more fabrics with basalt fibers, in particular at least one ply and advantageously at least two plies. Advantageously, the polymer resin provides adhesion between the layers after assembly.

[0110] The composite frame 12, the additional layer 13 and / or the possible second layer 5 using fabrics with basalt fibers may comprise NCF type fabrics (for “Non Crimp Fabric” in English, i.e. sewn multi-axial fabric).

[0111] Generally, the composite frame 12 may have a transverse dimension di2, in particular a width, of between 30 mm and 100 mm, and for example of the order of 60 mm for a photovoltaic module 1 of dimensions 700 mm x

[0112] 680 mm. In the case of the examples in figures 3 and 4 for which the composite frame

[0113] 12 is monolithic, the thickness ei2 of the frame 12 is equal to the thickness en of the central layer 11.

[0114] The embodiments of Figures 5 to 9 make it possible to illustrate several configurations for the composite frame 12 in the form of a multi-layer structure. Then, the thickness ei2 of the frame 12 is greater than the thickness en of the central layer 11.

[0115] In particular, the exemplary embodiments of Figures 5 and 6 illustrate a composite frame 12 in the form of a sandwich-type structure. It then comprises a main layer forming the core 14 of the frame 12 and two covering layers forming skin layers 15, 16, arranged on either side of the core 14 so that the core 14 is sandwiched between the two skin layers 15, 16.

[0116] The core 14 of the composite frame 12 has low rigidity while the skin layers 15, 16 have significant rigidity, in particular of the order of 20 GPa to 100 GPa, or even between 80 and 100 GPa or even between 20 and 50 GPa at 25°C.

[0117] The core 14 of the composite frame 12 is for example formed by a low density structure of less than 500 kg / m 3 , for example 100 kg / m 3, including a cellular structure such as low density foam, for example polyurethane (PU), polyvinyl chloride (PVC) and / or polyethylene terephthalate (PET), honeycomb, wood, balsa and / or cork.

[0118] The skin layers 15, 16 are for example formed by a composite material comprising a polymer resin and fibers, in particular glass, carbon, aramid and / or natural fibers, in particular basalt, in particular in the form of fabrics, for example woven, non-woven and / or sewn, in particular in the form of one or more plies, for example between 1 and 6 plies, preferably 2 plies. The skin layers 15, 16 may comprise different types of matrices, for example thermosetting and / or thermoplastic.

[0119] The thicknesses ei, ei6 of the skin layers 15, 16 may be between 0.2 mm and 2 mm, preferably being of the order of 0.5 mm.

[0120] The skin layer 16 forms the rear face of the photovoltaic module 1, which is therefore here devoid of a second layer 5 as described previously. The skin layer 16 thus has a transverse dimension relative to the vertical stacking axis X of the composite frame 12 which is equal to the transverse dimension dio relative to the vertical stacking axis X of the composite structure 10.

[0121] The sandwich-type structure thus formed is advantageous in that it makes it possible to increase the inertia and the rigidity of the composite frame 12 in bending, in particular by up to a factor of 30, while preserving the low mass generated. Indeed, a sandwich-type structure has a bending rigidity proportional to the cube of its thickness. It is therefore possible, by increasing the thickness of the core 14, to significantly increase its bending moment of inertia and obtain a considerable increase in the rigidity of the structure while minimizing the increase in mass. Nevertheless, the choice of the thickness of the core 14 is made with the objective of a minimum mass for the required mechanical constraints, in particular the resistance to shear, bending and / or impact.

[0122] In addition, the determination of the respective thicknesses of the skin layers 15, 16 and of the core 14 is done so as to resist the bending moments, the shear, and the axial stresses induced by the forces applied to the construction elements of the sandwich-type structure. Mechanical properties and lightening are typically the main criteria involved in the choice of constituents.

[0123] Furthermore, the embodiment example of figure 6 makes it possible to illustrate the possibility of having a core 14 of the composite frame 12 of trapezoidal section in a plane comprising the vertical axis X.

[0124] A trapezoidal section facilitates the implementation of composite folds and the closure of the sandwich-type structure with respect to the external environment.

[0125] It should also be noted that during implementation, the excess thickness of the composite frame 12 relative to the rest of the composite structure 10 can possibly be compensated for by the use of silicone sheets, for example of the Mosite type, in order to be able to apply uniform pressure to the assembly.

[0126] The example shown in Figure 7 further illustrates an embodiment of the composite frame 12 in the form of a tubular-type structure. This structure comprises a composite hollow body 12, which is for example of rectangular section in a plane comprising the vertical axis X. This composite hollow body 12 in the form of a tube thus defines an internal cavity filled with air. A second layer 5 is present here to form the rear face of the photovoltaic module 1.

[0127] In addition, the example shown in Figure 8 makes it possible to illustrate an embodiment of the composite frame 12 in the form of an angle-type structure, comprising a solid composite body 12 defining an “L” shape in section in a plane comprising the vertical axis X. It should be noted that the internal angle ai2 formed by the “L” shape defines a housing for the second layer 5, also present in this example. In addition, the transverse dimension di2 relative to the vertical stacking axis X of the composite frame 12 is advantageously greater than the transverse dimension ds relative to the vertical stacking axis X of the second layer 5.

[0128] The composite frames 12 of the examples in figures 7 and 8 are thus formed by profiles, in particular pultruded and integrated into the co-firing structure.

[0129] It should also be noted that, unlike the examples of figures 3 to 7, the example of figure 8 represents transverse dimensions dsa, dsb of the front 3a and rear 3b layers of the encapsulating assembly 3 which are smaller and in particular of the order of the transverse dimension of the central layer 11.

[0130] In addition, one or more bonding films 17, shown in dotted lines in Figures 7 and 8, may be integrated between the composite frame 12 and at least one of the first 2 and second 5 layers or the encapsulating assembly 3 to allow better adhesion between the different materials in order to guarantee good performance of the structure produced with regard to the strength, heat resistance, wet aging required, as well as the parameters for implementing the module during manufacturing.

[0131] In the embodiment example of Figure 9, the principle of a composite frame 12 of sandwich structure type of Figure 5 is repeated. However, the skin layer 16 no longer forms the rear face, this being produced by means of a second dedicated layer 5. The skin layer 16 is then similar to the skin layer 15. In all the examples of Figures 3 to 9, the photovoltaic module 1 can be obtained by a conventional single-step lamination process, for example by hot lamination under vacuum at a temperature of approximately 150°C for approximately 15 minutes, or by a transformation process used for composite materials, in particular by infusion, resin transfer molding (or RTM for "Resin Transfer Molding" in English) and / or by consolidation of prepregs.Thus, a composite frame 12 integrated inside the photovoltaic module 1 is advantageously obtained, making it possible to avoid the use of the usual aluminum frame and thus considerably reduce the surface weight of the module while guaranteeing sufficient rigidity.

[0132] Of course, the invention is not limited to the embodiment example which has just been described. Various modifications can be made to it by those skilled in the art.

Claims

DEMANDS 1. Photovoltaic module (1) obtained from a stack, formed along a vertical stacking axis (X), comprising at least: - a first transparent layer (2) forming the front face of the photovoltaic module (1), intended to receive a luminous flux, - a plurality of photovoltaic cells (4) arranged side by side and electrically connected to each other, - an assembly encapsulating (3) the plurality of photovoltaic cells (4), characterized in that it further comprises: - a composite structure (10) forming a frame for the photovoltaic module (1), comprising at least: - a central layer (11), - a composite frame (12), disposed at least in part all around the periphery (P) of the central layer (11) so as to surround at least in part the central layer (11), the composite frame (12) being at least in part formed of a composite material comprising a polymer resin and fibers, a transverse dimension (dl2) of the composite frame (12) being equal to a transverse dimension (d2) of the first transparent layer (2) forming the front face of the photovoltaic module, and to a transverse dimension (d3a, d3b) of the assembly encapsulating (3) the plurality of photovoltaic cells (4), the stiffness of the composite frame (12) being greater than the stiffness of the central layer (11), the composite frame (12) having a Young's modulus (E12) greater than 10 GPa at 25°C, the assembly encapsulating (3) the plurality of photovoltaic cells (4) being located at least in part between said first layer (2) and said composite structure (10).

2. Module according to claim 1, characterized in that the first layer (2), the middle layer (11) and / or the composite frame (12) are at least partly formed from a composite material comprising a polymer resin and fibers, the fibers being in particular glass fibers, carbon fibers, aramid fibers and / or natural fibers, in particular hemp fibers, flax fibers and / or basalt fibers, and the polymer resin being in particular selected from: polyurethane (PU), polypropylene (PP), epoxy, polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyamide (PA), a fluorinated polymer, in particular polyvinyl fluoride (PVF) or polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE) and / or fluorinated ethylene propylene (FEP).

3. Module according to claim 1 or 2, characterized in that the transverse dimension (dw; di2) with respect to the vertical stacking axis (X) of the composite frame (12) is greater than the transverse dimension (dj with respect to the vertical stacking axis (X) of the plurality of photovoltaic cells (4).

4. Module according to any one of the preceding claims, characterized in that the stack further comprises a second layer (5) forming the rear face of the photovoltaic module (1), said composite structure (10) being located between the first (2) and second (5) layers.

5. Module according to any one of the preceding claims, characterized in that the composite structure (10) comprises at least one additional layer (13), in particular located between the assembly formed by the central layer (11) and the composite frame (12) and the assembly formed by the plurality of photovoltaic cells (4) and the encapsulating assembly (3).

6. Module according to any one of the preceding claims, characterized in that the composite frame (12) is a monolithic structure, in particular with a thickness (ei2) of the frame (12) equal to the thickness (en) of the central layer (11).

7. Module according to any one of claims 1 to 5, characterized in that the composite frame (12) is a multilayer structure, in particular with a thickness (in) of the frame (12) greater than the thickness (in) of the central layer (11).

8. Module according to claim 7, characterized in that the composite frame (12) is a sandwich-type structure, comprising a main layer forming the core (14) of the composite frame (12) and two cover layers forming skin layers (15, 16), arranged on either side of the core (14) so ​​that the core (14) is sandwiched between the two skin layers (15, 16).

9. Module according to claim 8, characterized in that the web (14) of the composite frame (12) has a trapezoidal cross-section in a plane including the vertical axis (X).

10. Module according to claim 8 or 9, characterized in that the core (14) of the composite frame (12) is at least partly formed by a low-density structure of less than 500 kg / m³ 3 , for example 100 kg / m 3 , in particular an alveolar structure such as low-density foam, for example polyurethane (PU), polyvinyl chloride (PVC) and / or polyethylene terephthalate (PET), honeycomb, wood, balsa and / or cork, and in that the skin layers (15, 16) are at least partly formed from a composite material comprising a polymer resin and fibers.

11. Module according to any one of claims 8 to 10, except claim 4, characterized in that one (16) of the two skin layers (15, 16) forms the rear face of the photovoltaic module (1).

12. Module according to any one of claims 1 to 7, characterized in that the composite frame (12) is a tubular type structure, comprising a composite hollow body (12), in particular of rectangular or square cross-section in a plane including the vertical axis (X).

13. Module according to any one of claims 1 to 7, characterized in that the composite frame (12) is an angle-type structure, comprising a composite solid body (12) defining an "L" shape in section in a plane including the vertical axis (X).

14. Module according to any one of the preceding claims, characterized in that the transverse dimension (dj with respect to the vertical stacking axis (X) of the plurality of photovoltaic cells (4) is greater than or equal to the transverse dimension (du) with respect to the vertical stacking axis (X) of the central layer (11).

15. Method for producing a photovoltaic module (1) according to any one of the preceding claims, from a stack formed along a vertical stacking axis (X), comprising: - a first transparent layer (2) forming the front face of the photovoltaic module (1), intended to receive a luminous flux, - a plurality of photovoltaic cells (4) arranged side by side and electrically connected to each other, - an assembly encapsulating (3) the plurality of photovoltaic cells (4), - a composite structure (10) forming a frame for the photovoltaic module (1), comprising at least: - a central layer (11), - a composite frame (12), disposed at least partially around the periphery (P) of the central layer (11) so as to surround at least partially the central layer (11), the composite frame (12) being at least partially formed of a composite material comprising a polymer resin and fibers, a transverse dimension (dl2) of the composite frame (12) being equal to a transverse dimension (d2) of the first transparent layer (2) forming the front face of the photovoltaic module, and to a transverse dimension (d3a, d3b) of the assembly encapsulating (3) the plurality of photovoltaic cells (4), the rigidity of the composite frame (12) being greater than the rigidity of the central layer (11), the composite frame (12) having a Young's modulus (E12) greater than 10 GPa at 25°C, the assembly encapsulating (3) the plurality of photovoltaic cells (4) being located at least partially between said first layer (2) and said composite structure (10),the process comprising the step of manufacturing the photovoltaic module (1) by a process of lamination, infusion, resin transfer molding and / or consolidation of prepregs, so that the composite frame (12) is integrated inside the photovoltaic module (1).

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