FR3081614A1 - PHOTOVOLTAIC MODULE COMPRISING ONE OR MORE BYPASS DIODES ON THE BACK SIDE OF A MODULE PHOTOVOLTAIC CELL - Google Patents

Abstract

The main object of the invention is a light photovoltaic module (1) comprising: a first transparent layer (2) forming the front face, photovoltaic cells (4) electrically connected to each other by electrical contact elements (6) called connecting conductors (6), an assembly encapsulating (3) the photovoltaic cells (4), and a second layer (5), the encapsulating assembly (3) and the photovoltaic cells (4) being located between the first (2) and second (5) layers, characterized in that, for at least a plurality of photovoltaic cells (4), one or more bypass diodes (8) are secured to the rear face (4b) of each photovoltaic cell (4), and electrically connected to one or more photovoltaic cells (4) to be protected.

Description

PHOTOVOLTAIC MODULE HAVING ONE OR MORE BYPASS DIODES ON THE BACK OF A PHOTOVOLTAIC CELL OF THE MODULE

DESCRIPTION

TECHNICAL AREA

The present invention relates to the field of photovoltaic modules, which comprise a set of photovoltaic cells connected to each other electrically, and preferably so-called “crystalline” photovoltaic cells, that is to say which are based on monocrystalline or multicrystalline silicon. It particularly relates to the integration of bypass diodes, also called bypass diodes, within a photovoltaic module.

The invention can be implemented for numerous applications, for example autonomous and / or on-board applications, being particularly concerned, but not exclusively, by applications which require the use of flexible photovoltaic modules, without glass and ultra-light , in particular of a weight per unit area less than 1 kg / m ² , and in particular less than 800 g / m ² , or even less than 600 g / m ² , and of small thickness, in particular less than 2 mm, even 1 mm. It can thus in particular be applied to buildings such as habitats or industrial premises (tertiary, commercial, etc.), for example for the realization of their roofs, for the design of urban furniture, for example for public lighting , road signs or even recharging of electric cars, or even be used for nomadic applications, in particular for integration on cars, buses or boats, among others.

The invention thus proposes a photovoltaic module comprising one or more bypass diodes on the rear face of a photovoltaic cell of the module, as well as a method for producing such a photovoltaic module.

PRIOR STATE OF THE 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 light flux. It is traditionally produced in a single glass plate, having a thickness typically between 2 and 4 mm, conventionally of the order of 3 mm.

The second layer forming the rear face of the photovoltaic module can for its part be made on the basis of glass, metal or plastic, among others. It is often formed by a polymer 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 μm.

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 lying opposite the face front of the photovoltaic module intended to receive a luminous flux) and rear (faces located opposite the rear face of the photovoltaic module) of each of the photovoltaic cells, or even only on the rear face for photovoltaic cells of the IBC type (for “ Interdigitated Back Contact ”.

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

Furthermore, the photovoltaic cells, located between the first and second layers respectively forming the front and rear faces of the photovoltaic module, can be encapsulated. Conventionally, 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 connection conductors are arranged. Each layer of encapsulant may have a thickness of at least 0.2 mm and a Young's modulus typically between 2 and 400 MPa at room temperature.

There has thus been shown partially and schematically, respectively in section in FIG. 1 and in exploded view in FIG. 2, a conventional example of a photovoltaic module 1 comprising crystalline photovoltaic cells 4.

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

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

FIG. 1A also represents an alternative embodiment of the example of FIG. 1 in which the photovoltaic cells 4 are of the IBC type, the connecting conductors 6 being only disposed against the rear faces of the photovoltaic cells 4.

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.

Usually, the method for producing the photovoltaic module 1 comprises a step called vacuum lamination of the different layers described above, at a temperature greater than or equal to 120 ° C, or even 140 ° C, or even 150 ° C, and 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 include the photovoltaic cells 4, at the same time as adhesion is created at all the interfaces between the layers, namely between the front face 2 and the front layer of encapsulation material 3a, the layer of encapsulation material 3a and the front faces 4a of the photovoltaic cells 4, the rear faces 4b of the photovoltaic cells 4 and the rear layer of encapsulation material 3b, and the 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 by means of an aluminum profile.

In a standard photovoltaic module 1, such as that of FIGS. 1 and 2, composed of 60 photovoltaic cells 4, bypass diodes (one for 20 cells) are additionally integrated in the junction box 7 glued to the outside of the module 1.

Thus, in the case of shading of one or more photovoltaic cells 4 in the photovoltaic module 1, these bypass diodes make it possible both to avoid deterioration of the module by the hotspot phenomenon (“hotspot” in English ) and limit the loss of electrical productivity associated with shading.

The number of photovoltaic cells 4 per bypass diode can be defined according to different criteria, such as: the maximum withstand in reverse voltage of the photovoltaic cell before breakdown; the electrical productivity required; the maximum temperature not to be exceeded in the event of shade; the cost ; architecture and dimensions of the photovoltaic module, among others.

In the case of a standard photovoltaic module, for example for a roof application or for a photovoltaic field, the best compromise found is a bypass diode for all 20 photovoltaic cells.

However, in the case of new applications where the constraints of use are more severe, in particular when problems of heating and variable shading are more frequent, it may be necessary to integrate more bypass diodes with sometimes situations may require several bypass diodes per photovoltaic cell in order to overcome possible reliability problems in the event of a bypass diode failure.

Consequently, there is a need to design an alternative solution for integrating the bypass diodes in a photovoltaic module.

STATEMENT OF THE INVENTION

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

According to one of its aspects, the subject of the invention is therefore a photovoltaic module comprising:

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

- a plurality of photovoltaic cells arranged side by side and electrically connected to each other, or interconnected, by electrical contact elements called connecting conductors, formed in particular by tapes (or tapes) or wires of tinned copper,

- an assembly encapsulating the plurality of photovoltaic cells,

- A second layer, the encapsulating assembly and the plurality of photovoltaic cells being located between the first and second layers.

For at least a plurality of photovoltaic cells, in particular all of the photovoltaic cells, one or more bypass diodes are secured, for example by assembly and / or bonding, to the rear face of each photovoltaic cell, and electrically connected to one or more photovoltaic cells to protect.

The electrical connection of the bypass diode (s) of each photovoltaic cell to one or more photovoltaic cells to be protected is advantageously made by connection of the anode of a bypass diode to the anode of a photovoltaic cell, and connection of the cathode of this bypass diode to the cathode of this photovoltaic cell. Indeed, according to the generator / receiver convention, a bypass diode is a receiver with the negative pole at the cathode and the positive pole at the anode, and a photovoltaic cell is a generator with the positive pole at the cathode and the pole negative at the anode.

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 "encapsulating" or "encapsulated", it should be understood that the plurality of photovoltaic cells is arranged in a volume, for example hermetically sealed from liquids, at least partly formed by at least two layers of encapsulation material (s), joined together after lamination to form the encapsulating assembly.

In fact, initially, that is to say before any lamination operation, the encapsulating assembly consists of at least two layers of encapsulation material (s), called core layers, between which the plurality of photovoltaic cells is encapsulated. However, during the layer lamination operation, the layers of encapsulation material melt to form, after the lamination operation, only one solidified layer (or assembly) in which the photovoltaic cells are embedded.

Thanks to the invention, it may be possible to avoid the loss of active surface, the bypass diodes and the associated connectors being located on the rear face of the photovoltaic cells. In addition, it may be possible to manage the thermal of a bypass diode in operation by allowing a coupling with the photovoltaic cell to be protected so that it is then used as a heat sink and allows the temperature of the diode to be reduced. bypass in operation. In addition, the invention can make it possible to limit as much as possible the excess mass associated with the integration of bypass diodes, namely the components and the connectors, in the case where lightness is an important criterion. The interconnection of the bypass diodes can also be facilitated and the number of bypass diodes per cell may not be limited. Furthermore, the invention provides a solution for integrating bypass diodes which can be compatible with any type of crystalline silicon photovoltaic cell and any type of bypass diode.

In addition, the bypass diodes are advantageously in series from one photovoltaic cell to another, and as soon as there are at least two bypass diodes per cell, the diodes of the same cell are in parallel with each other. . If one diode turns out to be faulty, the second takes over.

The photovoltaic module according to the invention may also include one or more of the following characteristics taken in isolation or according to any possible technical combination.

The second layer can form the rear face of the photovoltaic module. However, it can also be interposed between the encapsulating assembly and at least one additional layer, for example of protection, which will then form the rear face of the module.

According to a first embodiment of the invention, the photovoltaic cells can be electrically connected to each other by connecting conductors respectively disposed against the front and rear faces of each of the photovoltaic cells. Advantageously, this configuration corresponds to a technology of photovoltaic cells with front face and rear face contacts.

Thus, for each photovoltaic cell of said at least a plurality of photovoltaic cells, the bypass diode or diodes can be positioned on a connection conductor of the rear face of the photovoltaic cell, this connection conductor allowing the electrical connection of the first polarity of the bypass diode (s). One or more additional connection conductors can be positioned on the bypass diode (s), opposite to the connection conductor on the rear face of the photovoltaic cell, this or these additional connection conductors allowing the electrical connection of the second polarity bypass diode (s).

According to a second embodiment of the invention, the photovoltaic cells can be electrically connected to each other by connecting conductors arranged against the rear face of each of the photovoltaic cells. Advantageously, this configuration corresponds to a technology of photovoltaic cells with rear face contacts of the IBC type (for “Interdigitated Back Contact” in English).

Thus, for each photovoltaic cell of said at least a plurality of photovoltaic cells, the bypass diode (s), as well as the connecting conductor (s) on the rear face of a photovoltaic cell, can be electrically isolated at least partially, in particular totally, from the surface of the photovoltaic cell.

In addition, for each photovoltaic cell of said at least a plurality of photovoltaic cells, several bypass diodes can be secured to the rear face of each photovoltaic cell, and electrically connected to one or more photovoltaic cells to be protected.

Furthermore, for each photovoltaic cell of said at least a plurality of photovoltaic cells, the bypass diode or diodes can be positioned at or near an edge of the photovoltaic cell.

In the case of photovoltaic cell technology with front and rear face contacts, such positioning of the bypass diode (s) sufficiently close to the edge of the photovoltaic cell can make it possible to limit the length of the additional connection conductor (s) and thus limit the associated excess mass.

In addition, among said plurality of photovoltaic cells, at least one portion, in particular all, of one or more photovoltaic cells can be used as a bypass diode by connecting said portion in parallel and in opposite polarity on the rear face d '' one or more photovoltaic cells to protect.

Advantageously, the first layer may comprise at least one polymeric material and has a thickness of less than 50 μm, and advantageously between 5 μm and 25 μm. It is advantageously constituted by said at least one polymer material.

In addition, the second layer may comprise at least one composite material of the prepreg type based on polymer resin and fibers, and it may have a surface weight of less than 150 g / m ² , and advantageously between 50 g / m ² and 115 g / m ² . It can for example be constituted by said at least one composite material.

In addition, the encapsulating assembly can have a maximum thickness of less than 150 μm.

It is thus possible to obtain an ultra-light and flexible photovoltaic module. In addition, by the use of a rear face made of a polymer / fiber prepreg composite, the photovoltaic module can have excellent mechanical and thermomechanical properties while retaining flexibility without degradation of the photovoltaic cells under bending stress. In particular, it can accept radii of curvature of about 50 cm, or even 20 cm in some cases, without degradation of the cells. In addition, in particular by reducing the thicknesses of its constituent elements, the photovoltaic module can make it possible to achieve required surface weights less than 1 kg / m ² , in particular less than 800 g / m ² , and very particularly less than 600 g. / m ² , making it by definition ultra-light.

The first layer and / or the second layer of the photovoltaic module can be formed in one or more parts, namely that they can be monolayer or multilayer.

The second layer may in particular have a thickness of between 50 μm and 80 μm.

Said at least one composite material of the prepreg type can comprise a polymer resin impregnation rate of between 30 and 70% by mass.

Said at least one composite material of the second layer can be a prepreg based on polymer resin and fibers, the polymer being chosen from polyester, epoxy and / or acrylic, among others, and the fibers being chosen from glass, carbon and / or aramid fibers, among others.

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

Furthermore, the photovoltaic module advantageously has a surface weight of less than 1 kg / m ² , in particular less than 800 g / m ² , in particular still less than 600 g / m ² .

In addition, the encapsulating assembly may have a maximum thickness of between 20 μιτι and 100 μιτι, and preferably between 50 and 75 μιτι.

The encapsulating assembly can be formed by at least one layer comprising at least one encapsulation material of polymer type chosen from: acid copolymers, ionomers, poly (ethylene-vinyl acetate) (EVA), acetals vinyl, such as polyvinylbutyrals (PVB), polyurethanes, polyvinyl chlorides, polyethylenes, such as linear low density polyethylenes, polyolefin elastomers of copolymers, copolymers of a-olefins and a-, βesters of carboxylic to ethylenic acid, such as ethylene-methyl acrylate copolymers and ethylene-butyl acrylate copolymers, silicone elastomers and / or epoxy resins, among others.

Preferably, the encapsulating assembly can be produced from two layers of polymer material (s), in particular two layers of ionomer, the Young's modulus of which is much greater than that of poly (ethylene-vinyl acetate) (EVA) but still between 2 and 400 MPa at room temperature allowing better mechanical properties, between which the photovoltaic cells are arranged, each layer having a thickness less than 75 μιτι, and preferably less than 50 μητ

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

Furthermore, the photovoltaic cells can have a thickness of between 1 and 300 μιτι, in particular between 1 and 200 μιτι, and advantageously between 70 μιτι and 160 μιτι.

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

In addition, the spacing between two neighboring photovoltaic cells, or alternatively consecutive or adjacent, can be greater than or equal to 1 mm, in particular between 1 and 30 mm, and preferably equal to 2 mm.

In addition, the thickness of the interconnecting connection conductors of the photovoltaic cells, and those used to interconnect the strings of cells (or “strings” according to the common name in English), has been adapted to be compatible with the lamination process. and the small thickness of the encapsulant. For example, in the case of cells with front face-rear face contact, their thickness is advantageously reduced by at least 50% compared to that of those used in a standard module. The interconnection connecting conductors of such cells can have a thickness of less than 100 μm and a width of less than 3 mm. For the interconnection link conductors of "string", the thickness is advantageously strictly less than 200 μm and the width less than 5 mm.

In addition, the invention also relates, according to another of its aspects, to a process for producing a photovoltaic module as defined above, characterized in that it comprises the step of hot lamination, at a temperature between 130 ° C and 170 ° C, in particular of the order of 150 ° C, and for a duration of the lamination cycle of at least 10 minutes, in particular between 10 and 20 minutes, of the constituent layers of the photovoltaic module.

For said at least a plurality of photovoltaic cells, the bypass diode or diodes can advantageously be secured, for example by assembly and / or bonding, to the rear face of each photovoltaic cell and electrically connected to one or more photovoltaic cells to be protected, before said hot lamination step of the process according to the invention.

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

BRIEF DESCRIPTION OF THE DRAWINGS

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

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

FIG. 1A represents an alternative embodiment of the example of FIG. 1 in which the photovoltaic cells are of the IBC type,

- Figure 2 shows, in exploded view, the photovoltaic module of Figure

1

FIGS. 3 and 4 partially illustrate, respectively in section and in view from below, two exemplary embodiments of chains of photovoltaic cells for photovoltaic modules according to the invention, and

- Figure 5 partially illustrates, from below, the use of a photovoltaic cell as a bypass diode for a photovoltaic module according to the invention.

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

In addition, the different parts shown in the figures are not necessarily shown on 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 and 4 partially illustrate, respectively in section and in bottom view, two embodiments of chains ("string" in English) of photovoltaic cells 4 for photovoltaic modules 1 according to the invention.

It is considered here that the photovoltaic cells 4, interconnected by connecting conductors 6 in the form of soldered tinned copper ribbons, are “crystalline” cells, that is to say that they comprise monocrystalline or silicon, and that they have a thickness between 1 and 250 μm.

In addition, the encapsulating assembly 3 is chosen to be produced from two layers of ionomer between which the photovoltaic cells 4 are arranged, each layer being of thickness less than 50 μm.

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 an ultra-light photovoltaic module 1, with a surface weight of less than 1 kg / m ² , and preferably less than 0.8 kg / m ² , or even 0.6 kg / m ² .

Of course, these choices are in no way limiting. It should also be noted that the elements already described with reference to Figures 1 and 2 are not necessarily described again here.

First of all, reference is made to FIG. 3 which partially illustrates, in section, an embodiment of a “string” of photovoltaic cells 4 of a photovoltaic module 1 according to the invention.

The photovoltaic module 1 thus comprises a plurality of photovoltaic cells 4 arranged side by side and interconnected with one another by connecting conductors 6.

Before the hot lamination step, a bypass diode 8 per photovoltaic cell 4 is bonded to the rear face 4b of each photovoltaic cell 4, and electrically connected to one or more photovoltaic cells 4 to be protected. More specifically, the electrical connection of the bypass diode 8 of each photovoltaic cell 4 is made by connection of the anode of a bypass diode 8 to the anode of a photovoltaic cell 4, and connection of the cathode of this bypass diode 8 at the cathode of this photovoltaic cell 4.

In the example of FIG. 3, the technology of cells with front and rear face contacts is illustrated. Thus, the photovoltaic cells 4 are electrically connected to each other by connecting conductors 6 respectively disposed against the front 4a and rear 4b faces of each of the photovoltaic cells 4.

In this case, the bypass diode 8 is positioned on a connecting conductor 6 of the rear face 4b of the photovoltaic cell 4, this connecting conductor 6 allowing the electrical connection of the first polarity of the bypass diode 8.

In addition, an additional connection conductor 9 is positioned on the bypass diode 8, opposite to the connection conductor 6 of the rear face 4b of the photovoltaic cell 4, this additional connection conductor 9 allowing the electrical connection of the second polarity of the bypass diode 8.

The positioning of the bypass diode 8 sufficiently close to the edge of the cell 4 makes it possible to limit the length of the additional connection conductor 9 and thus to limit the associated excess mass.

Furthermore, FIG. 4 illustrates the technology of photovoltaic cells 4 with rear face contacts of the IBC type.

Thus, the photovoltaic cells 4 are electrically connected to each other by connecting conductors 6 all disposed against the rear face of each of the photovoltaic cells 4. The positioning of the bypass diode 8 on the rear face 4b of the cell 4 is free.

In both cases of an IBC type technology and of a front / rear face polarity, for each photovoltaic cell 4, the bypass diode 8, as well as the connecting conductor 6 on the rear face of the photovoltaic cell 4 , are electrically isolated at least partially, in particular totally, from the surface of the photovoltaic cell 4 as a function of the different polarities in contact.

Furthermore, the invention also allows the use of a photovoltaic cell 4 as a bypass diode 8. This cell 4 is then connected in parallel and in opposite polarity on the rear face of the photovoltaic cell to be protected. It is then not necessary to have an entire cell as a bypass diode, the necessary area can be calculated according to the current to be passed and the power to be dissipated.

FIG. 5 illustrates this aspect for the case of the technology of photovoltaic cells 4 with front face and rear face contacts with a piece of cell used as a bypass diode.

Thus, depending on the number of connection points, two in this example of FIG. 5, it is possible to have several bypass diodes 8 in parallel per photovoltaic cell 4 on the condition of having a cut out of the cell used in as a bypass diode between each connection point.

The integration of the bypass diode on the rear face and in contact with the photovoltaic cell allows it to be used as a heat sink for the bypass diode in operation. The thermal coupling of these two components makes it possible to reduce the temperature of the diode.

Examples of specific achievements

We will now describe three specific embodiments A, B and C of photovoltaic modules 1 according to the invention.

The three examples A, B and C were made with the same encapsulation materials but with different photovoltaic cells or bypass diodes:

In the first example A, the photovoltaic cells comprise 4 photovoltaic cells of the IBC type with a thickness of the order of 160 μm each with a bypass diode of the incorporated diode type SBR12U45LH1, in the central position on the rear face of the cell.

In the second example B, the photovoltaic cells comprise 4 heterojunction cells based on amorphous and monocrystalline silicon with a thickness of the order of 115 μm each with two bypass diodes of the incorporated diode type SBR12U45LH1.

In the third example C, the photovoltaic cells comprise 4 homojunction cells of the PERT type (for “Passivated Emitter, Rear Totally-diffused” in English) based on monocrystalline silicon with a thickness of the order of 160 μm with a photovoltaic cell used as a bypass diode per cell.

For each example A, B and C, the photovoltaic module is implemented in a single step of hot lamination under vacuum, after joining of the bypass diodes.

For the three exemplary embodiments A, B and C, the integration of the bypass diodes on the rear face of the photovoltaic cells advantageously has no impact on the active surface of the photovoltaic module.

In addition, the integration of the bypass diodes does not introduce mechanical degradation of the photovoltaic cells during the module manufacturing process.

In addition, the operation of the bypass diodes was validated under shading with measurement of electrical performance and observation by infrared camera of the bypass diode heating.

The thermal coupling between a bypass diode and a photovoltaic cell has also been validated. Observation of the infrared images shows that the heating surface is in all cases very much greater than the surface of the diode used.

In addition, the accelerated aging behavior in thermal cycling enclosure according to the IEC 61215 terrestrial standard has also been demonstrated over more than 600 cycles with power losses very much less than 5% after 200 thermal cycles.

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

Claims (13)

1. Photovoltaic module (1) comprising: a first transparent layer (2) forming the front face of the photovoltaic module (1), intended to receive a light flux, - a plurality of photovoltaic cells (4) arranged side by side and electrically connected to each other by electrical contact elements (6) called connecting conductors (6), an encapsulating assembly (3) the plurality of photovoltaic cells (4b ·· a second layer (5), the encapsulating assembly (3) and the plurality of photovoltaic cells (4) being located between the first (2) and second (5) layers, characterized in that, for at least a plurality of cells photovoltaic (4), one or more bypass diodes (8) are secured to the rear face (4b) of each photovoltaic cell (4), and electrically connected to one or more photovoltaic cells (4) to be protected. 2. Module according to claim 1, characterized in that the photovoltaic cells (4) are electrically connected to each other by connecting conductors (6) respectively disposed against the front and rear faces of each of the photovoltaic cells (4). 3. Module according to claim 2, characterized in that, for each photovoltaic cell (4) of said at least a plurality of photovoltaic cells (4), the bypass diode or diodes (8) are positioned on a connecting conductor ( 6) of the rear face (4b) of the photovoltaic cell (4), this connecting conductor (6) allowing the electrical connection of the first polarity of the bypass diode (s) (8), and in that one or more additional connection conductors (9) are positioned on the bypass diode (s) (8), opposite to the connection conductor (6) on the rear face (4b) of the photovoltaic cell (4), this to these conductors additional link (9) allowing the electrical connection of the second polarity of the bypass diode (s) (8). 4. Module according to your claim 1, characterized in that the photovoltaic cells (4) are electrically connected to each other by connecting conductors (6) disposed against the rear face of each of the photovoltaic cells (4). 5. Module according to claim 4, characterized in that, for each photovoltaic cell (4) of said at least a plurality of photovoltaic cells (4), 10 the one or more bypass diodes (8) and the or the connecting conductors (6) on your back side d ^f a photovoltaic cell (4) are electrically insulated at least partially, in particular completely, to a surface of the photovoltaic cell (4). 6. Module according to claim 4 or 5, characterized in that, for Each photovoltaic cell (4) of said at least a plurality of photovoltaic cells (4), several bypass diodes (8) are secured to the rear face (4b) of each photovoltaic cell (4), and electrically connected to one or more several photovoltaic cells (4) to be protected, 20 7. Module according to any one of the preceding claims, characterized in that, for each photovoltaic cell (4) of said at least a plurality of photovoltaic cells (4), ta or the bypass diodes ( 8) outlet positioned at or near an edge of the photovoltaic cell (4). 8. Module according to any one of the preceding claims, characterized in that, among said plurality of photovoltaic cells (4), at least a portion, in particular your whole, of one or more photovoltaic cells (4) is used in as a bypass diode by connecting said portion in parallel and in opposite polarity on the rear face of one or more photovoltaic cells (4) to be protected. 9. Module according to any one of the preceding claims, characterized in that the first layer (2) comprises at least one polymer material and has a thickness of less than 50 μm, in that the second layer (5) comprises at least one composite material of the prepreg type based on polymer resin and fibers, and has a surface weight of less than 150 g / m ² , and in that the encapsulating assembly (3) has a maximum thickness of less than 150 μm. 10. Module according to claim 9, characterized in that said at least one composite material of the second layer (5) is a prepreg based on polymer resin and fibers, the polymer being chosen from polyester, epoxy and / or acrylic, and the fibers being chosen from glass, carbon and / or aramid fibers. IL Module according to claim 9 or 10, characterized in that said at least one polymeric material of the first layer (2) is chosen from: polycarbonate (PC), polymethyl methacryate (PMMA), polyethylene terephthalate ( PET), polyamide (PA), a fluorinated polymer, in particular polyvinyl fluoride (PVF) or polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), polytetrafluoroethylene (PTFE) ), Polychiorotrifiuoroethylene (PCTFE) and / or fluorinated ethylene propylene (FEP). 12. Module according to any one of the preceding claims, characterized in that it has a surface weight of less than 1 kg / m ² , in particular less than 800 g / m ² , in particular still less than 600 g / m ² . 13. A method of producing a photovoltaic module (1) according to any one of the preceding claims, characterized in that it comprises the step of hot lamination, at a temperature between 130 ^e C and 170 ° C, in particular of the order of 150 ^e C, and for a duration of the lamination cycle of at least 10 minutes, in particular between 10 and 20 minutes, of the constituent layers (2, 3, 4, 5) of the photovoltaic module (1 ). 14. Method according to claim 13, characterized in that, for said 5 at least a plurality of photovoltaic cells (4), the bypass diode (s) (8) are secured to the rear face (4b) of each photovoltaic cell (4) and electrically connected to one or more photovoltaic cells (4) to protect, before said hot lamination step.