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 FRONT IN GLASS AND POLYMER 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, that is to say, those based on monocrystalline or multicrystalline silicon.

[0002] The invention can be implemented for numerous applications, including civil and / or military applications, for example autonomous and / or embedded applications, being particularly relevant to applications requiring the use of lightweight and rigid photovoltaic modules, especially those with a weight per unit area of ​​less than 5 kg / m2, or even 6 kg / m2. It can thus be applied in particular 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 charging of electric cars, or even be used for mobile 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 manufacturing such a photovoltaic module. PRIOR TECHNOLOGY

[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 light flux. It is traditionally made of a single sheet of glass, in particular tempered glass, with a thickness typically between 2 and 4 mm, classically on the order of 3 mm.

[0006] The second layer forming the back face of the photovoltaic module can be made of glass, metal, or plastic, among other materials. It is often formed by a polymeric structure based on an electrically insulating polymer, by 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 300 pm.

[0007] Photovoltaic cells can be electrically connected to each other by front and rear electrical contact elements, called connecting conductors, and formed for example by tinned copper strips, respectively arranged against the front faces (faces facing the front face of the photovoltaic module intended to receive a light 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 in which the contacts are made on the back face of the cell in the form of interdigitated combs. They are described, for example, in US patent 4,478,879 A.

[0009] Furthermore, the photovoltaic cells, located between the first and second layers forming the front and rear faces of the photovoltaic module respectively, can be encapsulated. Typically, the encapsulant chosen is an elastomer (or rubber) type polymer, and may, for example, consist of two layers (or films) of poly(ethylene-vinyl acetate) (EVA) between which the photovoltaic cells and the cell connecting conductors are arranged. Each encapsulant layer 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 cross-section on [Fig.1] and in exploded view on [Fig.2].

[0011] As described previously, the photovoltaic module 1 has a front face 2, generally made of transparent tempered glass approximately 3 mm thick, 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 located 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.1A further represents a variant embodiment of the example in Fig.1 in which the photovoltaic cells 4 are of type IBC, the connecting conductors 6 being only arranged 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 the operation of the module. Typically, this junction box 7 is made of plastic or rubber and is completely sealed.

[0015] Typically, the process for manufacturing the photovoltaic module 1 includes 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 lamination cycle duration generally of at least 10 minutes, or even 15 minutes.

[0016] During this lamination step, the encapsulation material layers 3a and 3b melt and come together to enclose the photovoltaic cells 4, at the same time as adhesion is created at all 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 back faces 4b of the photovoltaic cells 4 and the back layer of encapsulation material 3b, and the back layer of encapsulation material 3b and the back face 5 of the photovoltaic module 1. The resulting photovoltaic module 1 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 in thick glass and the aluminium frame, allowing it, in particular and in the majority of cases, to comply with the IEC 61215 and IEC 61730 standards.

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

[0019] The high weight of the photovoltaic module 1 is primarily due to the presence of thick glass, approximately 3 mm thick, forming the front face 2. The glass has a high density, on the order of 2.5 kg / m² / mm of thickness, and the aluminum frame. To withstand the stresses during manufacturing and also for safety reasons, such as the risk of cuts, the glass is tempered. However, the industrial infrastructure for thermal tempering is configured to process glass at least 2 mm thick. Furthermore, the choice of a glass thickness of approximately 3 mm is also related to mechanical strength. 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 allow 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 maintaining the usual architecture and manufacturing method, with the primary goal 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 impact, mechanical load, and differential expansion.

[0022] An alternative is the use of composite materials, in particular reinforcements, for example of glass fibers, carbon fibers, or natural fibers such as flax, hemp, among others, which are added to the standard encapsulant to form a polymer / fiber composite combined with a polymer protective film on the front face. The weight reduction can be significant despite reduced transparency and uncertainty regarding performance over periods exceeding 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. Examples include French patent application FR 2 955 051 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 reinforcements alone or in composites, such as European patent application EP 2 863 443 A1, and international applications WO 2018 / 076525 A1, WO 2019 / 006764 A1, and WO 2019 / 006765 A1. Description of the invention

[0024] There is therefore a need to design an alternative photovoltaic module solution intended to be lightweight in order to adapt to certain applications, all by exhibiting sufficient mechanical properties to allow 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 remedy at least partially the needs mentioned above and the disadvantages relating to the achievements 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, designed 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 encapsulating the plurality of photovoltaic cells 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, referred to as the "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, approximately 3 mm thick, usually used on the front panel of a conventional photovoltaic module, with a combination of polymer layer(s) and thin glass layer(s). Thus, the use of thin glass and polymer makes it possible to obtain a low mass and transparency equivalent to a standard module. Compared to commercially available lightweight modules, the presence of thin glass in the structure provides better resistance to impacts, thermomechanical expansion, 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 about 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, especially the polymer front layer, can be greater than 80%. Similarly, the optical transparency, between 300 and 1200 nm, the 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 must 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 consists of at least two layers of encapsulating 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 encapsulating material melt to form, after the lamination operation, only a single solidified layer (or set) 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, through the use of thin glass, can have a surface weight of less than 6 kg / m², or even 5 kg / m², while maintaining 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 hail.

[0041] The photovoltaic module according to the invention may further comprise one or more of the following characteristics taken individually or in any possible technical combinations.

[0042] The front glass layer may advantageously have a thickness less than or equal to 1.5 mm, preferably between 500 pm 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 may be less resistant to impacts, particularly those from hailstones. However, being placed between protective polymer layers, especially between the polymer front layer and the interface front layer, the untempered glass can be protected from impacts. 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, making the photovoltaic module adaptable to numerous applications.

[0044] Furthermore, removing the thick glass from the front face of a conventional photovoltaic module can lead to a loss of the module's mechanical strength. Therefore, in order to be to maintain a rigid module, the rear face of the module can be designed to provide sufficient mechanical rigidity.

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

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

[0047] The use of a composite sandwich panel type back 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 have a honeycomb structure, for example in the form of a honeycomb, in particular made of metal, for example aluminium, polyimide, polycarbonate (PC), polypropylene (PP) or high-performance synthetic fibres, for example of the Nomex® type.

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

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

[0051] The rear panel plates may, where appropriate, be covered with a mono or multilayer 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 even 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 include a rear layer having a honeycomb structure, without the use of covering underlayers, for example a honeycomb structure of the cellular polycarbonate type.

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

[0055] - a back layer made of at least one polymer material, referred to as the "back layer "polymer", and

[0056] - at least one back assembly comprising a back interface layer and a glass back layer, the glass back layer having in particular a thickness less than or equal to 2 mm, preferably even less than or equal to 1.5 mm, particularly ranging in thickness from 500 µm to 1 mm, and notably made of non-tempered glass,

[0057] said at least one back assembly being located between the polymer back layer and the encapsulating assembly, and the interface back layer of said at least one back assembly being located between the polymer back layer and the glass back 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 may also comprise a combination of thin glass(s) 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 consisting mainly of organic and / or inorganic fibers, and preferably a layer made 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 unimpregnated, in particular with a polymer material. Such a reinforcement layer may be described as fiber-reinforced, woven, or non-"dry." In particular, such a reinforcement layer is neither 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, including hemp, flax and / or silk, among others.

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

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

[0064] In addition, the polymer material of the front polymer layer and / or the rear polymer layer can be selected 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] Furthermore, the front polymer layer and / or the back polymer layer may have a UV cutoff filter between 320 nm and 450 nm, which corresponds to the wavelength at which the transmission rate is 50%. In this way, the underlying layers can be protected from aging by ultraviolet (UV) radiation and possibly from hydrolysis, thus giving the photovoltaic module an extended lifespan.

[0066] The front interface layer and / or the rear interface layer can allow bonding between the front polymer layer, respectively the rear polymer 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 between 50 pm and 600 pm, preferably between 400 pm and 600 pm, or even between 400 pm and 500 pm.

[0068] The front interface layer and / or the rear interface layer may have a Young's modulus 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 joining a front layer of encapsulating material and a rear layer of encapsulating material on either side of the photovoltaic cells.

[0070] In addition, the encapsulating assembly, the front interface layer and / or the possible rear interface layer may be formed by at least one layer comprising at least one polymer-type encapsulating material selected 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, α-olefin copolymers 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 encapsulation material of the encapsulating assembly is identical to the material of the front interface layer and any rear interface layer. In this way, it may be possible to simplify the manufacturing process.

[0072] According to a particular embodiment, one of the front encapsulation material layers and rear encapsulation material layers of the encapsulating assembly, in particular the rear encapsulation material layer, may comprise an encapsulation material identical to that of the front interface layer, and the other of the front encapsulation material layers and rear encapsulation material layers of the encapsulating assembly, in particular the front encapsulation material layer, 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. Furthermore, 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 can be selected 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, photovoltaic cells can 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 also include a junction box, intended to receive the wiring necessary for the operation of the photovoltaic module, which may be positioned on the front or rear face of the module, preferably on the front face.

[0077] Furthermore, the spacing between two neighboring, consecutive, or adjacent photovoltaic cells can, 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, particularly of the "shingle" type (as it is known in English), neighboring, 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 layer, 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 identical or different. In particular, the thickness of the front glass layer of the first assembly The front layer may be greater than the thickness of the front glass layer of the second front assembly.

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

[0084] - a back layer made of at least one polymer material, referred to as the "back layer "polymer", and

[0085] - a first back assembly comprising a back 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 µm and 1 mm, and being in particular made of non-tempered glass,

[0086] - a second back assembly comprising a back 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 µm and 1 mm, and being in particular made of non-tempered glass,

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

[0088] Furthermore, the invention also relates, according to another aspect, 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, designed 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 panels 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, referred to as the "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 process includes 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 can 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 lamination cycle duration 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, making it possible to protect it against impacts.

[0100] The photovoltaic module and the method of embodiment according to the invention may comprise any of the characteristics previously stated, taken in isolation or in any technically possible combinations with other characteristics. Brief description of the drawings

[0101] The invention will be better understood upon reading the detailed description that follows, the non-limiting examples of its implementation, and upon examination of the schematic and partial figures in the accompanying drawing, in which:

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

[0103] [Fig.1A] represents a variant embodiment of the example in [Fig.1] in which the photovoltaic cells are of the IBC type,

[0104] [Fig.2] represents, in exploded view, the photovoltaic module of the [Fig.1],

[0105] [Fig.3] illustrates, in perspective and exploded view, a first example of the realization of a photovoltaic module according to the invention,

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

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

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

[0109] [Fig.6] illustrates, in perspective and exploded view, a fourth example of the realization of a photovoltaic module according to the invention.

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

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

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

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

[0114] Here, the photovoltaic cells 4, interconnected by welded tinned copper strips, similar to those shown in Figures 1, IA and 2, are considered to be "crystalline" cells, that is to say, they contain mono- or multi-crystalline silicon, and they have a thickness of between 1 and 250 pm.

[0115] In addition, the polymer front layer 2a can be a fluorinated polymer film, with a thickness of approximately 20 pm, 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, type A formed from a thermoplastic polyolefin (TPO) elastomer or type B formed from an ionically crosslinked thermoplastic copolymer, for example, a lonomer. The thickness may be between 500 and 600 µm. In particular, a type B polymer encapsulating film may be KuranSeal-ES® (PV8729D / UV CUT) from Kurabo, with a thickness of 500 µm.

[0117] The glass layers 2c, 2e and 5c may comprise a thin, untempered glass of thickness between 500 and 800 pm, for example on the order of 550 pm.

[0118] The second layer 5, when in the form of a back panel 5, may comprise a polypropylene honeycomb core 9a and composite skins or glass-reinforced polypropylene plates 9b, 9c 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 by no means exhaustive.

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

[0121] In order to describe the different configurations envisaged, we refer first of all to [Fig.3] which illustrates, in perspective and exploded view, a first example of the realization of a photovoltaic module 1 conforming to 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 process according to the invention. Once the lamination step has been carried out, ensuring hot pressing under vacuum, the different layers are in fact 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 light 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 on the rear face, as shown in Figures 1, IA and 2, of the photovoltaic module 1.

[0125] In accordance with the invention, and in a manner common to the examples in Figures 3 to 6, the first layer 2 comprises a front layer made of a polymer material 2a, referred to as "polymer front layer 2a", and a first front assembly 2b, 2c comprising an interface front layer 2b and a glass front layer, advantageously made of untempered glass 2c.

[0126] Advantageously, the front layer of glass 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 pm 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 back panel 5 made of composite material, comprising a main sublayer, forming the core 9a of the back panel 5, and two covering sublayers, each forming a plate 9b, 9c of the back 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 back panel 5 having a honeycomb structure 12. [Fig. 3A] schematically represents, in more detailed cross-section, 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 fiber-based reinforcements, woven or non-woven, in particular glass, carbon, aramid fibers and / or natural fibers, in particular hemp, flax and / or silk, among others.

[0129] The photovoltaic module 1 is obtained by means of a single step of hot lamination under vacuum, for example at a temperature of about 150°C for about 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. This further improves the shock resistance of the photovoltaic module 1 due to a higher Young's modulus.

[0131] Furthermore, [Fig.4] illustrates a second example of an embodiment according to the invention.

[0132] In this example, unlike that of [Fig. 3], the first layer 2 also comprises a second front assembly 2d, 2e, including a front interface layer 2d and a front glass layer, advantageously made of untempered glass 2e. The front glass layer 2e has a thickness e2e of 2 mm or less, or even 1.5 mm or less, and in particular between 500 µm and 1 mm. In other words, this embodiment involves doubling the glass thickness in the first layer 2. This results in a photovoltaic module 1 with a surface weight of 6 kg / cm². The impact resistance of the photovoltaic module 1 is further improved.

[0133] Furthermore, 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 layer of glass 2b and the second front layer of glass 2e have the same thickness. Alternatively, it is possible to use different glass thicknesses, for example, a thickness e2b of approximately 500 µm and a thickness e2e of approximately 300 µm. Thus, if we consider that 800 µm of glass can meet the shock resistance requirements of 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. Alternating rigid and elastomeric materials thus makes it possible to modify the propagation speed of shock waves, since the speed of a shock wave is directly proportional to the Young's modulus and Poisson's ratio of the material used. Inserting flexible elastomeric layers between layers of more rigid materials therefore slows down the propagation of shock waves. Moreover, at each interface encountered, the shock wave can be partially transmitted and / or reflected. Repeating the alternation of these polymer layers with different Young's moduli therefore allows, on the one hand, the slowing down of shock waves and, on the other hand, the reduction of their intensity before they 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 yet a third embodiment, the principle of which is to use on the rear panel the same encapsulation architecture as in front face, symmetrically. This allows us to obtain a bifacial and lightweight photovoltaic module 1.

[0138] Thus, the second layer 5 here comprises a back layer made of a polymer material 5a, called "polymer back layer 5a", and a first back assembly 5b, 5c comprising an interface back layer 5b and a glass back layer, preferably untempered 5c.

[0139] The back layer of glass 5c has a thickness e5c of 550 pm, and the front layer of glass 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 3b are herein type B encapsulant films.

[0141] Furthermore, [Fig.6] illustrates a fourth embodiment corresponding to a variant of the example in [Fig.5] in which the use of thin glass, preferably untempered, on the front and back faces is carried out asymmetrically.

[0142] In particular, two thin glasses 2c and 2e can be used on the front face with identical or different thicknesses, and a thin glass 5c can be used on the back face. More specifically 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 back 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 3b are herein type B encapsulant films.

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

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

[0146] Of course, the invention is not limited to the embodiments just described. Various modifications can be made to them by a person skilled in the art.

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

Claims

1. Claims 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 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 second layer (5) forming the rear face of the module photovoltaic (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 back layer made of at least one polymer material (5a), called “polymer back layer (5a)”, and - a first rear assembly (5b, 5c) comprising a rear interface layer (5b) and a rear glass layer (5c), - a second rear assembly comprising a rear interface layer and a rear glass layer, said first rear assembly (5b, 5c) being located between the polymer rear layer (5a) and the second rear assembly, itself located between the first rear assembly (5b, 5c) and the encapsulating assembly (3).

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 any one of the preceding claims, characterized in that the polymer front layer (2a) and / or the polymer rear layer (5a) have a thickness (e2a, e5a) of between 15 pm and 300 pm, in particular between 20 pm and 50 pm.

5. Module according to any one of the preceding claims, characterized in that the front interface layer (2b; 2d) and / or the rear interface layer (5b) have a thickness (e2b, e2d; e5b) of between 50 pm and 600 pm, in particular between 400 pm and 600 pm, in particular between 400 pm and 500 pm.

6. Module according to any one of the preceding claims, characterized in that the polymer material of the polymer front layer (2a) and / or of the polymer back layer (5a) 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.

7. Module according to any one of the preceding claims, characterized in that the encapsulating assembly (3), the front interface layer (2b; 2d) and / or the rear interface layer (5b) 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, elastomeric polyolefins of copolymers, copolymers of α-olefins and α-, [3-ethylenic carboxylic acid esters, such as ethylene-methyl acrylate copolymers and copolymers ethylene-butyl acrylate, silicone elastomers and / or elastomers based on crosslinked thermoplastic polyolefin.

8. 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).

9. Module according to claim 8, 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.

10. Module according to claim 9, 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).

11. Module according to any one of the preceding claims, characterized in that the rear glass layer (5c) of the first rear assembly (5b, 5c) has a thickness (e5c) 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, and / or the rear glass layer of the second rear assembly has 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.

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 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 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 back layer made of at least one polymer material (5a), called “polymer back layer (5a)”, and - a first rear assembly (5b, 5c) comprising a rear interface layer (5b) and a rear glass layer (5c), - a second rear assembly comprising a rear interface layer and a rear glass layer, said first rear assembly (5b, 5c) being located between the polymer rear layer (5a) and the second rear assembly, itself located between the first rear assembly (5b, 5c) and the encapsulating assembly (3), 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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