Lightweight and flexible photovoltaic module comprising a front layer consisting of a polymer and a rear layer consisting of a composite material

Abstract

The present invention relates to a lightweight photovoltaic module (1), comprising: a first transparent layer (2) forming a front face, a photovoltaic cell (4), an assembly (3) encapsulating the photovoltaic cell (4), and a second layer (5), wherein the encapsulation assembly (3) and the photovoltaic cell (4) are arranged between the first layer (2) and the second layer (5). The present invention is characterized in that the first layer (2) comprises a polymer material and has a thickness (e2) of less than 50 μm; and the second layer (5) comprises at least one composite material of the prepreg type comprising a polymer resin and fibers, the weight per unit area of ​​which is less than 150 g / m 2 , and the packaging component (3) has a maximum thickness (e3) less than 150 μm.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic modules comprising an assembly of photovoltaic cells electrically connected to one another, and preferably so-called “crystalline” photovoltaic cells, ie photovoltaic cells based on monocrystalline or multicrystalline silicon.

[0002] The present invention can be used in a variety of applications, such as stand-alone and / or airborne applications, especially applications requiring the use of flexible, glass-free and ultra-light photovoltaic modules, in particular, with a unit area weight of less than 1 kg / m 2 , and especially less than 800 g / m 2 , or even less than 600g / m 2 , and a small thickness, in particular less than 1 mm. It can therefore be used in particular in buildings such as residential or industrial sites (tertiary, commercial...), for example for the manufacture of roofs, for the design of street furniture, for example for public lighting, road signs or for charging electric vehicles, or even for nomadic applications, in particular for integration into cars, buses or ships.

[0003] The invention therefore provides an ultralight and flexible photovoltaic module and a method for manufacturing such a photovoltaic module, the photovoltaic module comprising a first layer made of polymer material, forming the front face of the module, and a second layer made of composite material. Background Art

[0004] A photovoltaic module is an assembly of photovoltaic cells arranged side by side between a first transparent layer forming the front face of the photovoltaic module and a second layer forming the rear face of the photovoltaic module.

[0005] Advantageously, the first layer forming the front face of the photovoltaic module is transparent to enable the photovoltaic cells to receive the light flux. Conventionally, this first layer is made of a single glass plate, the thickness of which is generally between 2 and 4 mm, conventionally about 3 mm.

[0006] The second layer forming the rear face of the photovoltaic module may in particular be based on glass, metal or plastic. It is often formed by a polymeric structure based on an electrically insulating polymer, for example of the polyethylene terephthalate (PET) or polyamide (PA) type, which may be protected by one or more layers based on a fluorinated polymer, such as polyvinyl fluoride (PVF) or polyvinylidene fluoride (PVDF), and has a thickness of about 400 μm.

[0007] The photovoltaic cells can be electrically connected to each other via front and rear electrical contact elements (called connecting cables) and are formed, for example, by tinned copper strips, which are arranged respectively against the front face (the face facing the front face of the photovoltaic module for receiving the light flux) and the rear face (the face facing the rear face of the photovoltaic module) of each photovoltaic cell, or even only at the rear face of an IBC (Interdigitated Back Contact) type photovoltaic cell.

[0008] It should be noted that photovoltaic cells of the IBC ("Interdigitated Back Contact") type are structures in which the contacts are made on the rear face of the cell in the form of interdigitated combs. They are described, for example, in patent US 4,478,879A.

[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. Conventionally, the selected sealant corresponds to an elastomeric type polymer (or rubber) and can, for example, consist of using two poly(ethylene-vinyl acetate) (EVA) layers (or films) between which the photovoltaic cells and the connecting cables of the cells are arranged. Each sealant layer has a thickness of at least 0.2 mm and a Young's modulus at room temperature typically between 2 MPa and 400 MPa.

[0010] exist Figure 1 Cross-sectional view and Figure 2 A conventional example of a photovoltaic module 1 comprising a crystalline photovoltaic cell 4 is shown partially and schematically in exploded views of FIG.

[0011] As described above, the photovoltaic module 1 includes a front surface 2 and a rear surface 5, wherein the front surface 2 is generally made of transparent tempered glass with a thickness of about 3 mm, and the rear surface 5 is composed of, for example, an opaque or transparent, single-layer or multi-layer polymer sheet with a Young's modulus greater than 400 MPa at room temperature.

[0012] Located between the front face 2 and the rear face 5 of the photovoltaic module 1 are photovoltaic cells 4 , which are electrically connected to each other by connection cables 6 and are immersed between two front and rear encapsulation material layers 3 a , 3 b , both forming a sealant assembly 3 .

[0013] Figure 1A It further shows Figure 1 In an alternative embodiment of the example of , in which the photovoltaic cell 4 is of the IBC type, the connection cable 6 is arranged only against the rear face of the photovoltaic cell 4 .

[0014] also, Figure 1 and Figure 2Also shown is a junction box 7 of the photovoltaic module 1, which is used to house the wiring required for the operation of the module. Conventionally, this junction box 7 is made of plastic or rubber and has complete impermeability.

[0015] Typically, the method for manufacturing the photovoltaic module 1 comprises a step of vacuum lamination of the above-mentioned layers, the lamination being carried out at a temperature greater than or equal to 120°C, or even 140°C, more even 150°C, and less than or equal to 170°C (typically between 145°C and 160°C), and the time period of the lamination cycle being at least 10 minutes, or even 15 minutes.

[0016] In this lamination step, the encapsulation material layers 3a and 3b melt and embed into the photovoltaic cell 4, while adhesion is generated at all interfaces between these layers, i.e., between the front face 2 and the front encapsulation material layer 3a, between the encapsulation material layer 3a and the front face 4a of the photovoltaic cell 4, between the rear face 4b of the photovoltaic cell 4 and the rear encapsulation material layer 3b, and between the rear encapsulation material layer 3b and the rear face 5 of the photovoltaic module 1. The obtained photovoltaic module 1 is then typically framed by an aluminum profile.

[0017] Due to the use of a thick glass front face 2 and an aluminium frame, this structure has now become standard with great mechanical strength, especially enabling it to comply with the IEC 61215 and IEC 61730 standards in most cases.

[0018] However, according to the conventional design of the prior art, such a photovoltaic module 1 has the disadvantage of being high in weight, in particular, the weight per unit area is about 12 kg / m 2 , and therefore is not suitable for certain applications where lightweighting is a priority.

[0019] The high weight of the photovoltaic module 1 is mainly due to the presence of thick glass with a thickness of about 3 mm to form the front face 2 and the aluminum frame. The density of the glass is very high, about 2.5 kg / m 2 / mm thick. In order to be able to withstand the stresses during production and also for safety reasons (for example due to the risk of cutting), the glass is tempered. However, the industrial infrastructure for hot tempering is constructed to handle glass that is at least 3 mm thick. In addition, the choice of glass of about 3 mm thickness is also related to mechanical strength at a standard pressure of 5.4 kPa. Finally, the glass itself accounts for nearly 70% of the weight of the photovoltaic module 1, while the aluminum frame surrounding the photovoltaic module 1 accounts for more than 80% of the weight of the photovoltaic module 1.

[0020] Therefore, in order to obtain a significant reduction in the weight of photovoltaic modules so that they can be used in new applications that require lightness and formability, an alternative to the use of thick glass on the front face of the module is needed. Therefore, one of the problems is to replace the glass front face with a new plastic material while maintaining the usual architecture and implementation methods, the main purpose of which is to significantly reduce the weight per unit area.

[0021] Therefore, sheets of polymers such as polycarbonate (PC), polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE) or fluorinated ethylene propylene (FEP) can replace glass. However, when only such thin polymer sheets are considered to replace glass, the photovoltaic cell becomes very susceptible to shocks and mechanical loads.

[0022] Replacing glass on the front face of photovoltaic modules is already the subject of several patents or patent applications in the prior art. In this regard, mention may be made of French patent application FR 2955051 A1, US patent application US 2005 / 0178428 A1 or international applications WO 2008 / 019229 A2 and WO 2012 / 140585 A1.

[0023] The weight per unit area of ​​the obtained lightweight and flexible photovoltaic module is typically lower than or equal to 6 kg / m 2 , which is much lower than the weight of photovoltaic modules usually made of thick glass on the front. However, the weight per unit area of ​​such photovoltaic modules rarely reaches less than 1 kg / m 2 The weight per unit area. Summary of the invention

[0024] Therefore, there is a need to design an alternative solution for photovoltaic modules that are flexible and ultra-light to be suitable for certain applications, while having sufficient mechanical properties to enable the photovoltaic modules to resist impact and mechanical loads, especially in compliance with IEC 61215 and IEC61730 standards.

[0025] Therefore, an object of the present invention is to at least partially remedy the above mentioned needs and disadvantages associated with the embodiments of the prior art.

[0026] According to one aspect of the present invention, an object of the present invention is a photovoltaic module, the photovoltaic module comprising:

[0027] - a first transparent layer forming the front face of the photovoltaic module, for receiving the light flux,

[0028] - a plurality of photovoltaic cells arranged side by side and electrically connected to each other,

[0029] - assemblies that encapsulate multiple photovoltaic cells,

[0030] - A second layer, a sealant assembly and a plurality of photovoltaic cells are located between the first layer and the second layer.

[0031] The first layer comprises at least one polymeric material and has a thickness less than 50 μm, advantageously a thickness comprised between 5 μm and 25 μm. Advantageously, the first layer consists of said at least one polymeric material.

[0032] Furthermore, the second layer comprises at least one polymer resin and a composite material of prepreg type based on fibers and having a weight per unit area lower than 150 g / m 2 , advantageously between 50 g / m 2 Up to 115g / m 2 The second layer may, for example, consist of the at least one composite material.

[0033] Furthermore, the sealant component has a maximum thickness of less than 150 μm.

[0034] The photovoltaic module may further comprise an additional layer forming a rear face of the photovoltaic module, the second layer being located between the additional layer and the sealant assembly.

[0035] The additional layer may be formed of the same material as the first layer forming the front face of the photovoltaic module, which material is preferably ethylene chlorotrifluoroethylene (ECTFE), also known as

[0036] Preferably, the thickness of the additional layer may be less than or equal to the thickness of the first layer.

[0037] Advantageously, the additional layer may enable dielectric insulation of the module.

[0038] Advantageously, therefore, the principle of the invention consists in replacing the standard thick glass of about 3 mm thickness usually used in conventional photovoltaic modules with a first thinner layer of polymeric material and in modifying the rear face of the photovoltaic module to provide the presence of a polymer / fiber prepreg type composite material.

[0039] It is noted that the first layer and / or the second layer of the photovoltaic module may be formed in one or more parts, ie they may be single-layered or multi-layered.

[0040] The term "transparent" means that the material of 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.

[0041] Further, by "encapsulated" or "sealed", it is understood that a plurality of photovoltaic cells are arranged in a volume, for example hermetically sealed with respect to a liquid, at least partially formed by at least two layers of encapsulating material, joined to each other after lamination to form a sealant assembly.

[0042] In fact, initially, i.e. before any lamination operation, the sealant assembly consists of at least two layers of encapsulating material (called core layers) between which a plurality of photovoltaic cells are sealed. However, during the operation of laminating these layers, the layers of encapsulating material melt to form, after the lamination operation, a solidified layer (or assembly) in which only the photovoltaic cells are embedded.

[0043] By virtue of the advantages of the present invention, it is thus possible to obtain new types of ultralight and flexible photovoltaic modules. Furthermore, by using a front face formed of a polymer having a thickness of less than 50 μm, the photovoltaic module according to the present invention maintains the same electrical performance, or even better than that of a standard module. Furthermore, by using a rear face of a polymer / fiber prepreg composite, the photovoltaic module according to the present invention has excellent mechanical and thermomechanical properties while maintaining flexibility without degradation of the photovoltaic cell under bending stress. In particular, the photovoltaic cell can support a radius of curvature of about 50 cm, and in some cases even 20 cm, without degradation of the cell. Further, in particular by reducing the thickness of the constituent elements of the photovoltaic module, the photovoltaic module according to the present invention can achieve the desired weight per unit area of ​​less than 1 kg / m 2 , especially below 800g / m 2 , more particularly less than 600 g / m 2 , which by definition makes photovoltaic modules ultra-light.

[0044] The photovoltaic module according to the invention may also comprise one or more of the following features, taken alone or according to any possible technical combination.

[0045] The second layer may form the rear face of the photovoltaic module. However, it is also possible for the second layer to be inserted between the sealant assembly and at least one other layer, such as a protective layer, thereby forming the rear face of the module.

[0046] In particular, the second layer may have a thickness between 50 μm and 80 μm.

[0047] The second layer may be discontinuous in order to further reduce the weight per unit area associated with the layer while maintaining the mechanical properties of the photovoltaic module. In particular, the second layer may include one or more holes, which specifically correspond to one or more raw material removal portions and are formed on one or more photovoltaic cells. In the case of discontinuity, the total surface coverage of the second layer is preferably greater than 30%.

[0048] The at least one prepreg type composite material may include an impregnation rate of polymer resin between 30% and 70% by weight.

[0049] The at least one composite material of the second layer may be a polymer resin and fiber-based prepreg, the polymer being selected from polyester, epoxy and / or acrylic, and the fiber being selected from glass, carbon and / or aramid fibers, among others.

[0050] The at least one polymer material of the first layer can be selected from: polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyamide (PA), fluorinated polymers, in particular polyvinyl fluoride (PVF) or polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE) and / or fluorinated ethylene propylene (FEP).

[0051] Furthermore, the photovoltaic modules advantageously have a weight per unit area of ​​less than 1 kg / m 2 , especially below 800g / m 2 , even especially below 600g / m 2 .

[0052] Furthermore, the sealant component may have a maximum thickness between 20 μm and 100 μm, and preferably between 50 μm and 75 μm.

[0053] The sealant assembly can be formed from at least one layer comprising at least one polymeric encapsulating material selected from the group consisting of acid copolymers, ionomers, poly(ethylene vinyl acetate) (EVA), vinyl acetals (e.g., polyvinyl butyral (PVB)), polyurethanes, polyvinyl chloride, polyethylene (e.g., low density linear polyethylene), copolymer elastomer polyolefins, α-olefins and α, β-vinyl carboxylate copolymers (e.g., ethylene methyl acrylate copolymers and ethylene butyl acrylate copolymers), silicone elastomers and / or epoxy resins.

[0054] Preferably, the sealant assembly can be made of two layers of polymeric material, in particular two layers of ionomer, in particular two layers of ionomer, the Young's modulus of which is much larger than that of poly(ethylene-vinyl acetate) (EVA), but always between 2 MPa and 400 MPa at room temperature so as to have better mechanical properties, between which a photovoltaic cell is arranged, the thickness of each layer being less than 75 μm, and preferably less than 50 μm.

[0055] The photovoltaic cell can be selected from: a homojunction or heterojunction photovoltaic cell based on single crystal silicon (c-Si) and / or multicrystalline silicon (mc-Si); and / or an IBC (interdigitated back contact) type photovoltaic cell; and / or a photovoltaic cell comprising at least one of amorphous silicon (a-Si), microcrystalline silicon (μC-Si), cadmium telluride (CdTe), copper indium selenide (CIS) and copper indium gallium diselenide (CIGS).

[0056] Furthermore, the thickness of the photovoltaic cell may be between 1 μm and 300 μm, in particular between 1 μm and 200 μm and advantageously between 70 μm and 160 μm.

[0057] The photovoltaic module may also include a junction box for housing the wiring required to operate the photovoltaic module.

[0058] Furthermore, the spacing between two adjacent, or consecutive or adjacent photovoltaic cells may be greater than or equal to 1 mm, in particular between 1 mm and 30 mm, and preferably equal to 2 mm.

[0059] Furthermore, the thickness of the interconnection ribbons of the photovoltaic cells and of the interconnection ribbons used to interconnect strings of cells has been adapted to be compatible with the lamination process and the small thickness of the sealant. For example, in the case of cells with front-face-rear-face contact, the thickness of the interconnection ribbons of such cells is advantageously reduced by at least 50% with respect to the thickness of the ribbons used in standard modules. The thickness of the interconnection ribbons of such cells may be lower than 100 μm and the width may be lower than 3 mm. For string-shaped interconnection ribbons, their thickness is advantageously strictly lower than 200 μm and their width is lower than 5 mm.

[0060] Furthermore, photovoltaic modules may include electronic components inside the photovoltaic laminate, such as bypass diodes.

[0061] Furthermore, according to another aspect of the present invention, another object of the present invention is a method for manufacturing a photovoltaic module as defined above, characterized in that the method comprises the following hot lamination step: hot lamination of the constituent layers of the photovoltaic module at a temperature between 130°C and 170°C, in particular at about 150°C, in a lamination cycle with a time period of at least 10 minutes, in particular between 10 minutes and 20 minutes.

[0062] Furthermore, the method may comprise a step of laminating the constituent layers of the photovoltaic module between two anti-stick damping layers.

[0063] The photovoltaic module and the manufacturing method according to the invention may comprise any of the features described above alone or in any technically feasible combination with other features. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The invention may be better understood by reading the following detailed description which is an example of a non-limiting embodiment, and by examining the schematic and partial views of the accompanying drawings, in which:

[0065] - Figure 1 A conventional example of a photovoltaic module including a crystalline photovoltaic cell is shown in cross-sectional view.

[0066] - Figure 1A It indicated Figure 1 An alternative embodiment of the example in which the photovoltaic cell is of IBC type,

[0067] - Figure 2 Shown in exploded view Figure 1 of photovoltaic modules,

[0068] - Figure 3 An example of an embodiment of a photovoltaic module according to the invention is shown in a cross-sectional exploded view,

[0069] - Figure 4 The construction of a photovoltaic module according to the invention is shown in an exploded cross-sectional view during the steps of making the module,

[0070] - Figure 5 An alternative embodiment of the second layer of a photovoltaic module according to the invention is shown in a partial bottom view, and

[0071] - Figure 6 The exploded view in cross section shows the Figure 3 An alternative embodiment of a photovoltaic module.

[0072] The same reference numbers may refer to the same or similar elements throughout the drawings.

[0073] Furthermore, the different parts represented in the figures are not necessarily drawn to the same scale in order to make the drawings easier to read. DETAILED DESCRIPTION

[0074] Figure 1 and Figure 2 It has already been described in the section relating to the state of the art.

[0075] Figure 3 and Figure 4 An embodiment of a photovoltaic module 1 according to the invention is shown in cross section and in an exploded view.

[0076] The photovoltaic cells 4 interconnected by soldered tinned copper ribbons may be considered here to be "crystalline" cells, ie comprising single-crystalline or multicrystalline silicon and having a thickness between 1 μm and 250 μm.

[0077] Furthermore, the sealant component 3 is selected to be made of two layers of ionomer, between which the photovoltaic cell 4 is arranged, and the thickness of each layer is less than 50 μm.

[0078] Advantageously, the invention provides for a specific choice of materials forming the front and rear faces of the photovoltaic module 1 in order to obtain a weight per unit area of ​​less than 1 kg / m 2 , and preferably less than 0.8kg / m 2 , or even lower than 0.6kg / m 2 Ultra-light photovoltaic modules1.

[0079] Of course, these options are by no means limiting.

[0080] First refer to Figure 3 , Figure 3 An example of embodiment of a photovoltaic module 1 according to the invention is shown in a cross-sectional exploded view.

[0081] It should be noted that Figure 3 Corresponds to an exploded view of a photovoltaic module 1 before the lamination step of the method according to the invention. Once this lamination step has been carried out (ensuring hot vacuum pressing), the different layers are actually superimposed on one another.

[0082] Therefore, the photovoltaic module 1 includes a first layer 2, a plurality of photovoltaic cells 4 arranged side by side and electrically connected to each other, and an assembly 3 encapsulating the plurality of photovoltaic cells 4, wherein the first layer is a thin film made of at least one polymer material with a thickness e2 less than 50 μm, forming the front face of the photovoltaic module 1 and used to receive light flux.

[0083] The polymer material of the first layer 2 can be selected from: polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyamide (PA), fluorinated polymers, in particular polyvinyl fluoride (PVF) or polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE) and / or fluorinated ethylene propylene (FEP).

[0084] In addition, the rear face of conventional photovoltaic modules is conventionally / Polyethylene terephthalate The photovoltaic module 1 comprises a laminate of a multilayer polymer of the (or TPT) type having a thickness of about 300 μm, the photovoltaic module 1 comprising a second layer 5 forming the rear face of the photovoltaic module 1, the second layer having a total basis weight of less than 150 g / m 2 The invention relates to a polymer / continuous fiber prepreg composite material. Moreover, the thickness of the prepreg fabric is less than 50 μm, and the mass percentage of the impregnation rate of the polymer resin is between 30% and 70%.

[0085] The composite material of the second layer 5 may be a polymer resin and fiber-based prepreg, the polymer being selected from polyester, epoxy and / or acrylic, and the fibers being selected from glass, carbon and / or aramid fibers.

[0086] The thickness e5 of the second layer 5 may be between 50 μm and 80 μm.

[0087] Furthermore, the total thickness e3 of the sealant assembly 3 is less than 150 μm, preferably between 20 μm and 100 μm.

[0088] The sealant component 3 may be made of at least one polymeric material selected from the group consisting of acid copolymers, ionomers, poly(ethylene-vinyl acetate) (EVA), vinyl acetals (e.g. polyvinyl butyral (PVB)), polyurethanes, polyvinyl chloride, polyethylene (e.g. low-density linear polyethylene), copolymer elastomers polyolefins, α-olefins and α,β-vinyl carboxylate copolymers (e.g. ethylene-methyl acrylate copolymers and ethylene-butyl acrylate copolymers), silicone elastomers and / or epoxy resins. It may be made of two polymer layers 3a and 3b, in particular two poly(ethylene-vinyl acetate) (EVA) layers, between which a photovoltaic cell 4 is arranged. The thickness e3a of the layer 3a and the thickness e3b of the layer 3b are both less than 50 μm.

[0089] In addition, the photovoltaic cell 4 can be selected from: a photovoltaic cell based on a homojunction or heterojunction of monocrystalline silicon (c-Si) and / or polycrystalline silicon (mc-Si); and / or an IBC type photovoltaic cell; and / or a photovoltaic cell including at least one material of amorphous silicon (a-Si), microcrystalline silicon (μC-Si), cadmium telluride (CdTe), copper indium selenide (CIS) and copper indium gallium diselenide (CIGS). Their thickness is between 1 μm and 300 μm, and in particular between 1 μm and 200 μm.

[0090] The manufacture of the photovoltaic module 1 is carried out by a single step of thermal lamination of the constituent layers 2, 3, 4, 5 of the stack forming the photovoltaic module 1 at a temperature between 130°C and 170°C, in particular at about 150°C, in a lamination cycle with a period of at least 10 minutes, in particular between 10 minutes and 20 minutes.

[0091] However, considering the small thickness of the sealant assembly 3, it is desirable to be able to laminate the stack between two anti-adhesive damping sheets; to be compatible with a thermal lamination method; to avoid any damage to the photovoltaic cells during the pressing step, which is related to the excessive thickness of the copper tape on the photovoltaic cells 4.

[0092] therefore, Figure 4 Represents a photovoltaic module similar to 1 Figure 3 but with two anti-stick damping layers 8 on either side of the stack to avoid any damage to the photovoltaic cells 4.

[0093] also, Figure 5 An alternative embodiment of the second layer 5 of the photovoltaic module 1 according to the invention is shown in a partial bottom view.

[0094] This alternative embodiment illustrates the fact that the second layer 5 , being a prepreg, can be discontinuous in order to further reduce the weight per unit area associated with this layer 5 while maintaining the mechanical properties of the photovoltaic module 1 .

[0095] Thus, the second layer 5 comprises a portion of stock removal forming holes 9 situated on the photovoltaic cells 4. This stock removal is made below the photovoltaic cells 4, indicated by dashed lines, which corresponds to the area where the mechanical strength is ensured by these cells 4. In other words, the material of the prepreg formed by the second layer 5 is removed below the cells 4, but remains between the cells 4 and on the edges of the layer 5.

[0096] Examples of Specific Embodiments

[0097] Two examples of specific embodiments A and B of a photovoltaic module 1 according to the invention will now be described.

[0098] Examples A and B are made with the same encapsulation material but using different photovoltaic cells:

[0099] In a first example A, the photovoltaic cell 4 comprises 24 heterojunction cells based on amorphous single silicon crystals, with a thickness of about 115 μm.

[0100] In a second example B, the photovoltaic cell 4 comprises 30 IBC type cells, the thickness of which is approximately 160 μm.

[0101] Furthermore, for these two examples A and B, the constituent layers are as follows:

[0102] The first layer 2 forming the front face is an ethylene chlorotrifluoroethylene (ECTFE) film of the company Rayotec, type ECT 025, having a thickness of approximately 25 μm.

[0103] The sealant layers 3a and 3b are ionomer films available from the Jurasol series sold by the company Juraplast and have a thickness of approximately 50 μm.

[0104] The second layer 5 forming the rear face is a prepreg composite film of the glass fabric type impregnated with epoxy resin, for example Hexply M77 from the company Hexcel.

[0105] For each of Examples A and B, the photovoltaic modules are implemented in a single hot vacuum lamination step. During this step, it is desirable to properly harden the rear face formed by the second layer 5 in order to obtain the desired mechanical properties. The hot lamination procedure is therefore optimized (temperature, pressure, time period ...) so that the composite material hardens sufficiently without any visual defects and without damaging the photovoltaic cells 4. This cross-linking is checked by measuring the glass transition by differential scanning calorimetry (DSC).

[0106] In addition, as previously referenced Figure 4 As described, in order to avoid damage to the photovoltaic cells 4, the photovoltaic module 1 is laminated between two anti-adhesive damping sheets 8, the thickness of which is about 0.50 mm.

[0107] For both examples of embodiments A and B, a weight per unit area of ​​less than 800 g / m 2 And the light output is greater than 180W / m 2 Photovoltaic module 1.

[0108] Furthermore, advantageously, for both Examples A and B, the electroluminescence imaging after implementation showed no degradation in the photovoltaic cells 4 even after a flexure or bending of less than 50 cm, thus confirming the compatibility of the new material used with the conventional thermal lamination process for making the photovoltaic module 1. The electrical performance of the photovoltaic module 1 is the same as or even better than that of a photovoltaic module in a standard configuration, thanks to the better optical transparency of the material used.

[0109] Additionally, resistance to accelerated aging in a thermal cycling chamber according to floor standard IEC61215 has been demonstrated after more than 600 cycles.

[0110] in addition, Figure 6 It shows that according to the present invention Figure 3 An alternative embodiment of the photovoltaic module 1 .

[0111] Figure 6 The module in may include all the above features, especially with Figures 3 to 5 The relevant features will therefore not be described in detail.

[0112] However, in this example, the photovoltaic module 1 has an additional layer 10 forming the back side of the photovoltaic module 1 , the second layer 5 being located between the additional layer 10 and the sealant assembly 3 .

[0113] This additional layer 10 is made of the same material as the first layer 2 forming the front side of the photovoltaic module 1. Advantageously, this material corresponds to ethylene chlorotrifluoroethylene (ECTFE), also known as

[0114] In addition, the additional layer 10 has a thickness of Figure 6 In this example, θ is less than or equal to the thickness e2 of the first layer 2. Advantageously, the additional layer 10 provides the module 1 with an advantageous dielectric insulation.

[0115] Of course, the present invention is not limited to the exemplary embodiments described above, and various modifications may be made thereto by those skilled in the art.

Claims

1. A photovoltaic module (1), comprising: - a first transparent layer (2) forming the front face of the photovoltaic module (1) for receiving the light flux, - a plurality of photovoltaic cells (4), which are arranged side by side and are electrically connected to each other, - a sealant assembly (3) encapsulating the plurality of photovoltaic cells (4), - a second layer (5), said sealant assembly (3) and said plurality of photovoltaic cells (4) being located between said first transparent layer (2) and said second layer (5), characterised in that said first transparent layer (2) comprises at least one polymeric material and has a thickness (e2) less than 50 μm; - an additional layer (10) forming the rear face of the photovoltaic module (1), the second layer (5) being located between the additional layer (10) and the sealant assembly (3); The second layer (5) comprises at least one polymer resin and a prepreg-type composite material based on fibers, and the weight per unit area of ​​the second layer is less than 150 g / m 2 ; The sealant component (3) has a maximum thickness (e3) of less than 150 μm; The additional layer (10) is composed of the same material as the first transparent layer (2) forming the front face of the photovoltaic module (1); The thickness of the additional layer (10) is less than or equal to the thickness of the first transparent layer (2); The at least one polymer material of the first transparent layer (2) is selected from the group consisting of: polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyamide (PA), and fluorinated polymer.

2. The photovoltaic module according to claim 1, characterized in that: The at least one prepreg-type composite material has an impregnation rate of polymer resin ranging from 30% to 70% by weight.

3. The photovoltaic module according to claim 1 or 2, characterized in that: The second layer (5) is discontinuous and comprises one or more holes (9) formed on one or more photovoltaic cells (4).

4. The photovoltaic module according to claim 1 or 2, characterized in that: Said at least one composite material of said second layer (5) is a polymeric resin and a fiber-based prepreg, said polymeric resin being selected from polyester, epoxy and / or acrylic, and said fibers being selected from glass, carbon and / or aramid fibers.

5. The photovoltaic module according to claim 1 or 2, characterized in that: The fluorinated polymer is selected from the group consisting of polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE) and / or fluorinated ethylene propylene (FEP).

6. The photovoltaic module according to claim 1 or 2, characterized in that: The weight per unit area of ​​the photovoltaic module is less than 1 kg / m 2 .

7. The photovoltaic module according to claim 1 or 2, characterized in that: The maximum thickness (e3) of the sealant component (3) is between 20 μm and 100 μm.

8. The photovoltaic module according to claim 1 or 2, characterized in that: The sealant component (3) is formed by at least one layer, which includes at least one polymeric encapsulating material selected from the following: acid copolymers; ionomers; poly(ethylene-vinyl acetate) (EVA); vinyl acetal; polyurethane; polyvinyl chloride; polyethylene; copolymer elastomer polyolefin; α-olefin and α, β-vinyl carboxylate copolymers; silicone elastomer and / or epoxy resin.

9. The photovoltaic module according to claim 1 or 2, characterized in that: The photovoltaic cell (4) is selected from: a homojunction or heterojunction photovoltaic cell based on single crystal silicon (c-Si) and / or multicrystalline silicon (mc-Si); and / or an IBC type photovoltaic cell; and / or a photovoltaic cell including at least one material of amorphous silicon (a-Si), microcrystalline silicon (μC-Si), cadmium telluride (CdTe), copper indium selenide (CIS) and copper indium gallium diselenide (CIGS).

10. The photovoltaic module according to claim 1 or 2, characterized in that: The thickness of the photovoltaic cell (4) is between 1 μm and 300 μm.

11. The photovoltaic module according to claim 1 or 2, characterized in that: The additional layer (10) consists of the same material as that of which the first transparent layer (2) forming the front face of the photovoltaic module (1) is made, this material being ethylene chlorotrifluoroethylene (ECTFE).

12. The photovoltaic module according to claim 6, characterized in that: The weight per unit area of ​​the photovoltaic module is less than 800 g / m 2 .

13. The photovoltaic module according to claim 6, characterized in that: The weight per unit area of ​​the photovoltaic module is less than 600 g / m 2 .

14. The photovoltaic module according to claim 7, characterized in that: The maximum thickness (e3) of the sealant component (3) is between 50 μm and 75 μm.

15. The photovoltaic module according to claim 8, characterized in that: The vinyl acetal is polyvinyl butyral (PVB).

16. The photovoltaic module according to claim 8, characterized in that: The polyethylene is low-density linear polyethylene.

17. The photovoltaic module according to claim 8, characterized in that: The α-olefin and α, β-vinyl carboxylate copolymers are ethylene-methyl acrylate copolymers and ethylene-butyl acrylate copolymers.

18. The photovoltaic module according to claim 10, characterized in that: The thickness of the photovoltaic cell (4) is between 1 μm and 200 μm.

19. The photovoltaic module according to claim 10, characterized in that: The thickness of the photovoltaic cell (4) is between 70 μm and 160 μm.

20. A method for producing a photovoltaic module according to any one of claims 1 to 19, characterized in that: The method comprises the following step of thermal lamination: thermal lamination of the constituent layers (2, 3, 4, 5) of the photovoltaic module (1) at a temperature between 130° C. and 170° C. in a lamination cycle with a period of at least 10 minutes.

21. The method according to claim 20, characterized in that The method comprises the steps of laminating the constituent layers (2, 3, 4, 5) of the photovoltaic module (1) between two anti-stick damping layers (8).

22. The method according to claim 20, characterized in that The temperature is 150°C.

23. The method according to claim 20, characterized in that The time period is between 10 minutes and 20 minutes.

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