WO2017085017A1

WO2017085017A1 - Lightweight photovoltaic module comprising a front layer made from glass or polymer and a rear honeycomb layer

Info

Publication number: WO2017085017A1
Application number: PCT/EP2016/077587
Authority: WO
Inventors: Julien GAUME; Paul Lefillastre; Gilles GOAER; Nam Le Quang; Samuel WILLIATTE
Original assignee: Commissariat A L'energie Atomique Et Aux Energies Alternatives; Edf Enr Pwt
Priority date: 2015-11-16
Filing date: 2016-11-14
Publication date: 2017-05-26
Also published as: FR3043840A1; FR3043840B1

Abstract

The main subject matter of the invention is a lightweight photovoltaic module (1) comprising: a first transparent layer (2) forming the front face; photovoltaic cells (4); an assembly (3) encapsulating the photovoltaic cells (4); and a second layer (5) forming the rear face and comprising inner (8i) and outer (8e) surfaces. The encapsulating assembly (3) and the photovoltaic cells (4) are located between the first (2) and second (5) layers. The module is characterised in that: the first layer (2) is made from glass and/or polymer material and has a thickness (e2) that is less than or equal to 1.1 mm; the inner (8i) and outer (8e) surfaces are substantially planar; and the second layer (5) comprises a rear panel (5, 5b) made from composite material, comprising a core (9a) and two plates (9b, 9c) disposed on each side of the core (9A), said core comprising a honeycomb structure (12).

Description

LIGHTWEIGHT PHOTOVOLTAIC MODULE HAVING FRONT GLASS OR POLYMER LAYER AND ALVEOLAR REAR LAYER

DESCRIPTION TECHNICAL FIELD

The present invention relates to the field of photovoltaic modules, which comprise a set of photovoltaic cells interconnected electrically, and preferably photovoltaic cells called "crystalline", that is to say which are based on monocrystalline silicon or multicrystalline.

The invention can be implemented in many applications, being particularly concerned with applications that require the use of lightweight photovoltaic modules, in particular a weight per unit area lower than or equal to 7 kg / m ^2, in particular less than or equal to 6 kg / m ² , or even 5 kg / m ² , and having mechanical strength properties in accordance with the standards I EC 61215 and I EC 61730. It can therefore be applied in particular for buildings such as roofs. or industrial premises (tertiary, commercial, etc.), for example for the construction of their roofs, for the design of street furniture, for example for street lighting, road signs or the retrofit of electric cars. , or even be used for mobile applications, especially for integration on cars, buses or boats, among others.

The invention thus proposes a photovoltaic module comprising a first layer forming the front face of the module, made of glass and / or polymeric material, and a second layer forming the rear face of the module, comprising a rear panel provided with a core with a honeycomb structure, as well as a method of producing such a photovoltaic module.

STATE OF THE PRIOR ART

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.

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 in a single glass plate, having a thickness typically between 2 and 4 mm, typically of the order of 3 mm.

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

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 tinned copper strips, respectively arranged against the front faces (faces facing the face before the photovoltaic module intended to receive a luminous flux) and rear (faces facing the rear face of the photovoltaic module) of each of the photovoltaic cells.

Moreover, the photovoltaic cells, located between the first and second layers respectively forming the front and rear faces of the photovoltaic module, can be encapsulated. In a conventional manner, the encapsulant chosen corresponds to a polymer of the elastomer (or rubber) type, and may 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 encapsulant layer may have a thickness of at least 0.2 mm and a Young's modulus typically between 2 and 400 MPa at room temperature. A conventional 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.

As previously described, the photovoltaic module 1 comprises a front face 2, generally made of transparent tempered glass with a thickness of about 3 mm, and a rear face 5, for example constituted by a transparent or opaque, monolayer or multilayer polymer sheet. , having a Young's modulus greater than 400 MPa at room temperature.

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

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. Conventionally, this junction box 7 is made of plastic or rubber, and has a complete seal.

In the usual way, the method for producing the photovoltaic module 1 comprises a so-called vacuum lamination step of the various layers described above, at a temperature greater than or equal to 120 ° C., even 140 ° C. or even 150 ° C., and lower. or equal to 170 ° C, typically between 145 and 160 ° C, and for a duration of the lamination cycle of at least 10 minutes, or even 15 minutes.

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 the adhesion is created at all the interfaces between the layers, namely between the front face 2 and the encapsulation material front layer 3a, the encapsulation material layer 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 layer rear of encapsulation material 3b and the rear face 5 of the photovoltaic module 1. The photovoltaic module 1 obtained is then framed, typically through an aluminum profile. Such a structure has now become a standard that has a significant mechanical strength through the use of a front face 2 of thick glass, allowing it in most cases to meet the standards IEC 61215 and IEC 61730.

However, such a photovoltaic module 1 according to the conventional design of the prior art has the disadvantage of having a high weight, in particular a weight per unit area of about 12 kg / m ² , and is thus not suitable for certain applications for which lightness is a priority.

This high weight of the photovoltaic module 1 comes mainly from the presence of the thick glass, with a thickness of about 3 mm, to form the front face 2, the density of the glass being indeed high, of the order of 2.5 kg / m ² / mm thick. In order to withstand the constraints during manufacture and also for safety reasons, for example because of the risk of cutting, the glass is tempered. However, the industrial infrastructure of thermal quenching is configured to process glass at least 3 mm thick. In addition, the choice of having a glass thickness of about 3 mm is also related to a standard pressure strength of 5.4 kPa. As a result, the glass alone accounts for almost 70% of the weight of the photovoltaic module 1, and more than 80% with the aluminum frame around the photovoltaic module 1.

Also, in order to obtain a significant reduction in the weight of a photovoltaic module to allow its use in new applications demanding in terms of lightness, there is a need to find an alternative solution to the use of a thick glass about 3 mm on the front of the module.

For this, solutions have been proposed in the patent literature to develop other types of light and flexible photovoltaic modules, devoid of a metal frame, from cells based on the alloy CIGS (copper, indium, gallium and selenide) or based on thin-film silicon, while replacing the glass on the front face with lighter and thinner polymer materials. Thus, for example, patent application FR 2 955 051 A1, patent application US 2005/0178428 A1 or international applications WO 2008/019229 A2 and WO 2012/140585 A1. The photovoltaic modules obtained have a much lower surface weight than photovoltaic modules conventionally made with thick glass on the front face. However, their mechanical properties are not sufficient to withstand the stresses, particularly mechanical, imposed in particular by the IEC 61215 standard.

Other solutions of the prior art relate to the use of a thin glass on the front face of the photovoltaic module. This thin glass can be applied to the photovoltaic module provided that it has been previously "hardened" by the chemical quenching process. It is then possible to obtain in a simple manner a significant weight gain. In this respect, it is possible to cite the international applications WO 2010/019829

Al, WO 2013/024738 A1 and WO 2008/139975 A1, as well as European Patent Application EP 2 404 321 A1.

However, the simple replacement of thick glass about 3 mm thick by a thin glass on the front of the photovoltaic module has the effect of degrading the mechanical strength properties of the module, so that it no longer has a structure sufficient to withstand the stresses, especially mechanical, imposed in particular by the IEC 61215 standard.

To overcome this problem, some solutions then provide for reinforcing the rear face of the photovoltaic module, provided with a metal frame, using metal sleepers in order to avoid bending when subjected to a mechanical load . For example, the European patent application EP 2 702 613 can be cited.

Al.

Nevertheless, although these solutions make it possible to reduce the weight of the photovoltaic module while respecting the standards imposed on the mechanical properties, they require a significant reinforcement of the frame and the surface weight of this type of photovoltaic module remains greater than 7 kg / m ² when the thin glass used has a thickness greater than or equal to 1.1 mm. STATEMENT OF THE INVENTION

There is thus a need to design an alternative photovoltaic module solution designed to be light enough to adapt to certain applications, while having mechanical properties that allow it to comply with IEC 61215 and IEC 61730 standards.

The object of the invention is to at least partially remedy the needs mentioned above and the drawbacks relating to the embodiments of the prior art.

The invention thus has, according to one of its aspects, a photovoltaic module comprising:

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

a plurality of photovoltaic cells arranged side by side and electrically connected to each other,

an assembly encapsulating the plurality of photovoltaic cells,

a second layer forming the rear face of the photovoltaic module, the second layer having an internal surface, in contact with the encapsulating assembly, and an external surface, opposite to the internal surface, the encapsulating assembly and the plurality of photovoltaic cells being between the first and second layers, characterized in that the first layer is made of glass and / or at least one polymeric material and has a thickness less than or equal to 1.1 mm,

in that the inner and outer surfaces of the second layer are substantially planar,

and in that the second layer further comprises a rear layer forming a rear panel of composite material, comprising a main underlayer, forming the core of the back panel, and two overlapping sub-layers, each forming a plate of the panel rear, disposed on either side of the core so that the soul is sandwiched between the two plates, the core of the rear panel having a honeycomb structure. Thus, advantageously, the principle of the invention consists both in replacing the standard thick glass of a thickness of about 3 mm, usually used in a conventional photovoltaic module, with a thinner first layer of glass and or at least one polymeric material, and modifying the rear face of the photovoltaic module to predict the presence of a cellular structure.

As will be explained later through the preferred embodiments of the invention, the second layer of the photovoltaic module can be formed in one or more parts, namely that it can consist of a single layer, monolayer or multilayer, comprising said cellular structure or in an assembly comprising at least two layers, one of which comprises said honeycomb structure, each of said at least two layers being monolayer or multilayer, and whose meeting forms the second layer. In particular, the second layer in the form of a single portion may consist of a cellular reinforcement disposed in contact with the encapsulating assembly, while the second layer in the form of several parts may consist of a first layer, monolayer or multilayer, similar a layer forming the rear face of a photovoltaic module according to the conventional design of the prior art, and a second layer in the form of a cellular reinforcement.

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.

In addition, by the term "encapsulant" or "encapsulated", it should be understood that the plurality of photovoltaic cells is arranged in a volume, for example hermetically sealed vis-à-vis liquids, at least partly formed by at least two layers of encapsulation material, joined together after lamination to form the encapsulating assembly.

Indeed, initially, that is to say before any lamination operation, the encapsulating assembly consists of at least two layers of encapsulation material, 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, a single layer (or set) solidified in which the photovoltaic cells are embedded.

Thanks to the invention, it may thus be possible to obtain a new type of rigid photovoltaic module, having a weight substantially less than that of a conventional photovoltaic module as described above, in particular almost twice the weight of a conventional photovoltaic module. conventional module, namely a weight less than or equal to 7 kg / m ² or 6 kg / m ² , or even 5 kg / m ² , against about 12 kg / m ² for a conventional module. In addition, the photovoltaic module proposed by the invention retains mechanical properties equivalent to those of traditional photovoltaic modules using a thick glass about 3 mm thick on the front face.

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

Preferably, the rear panel, in particular the honeycomb structure, is devoid of relief projecting relative to its surface.

The first layer may be made of glass, and in particular tempered glass, textured or non-textured.

The first layer may also be made of at least one polymeric material, for example textured or non-textured, in particular chosen from: polycarbonate (PC), polymethyl methacrylate (PMMA), in particular single-phase PMMA (non-shock) or PMMA multiphase (shock), for example nanostructured PMMA shock, such as that sold by the company Altuglas ^® under the brand Altuglas ^® Shield-Up ^®, polyethylene terephthalate (PET), polyamide (PA), a polymer fluoro, especially polyvinyl fluoride (PVF) or polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), polytetrafluoroethylene (PTFE) and / or polychlorotrifluoroethylene (PCTFE).

According to a first embodiment of the invention, the second layer may consist of an assembly of at least a first rear layer, in contact with the encapsulating assembly, and a second alveolar rear layer so that the first back layer is disposed between the encapsulant assembly and the second alveolar back layer, the inner surface of the second layer being formed by the inner surface, in contact with the encapsulating assembly, the first back layer and the outer surface of the second layer being formed by the outer surface of the second alveolar back layer, which forms the back panel comprising the core provided with the honeycomb structure.

The second layer may further comprise an adhesive layer between the first rear layer and the second alveolar back layer, to allow the assembly of the second alveolar back layer to the first back layer.

By "adhesive layer" is meant a layer allowing, once the assembly formed by the first layer, the encapsulating assembly, the photovoltaic cells and the first rear layer formed, to the second alveolar back layer to adhere to the first back layer. This is a layer for chemical compatibility and adhesion between the first back layer and the second alveolar back layer. In particular, the adhesive layer may in particular be a silicone adhesive. The adhesive layer may also be a pressure sensitive adhesive, also called PSA for "Pressure Sensitive Adhesive". PSA is composed of an elastomer base having a low molecular weight thermoplastic tacky resin, for example of the ester type. The elastomer base is for example an acrylic, a rubber (butyl, natural or silicone), a nitrile, a styrene block copolymer (SBC) (for example, styrene-butadiene-styrene (SBS), styrene-ethylene / butylene styrene (SEBS), styrene-ethylene / propylene (SEP), styrene-isoprene-styrene (SIS)) or a vinyl ether. The elastomer base can also be ethylene-vinyl acetate, or EVA for "Ethylene-Vinyl Acetate" in English, with a high level of vinyl acetate.

Furthermore, the first back layer may comprise a single or multilayer polymer film.

Preferably, the first backing layer comprises a film type Tedlar ^® / polyethylene terephthalate (PET) / Tedlar ^® (or TPT). The first back layer may also comprise a polyolefin-based polymer film, in particular a film multilayer coextruded polypropylene (PP), polyamide (PA) and polyethylene (PE), for example a film Reflexolar ^® range marketed by Renolit. The first back layer may also comprise a polymer film based on polyamide grafted polyolefins, for example a film obtained from the Jurasol BS1 range marketed by Juraplast.

In general, the first back layer can still be made as in the back layer of a photovoltaic module of conventional design, namely based on glass, metal or plastic, among others. It may for example be formed by a polymeric structure based on an electrically insulating polymer, for example polyethylene terephthalate (PET), polyamide (PA) or polypropylene (PP) which can be protected by one or more layers based on fluorinated polymers, such as polyvinyl fluoride (PVF) or polyvinylidene fluoride (PVDF).

In addition, the first rear layer may have a thickness between 150 and 600 μιη, in particular of the order of 400 μιη.

Advantageously, the first rear layer has an inner surface, in contact with the encapsulating assembly, substantially flat and an outer surface, in contact with the second substantially cellular planar rear layer.

Advantageously, the second alveolar back layer forms a mechanical reinforcement fixed to the first rear layer. In other words, it forms a part ensuring the mechanical strength of the photovoltaic module.

Preferably, the dimensions of the second alveolar rear layer are at least equal to the dimensions of the first layer of the photovoltaic module.

According to a second embodiment of the invention, the second rear layer may be constituted by a single alveolar rear layer, in contact with the encapsulating assembly, forming the rear panel comprising the core provided with the honeycomb structure.

In general, the core of the rear panel may comprise a cellular structure in the form of a honeycomb, in particular made of metal, for example aluminum, polyimide, polycarbonate (PC), polypropylene (PP) or synthetic fibers high performance, for example Nomex ^® type. In a variant, the core of the rear panel may comprise a cellular structure in the form of foam, in particular made of polyethylene terephthalate (PET) or polyurethane (PU). Such a structure can also be called cell structure, for example closed cell.

In addition, the plates of the rear panel may be made of composite material, for example of prepreg type (also called prepeg) based on glass fibers and epoxy resin, metal, especially aluminum, polycarbonate (PC) or polymethylmethacrylate (PMMA).

The rear panel plates may, where appropriate, be covered with a monolayer or multilayer polymer film, e.g., Tedlar ^® kind.

Furthermore, the photovoltaic module advantageously has a basis weight less than or equal to 7 kg / m ² , especially less than or equal to 6 kg / m ² , especially still less than or equal to 5 kg / m ² . Preferably, such a photovoltaic module comprises, for example, about sixty crystalline silicon photovoltaic cells of dimension 156 mm × 156 mm. The invention is however not limited to a fixed number of cells and could be applied to modules having more or fewer cells.

In addition, the rear panel may have a basis weight less than or equal to 3 kg / m ² , especially less than or equal to 2 kg / m ² , in particular still less than or equal to 1 kg / m ² .

In addition, the second back layer may comprise a plurality of attachment zones, intended to allow the attachment of the photovoltaic module to support crosspieces to form a panel of photovoltaic modules.

The attachment zones may advantageously be configured to allow spacing of said support rails, for example between 735 and 1045 mm.

Furthermore, the second layer may comprise means for reinforcing at least one attachment zone, in particular all the attachment zones, comprising in particular a composite material, for example a mixture of epoxy / glass beads, wood, a thermosetting polymer, metal, for example aluminum, among others.

In addition, the second layer may comprise means for reinforcing at least one of its longitudinal edges, in particular of its two longitudinal edges, intended to reinforce the resistance of the second layer during a hot lamination step, comprising in particular a polymeric material, for example epoxy, wood or metal, for example aluminum, among others.

In addition, the encapsulant assembly can be made from at least one polymeric 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, elastomeric polyolefins of copolymers, α-olefin copolymers and α-, β-acid esters. carboxylic to ethylenic, such as ethylene-methyl acrylate copolymers and ethylene-butyl acrylate copolymers, silicone elastomers and / or epoxy resins, among others.

Preferably, the encapsulant assembly can be made from two layers of poly (ethylene-vinyl acetate) (EVA) with a thickness of at least 200 μιη, between which the photovoltaic cells are arranged.

The photovoltaic cells may be chosen from: homojunction or heterojunction photovoltaic cells based on monocrystalline silicon (c-Si) and / or multi-crystalline (mc-Si), and / or photovoltaic cells comprising at least one of silicon amorphous (a-Si), microcrystalline silicon (C-Si), cadmium telluride (CdTe), copper-indium selenide (CIS) and copper-indium / gallium diselenide (CIGS), among others.

Moreover, the photovoltaic cells may have a thickness of between 1 and 300 μιη.

The photovoltaic module may further include a junction box, intended to receive the wiring necessary for the operation of the photovoltaic module.

The junction box can be integrated in the thickness of the back panel, especially in the thickness of the core of the back panel. At least a portion of the wiring connected to the junction box may pass through the back panel plate opposite the back panel plate forming the rear exterior face of the photovoltaic module.

In addition, the junction box may include bypass diodes. Moreover, even though the first layer forming the front face of the photovoltaic module is transparent, the second layer forming the rear face of the photovoltaic module may or may not be transparent, being in particular opaque.

In addition, the spacing between two adjacent photovoltaic cells, or consecutive or adjacent cells, may be greater than or equal to 1 mm, in particular between 1 and 30 mm, and preferably equal to 3 mm.

In addition, the invention further relates, in another of its aspects, to a method of producing a photovoltaic module as defined above, characterized in that it comprises the step of hot lamination at a temperature greater than or equal to 120 ° C and for a duration of the lamination cycle of at least 10 minutes, at least a portion of the constituent layers of the photovoltaic module.

According to a first variant, the method can be implemented for producing a photovoltaic module according to the first embodiment of the invention described above, and can then comprise the following two successive steps:

a) hot lamination, at a temperature greater than or equal to 120 ° C and for a duration of the lamination cycle of at least 10 minutes, of the assembly formed by the first layer, the encapsulating assembly, the photovoltaic cells and the first back layer for obtaining a photovoltaic laminate,

b) assembling the second rear layer on said photovoltaic laminate, in particular on the first rear layer, by means of an adhesive layer.

According to a second variant, the method can still be implemented for producing a photovoltaic module according to the second embodiment of the invention described above, and can then comprise the single hot lamination step, at a temperature greater than or equal to 120 ° C and during a period of lamination of at least 10 minutes of the assembly formed by the first layer, the encapsulating assembly, the photovoltaic cells and the second layer.

As indicated above, the second layer may comprise a plurality of attachment zones, intended to allow the attachment of the photovoltaic module to support crosspieces to form a panel of photovoltaic modules, and then the method may comprise the local reinforcement step of at least one fastening zone, in particular all the fastening zones, by means of reinforcement means, comprising in particular a composite material, for example an epoxy / glass bead mixture, wood, a thermosetting polymer, metal, for example aluminum, among others.

Furthermore, the method may further include the step of locally reinforcing at least one of the longitudinal edges, in particular the two longitudinal edges, of the second layer by means of reinforcement means, intended to reinforce the resistance of the second layer. during the hot lamination step, comprising in particular a polymeric material, for example epoxy, wood or metal, for example aluminum, among others.

In addition, the method may include the step of integrating a junction box, intended to receive the wiring necessary for the operation of the photovoltaic module, in the thickness of the rear panel, in particular in the thickness of the soul of the back panel.

The step of integrating the junction box into the thickness of the rear panel may comprise the following successive steps:

a) machining a portion of the plate forming the rear outer face of the photovoltaic module and the honeycomb structure to form an insertion cavity of the junction box,

b) positioning the bottom of the junction box in said insertion cavity,

c) placing at least a portion of the wiring connected to the junction box through the plate opposite to the plate forming the rear exterior face of the photovoltaic module, d) placing bypass diodes in the junction box and closing the junction box.

The photovoltaic module and the production method according to the invention may comprise any of the previously mentioned characteristics, taken separately or in any technically possible combination with other characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood on reading the following detailed description, non-limiting examples of implementation thereof, as well as on examining the schematic and partial figures of the appended drawing. on which :

FIG. 1 represents, in section, a conventional example of a photovoltaic module comprising crystalline photovoltaic cells,

FIG. 2 is an exploded view of the photovoltaic module of FIG.

1

FIG. 3 illustrates, in section and in exploded view, a first exemplary embodiment of a photovoltaic module according to the invention,

FIGS. 4A to 4C illustrate, in section and in assembled view, different steps of a first exemplary method according to the invention for producing a photovoltaic module similar to that of FIG. 3,

FIG. 5 illustrates, in section and in exploded view, a second exemplary embodiment of a photovoltaic module according to the invention,

FIG. 6 illustrates, in section and in assembled view, a step of a second exemplary method according to the invention for producing a photovoltaic module similar to that of FIG. 5;

FIG. 7 illustrates, in section, an alternative embodiment of the honeycomb structure of the core of a rear panel of a photovoltaic module according to the invention, FIGS. 8A, 8B and 8C illustrate, in section, various embodiments of a rear panel with a honeycomb core of a photovoltaic module according to the invention,

FIGS. 9A, 9B, 9C and 9D illustrate, in section, various embodiments of a rear panel with a foam core of a photovoltaic module according to the invention,

FIG. 10 represents, in bottom view, the rear face of the second layer of a particular embodiment of a photovoltaic module according to the invention, produced according to the principle of the second embodiment described with reference to FIG. figure 5,

FIG. 11 is an enlarged view of zone A of FIG. 10,

FIG. 12 illustrates, in section and in exploded view, the photovoltaic module of FIGS. 10 and 11,

FIG. 13 represents, in a view from below, the rear face of a second layer of a photovoltaic module according to the invention, integrating a junction box, and

FIGS. 14A to 14D illustrate, in section, different steps of integration of the junction box in the second layer of FIG. 13.

In all of these figures, identical references may designate identical or similar elements.

In addition, the different parts shown in the figures are not necessarily in a uniform scale, to make the figures more readable.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

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

Figures 3, 4A, 4B and 4C refer to a first embodiment of the invention, while Figures 5 and 6 refer to a second embodiment of the invention. For each of these two embodiments, it is considered that the photovoltaic cells 4, interconnected by soldered tinned copper strips, are "crystalline" cells, that is to say which are based on single or multicrystalline silicon, and they have a thickness between 1 and 300 μιη.

In addition, the encapsulating assembly 3 is chosen to be made from two layers of poly (ethylene-vinyl acetate) (EVA) between which the photovoltaic cells 4 are arranged, each layer having a minimum thickness of 300 μιη. , even 200 μιη. Alternatively, this encapsulating assembly 3 may also be a thermoplastic elastomer as previously described. Where appropriate, one or both layers forming the encapsulant assembly 3 may be stained.

Furthermore, although not shown in FIGS. 3 to 6, each photovoltaic module 1 may comprise a junction box, similar to the junction box 7 shown in FIGS. 1 and 2, intended to receive the wiring necessary for the operation. photovoltaic module 1, or else integrated in the rear panel 5, 5b as will be described later with reference to Figures 13 to 14D. This junction box can be made of plastic or rubber, being completely waterproof.

The photovoltaic cells 4, the encapsulating assembly 3 and the junction box 7 together constitute the so-called "incompressible" elements in the constitution of the photovoltaic module 1. They together have a surface weight of about 1.5 kg / m ² .

Advantageously, the invention provides a specific choice for the materials forming the front and rear faces of the photovoltaic module 1, so as to obtain a light photovoltaic module 1, of surface weight less than or equal to 7 kg / m ² , and preferentially less than or equal to 6 kg / m ² or 5 kg / m ² . In particular, the invention allows the removal of the thick glass layer, about 3 mm thick, at the front and the removal of the metal frame of the photovoltaic module, which together typically allow to provide rigidity photovoltaic module, but usually together represent about 80% of the total weight of a photovoltaic module. Thus, in the two embodiments described below, the first layer 2 forming the front face of the photovoltaic module 1 is a glass layer of thickness e2 less than 1.1 mm, previously "hardened" by the quenching process chemical.

Of course, these choices are in no way limiting as previously described.

Advantageously, the invention makes it possible to obtain a new photovoltaic module architecture that is lighter and thinner than a conventional photovoltaic module and meets the load tests of the IEC 61215 and IEC 61730 standards. This architecture is obtained by replacing the face traditional rear, also called "backsheet" in English, or by adding to the traditional rear face of a rear panel formed of two plates sandwiching a honeycomb core, sufficiently rigid for this panel alone ensures the mechanical strength of the photovoltaic module. First embodiment

Referring first to Figure 3 which illustrates, in section and exploded view, a first embodiment of a photovoltaic module 1 according to the invention.

It should be noted that FIG. 3 corresponds to an exploded view of the photovoltaic module 1 before the lamination steps of the first example method according to the invention, described hereinafter with reference to FIGS. 4A to 4C. Once the lamination steps performed, ensuring hot pressing and vacuum, the different layers are actually superimposed on each other.

The photovoltaic module 1 thus comprises a first transparent thin-film layer 2 and / or at least one polymer material having a thickness of less than or equal to 1.1 mm, forming the front face of the photovoltaic module 1 and intended to receive a luminous flux, a plurality of photovoltaic cells 4 arranged side by side and electrically connected to each other, and an assembly encapsulating the plurality of photovoltaic cells 4.

According to the invention, the photovoltaic module 1 further comprises a second layer 5 forming the rear face of the photovoltaic module 1, this second layer 5 being in this example constituted by a set of a first rear layer 5a, in contact with the encapsulating assembly 3, and a second layer alveolar rear 5b so that the first rear layer 5a is disposed between the encapsulating assembly 3 and the second alveolar rear layer 5b.

The inner surface 8i, in contact with the encapsulating assembly 3, of the first rear layer 5a is substantially flat so as to allow adhesion of the first rear layer 5a to the encapsulating assembly 3 during the lamination operation described later.

Similarly, the outer surface 8e of the second alveolar rear layer 5b is substantially planar so that the photovoltaic module 1 has a substantially flat outer rear surface, with a final appearance without relief.

In addition, according to the invention, the second alveolar rear layer 5b takes the form of a rear panel 5b, made of composite material. This rear panel 5b comprises a main sub-layer 9a forming the core 9a of the rear panel 5b, and two overlapping sub-layers forming front plates 9b and rear 9c of the rear panel 5b, disposed on either side of the rear panel 5b. 9a soul so that the core 9a is sandwiched between the two plates 9b, 9c. Advantageously, the core 9a of the rear panel 5b comprises a honeycomb structure 12, here in the form of a honeycomb. However, other forms of alveolar structure are possible as will appear below.

Moreover, in order to allow adhesion between the first rear layer 5a and the second alveolar rear layer 5b forming a cellular rear panel 5b, this assembly 5 forming the second layer further comprises an adhesive layer 10 between the first rear layer 5a and the second alveolar back layer 5b. In a preferred manner, this adhesive layer 10 may be a silicone adhesive.

The first back layer 5a can be made similarly to the back layer of a conventional photovoltaic module 1. Preferably, the first rear layer 5a is chosen to be a mono or multilayer polymer film, including the type Tedlar ^® / polyethylene terephthalate (PET) / Tedlar ^®, also known as TPT.

The thickness e5a of this first rear layer 5a can be between 150 and 600 μιη, being in particular of the order of 400 μιη. Advantageously, the first rear layer 5a has an inner surface 8i, in contact with the encapsulating assembly 3, substantially planar and an outer surface, in contact with the second substantially foamed rear layer 5b, substantially flat.

The dimensions of the second alveolar rear layer 5b are advantageously at least equal to those of the first layer 2 of the photovoltaic module 1.

FIGS. 4A to 4C illustrate, in section and in assembled view, different steps of the first exemplary method according to the invention for producing a photovoltaic module 1 similar to that of FIG. 3.

FIG. 4A is an isolated illustration of the second alveolar rear layer 5b forming the rear panel 5b, the adhesive layer 10 having been applied to the front plate 9b of the rear panel 5b.

FIG. 4B illustrates a photovoltaic laminate, obtained after hot lamination at a temperature greater than or equal to 120 ° C. and during a duration of the lamination cycle of at least 10 minutes, comprising the first layer 2, the encapsulating assembly 3 and the photovoltaic cells 4, and the first rear layer 5a.

FIG. 4C illustrates the step of assembling the photovoltaic laminate of FIG. 4B by bonding the second alveolar rear layer 5b to the first rear layer 5a through the adhesive layer 10.

In other words, according to this embodiment, a cold bonding is carried out between the laminate illustrated in FIG. 4B and the rear panel 5b illustrated in FIG. 4A.

Indeed, in the case where the constituent materials of the rear panel 5b have glass transition temperatures or too low melting temperature, typically less than 120 ° C, it is not possible to laminate the rear panel 5b with the other constituent layers 2, 3, 4 of the photovoltaic module 1, at the risk of seeing the cellular core 9 of the rear panel 5b be crushed or deformed during hot pressing. Therefore, in this case, the realization is carried out by cold gluing of a photovoltaic laminate on the rear panel 5b. The rear panel 5b has a basis weight less than or equal to 3 kg / m ² . The thickness of the core 9a is less than or equal to 40 mm, and the thickness of the plates 9b, 9c is less than 1 mm.

Second embodiment

Referring now to Figure 5 which illustrates, in section and exploded view, a second embodiment of a photovoltaic module 1 according to the invention.

It should also be noted that FIG. 5 corresponds to an exploded view of the photovoltaic module 1 before the lamination step of the second exemplary method according to the invention, described hereinafter with reference to FIG. lamination carried out, ensuring a hot pressing and vacuum, the various layers are actually superimposed on each other.

The photovoltaic module 1 thus comprises a first transparent thin-film layer 2 and / or at least one polymer material, with a thickness of less than 1.1 mm, forming the front face of the photovoltaic module 1 and intended to receive a luminous flux. , a plurality of photovoltaic cells 4 arranged side by side and electrically connected to each other, and an assembly encapsulating the plurality of photovoltaic cells 4.

According to the invention, the photovoltaic module 1 further comprises a second layer 5 forming the rear face of the photovoltaic module 1, this second layer 5 being in this example constituted by a single alveolar rear layer 5, in contact with the encapsulant assembly 3, forming the back panel 5.

The inner surface 8i of this alveolar rear layer 5 is substantially planar so as to allow it to adhere to the encapsulating assembly 3 during the lamination operation, as is the external surface 8e of the alveolar rear layer 5 so that the module photovoltaic 1 has a substantially flat outer rear face, with a final appearance without relief.

In addition, this alveolar rear layer 5b in the form of a rear panel 5b is made of composite material. This rear panel 5b comprises a main sub-layer 9a forming the core 9a of the rear panel 5b, and two sub-layers of covering forming front plates 9b and rear 9c of the rear panel 5b, disposed on either side of the core 9a so that the core 9a is sandwiched between the two plates 9b, 9c. Advantageously, the core 9a of the rear panel 5b comprises a honeycomb structure 12, here also in the form of a honeycomb. However, other forms of alveolar structure are possible as will appear below.

FIG. 6 illustrates, in section, the photovoltaic module 1 obtained during the hot lamination step of the second exemplary method according to the invention.

During this lamination step, all the layers of the module 1, namely the first layer 2, the encapsulating assembly 3, the photovoltaic cells 4 and the alveolar rear layer 5 forming the rear panel 5 are laminated together to a temperature greater than or equal to 120 ° C and for a duration of the lamination cycle of at least 10 minutes.

During this single lamination step, the lamination pressure is between 800 mbar and the atmospheric pressure for a membrane laminator, or less than or equal to 3000 mbar for a plate laminator.

The rear panel 5b has a basis weight less than or equal to 3 kg / m ² . The thickness of the core 9a is less than or equal to 40 mm, and the thickness of the plates 9b, 9c is less than 1 mm.

Referring now to Figures 7 to 9D, we will now describe alternative embodiments of the rear panel 5, 5b, formed of the cellular core 9a sandwiched between the plates 9b and 9c, these variants being applicable to any type of module photovoltaic 1 according to the invention, and in particular of the type of Figure 3 according to the first embodiment of the invention and the type of Figure 5 according to the second embodiment of the invention.

Thus, as described above with reference to the embodiments of FIGS. 3 and 5, the honeycomb structure 12 of the core 9a of the rear panel 5, 5b may be in the form of a honeycomb. It may in particular be made of metal, in particular aluminum, polyimide, polycarbonate (PC), polypropylene (PP) or synthetic high performance fibers, such as Nomex ^® type marketed by the company Du Pont de Nemours.

As a variant, as illustrated by FIG. 7, the honeycomb structure 12 of the core 9a of the rear panel 5, 5b may comprise a foam, for example a polymer foam, in particular made of polyurethane (PU) or polyethylene terephthalate (PET). ), or a metal foam, for example aluminum.

Furthermore, the front plates 9b and rear 9c of the rear panel 5, 5b may be made of composite material, in particular from fiber-reinforced composite materials (glass, carbon, linen, etc.), and for example of the prepreg fiber type. glass / epoxy, made of metal, for example aluminum, polycarbonate (PC), polymethylmethacrylate (PMMA) or from prepregs.

When the front plates 9b and rear 9c of the rear panel 5, 5b are electrically conductive, especially metal, and for example aluminum, especially in the case of the front plate 9b can be in contact with the encapsulating assembly 3 in the case of the second embodiment of the invention, the plates 9a and 9b may be coated with an insulating film monolayer or multilayer polymer, for example of the type Tedlar ^®, for imparting the electrical insulation required to meet the standards .

Furthermore, FIGS. 8A to 9D illustrate the possibilities of providing local reinforcement of the rear panel 5, 5b at its longitudinal edges and / or at the level of the attachment zones 13, intended to allow the fixing of the photovoltaic module 1 to cross supports, as shown in Figure 10 described later.

FIGS. 8A, 8B and 8C are specific to the case of a honeycomb structure 12 of the core 9a of the rear panel 5, 5b comprising a honeycomb structure, and FIGS. 9A, 9B, 9C and 9D are specific to the case of a honeycomb structure 12 of the core 9a of the rear panel 5, 5b comprising a foam structure.

In FIG. 8A, the rear panel 5, 5b is devoid of any reinforcing means. On the other hand, in FIG. 8B, the rear panel 5, 5b comprises means 15 for reinforcing its longitudinal edge 5i, 5bi, designed to reinforce the resistance of the rear panel 5, 5b during the hot lamination step. These reinforcing means 15 comprise for example a polymeric material, for example epoxy.

In FIG. 8C, the rear panel 5, 5b comprises reinforcing means 14 of the fastening zones 13 enabling the module 1 to be fastened to the support struts to form the panel of photovoltaic modules. These reinforcing means 14 comprise for example a composite material, for example a mixture of epoxy / hollow glass beads type.

Moreover, in FIG. 9A, the rear panel 5, 5b, provided with a foam core 9a, is devoid of any reinforcement means.

On the other hand, in FIG. 9C, the rear panel 5, 5b comprises reinforcing means 15 of its longitudinal edge 5i, 5bi intended to reinforce the resistance of the rear panel 5, 5b during the hot lamination step. These reinforcing means 15 comprise for example a polymeric material, for example epoxy. To integrate these reinforcing means 15 to the rear panel 5, 5b, a recess EV is previously made in the foam 12, as shown in Figure 9B.

Finally, in FIG. 9D, the rear panel 5, 5b includes means 14 for reinforcing the attachment zones 13 for fixing the module 1 to the support rails to form the panel of photovoltaic modules. These reinforcing means 14 comprise for example a composite material, for example a mixture of epoxy / hollow glass beads type. These reinforcing means 14 may be integrated in the rear panel 5, 5b after the formation of a recess, as explained previously with the help of Figure 9B.

Particular example of realization

We will now describe a particular embodiment of a photovoltaic module 1 according to the invention, made according to the principle of the second embodiment of the invention, as described above with reference to Figure 5. Thus, FIG. 10 represents, in a view from below, the rear face of the second layer 5 of this particular example of photovoltaic module 1 according to the invention, FIG. 11 is an enlarged view of zone A of FIG. and FIG. 12 illustrates, in section and in exploded view, this photovoltaic module 1.

As can be seen in FIG. 12, the photovoltaic module 1 comprises a front face 2 consisting of a coating of the ECTFE type (acronym of "Ethylene Chloro Trifluoro Ethylene") with a thickness of approximately 50 μιη, an encapsulating assembly 3 a plurality of photovoltaic cells 4 and a second layer 5 forming the rear panel 5.

The encapsulating assembly 3 is more precisely obtained from a first polymer-based encapsulant layer 3a, itself comprising two polymer sub-layers, and a second polymer-based encapsulant layer 3b, itself comprising a first polymer sub-layer 3bl and a second sub-layer 3b2 made of white polymer.

To achieve this module 1, a single hot lamination step is performed without use of wedge.

The back panel 5 has a web 9a provided with a structure 12 honeycomb made of Nomex ^® and having a E9A thickness of about 15 mm. This core 9a is sandwiched between two front 9b and rear 9c plates, made of epoxy / glass fiber prepregs, with thicknesses e9b and e9c of about 200 μιη.

As illustrated in FIGS. 10 and 11, the rear panel 5 comprises a plurality of attachment zones 13 intended to allow the photovoltaic module 1 to be fastened to support beams to form a panel of photovoltaic modules 1, and configured to allow a spacing of said support rails, for example between 735 and 1045 mm. These attachment zones 13 have been reinforced with reinforcing means 14 comprising a mixture of epoxy / hollow glass beads with a density of about 0.6. In addition, the longitudinal edges 5 ₁ and 5 ₂ of the back panel 5 have also been reinforced by reinforcement means 15 comprising epoxy. Furthermore, in this exemplary embodiment of photovoltaic module 1 according to the invention, preferably comprising sixty crystalline silicon photovoltaic cells of dimension 156 mm × 156 mm, the length Lp of the rear panel 5 is about 1685 mm and the width lp of the back panel 5 is about 1025 mm. In addition, the distance Df between a transverse edge 53 or ₅₄ of the rear panel 5 and an adjacent fixing zone 13 is of the order of 300 mm, while the length Lf of a fixing zone 13 is of the order 200 mm and the width If of a fastening zone 13 is of the order of 30 mm. According to another exemplary embodiment of the invention, the front and rear faces of the panel may have the same dimensions, or the rear face of the panel may have a length and a width up to 6 mm higher than those of the face. before.

Such a photovoltaic module 1 then has a surface weight of about 5.2 kg / m ² , with the presence of a junction box 7 (not shown).

After a mechanical load test pushed to 7000 Pa, against 5400 Pa for the most severe test of resistance to snow required by the IEC 61215 standard, no crack was detected on the photovoltaic module 1.

We will now describe with reference to FIGS. 13 to 14D the possibility of integrating a junction box 7 into the thickness of the rear panel 5.

More precisely, FIG. 13 represents, in a view from below, the rear face of a second layer 5 of a photovoltaic module 1 according to the invention, integrating a junction box 7, and FIGS. 14A to 14D illustrate, in section, different steps of integration of the junction box 7 in the second layer 5 of Figure 13.

In FIG. 13, it can be seen that the junction box 7 is integrally or partially integrated in the thickness of the rear panel 5, more precisely in the thickness of the honeycomb structure 12 of the core 9a of the rear panel 5. This junction box 7 will allow the interconnection of the photovoltaic modules 1 and also makes it possible to integrate the bypass diodes 18.

To obtain this integration, the method for producing the photovoltaic module 1 may comprise the following successive steps consisting of: a) starting from the rear panel 5 illustrated in FIG. 14A, machining a portion of the rear plate 9c forming the rear exterior face of the photovoltaic module 1 and the honeycomb structure 12 to form an insertion cavity Cb of the junction box 7,

b) then position the bottom 16 of the junction box 7 in the insertion cavity Cb, as illustrated in FIG. 14B,

c) then, as illustrated in FIG. 14C, it is possible to put in place the wiring 17 connected to the junction box 7 through the front plate 9b,

d) Finally, as illustrated in FIG. 14D, bypass diodes 18 are placed in the junction box 7 and the junction box 7 is closed so that its outer surface substantially matches the outer surface. rear plate 9c to provide a substantially flat surface continuity.

Advantageously, by the use of a front face of glass of thickness less than or equal to 1.1 mm, or of polymer, the photovoltaic module 1 may have a basis weight of less than or equal to 7 kg / m ² , for example in the case of a first glass front layer 2, preferably less than or equal to 6 kg / m ² , or even 5 kg / m ² , for example in the case of a first front layer 2 comprising a film consisting of an ECTFE-type coating, at least almost two times lower than that of a conventional photovoltaic module.

This significant weight gain can allow the photovoltaic module 1 according to the invention to be installed on applications where a standard module of about 12 kg / m ² could not be applied.

In addition, by using composite materials to produce the second layer 5, specifically the second back layer 5b and the three-dimensional back layer 5, the photovoltaic module 1 according to the invention retains its mechanical properties to withstand the constraints of IEC standards. 61215 and IEC 61730.

In addition, the module obtained is compatible with an industrial line manufacturing standard photovoltaic modules. Of course, the invention is not limited to the embodiments which have just been described. Various modifications may be made by the skilled person.

Claims

Photovoltaic module (1) comprising:

a transparent first 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 encapsulating assembly (3) the plurality of photovoltaic cells

(4)

a second layer (5) forming the rear face of the photovoltaic module (1), the second layer (5) comprising an inner surface (8i), in contact with the encapsulating assembly (3), and an outer surface (8e) opposed to the inner surface (8i), 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) is made of glass and / or at least one polymeric material and has a thickness (e2) less than or equal to 1.1 mm, in that the inner (8i) and outer surfaces (8e) of the second layer (5) are substantially planar,

and in that the second layer (5) further comprises a rear layer forming a rear panel (5, 5b) of composite material, comprising a main underlayer, forming the core (9a) of the rear panel (5, 5b ), and two overlapping sub-layers, each forming a plate (9b, 9c) of the rear panel (5, 5b), 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, 5b) having a honeycomb structure (12), the rear panel (5, 5b) having a lower surface weight or equal to 3 kg / m ² .

2. Module according to claim 1, characterized in that the rear panel (5, 5b), in particular the honeycomb structure (12), is devoid of protruding relief relative to its surface.

3. Module according to claim 1 or 2, characterized in that the first layer (2) is made of glass.

4. Module according to claim 1 or 2, characterized in that the first layer (2) is made of at least one polymeric material, in particular chosen from: polycarbonate (PC), polymethyl methacrylate (PMMA), in particular PMMA single-phase (non-shock) or multi-phased PMMA (shock), for example nanostructured PMMA, polyethylene terephthalate (PET), polyamide (PA), a fluorinated polymer, especially polyvinyl fluoride (PVF) or polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), polytetrafluoroethylene (PTFE), and / or polychlorotrifluoroethylene (PCTFE).

5. Module according to any one of the preceding claims, characterized in that the second layer (5) is constituted by a set (5) of at least a first rear layer (5a), in contact with the encapsulating assembly ( 3), and a second honeycombed back layer (5b) so that the first back layer (5a) is disposed between the encapsulating assembly (3) and the second back layer (5b), the inner surface of the second layer (5b). ) being formed by the inner surface (8i), in contact with the encapsulating assembly (3), of the first rear layer (5a) and the outer surface of the second layer (5) being formed by the outer surface (8e) of the second rear layer (5b), which forms the rear panel (5b) comprising the core (9a) provided with the honeycomb structure (12).

6. Module according to claim 5, characterized in that the second layer (5) further comprises an adhesive layer (10) between the first rear layer (5a) and the second alveolar rear layer (5b), to allow assembly from the second alveolar back layer (5b) to the first back layer (5a).

7. Module according to claim 5 or 6, characterized in that the first back layer (5a) is a mono or multilayer polymer film.

8. Module according to one of claims 5 to 7, characterized in that the first rear layer (5a) has a thickness (e5a) between 150 and 600 μιη, in particular of the order of 400 μιη.

9. Module according to one of claims 1 to 4, characterized in that the second layer (5) is constituted by a single alveolar rear layer (5) in contact with the encapsulant assembly (3) forming the rear panel (5) comprising the core (9a) provided with the honeycomb structure (12).

10. Module according to any one of the preceding claims, characterized in that the core (9a) of the rear panel (5, 5b) comprises a cellular structure in the form of a honeycomb, in particular made of metal, for example in aluminum, polyimide, polycarbonate (PC), polypropylene (PP) or high performance synthetic fibers.

11. Module according to any one of claims 1 to 9, characterized in that the core (9a) of the rear panel (5, 5b) comprises a cellular structure in the form of foam, in particular made of polyethylene terephthalate (PET ) or polyurethane (PU).

12. Module according to any one of the preceding claims, characterized in that the plates (9b, 9c) of the rear panel (5, 5b) are made of composite material, for example of prepreg type based on glass fibers and epoxy resin, made of metal, for example aluminum, polycarbonate (PC) or polymethylmethacrylate (PMMA) or from prepregs.

13. Module according to any one of the preceding claims, characterized in that the plates (9b, 9c) of the rear panel (5, 5b) are covered with a single or multilayer polymer film.

14. Module according to any one of the preceding claims, characterized in that it has a basis weight less than or equal to 7 kg / m ² , especially less than or equal to 6 kg / m ² , in particular still less than or equal to 5 kg / m ² .

15. Module according to any one of the preceding claims, characterized in that the rear panel (5, 5b) has a basis weight less than or equal to 2 kg / m ² , especially less than or equal to 1 kg / m ² .

16. Module according to any one of the preceding claims, characterized in that the second layer (5) comprises a plurality of attachment zones (13), intended to allow the attachment of the photovoltaic module (1) to cross supports to form a panel of photovoltaic modules. .

17. Module according to claim 16, characterized in that the attachment zones (13) are configured to allow a spacing of said support crosspieces, in particular between 735 and 1045 mm.

18. Module according to claim 16 or 17, characterized in that the second layer (5) comprises reinforcing means (14) of at least one attachment zone (13), comprising in particular a composite material, for example a mixture epoxy type / glass beads, wood, a thermosetting polymer, metal, for example aluminum.

19. Module according to any one of the preceding claims, characterized in that the second layer (5) comprises reinforcing means (15) of at least one of its longitudinal edges (5i, 5 ₂ ), intended to reinforce the resistance of the second layer (5) during a hot lamination step, comprising in particular a polymeric material, for example epoxy, wood or metal, for example aluminum.

20. Module according to any one of the preceding claims, characterized in that the encapsulant assembly (3) is made from at least one polymeric 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, elastomeric polyolefins of copolymers, copolymers of α-olefins and α-, β-carboxylic to ethylenic acid esters, such as ethylene-methyl acrylate copolymers and ethylene-butyl acrylate copolymers, silicone elastomers and / or epoxy resins.

21. Module according to claim 20, characterized in that the encapsulant assembly (3) is made from two layers of poly (ethylene-vinyl acetate) (EVA) between which are arranged the photovoltaic cells (4).

22. Module according to any one of the preceding claims, characterized in that the photovoltaic cells (4) are chosen from: homojunction or heterojunction photovoltaic cells based on monocrystalline silicon (c-Si) and / or multi-crystalline (mc -Si), and / or photovoltaic cells comprising at least one of amorphous silicon (a-Si), microcrystalline silicon (C-Si), cadmium telluride (CdTe), copper-indium selenide (CIS) and copper-indium / gallium diselenide (CIGS).

23. Module according to any one of the preceding claims, characterized in that the photovoltaic cells (4) have a thickness between 1 and 300 μιη.

24. Module according to any one of the preceding claims, characterized in that it further comprises a junction box (7) for receiving the wiring necessary for the operation of the photovoltaic module (1).

25. Module according to claim 24, characterized in that the junction box (7) is integrated in the thickness of the rear panel (5, 5b), in particular in the thickness of the core (9a) of the rear panel ( 5, 5b).

Module according to claim 25, characterized in that at least a part of the wiring (17) connected to the junction box (7) passes through the plate (9b) of the rear panel (5, 5b) opposite the plate ( 9c) of the rear panel (5, 5b) forming the rear outer face of the photovoltaic module (1).

27. Module according to one of claims 24 to 26, characterized in that the junction box (7) comprises the diodes (18) bypass.

28. A method of producing a photovoltaic module (1) according to any one of the preceding claims, characterized in that it comprises the hot lamination step, at a temperature greater than or equal to 120 ° C and during a duration of the lamination cycle of at least 10 minutes, of at least part of the constituent layers (2, 3, 4, 5, 2, 3, 4, 5a) of the photovoltaic module (1).

29. The method of claim 28, characterized in that it is implemented for the realization of a photovoltaic module (1) according to any one of claims 5 to 27, except claim 9, and in that it comprises the following two successive steps:

a) hot lamination, at a temperature greater than or equal to 120 ° C and for a duration of the lamination cycle of at least 10 minutes, of the assembly formed by the first layer (2), the encapsulating assembly (3 ), the photovoltaic cells (4) and the first rear layer (5a) for obtaining a photovoltaic laminate, b) assembling the second rear layer (5b) on said photovoltaic laminate, in particular on the first rear layer (5a), by means of an adhesive layer (10).

30. The method of claim 28, characterized in that it is implemented for the realization of a photovoltaic module (1) according to any one of claims 9 to 27, and in that it comprises the unique hot lamination step, at a temperature greater than or equal to 120 ° C and during a lamination cycle time of at least 10 minutes, of the assembly formed by the first layer (2), the encapsulating assembly (3 ), the photovoltaic cells (4) and the second layer (5).

31. Method according to one of claims 28 to 30, characterized in that the second layer (5) comprises a plurality of fixing areas (13) for allowing the attachment of the photovoltaic module (1) to cross supports for forming a panel of photovoltaic modules, and in that the method comprises the step of local reinforcement of at least one attachment zone (13) by means of reinforcement means (14), in particular comprising a composite material, for example a mixture of epoxy type / glass beads, wood, a thermosetting polymer, metal, for example aluminum.

32. Method according to any one of claims 28 to 31, characterized in that it comprises the local step of reinforcing at least one of the longitudinal edges (5i, 5 ₂ ) of the second layer (5) by the biasing reinforcing means (15), provided to enhance the resistance of the second layer (5) during the hot lamination step, comprising in particular a polymeric material, for example epoxy, wood or metal, for example aluminum.

33. Method according to any one of claims 28 to 32, characterized in that it comprises the step of integrating a junction box (7) for receiving the wiring necessary for the operation of the photovoltaic module. (1), in the thickness of the rear panel (5, 5b), in particular in the thickness of the core (9a) of the rear panel (5, 5b).

34. The method of claim 33, characterized in that the step of integrating the junction box (7) in the thickness of the rear panel (5, 5b) comprises the following successive steps:

a) machining a portion of the plate (9c) forming the rear exterior face of the photovoltaic module (1) and the honeycomb structure (12) to form an insertion cavity (Cb) of the junction box (7) ,

b) positioning the bottom (16) of the junction box (7) in said insertion cavity (Cb),

c) placing at least a portion of the wiring (17) connected to the junction box (7) through the plate (9b) opposite to the plate (9c) forming the rear exterior face of the photovoltaic module (1). )

d) placing bypass diodes (18) in the junction box (7) and closing the junction box (7).