LIGHTWEIGHT PHOTOVOLTAIC MODULE WITH A GLASS AND POLYMER FRONT LAYER

Abstract

The main object of the invention is a photovoltaic module (1) obtained from a stack comprising: a first transparent layer (2) forming the front face; a plurality of photovoltaic cells (4); an encapsulating assembly (3) for the plurality of cells (4); and a second layer (5) forming the rear face. The first layer (2) comprises: a front layer made of at least one polymer material (2a); at least one front assembly (2b, 2c) comprising an interface front layer (2b) and a glass front layer (2c), the latter with a thickness less than or equal to 2 mm, said at least one front assembly (2b, 2c) being located between the polymer front layer (2a) and the encapsulating assembly (3), and the interface front layer (2b) of said at least one front assembly (2b, 2c) being located between the polymer front layer (2a) and the glass front layer (2c). Figure 3

Description

Title of the invention: LIGHTWEIGHT PHOTOVOLTAIC MODULE COMPRISING A LAYER GLASS AND POLYMER FRONT 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 civil and / or military, for example autonomous and / or embedded applications, being particularly concerned with applications which require the use of light and rigid photovoltaic modules, in particular with a weight per unit of surface area of ​​less than 5 kg / m2, or even 6 kg / m2. It can thus in particular be applied to buildings such as homes or industrial premises (tertiary, commercial, etc.), 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, among others.

[0003] The invention thus proposes a lightweight photovoltaic module obtained by a stack comprising a first layer of glass and polymer forming the front face of the module, as well as a method for producing such a photovoltaic module. STATE OF THE 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 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 the order of 300 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).

[0008] It should be noted that IBC (“Interdigitated Back Contact”) type photovoltaic cells 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.

[0009] 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 elastomer (or rubber) 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.

[0010] 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].

[0011] 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 sheet, opaque or transparent, single-layer or multi-layer, having a Young's modulus greater than 400 MPa at room temperature.

[0012] 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.

[0013] [Fig.lA] further represents an alternative embodiment of the example of [Fig.l] in which the photovoltaic cells 4 are of the IBC type, the connecting conductors 6 being arranged only against the rear faces of the photovoltaic cells 4.

[0014] Furthermore, Figures 1 and 2 also show the junction box 7 of the photovoltaic module 1, intended to receive the wiring necessary for operating the module. Conventionally, this junction box 7 is made of plastic or rubber, and is completely waterproof.

[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 generally 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 front 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.

[0018] Nevertheless, such a photovoltaic module 1 according to the conventional design of the prior art has the disadvantage of having a relatively high weight, in particular a weight per unit area of ​​approximately 10 to 12 kg / m2, and is thus not suitable for certain applications for which lightness is a priority.

[0019] 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 / 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 2 mm thickness. In addition, the choice of having a glass thickness of approximately 3 mm is also linked to mechanical resistance at the standard pressure of 5.4 kPa. Ultimately, the glass alone represents almost 70% of the weight of the photovoltaic module 1, and more than 80% with the aluminum frame around the photovoltaic module 1.

[0020] Also, in order to obtain a significant reduction in the weight of a photovoltaic module to enable its use in applications requiring lightness, for example commercial roofs, there is a need to find an alternative solution to the use of thick glass on the front face of the module.

[0021] One possibility is to replace the glass front face with plastic materials while retaining the usual architecture and method of implementation with the primary aim of significantly reducing the surface weight. Thus, polymer sheets, such as polycarbonate (PC), polyethylene terephthalate (PET), 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 the replacement of glass with such a thin polymer sheet is considered, the photovoltaic cell becomes very vulnerable to shock, mechanical load and differential expansion.

[0022] An alternative is the use of composite materials, in particular reinforcements, for example of the glass fiber type, carbon fiber or natural fibers such as flax, hemp, among others, which complement the standard encapsulant to form a polymer / fiber type composite associated with a polymer protective film on the front face. The weight saving can be significantly important despite less good transparency and uncertainty on the performance aspects over periods greater than 20 years.

[0023] The elimination of glass on the front face of photovoltaic modules has been the subject of several patents or patent applications in the prior art. Mention may thus be made in this respect of patent application FR 2 955 051 A1, American patent application US 2005 / 0178428 A1 or international applications WO 2008 / 019229 A2 and WO 2012 / 140585 A1. Other patents or patent applications have described the use of reinforcements alone or in composites, such as for example European patent application EP 2 863 443 A1, or international applications WO 2018 / 076525 A1, WO 2019 / 006764 A1 and WO 2019 / 006765 A1. Statement of the invention

[0024] There is thus a need to design an alternative solution for a photovoltaic module designed to be lightweight in order to adapt to certain applications, while by presenting sufficient mechanical properties allowing it to be resistant to shocks and mechanical load, and in particular to the standards IEC 61215 and IEC 61730.

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

[0026] The invention thus relates, according to one of its aspects, to a photovoltaic module obtained from a stack comprising:

[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 connected electrically between them,

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

[0030] - a second layer forming the rear face of the photovoltaic module, the assembly encapsulant and the plurality of photovoltaic cells being located between the first and second layers,

[0031] characterized in that the first layer comprises:

[0032] - a front layer made of at least one polymer material, called “front layer polymer", and

[0033] - at least one front assembly comprising a front interface layer and a front glass layer, the front glass layer having a thickness less than or equal to 2 mm,

[0034] said at least one front assembly being located between the polymer front layer and the encapsulating assembly, and the interface front layer of said at least one front assembly being located between the polymer front layer and the glass front layer.

[0035] Advantageously, the invention allows the replacement of the standard thick glass with a thickness of approximately 3 mm, usually used on the front face in a conventional photovoltaic module, by a combination of polymer layer(s) and thin glass layer(s). Thus, the use of thin glass(es) and polymer(s) makes it possible to obtain a low mass and a transparency equivalent to a standard module. If the invention is compared to commercially available lightweight modules, the presence of thin glass in the structure allows better resistance to shocks, thermomechanical expansions and moisture penetration.

[0036] 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.

[0037] In particular, the optical transparency, between 300 and 1200 nm, of the first layer forming the front face of the photovoltaic module, in particular the polymer front layer, may be greater than 80%. Similarly, the optical transparency, between 300 and 1200 nm, of the encapsulating assembly can be greater than 90%, as can that of the front interface layer.

[0038] 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.

[0039] 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.

[0040] Furthermore, thanks to the invention, it may be possible to obtain a new type of lightweight photovoltaic module which, by using thin glass, can have a surface weight of less than 6 kg / m2, or even 5 kg / m2, while retaining the optical transparency of the front face and ensuring good reliability of the photovoltaic module with low thermomechanical expansion and high durability. In addition, the use of the polymer front layer and interface layer(s) makes it possible to protect the thin glass from impacts, particularly hailstones.

[0041] 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.

[0042] The front glass layer may advantageously have a thickness less than or equal to 1.5 mm, preferably between 500 μm and 1 mm.

[0043] Furthermore, the front glass layer can advantageously be made of untempered glass. In other words, the glass does not undergo any thermal or chemical tempering. Indeed, untempered glass can be less resistant to impacts, in particular those linked to hailstone impacts. However, being placed between protective polymer layers, in particular between the polymer front layer and the interface front layer, the untempered glass can be protected from impacts. The untempered glass can also provide a moisture barrier for the photovoltaic cells. The use of untempered glass, rather than tempered glass, can significantly reduce costs so as to make the photovoltaic module adaptable to many applications.

[0044] Furthermore, the removal of the thick glass on the front face of the conventional photovoltaic module can lead to a loss of mechanical strength of the module. Also, to be able to to maintain a rigid module, the rear face of the module can be designed to have sufficient mechanical rigidity.

[0045] In particular, according to a first possibility, the second layer can thus comprise:

[0046] - a rear layer forming a rear panel made of composite material, comprising a main sub-layer, forming the core of the rear panel, and two covering sub-layers, each forming a plate of the rear panel, arranged on either side of the core so that the core is sandwiched between the two plates, the core of the rear panel comprising a honeycomb structure.

[0047] The use of a composite sandwich panel type rear face can allow the photovoltaic module according to the invention to have very good mechanical and thermomechanical properties while maintaining a low weight.

[0048] The core of the rear panel may comprise a honeycomb structure, for example in the form of a honeycomb, in particular made of metal, for example aluminum, polyimide, polycarbonate (PC), polypropylene (PP) or high-performance synthetic fibers, for example of the Nomex® type.

[0049] Alternatively, the core of the rear panel may comprise a cellular structure in the form of foam, in particular made of polyethylene terephthalate (PET), polyvinyl chloride (PVC) or polyurethane (PU).

[0050] Furthermore, the rear panel plates can be made of composite material, for example of the glass fiber / epoxy prepreg type, of metal, in particular aluminum, of polycarbonate (PC), of polymethyl methacrylate (PMMA) or from prepregs.

[0051] The rear panel plates may, if necessary, be covered with a single or multi-layer polymer film, for example of the Tedlar® type.

[0052] In addition, the rear panel may have a surface weight less than or equal to 3 kg / m2, in particular less than or equal to 2 kg / m2, in particular still less than or equal to 1 kg / m2.

[0053] It should be noted that, rather than having a sandwich panel type rear face, the second layer may still comprise a rear layer comprising a honeycomb structure, without the use of covering sub-layers, for example a honeycomb structure of the honeycomb polycarbonate type.

[0054] According to a second possibility, the second layer may comprise:

[0055] - a back layer made of at least one polymer material, called “back layer polymer", and

[0056] - at least one rear assembly comprising a rear interface layer and a glass back layer, the glass back layer having in particular a thickness less than or equal to 2 mm, preferably still less than or equal to 1.5 mm, in particular between 500 pm and 1 mm, and being made in particular of non-tempered glass,

[0057] said at least one rear assembly being located between the polymer rear layer and the encapsulating assembly, and the interface rear layer of said at least one rear assembly being located between the polymer rear layer and the glass rear layer.

[0058] Thus, the second layer can be obtained according to a principle analogous to that used for the first layer. In particular, the second layer can also comprise a combination of thin glass(es) and polymer(s). The second layer may or may not be identical to the first layer.

[0059] According to a third possibility, the second layer may comprise a layer of fiber-based reinforcements.

[0060] By "fiber-based reinforcement layer" is meant a layer comprising mainly organic and / or inorganic fibers, and preferably a layer consisting of organic and / or inorganic fibers. Advantageously, a fiber-based reinforcement layer provides mechanical reinforcement to the stack of layers intended to form the photovoltaic module. Before lamination, the fibers of a fiber-based reinforcement layer are preferably not impregnated, in particular with a polymer material. Such a reinforcement layer may be said to be fibered, woven or not "dry". In particular, such a reinforcement layer is not a prepreg layer, nor a composite layer.

[0061] The fiber-based reinforcement layer may comprise woven or non-woven fibers. It may also have a surface weight of between 20 g / m2 and 1500 g / m2, and preferably between 300 g / m2 and 800 g / m2. It may comprise glass, carbon, aramid fibers and / or natural fibers, in particular hemp, linen and / or silk, among others.

[0062] The glass used for the front glass layer and / or the back glass layer may in particular be soda-lime glass, based on silica, calcium and sodium.

[0063] Furthermore, the polymer front layer and / or the polymer rear layer may have a thickness of between 15 μm and 300 μm, in particular between 20 μm and 50 μm.

[0064] In addition, the polymer material of the polymer front layer and / or the polymer back layer may be chosen from: 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), fluorinated ethylene propylene (FEP) and / or a multilayer film comprising one or more of the aforementioned polymers, among others.

[0065] In addition, the polymer front layer and / or the polymer back layer may have a UV cutoff filter between 320 nm and 450 nm, which corresponds to the wavelength for which the transmission rate is equal to 50%. In this way, the underlying layers can be protected from aging by ultraviolet (UV) radiation and possibly from hydrolysis, which gives the photovoltaic module an extended lifetime.

[0066] The front interface layer and / or the back interface layer may allow bonding between the polymer front layer, respectively the polymer back layer, and a glass layer, or between two glass layers.

[0067] The front interface layer and / or the rear interface layer may have a thickness of between 50 μm and 600 μm, preferably between 400 μm and 600 μm, or even between 400 μm and 500 μm.

[0068] The front interface layer and / or the rear interface layer may have a Young's modulus of between 2 and 300 MPa at 25°C, preferably between 100 and 200 MPa at 25°C.

[0069] The encapsulating assembly can be obtained by combining a front layer of encapsulating material and a rear layer of encapsulating material on either side of the photovoltaic cells.

[0070] Furthermore, the encapsulating assembly, the front interface layer and / or the optional rear interface layer may be formed by at least one 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, among others.

[0071] Preferably, the encapsulating material of the encapsulating assembly is identical to the material of the front interface layer, and of the possible rear interface layer. In this way, it may be possible to facilitate the manufacturing process.

[0072] According to a particular embodiment, one of the front layers of encapsulation material and rear layers of encapsulation material of the encapsulating assembly, in particular the rear layer of encapsulation material, may comprise an encapsulation material identical to that of the front interface layer, and the other of the front layers of encapsulation material and rear layers of encapsulation material of the encapsulating assembly, in particular the front layer of encapsulation material, may comprise an encapsulation material different from that of the front interface layer.

[0073] 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.

[0074] In addition, the photovoltaic cells may be chosen from: homojunction or heterojunction photovoltaic cells based on monocrystalline silicon (c-Si) and / or multicrystalline silicon (mc-Si), and / or IBC type photovoltaic cells, and / or photovoltaic cells comprising at least one material from amorphous silicon (a-Si), microcrystalline silicon (pC-Si), cadmium telluride (CdTe), copper-indium selenide (CIS), copper-indium / gallium diselenide (CIGS), and perovskites, among others.

[0075] Furthermore, the photovoltaic cells may have a thickness of between 1 and 300 pm, in particular between 1 and 200 pm, and advantageously between 70 pm and 160 pm.

[0076] The photovoltaic module may further comprise a junction box, intended to receive the wiring necessary for operating the photovoltaic module, which may be positioned on the front face or the rear face of the module, preferably on the front face.

[0077] Furthermore, the spacing between two neighboring, or consecutive or adjacent, photovoltaic cells may in certain configurations be greater than or equal to 1 mm, in particular between 1 mm and 30 mm, and preferably equal to 2 mm. In other configurations, in particular of the “shingle” type according to the English name (or “bardeau” in French), the neighboring, or consecutive or adjacent, photovoltaic cells may overlap or have a spacing of less than 1 mm.

[0078] According to a particular embodiment, the first layer may comprise:

[0079] - a first front assembly comprising a front interface layer and a layer front glass, the front glass layer having a thickness less than or equal to 2 mm,

[0080] - a second front assembly comprising a front interface layer and a front glass layer, the front glass layer having a thickness less than or equal to 2 mm,

[0081] the first front assembly being located between the polymer front layer and the second front assembly, itself located between the first front assembly and the encapsulating assembly.

[0082] The thickness of the front glass layer of the first front assembly and the thickness of the front glass layer of the second front assembly may be the same or different. In particular, the thickness of the front glass layer of the first assembly front may be greater than the thickness of the front glass layer of the second front set.

[0083] In addition, the second layer may comprise:

[0084] - a back layer made of at least one polymer material, called “back layer polymer", and

[0085] - a first rear assembly comprising a rear interface layer and a glass back layer, the glass back layer having in particular a thickness less than or equal to 2 mm, in particular less than or equal to 1.5 mm, in particular between 500 pm and 1 mm, and being in particular made of non-tempered glass,

[0086] - a second rear assembly comprising a rear interface layer and a glass back layer, the glass back layer having in particular a thickness less than or equal to 2 mm, in particular less than or equal to 1.5 mm, in particular between 500 pm and 1 mm, and being in particular made of non-tempered glass,

[0087] said first rear assembly being located between the polymer rear layer and the second rear assembly, itself located between the first rear assembly and the encapsulating assembly.

[0088] Furthermore, the invention also relates, according to another of its aspects, to a method for producing a photovoltaic module, in particular as defined above, from a stack comprising:

[0089] - a first transparent layer forming the front face of the photovoltaic module, intended to receive a luminous flux,

[0090] - a plurality of photovoltaic cells arranged side by side and connected electrically between them,

[0091] - an assembly encapsulating the plurality of photovoltaic cells,

[0092] - a second layer, the encapsulating assembly and the plurality of cells photovoltaic being located between the first and second layers,

[0093] characterized in that the first layer comprises:

[0094] - a front layer made of at least one polymer material, called “front layer polymer", and

[0095] - at least one front assembly comprising a front interface layer and a front glass layer, the front glass layer having a thickness less than or equal to 2 mm,

[0096] said at least one front assembly being located between the polymer front layer and the encapsulating assembly, and the interface front layer of said at least one front assembly being located between the polymer front layer and the glass front layer,

[0097] and in that the method comprises the step of hot and vacuum lamination of the constituent layers of the stack to obtain the photovoltaic module.

[0098] The hot and vacuum lamination step may in particular be 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.

[0099] Thus, it is possible to obtain total encapsulation of the thin glass allowing it to be protected against impacts.

[0100] 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

[0101] 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:

[0102] [Fig-1] represents, in section, a classic example of a photovoltaic module comprising crystalline photovoltaic cells,

[0103] [Fig.lA] represents an alternative embodiment of the example of [Fig.l] in which the photovoltaic cells are of the IBC type,

[0104] [Fig.2] represents, in exploded view, the photovoltaic module of [Fig.l],

[0105] [Fig.3] illustrates, in perspective and in exploded view, a first example of embodiment of a photovoltaic module in accordance with the invention,

[0106] [Fig.3A] illustrates, in section, an example of a back layer used for the photovoltaic module shown in [Fig.3],

[0107] [Fig.4] illustrates, in perspective and in exploded view, a second example of embodiment of a photovoltaic module in accordance with the invention,

[0108] [Fig.5] illustrates, in perspective and in exploded view, a third example of embodiment of a photovoltaic module in accordance with the invention, and

[0109] [Fig.6] illustrates, in perspective and in exploded view, a fourth example of embodiment of a photovoltaic module in accordance with the invention.

[0110] Throughout these figures, identical references may designate identical or similar elements.

[0111] In addition, the different parts represented in the figures are not necessarily shown on a uniform scale, in order to make the figures more readable. Description of the embodiments

[0112] Figures 1, 1A and 2 have already been described in the section relating to the state of the prior art.

[0113] Figures 3 to 6 illustrate four distinct embodiments of photovoltaic modules 1 in accordance with the invention.

[0114] It is considered here that the photovoltaic cells 4, interconnected by soldered tinned copper strips, similar to those shown in FIGS. 1, 1A 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.

[0115] In addition, the polymer front layer 2a may be a fluorinated polymer film, with a thickness of the order of 20 μm, in particular made of ethylene chlorotrifluoroethylene (ECTFE), for example of the Amcor® ECTFE 020 type.

[0116] The interface layers 2b, 2d and 5b may comprise a polymer encapsulating film, for example of type A formed by a thermoplastic elastomer based on polyolefin (TPO) or of type B formed by an ionically crosslinked thermoplastic copolymer, for example of the monomer type. The thickness may be between 500 and 600 μm. In particular, for a polymer encapsulating film of type B, it may be KuranSeal-ES® (PV8729D / UV CUT) from the company Kurabo, with a thickness of 500 μm.

[0117] The glass layers 2c, 2e and 5c may comprise a thin, non-tempered glass with a thickness of between 500 and 800 μm, for example of the order of 550 μm.

[0118] The second layer 5, when in the form of a rear panel 5, may comprise a polypropylene honeycomb core 9a and composite skins or plates 9b, 9c made of glass-reinforced polypropylene with a thickness of, for example, between 6 and 10 mm, for example of the Nidapan® 8 GR 600 type with a thickness of 10 mm.

[0119] Of course, these choices are in no way limiting.

[0120] For all the stacking examples described with reference to figures 3 to 6, tests were carried out against mechanical impacts of the hailstone type for energy levels of 2 J representative of the IEC 61215 certification standard. The results demonstrated the fact that the integration of thin non-tempered glass in the module makes it possible to obtain a reduced weight while having impact resistance in accordance with the standards in force.

[0121] In order to describe the different configurations envisaged, reference is first made to [Fig. 3] which illustrates, in perspective and in exploded view, a first example of embodiment of a photovoltaic module 1 in accordance with the invention.

[0122] It should be noted that [Fig. 3] corresponds to an exploded view of the photovoltaic module 1 before the lamination step of the method according to the invention. Once the lamination step has been carried out, ensuring hot and vacuum pressing, the different layers are in reality in contact with each other, and in particular interpenetrated with each other.

[0123] The photovoltaic module 1, or more precisely the stack intended to form the photovoltaic module 1, 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, an assembly 3 encapsulating the plurality of photovoltaic cells 4, and a second layer 5 forming the rear face of the photovoltaic module 1.

[0124] It should also be noted that a junction box 7 can be arranged on the front face or even on the rear face, as shown in FIGS. 1, 1A and 2, of the photovoltaic module 1.

[0125] In accordance with the invention, and in a manner common to the examples of figures 3 to 6, the first layer 2 comprises a front layer made of a polymer material 2a, called “polymer front layer 2a”, and a first front assembly 2b, 2c comprising a front interface layer 2b and a front layer of glass, advantageously of non-tempered glass 2c.

[0126] Advantageously, the front glass layer 2c has a thickness e2c less than or equal to 2 mm, or even less than or equal to 1.5 mm, and in particular between 500 μm and 1 mm.

[0127] In this example, the front encapsulation layer 3a, the back encapsulation layer 3b and the front interface layer 2b are all type A encapsulant films.

[0128] The second layer 5 is formed by a rear panel 5 made of composite material, comprising a main sub-layer, forming the core 9a of the rear panel 5, and two covering sub-layers, each forming a plate 9b, 9c of the rear panel 5, arranged on either side of the core 9a so that the core 9a is sandwiched between the two plates 9b, 9c, the core 9a of the rear panel 5 comprising a honeycomb structure. [Fig. 3A] shows, schematically in section in more detail, the second layer 5 formed in the example of [Fig. 3]. It should be noted that alternatively, the second layer 5 could comprise a layer of reinforcements based on fibers, woven or not, in particular glass fibers, carbon fibers, aramid fibers and / or natural fibers, in particular hemp, linen and / or silk, among others.

[0129] The photovoltaic module 1 is obtained by means of a single vacuum hot lamination step, for example at a temperature of approximately 150°C for approximately 15 minutes. It has a surface weight of 4.4 kg / cm2.

[0130] It is also possible to use type B encapsulant films for the front encapsulation layer 3a, the rear encapsulation layer 3b and the front interface layer 2b. Then, the impact resistance of the photovoltaic module 1 is further improved due to a higher Young's modulus.

[0131] Furthermore, [Fig.4] illustrates a second example of an embodiment in accordance with the invention.

[0132] In this example, unlike that of [Fig. 3], the first layer 2 also comprises a second front assembly 2d, 2e comprising a front interface layer 2d and a front glass layer, advantageously made of non-tempered glass 2e. The front glass layer 2e has a thickness e2e less than or equal to 2 mm, or even less than or equal to 1.5 mm, and in particular between 500 pm and 1 mm. In other words, this embodiment provides for doubling the thickness of glass in the first layer 2. A photovoltaic module 1 with a surface weight equal to 6 kg / cm2 is then obtained. The impact resistance of the photovoltaic module 1 is further improved.

[0133] In addition, the first front interface layer 2b and the front 3a and rear 3b encapsulation layers are formed by type A encapsulant films, while the second front interface layer 2d is formed by a type B encapsulant film.

[0134] In the example of [Fig.4], the first front glass layer 2b and the second front glass layer 2e have the same thickness. Alternatively, it is possible to use different glass thicknesses, for example a thickness e2b of the order of 500 μm and a thickness e2e of the order of 300 μm. Thus, if we consider that 800 μm of glass can meet the need for shock resistance of the cells 4, it is possible to use for example a 500 μm glass and a 300 μm glass.

[0135] Indeed, it is known that elastomeric materials have vibration and shock damping properties. The alternation of rigid materials with elastomeric materials will thus make it possible to modify the speed of propagation of shock waves, because the speed of a shock wave is directly proportional to the Young's modulus and Poisson's ratio of the material used. The insertion of flexible elastomeric layers, between layers of more rigid materials, therefore makes it possible to slow down the propagation of shock waves. In addition, at each interface encountered, the shock wave can be transmitted and / or reflected in part. The repetition of the alternation of these polymer layers having different Young's moduli therefore makes it possible on the one hand to slow down the shock waves and on the other hand to reduce the intensity of the latter which reach the photovoltaic cells.

[0136] Also, for an equivalent quantity of glass, it may be more advantageous to distribute this quantity between at least two layers of glass of different thicknesses instead of a single layer of glass.

[0137] Furthermore, [Fig.5] illustrates a third embodiment example whose principle is to use the same encapsulation architecture on the rear face as on the front face, symmetrically. This allows us to obtain a bifacial and lightweight photovoltaic module.

[0138] Thus, the second layer 5 here comprises a rear layer made of a polymer material 5a, called “polymer rear layer 5a”, and a first rear assembly 5b, 5c comprising a rear interface layer 5b and a rear layer of glass, preferably not tempered 5c.

[0139] The back glass layer 5c has a thickness e5c of 550 pm, and the front glass layer 2c also has a thickness e2c of 550 pm.

[0140] The front interface layer 2b, the rear interface layer 5b, the front encapsulation layers 3a and rear encapsulation layers 3b are here type B encapsulant films.

[0141] Furthermore, [Fig.6] illustrates a fourth embodiment corresponding to a variant of the example of [Fig.5] in which the use of thin glasses, preferably not tempered on the front face and on the rear face, is carried out asymmetrically.

[0142] In particular, two thin glasses 2c and 2e can be used on the front face of identical or different thicknesses, and a thin glass 5c can be used on the back face. More precisely here, a first front layer of glass 2c has a thickness e2c of 500 pm, a second front layer of glass 2e has a thickness e2e of 300 pm, and a first rear layer of glass 5c has a thickness e5c of 550 pm.

[0143] In addition, the first front interface layer 2b, the second front interface layer 2d, the rear interface layer 5b, the front encapsulation layers 3a and rear encapsulation layers 3b are here type B encapsulant films.

[0144] In all the examples described above, the polymer front layer 2a and the polymer rear layer 5a have a thickness e2a, e5a of the order of 20 μm.

[0145] The front interface layers 2b, 2d and the rear interface layer 5b have a thickness e2b, e2d, e5b of the order of 600 μm.

[0146] Of course, the invention is not limited to the embodiments which have just been described. Various modifications can be made thereto by those skilled in the art.

[0147] In particular, these exemplary embodiments can be declined according to various variants using one or more of the materials mentioned previously to form the first layer 2 and the second layer 5.

Claims

Claims

1. Photovoltaic module (1) obtained from a stack comprising: - a first transparent layer (2) forming the front face of the photovoltaic module (1), intended to receive a light 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 second layer (5) forming the rear face of the photovoltaic module (1), the encapsulating assembly (3) and the plurality of photovoltaic cells (4) being located between the first (2) and second (5) layers, characterized in that the first layer (2) comprises: - a front layer made of at least one polymer material (2a), called "polymer front layer (2a)", and - at least one front assembly (2b, 2c; 2d, 2e) comprising a front interface layer (2b; 2d) and a front glass layer (2c; 2e), the front glass layer (2c; 2e) having a thickness (e2c;e2e) less than or equal to 2 mm, said at least one front assembly (2b, 2c; 2d, 2e) being located between the polymer front layer (2a) and the encapsulating assembly (3), and the interface front layer (2b; 2d) of said at least one front assembly (2b, 2c; 2d, 2e) being located between the polymer front layer (2a) and the glass front layer (2c; 2e), and in that the second layer (5) comprises: - a rear layer forming a rear panel (5) made of composite material, comprising a main sub-layer, forming the core (9a) of the rear panel (5), and two covering sub-layers, each forming a plate (9b, 9c) of the rear panel (5), arranged on either side of the core (9a) so that the core (9a) is sandwiched between the two plates (9b, 9c), the core (9a) of the rear panel (5) comprising a honeycomb structure.;

2. Module according to claim 1, characterized in that the front glass layer (2c; 2e) has a thickness (e2c; e2e) less than or equal to 1.5 mm, in particular between 500 pm and 1 mm.

3. Module according to claim 1 or 2, characterized in that the front glass layer (2c; 2e) is made of non-tempered glass.

4. Module according to one of claims 1 to 3, characterized in that the constituent layers of the stack are in contact with each other.

5. Module according to any one of the preceding claims, characterized in that the polymer front layer (2a) has a thickness (e2a) of between 15 pm and 300 pm, in particular between 20 pm and 50 pm.

6. Module according to any one of the preceding claims, characterized in that the front interface layer (2b; 2d) has a thickness (e2b, e2d) of between 50 pm and 600 pm, in particular between 400 pm and 600 pm, in particular between 400 pm and 500 pm.

7. Module according to any one of the preceding claims, characterized in that the polymer material of the polymer front layer (2a) is chosen from: 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), fluorinated ethylene propylene (FEP) and / or a multilayer film comprising one or more of the aforementioned polymers.

8. Module according to any one of the preceding claims, characterized in that the encapsulating assembly (3) and / or the front interface layer (2b; 2d) are formed by at least one 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 elastomer 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.

9. Module according to any one of the preceding claims, characterized in that the first layer (2) comprises: - a first front assembly (2b, 2c) comprising a front interface layer (2b) and a front glass layer (2c), the front glass layer (2c) having a thickness (e2c) less than or equal to 2 mm, - a second front assembly (2d, 2e) comprising a front interface layer (2d) and a front glass layer (2e), the front glass layer (2e) having a thickness (e2e) less than or equal to 2 mm, the first front assembly (2b, 2c) being located between the polymer front layer (2a) and the second front assembly (2d, 2e), itself located between the first front assembly (2b, 2c) and the encapsulating assembly (3).

10. Module according to claim 9, characterized in that the thickness (e 2c) of the front glass layer (2c) of the first front assembly (2b, 2c) and the thickness (e2e) of the front glass layer (2e) of the second front assembly (2d, 2e) are different.

11. Module according to claim 10, characterized in that the thickness (e2c) of the front glass layer (2c) of the first front assembly (2b, 2c) is greater than the thickness (e2e) of the front glass layer (2e) of the second front assembly (2d, 2e).

12. Method for producing a photovoltaic module (1) according to any one of the preceding claims, from a stack comprising: - a first transparent layer (2) forming the front face of the photovoltaic module (1), intended to receive a light 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 second layer (5), the encapsulating assembly (3) and the plurality of photovoltaic cells (4) being located between the first (2) and second (5) layers, characterized in that the first layer (2) comprises: - a front layer made of at least one polymer material (2a), called "polymer front layer (2a)", and - at least one front assembly (2b, 2c; 2d, 2e) comprising a front interface layer (2b; 2d) and a front glass layer (2c; 2e), the front glass layer (2c; 2e) having a thickness (e2c; e2e) less than or equal to 2 mm, said at least one front assembly (2b, 2c; 2d, 2e) being located between the polymer front layer (2a) and the encapsulating assembly (3), and the interface front layer (2b; 2d) of said at least one front assembly (2b, 2c; 2d, 2e) being located between the polymer front layer (2a) and the glass front layer (2c; 2e), in that the second layer (5) comprises: - a rear layer forming a rear panel (5) made of composite material, comprising a main sub-layer, forming the core (9a) of the rear panel (5), and two covering sub-layers, each forming a plate (9b, 9c) of the rear panel (5), arranged on either side of the core (9a) so that the core (9a) is sandwiched between the two plates (9b, 9c), the core (9a) of the rear panel (5) comprising a honeycomb structure, and in that the method comprises the step of hot and vacuum lamination of the constituent layers of the stack to obtain the photovoltaic module (1).

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