Lightweight photovoltaic module with a composite reinforcement frame

Abstract

The main object of the invention is a photovoltaic module (1) obtained from a stack comprising at least: a first layer (2), a plurality of photovoltaic cells (4), an assembly encapsulating (3) the photovoltaic cells (4), characterized in that it further comprises: a composite structure (10) forming a frame for the photovoltaic module (1), comprising an intermediate layer (13) and a composite reinforcement frame (12), of higher rigidity superimposed on one or more first predetermined zones (P) of the intermediate layer (13), the frame (12) having a Young's modulus greater than 10 GPa at 25°C. Figure for the abstract: Figure 3

Description

Title of the invention: Lightweight photovoltaic module comprising a composite reinforcement frame Technical field

[0001] 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.

[0002] The invention can be implemented for numerous applications, in particular autonomous and / or embedded 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 / m2, and of low thickness, in particular less than 5 mm. It can thus in particular be applied to 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.

[0003] The invention thus proposes a lightweight photovoltaic module comprising a composite reinforcement frame integrated into the structure of the module, as well as a method for producing such a photovoltaic module. Prior art

[0004] 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.

[0005] 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, having a thickness typically between 2 and 4 mm, conventionally of the order of 3 mm.

[0006] 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 polymeric 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.

[0007] 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" in English). 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.

[0008] 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.

[0009] A classic example of a photovoltaic module 1 comprising crystalline photovoltaic cells 4 has thus been partially and schematically represented, respectively in section in [Fig. 1] and in exploded view in [Fig. 2].

[0010] 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.

[0011] 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.

[0012] 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 in less than or equal to 170°C, typically between 145 and 165°C, and for a lamination cycle duration of at least 10 minutes, or even 15 minutes.

[0013] 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.

[0014] 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.

[0015] 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 / m2, or even 12 kg / m2, and is thus not suitable for certain applications for which lightness is a priority.

[0016] This high weight of the photovoltaic module 1 comes mainly from the presence of the 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 / m2 / mm of thickness, and the aluminum frame. To be able to withstand the constraints during manufacturing and also for safety reasons, for example due to the risk of cutting, the glass is tempered. However, the industrial infrastructure for thermal tempering is configured to process glass of 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 practically 70% of the weight of the photovoltaic module 1, and more than 80% with the aluminum frame around the photovoltaic module 1.

[0017] Also, in order to obtain 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.

[0018] Thus, polymer sheets, such as polycarbonate (PC), polymethacrylate Polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), or fluorinated ethylene propylene (FEP) can be an alternative to glass. However, when only replacing glass with such a thin sheet of polymers is considered, the photovoltaic cell becomes very vulnerable to shock, mechanical loading and differential expansion.

[0019] An alternative is the use of glass fiber composite materials on the front face, replacing standard glass. The weight saving can be significantly important despite less transparency.

[0020] 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 include patent applications FR 2 955 051 A1, FR 3 043 840 A1, FR 3 043 841 A1, FR 3 052 595 A1, FR 3 107 990 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.

[0021] 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 / m2 while saving the material used by reducing the useful volume of the module.

[0022] Also, there is also 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. Statement of the invention

[0023] The invention aims to at least partially remedy the needs mentioned above and the drawbacks relating to the embodiments of the prior art.

[0024] 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 IEC 61730 standards.

[0025] It also aims to improve the lightness of the frame while making it possible to stiffen the module produced.

[0026] 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:

[0027] - a first transparent layer forming the front face of the photovoltaic module, intended to receive a luminous flux,

[0028] - a plurality of photovoltaic cells arranged side by side and electrically connected tightly between them,

[0029] - an assembly encapsulating the plurality of photovoltaic cells,

[0030] characterized in that it further comprises:

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

[0032] - an intermediate layer,

[0033] - a composite reinforcement frame, arranged in direct contact with the intermediate layer located between the composite reinforcement frame and the assembly formed by the plurality of photovoltaic cells and the encapsulating assembly,

[0034] the rigidity of the composite reinforcement frame being higher in the superposition of one or more first predetermined zones of the intermediate layer than the rigidity in the superposition of one or more second predetermined zones of the intermediate layer,

[0035] the composite reinforcement frame having a Young's modulus greater than 10 GPa at 25°C,

[0036] the assembly encapsulating the plurality of photovoltaic cells being located at least in part between said first layer and said composite structure.

[0037] 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.

[0038] 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%.

[0039] 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.

[0040] 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.

[0041] Furthermore, thanks to the invention, it may be possible to obtain a new type of lightweight photovoltaic module which, by using a composite frame to replace the conventional aluminum frame, can have a surface weight of less than 5 kg / m2, while making it possible to stiffen the module, in particular an increase in the overall bending rigidity of the module. The composite frame is also advantageously lighter than a simple intermediate layer, which allows a saving in mass.

[0042] The photovoltaic module according to the invention may further comprise one or more of the following characteristics taken in isolation or in any possible technical combination.

[0043] The first predetermined zone(s) may comprise the periphery of the intermediate layer, or the perimeter of the intermediate layer.

[0044] The first predetermined zone(s) may also comprise one or more transverse zones of the intermediate layer, extending in particular from one edge to another of the intermediate layer, in particular perpendicularly or not, and / or from one angle to another of the intermediate layer, forming in particular a stiffening cross shape.

[0045] In addition, the first layer, the intermediate layer and / or the composite reinforcement frame may be at least partly formed by a composite material comprising a polymer resin and fibers.

[0046] 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.

[0047] 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 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), among others.

[0048] The first layer may be at least partly formed by a composite material comprising glass fibers impregnated with polymer resin.

[0049] Furthermore, the composite reinforcement 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.

[0050] The transverse dimension relative to the vertical stacking axis of the composite structure may advantageously be greater than the transverse dimension by relative to the vertical stacking axis of the plurality of photovoltaic cells.

[0051] According to a first variant, the composite reinforcement frame may comprise a discontinuous monolithic structure superimposed on the first predetermined zone(s) of the intermediate layer. The second predetermined zone(s) of the intermediate layer may not be covered by the composite reinforcement frame. The composite reinforcement frame may have the same rigidity as that of the intermediate layer and be made of the same material as that of the intermediate layer.

[0052] According to a second variant, the composite structure may comprise a multi-layer structure, in particular with a thickness of the composite reinforcement frame greater in superposition of one or more first predetermined zones of the intermediate layer than the thickness in superposition of one or more second predetermined zones of the intermediate layer.

[0053] The composite structure may be a sandwich-type structure, comprising a main layer forming the core and two first and second covering layers forming skin layers, one of which is formed by the intermediate layer, 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 structure may be of rectangular or trapezoidal section in a plane comprising the vertical axis.

[0055] The core of the composite structure may be at least partly formed by a low density structure of less than 500 kg / m3, for example 100 kg / m3, in particular a cellular structure such as a low density foam, for example made of polyurethane (PU), polyvinyl chloride (PVC) and / or polyethylene terephthalate (PET), a honeycomb, wood, balsa and / or cork.

[0056] The core of the composite structure may still correspond to a void.

[0057] 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.

[0058] Furthermore, the core of the composite structure may be located superimposed on the first predetermined zone(s) of the intermediate layer. The second predetermined zone(s) of the intermediate layer may be uncovered or covered by the second covering layer, other than the intermediate layer.

[0059] Furthermore, according to a variant, the composite reinforcement frame may be a tubular type structure, comprising a composite hollow body, in particular of rectangular section. tangular or square in a plane including the vertical axis.

[0060] In addition, the photovoltaic module may comprise an electrical connection cable, or cable output, connected to one or more connecting conductors connecting the photovoltaic cells together, and passing through the core of the composite structure, possibly arranged to allow the passage of the electrical connection cable, so as to allow the electrical connection of the photovoltaic module and / or the electrical attachment to another photovoltaic module.

[0061] The core of the composite structure may house at least one bypass diode connected to the electrical connection cable.

[0062] 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-, [3-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.

[0063] The encapsulating assembly may have a thickness of between 200 μm and 600 μm, in particular between 400 μm and 600 μm. 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.

[0064] 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:

[0065] - a first transparent layer forming the front face of the photovoltaic module, intended to receive a luminous flux,

[0066] - a plurality of photovoltaic cells arranged side by side and electrically connected tightly between them,

[0067] - an assembly encapsulating the plurality of photovoltaic cells,

[0068] - a composite structure forming a frame for the photovoltaic module, comprising at least:

[0069] - an intermediate layer,

[0070] - a composite reinforcement frame, arranged in direct contact with the intermediate layer located between the composite reinforcement frame and the assembly formed by the plurality of photovoltaic cells and the encapsulating assembly, the rigidity of the composite reinforcement frame being higher in the superposition of one or more first pre-zones determined from the intermediate layer that the rigidity in superposition of one or more second predetermined zones of the intermediate layer,

[0071] the composite reinforcement frame having a Young's modulus greater than 10 GPa at 25°C,

[0072] the assembly encapsulating the plurality of photovoltaic cells being located at least in part between said first layer and said composite structure,

[0073] 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 reinforcement frame is integrated inside the photovoltaic module.

[0074] The manufacturing step may comprise 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 duration of the lamination cycle of at least 5 minutes, or even 10 minutes, or even 15 minutes, in particular between 5 and 20 minutes.

[0075] The photovoltaic module and the production method according to the invention may comprise any of the characteristics previously stated, taken in isolation or in any technically possible combination with other characteristics. Brief description of the drawings

[0076] The invention may be better understood by reading the detailed description which follows, of non-limiting examples of its implementation, as well as by examining the schematic and partial figures of the attached drawing, in which:

[0077] [Fig-1] represents, in section, a classic example of a photovoltaic module comprising crystalline photovoltaic cells,

[0078] [Fig.2] represents, in exploded view, the photovoltaic module of [Fig.l],

[0079] [Fig.3]

[0080] [Fig.4]

[0081] [Fig.5]

[0082] [Fig.6]

[0083] [Fig.7] illustrate, in section, different examples of embodiment of photovoltaic modules in accordance with the invention, and

[0084] [Fig. 8]

[0085] [Fig.9]

[0086] [Fig. 10] illustrate, according to views from below, different possible positions for the composite reinforcement frame on the intermediate layer for a photovoltaic module according to the invention.

[0087] Throughout these figures, identical references may designate identical or similar elements.

[0088] Furthermore, the different parts represented in the figures are not necessarily on a uniform scale, in order to make the figures more readable. Detailed description of the invention

[0089] Figures 1 and 2 have already been described in the section relating to the state of the prior art.

[0090] Figures 3 to 10 illustrate different embodiments of photovoltaic modules 1 in accordance with the invention.

[0091] It is considered here that the photovoltaic cells 4, interconnected by soldered tinned copper strips 6, similar to those shown in FIGS. 1 and 2, are “crystalline” cells, that is to say that they comprise mono- or multi-crystalline silicon, and that they have a thickness of between 1 and 250 μm.

[0092] Furthermore, the transverse dimensions considered here may be widths and / or lengths.

[0093] Of course, these choices are in no way limiting.

[0094] In order to describe the different configurations envisaged, reference is first made to [Fig.3] which illustrates, in section, a first example of embodiment of a photovoltaic module 1 in accordance with the invention.

[0095] It should be noted that [Fig. 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.

[0096] 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.

[0097] In accordance with the invention, and in a manner common to the examples of figures 3 to 7, 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.

[0098] This composite structure 10 comprises an intermediate layer 13 and a frame of composite reinforcement 12, arranged in direct contact with the intermediate layer 13. This intermediate layer 13 is located between the composite reinforcement frame 12 and the assembly formed by the photovoltaic cells 4 and the encapsulating assembly 3.

[0099] The composite frame 12 makes it possible to stiffen the photovoltaic module 1. In particular, the rigidity of the composite reinforcement frame 12 is higher when superimposing first predetermined zones P, here the peripheral contour P of the intermediate layer 13 in the example of [Fig. 3], than when superimposing second predetermined zones N of the intermediate layer 13, here a central zone N of the intermediate layer not covered by the composite reinforcement frame 12 in the example of [Fig. 3].

[0100] Furthermore, the composite frame 12 has a Young's modulus 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.

[0101] The intermediate layer 13 therefore has one or more first predetermined zones P, T which are intended to be covered by the composite reinforcement frame 12 with first portions of the frame 12 of high rigidity, and also one or more second predetermined zones N which are intended to be covered by the composite reinforcement frame 12 with second portions of the frame 12 of lower rigidity or else intended not to be covered by the frame 12.

[0102] [Fig.8] illustrates, in a view from below, the intermediate layer 13 of the composite structure 10 comprising a second predetermined central zone N not covered by the composite reinforcement frame 12 and a first predetermined peripheral zone P covered by the composite reinforcement frame 12 with its highest rigidity corresponding to the rigidity of the frame 12.

[0103] It should be noted that, in order to promote the rigidity of the photovoltaic module 1, particularly in the case of large modules, the intermediate layer 13 may also comprise predetermined transverse zones T on which the frame 12 is superimposed with first portions of the frame 12 of higher rigidity.

[0104] These transverse zones T may extend from one edge to the other of the intermediate layer 13 or from one corner to the other of the intermediate layer 13. The transverse zones T may form a stiffening cross, for example with two transverse zones T extending from the four corners of the intermediate layer 13 as in the example of [Fig.9], or with two transverse zones T extending perpendicularly from one edge to the other of the intermediate layer 13 as in the example of [Fig.10].

[0105] The second predetermined zones N of the intermediate layer 13 may not be covered by the frame 12 or covered by second portions of the frame 12 of lower rigidity.

[0106] It should also be noted that the transverse dimension di0 relative to the vertical stacking axis X of the composite structure 10 is greater than the transverse dimension d4 relative to the vertical stacking axis X of the plurality of photovoltaic cells 4.

[0107] In all the examples of Figures 3 to 10, the transverse dimensions d2 of the first layer 2, d3a of the front layer 3a of the encapsulant 3, d3b of the rear layer 3b of the encapsulant 3 and di0 of the composite structure 10 are substantially identical, while the transverse dimension d4 of the plurality of photovoltaic cells 4 is smaller. In addition, the composite structure 10 makes it possible to define the rear face of the photovoltaic module 1.

[0108] 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.

[0109] The intermediate layer 13 and the composite reinforcement 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.

[0110] Advantageously, and in particular in the example of [Fig.3], the constituent materials of the intermediate layer 13 and of the frame 12 are identical.

[0111] The polymer resin, used to impregnate the fibers, both for the first layer 2, the intermediate layer 13 and the composite reinforcement frame 12 can be chosen 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).

[0112] Pre-impregnation may take place before shaping the photovoltaic module 1, for example by lamination, or the impregnation may take place during assembly, for example by injection of polymer resin during assembly.

[0113] Preferably, in all the embodiments of Figures 3 to 10, the intermediate layer 13 is for example made of a composite material comprising a polymer resin and one or more fabrics with natural fibers, in particular at least one ply and advantageously at least two plies. Advantageously, the polymer resin provides adhesion between the layers after assembly.

[0114] Furthermore, in the example of [Fig. 3], the composite reinforcement frame 12 comprises a discontinuous monolithic structure, formed from one or more plies of fibers. It is for example made up of one or more fabrics with basalt, glass or carbon fibers, in particular one ply or several plies. It is located superimposed on the first predetermined peripheral zone P of the intermediate layer 13, the second predetermined central zone N of the intermediate layer 13 not being covered by the composite reinforcement frame 12.

[0115] In an exemplary embodiment, the composite reinforcement frame 12 and / or the intermediate layer 13 may use fabrics with basalt fibers, for example NCF type fabrics (for “Non Crimp Fabric” in English, i.e. sewn multi-axial fabric).

[0116] Generally, the composite structure 10 may have a transverse dimension di0, 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 680 mm.

[0117] The exemplary embodiments of Figures 4 to 7 make it possible to illustrate several configurations for the composite structure 10 in the form of a multilayer structure. Then, the thickness ei2 of the frame 12 is greater in superposition of the first predetermined zone(s) P, T of the intermediate layer 13 than the thickness in superposition of the second predetermined zone(s) N of the intermediate layer 13.

[0118] In particular, the exemplary embodiments of Figures 4 to 6 illustrate a composite structure 10 in the form of a sandwich-type structure. It then comprises a main layer forming the core 14 and first and second covering layers forming skin layers 13, 16, the first skin layer being formed by the intermediate layer 13, arranged on either side of the core 14 so that the core 14 is sandwiched between the two skin layers 13, 16.

[0119] The core 14 of the composite structure 10 has low rigidity while the skin layers 13, 16 have high 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.

[0120] The core 14 may comprise a void. It may also be formed, for example, by a low-density structure of less than 500 kg / m3, for example 100 kg / m3, in particular a cellular structure such as a low-density foam, for example made of polyurethane (PU), polyvinyl chloride (PVC) and / or polyethylene terephthalate (PET), a honeycomb, wood, balsa and / or cork.

[0121] The skin layers 13, 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 13, 16 may comprise different types of matrices, for example thermosetting and / or thermoplastic.

[0122] The thicknesses ei6 of the skin layers 13, 16 may be between 0.2 mm and 2 mm, preferably being of the order of 0.5 mm.

[0123] The second skin layer 16 forms the rear face of the photovoltaic module 1. The second skin layer 16 thus has a transverse dimension relative to the vertical stacking axis X which is equal to the transverse dimension di0 relative to the vertical stacking axis X of the composite structure 10.

[0124] As visible in Figures 4 and 6, the core 14 of the composite structure 10 is located superimposed on the first predetermined peripheral zone P of the intermediate layer 13 while the second predetermined central zone N of the intermediate layer 13 is not covered. On the other hand, in the example of [Fig.5], the second predetermined central zone N of the intermediate layer 13 is covered by the central zone of the second covering layer 16, having a lower rigidity than that of the assembly formed by the core and the peripheral portions of the second covering layer 16.

[0125] The sandwich-type structure thus formed is advantageous in that it makes it possible to increase the inertia and the rigidity of the composite structure 10 in bending, in particular by up to a factor of 30, while preserving the low mass generated. Indeed, a sandwich-type structure has a rigidity in bending proportional to the cube of its thickness. It is therefore possible, by increasing the thickness of the core 14, to significantly increase its moment of inertia in bending 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.

[0126] In addition, the determination of the respective thicknesses of the skin layers 13, 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.

[0127] In the embodiments of Figures 4 and 5, the core 14 has a rectangular section in a plane comprising the vertical axis X, while this section is trapezoidal in the embodiment of [Fig.6].

[0128] A trapezoidal section makes it easier to implement the composite folds and close the sandwich-type structure relative to the exterior.

[0129] It should also be noted that during implementation, the excess thickness of the composite reinforcement 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.

[0130] The example shown in [Fig.7] also makes it possible to illustrate an embodiment of the composite reinforcement 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. This frame 12 can be formed by one or more profiles, in particular pultruded and integrated into the co-firing structure.

[0131] Furthermore, it should be noted that one or more bonding films can be integrated between the different layers described above 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.

[0132] Furthermore, in the examples of figures 4 to 7, one or more electrical connection cables 20 can be connected to one or more connecting conductors 6, in particular the tinned copper strips 6, making it possible to connect the cells 4 together, and can pass through the core 14 of the composite structure 10, either through a vacuum or air, or through the material constituting the core 14, for example a foam, which can, if necessary, be arranged to allow the passage of the cable(s) 20.

[0133] In this way, it is possible to make the electrical connection of the photovoltaic module 1 or to connect several photovoltaic modules together without needing to use one or more junction boxes as according to the embodiments of the prior art.

[0134] Furthermore, one or more bypass diodes 21, connected to the cable(s) 20, can also be integrated into the core 14 due to the thickness of the latter allowing this integration.

[0135] In all the examples of Figures 3 to 7, 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 structure 10 and a frame 12 integrated inside the photovoltaic module 1 are 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 ensuring sufficient rigidity.

[0136] It should also be noted that, in the examples of figures 5 and 7 for which the composite reinforcement frame 12 has a central discontinuity, its constituent elements, in particular the Q-shaped reinforcements of [Fig.5], can be formed by prefabricated parts added to the intermediate layer 13.

[0137] Of course, the invention is not limited to the embodiment which has just been described. Various modifications can be made to it by those skilled in the art.

[0138] In particular, the invention can be implemented for flat photovoltaic modules but also with other types of format, for example curved modules.

Claims

Claims

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: - an intermediate layer (13), - a composite reinforcing frame (12), arranged in direct contact with the intermediate layer (13) located between the composite reinforcing frame (12) and the assembly formed by the plurality of photovoltaic cells (4) and the encapsulating assembly (3), the composite structure (10) comprising a multi-layer structure (12) and being a sandwich-type structure, comprising a main layer forming the core (14) of the composite structure (10) and two first (13) and second (16) covering layers forming skin layers (13, 16), one of which is formed by the intermediate layer (13), arranged on either side of the core (14) so ​​that the core (14) is sandwiched between the two skin layers (13, 16), the core (14) of the composite structure (10) being at least partly formed by a low-density structure of less than 500 kg / m3, the rigidity of the composite reinforcement frame (12) being higher in the superposition of one or more predetermined first zones (P, T) of the intermediate layer (13) than the rigidity in the superposition of one or more predetermined second zones (N) of the intermediate layer (13), the composite reinforcement frame (12) having a Young's modulus (Ei2) greater than 10 GPa at 25°C, the assembly encapsulating (3) the plurality of photovoltaic cells (4) being located at least partly between said first layer (2) and said composite structure (10).

2. Module according to claim 1, characterized in that the first predetermined zones (P, T) comprise the periphery (P) of the intermediate layer (13).

3. Module according to claim 2, characterized in that the first predetermined zone(s) (P, T) comprise one or more transverse zones (T) of the intermediate layer (13), extending in particular from one edge to another of the intermediate layer (13), perpendicularly or not, and / or from one angle to another of the intermediate layer (13), forming in particular a stiffening cross shape.

4. Module according to one of the preceding claims, characterized in that the first layer (2), the intermediate layer (13) and / or the composite reinforcement frame (12) are at least partly formed by 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, flax and / or basalt, and the polymer resin being in particular 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).

5. Module according to any one of the preceding claims, characterized in that the composite reinforcing frame (12) comprises a discontinuous monolithic structure (12) superimposed on the first predetermined zone(s) (P, T) of the intermediate layer (13), the second predetermined zone(s) (N) of the intermediate layer (13) not being covered by the composite reinforcing frame (12), the composite reinforcing frame (12) having in particular the same rigidity as that of the intermediate layer (13) and being in particular made of the same material as that of the intermediate layer (13).

6. Module according to any one of claims 1 to 4, characterized in that the composite structure (10) of multilayer structure (12), has a thickness (ei2) of the composite reinforcement frame (12) greater in superposition of one or more first predetermined zones (P, T) of the intermediate layer (13) than the thickness in superposition of one or more second predetermined zones (N) of the inter- mediator (13).

7. Module according to any one of claims 1 to 6, characterized in that the core (14) of the composite structure (10) is of rectangular or trapezoidal section in a plane comprising the vertical axis (X).

8. Module according to claim 1 to 7, characterized in that the core (14) of the composite structure (10) is at least partly formed by a cellular structure such as a low density foam, for example polyurethane (PU), polyvinyl chloride (PVC) and / or polyethylene terephthalate (PET), a honeycomb, wood, balsa and / or cork.

9. Module according to any one of claims 1 to 7, characterized in that the core (14) of the composite structure (10) corresponds to a void.

10. Module according to claim 1 to 9, characterized in that the skin layers (13, 16) are at least partly formed by a composite material comprising a polymer resin and fibers.

11. Module according to any one of claims 1 to 10, characterized in that the core (14) of the composite structure (10) is located superimposed on the first predetermined zone(s) (P, T) of the intermediate layer (13), the second predetermined zone(s) (N) of the intermediate layer (13) being uncovered or covered by the second covering layer (16), other than the intermediate layer (13).

12. Module according to any one of claims 1 to 11, characterized in that it comprises an electrical connection cable (20) connected to one or more connecting conductors (6) connecting the photovoltaic cells (4) together, and passing through the core (14) of the composite structure (10), possibly arranged to allow the passage of the electrical connection cable (20), so as to allow the electrical connection of the photovoltaic module (1) and / or the electrical attachment to another photovoltaic module.

13. Module according to claim 12, characterized in that the core of the composite structure (10) houses at least one bypass diode (21) connected to the electrical connection cable (20).

14. Module according to any one of claims 1 to 13, characterized in that the composite reinforcement frame (12) is a tubular type structure, comprising a composite hollow body (12), in particular of rectangular or square section in a plane comprising the vertical axis (X).

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: - an intermediate layer (13), - a composite reinforcing frame (12), arranged in direct contact with the intermediate layer (13) located between the composite reinforcing frame (12) and the assembly formed by the plurality of photovoltaic cells (4) and the encapsulating assembly (3), the composite structure (10) comprising a multi-layer structure (12) and being a sandwich-type structure, comprising a main layer forming the core (14) of the composite structure (10) and two first (13) and second (16) covering layers forming skin layers (13, 16), one of which is formed by the intermediate layer (13), arranged on either side of the core (14) so ​​that the core (14) is sandwiched between the two skin layers (13, 16), the core (14) of the composite structure (10) being at least partly formed by a low-density structure of less than 500 kg / m3, the rigidity of the composite reinforcement frame (12) being higher in the superposition of one or more predetermined first zones (P, T) of the intermediate layer (13) than the rigidity in the superposition of one or more predetermined second zones (N) of the intermediate layer (13), the composite reinforcement frame (12) having a Young's modulus (Ei2) greater than 10 GPa at 25°C, the assembly encapsulating (3) the plurality of photovoltaic cells (4) being located at least partly between said first layer (2) and said composite structure (10), the method 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 reinforcement frame (12) is integrated inside the photovoltaic module (1).

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