Photovoltaic panel

Abstract

The present disclosure relates to a photovoltaic panel (1), having a front side (11), during operation being exposed to impacting radiation of the sun, and having a back side (12). From the front side (11) to the back side (12) the photovoltaic panel (1) comprises an optically transparent first pane (2), having a first front face (21) facing towards the front side (11) and comprising a first surface texture (22) and a first back face (23). An optically transparent second pane (3) is arranged behind the first pane (2) and has a second front face (31), interconnected to the first back face (23) of the first pane (2), and a second back face (32) comprising a second surface texture (33). An optically transparent layer (4), in which at least one solar cell (5) is at least partially embedded, is attached to the second surface texture (33) of the second back face (32) of the second pane (3). The second surface texture (33) is at least partially plated with at least one color active material (6) by which the visually apparent color at the front side (11) of the photovoltaic panel (1) is influenced and / or the optically transparent layer (4), between the solar cell (5) and the second surface texture (33), comprises at least one color active material (6) by which the visually apparent color at the front side (11) of the photovoltaic panel (1) is influenced. The present disclosure further relates to a facade element (100) or roof tile, comprising a photovoltaic panel (1).

Description

[0001] P29201 PCOO

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[0003] Photovoltaic Panel

[0004] FIELD OF THE DISCLOSURE

[0005] The present disclosure relates to a photovoltaic panel and a facade element or a roof tile.

[0006] BACKGROUND OF THE DISCLOSURE EP3757480B1, published on 30.12.2020 in the name of Fraunhofer Institute relates to a glazing unit for aesthetic design, which contains or consists of at least one polymer, wherein the polymer has a first structured surface to which a three-dimensional photonic structure is applied, which is configured to reflect a first subspectrum of incoming electromagnetic radiation and to transmit a second subspectrum of incoming electromagnetic radiation, the reflected portion corresponding to a higher harmonic and lying in the visible spectral range.

[0007] SUMMARY OF THE DISCLOSURE

[0008] Photovoltaics (PV) is the direct conversion of radiant energy into electrical energy using photovoltaic cells (i.e. solar cells). The underlying physical principle is the photoelectric effect. The direct current produced is usually converted to alternating current by an inverter and can be used in the building itself or, if more is produced than consumed, fed into the public grid. In addition to rooftop photovoltaic panels, solar panels can be integrated into facade construction and also generate electricity using photovoltaic facade panels.P29201 PCOO

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[0010] A solar facade or a solar roof is typically a large area of photovoltaic panels that use sunlight to generate electricity and / or heat. There are many reasons for choosing a solar facade or a solar roof. The most important - and most visible -difference between a solar facade and a conventional roof-mounted solar system is the tilt angle. The solar panels are mounted vertically on the building. Because they are mounted vertically on the house, the power output is more constant and less dependent on the angle of the sun's rays.

[0011] This means that solar facades on the east, west and south facades of a building comprising solar cells can produce electricity reliably in all seasons. There are even buildings that have successfully used photovoltaic panels on the north facade. However, the integration of photovoltaic panels into building facades is often unsatisfactory because of their appearance. Standard photovoltaic panels have a blue or black appearance due to the color of the photovoltaic cells embedded in them. This severely limits the freedom of architectural design.

[0012] In addition, facade-mounted photovoltaic panels are considered building-integrated photovoltaics and, as with rooftop installations, typically require a building inspectorate certificate of usability as a building product. This means that facademounted photovoltaic panels must demonstrate mechanical strength and stability, and must not splinter if damaged, so that falling parts do not endanger pedestrians passing by. Alternatively, the installation on the solar facade must be secured with additional measures such as stainless-steel mesh. However, this increases the cost of construction and compromises the aesthetics of the photovoltaic system.P29201 PCOO

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[0014] An objective of the present disclosure can therefore be seen in providing photovoltaic panels for facades and / or roofs that offer a high degree of design flexibility while meeting safety requirements.

[0015] The present disclosure relates to a photovoltaic panel, respectively a facade element or a roof tile comprising such a photovoltaic panel. The photovoltaic panels according to the disclosure usually comprise an improved arrangement of surface textures which interact and support each other.

[0016] The term surface texture as understood in the present context, refers to the topography of a surface, including all the small deviations from an ideal flat plane. It usually is defined by three primary characteristics that are surface roughness, waviness and lay. Surface roughness is directed to small, finely spaced deviations (e.g., peaks and valleys). According to Wikipedia, surface roughness, commonly shortened to roughness, is a measure of the total spaced surface irregularities. In engineering, this is what is usually meant by "surface finish." A lower number constitutes finer irregularities, i.e. , a smoother surface. Waviness is directed to larger, more widely spaced deviations. According to Wikipedia, waviness is the measure of surface irregularities with a spacing greater than that of surface roughness. Lay refers to the predominant direction or pattern of surface features.

[0017] Depending on the field of application, different surface textures are preferred. E.g. a glass pane may have on the outside a wave-like surface texture that features a regular, undulating pattern, where the surface rises and falls in a smooth, rhythmic manner. Alternatively or in addition, the wave-like surface texture may haveP29201 PCOO

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[0019] an irregular pattern. Irregular patterns create an unique optical effect, often distorting light and reflections while maintaining transparency. Alternatively or in addition, a sandblasted and / or etched surface may be appropriate that has a uniformly matte appearance, resulting from tiny, irregular pits and roughness across the surface. This texture diffuses light, offering a frosted, opaque finish that enhances privacy while reducing glare. While the wave-like texture emphasizes decorative aesthetics and pattern, the sandblasted or etched finish prioritizes functionality and a subdued, elegant look.

[0020] A photovoltaic panel according to the present disclosure typically has a front side, during operation being exposed to impacting radiation of the sun and having a back side. From the front side to the back side the photovoltaic panel typically comprises an optically transparent first pane, having a first front face facing towards the front side, which usually comprises a first surface texture and a first back face. The first pane is typically a glass pane, in particular a tempered glass pane. Good results can be achieved when the thickness of the first pane is from 1 mm to 20 mm, preferably 2 to 15 mm, more preferably 3 to 12 mm. This range for the first pane together with a second pane provides a good compromise between mechanical stability, especially in terms of impact resistance and weight. Depending on the size of the facade, the overall weight of a photovoltaic installation can add significant weight to the overall structure and a weight optimized design is therefore desired.

[0021] The photovoltaic panel typically further comprises an optically transparent second pane which is arranged behind the first pane and has a second front face, interconnected to the first back face of the first pane and a second back faceP29201 PCOO

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[0023] comprising a second surface texture. The first pane and the second pane may be transparent or semitransparent and firmly connected to one another by an optically transparent layer. Good results can be achieved when the first pane and the second pane consist of one and the same material, for example glass or a polymer material. The first and second pane may each be a rigid glass or plastic plate. The first and second front and / or first and second back face are usually formed by the respective material of the pane. At least the second surface texture can be made by an etching, rolling or blasting process.

[0024] Good results can be achieved when the first and second panes are interconnected to each other in a lamination process by an optically transparent layer (third layer) forming a laminated pane. The optically transparent layer is preferably a thermoplastic or cross-linking polymer intermediate layer, e.g. polyvinyl butyral (PVB) or ethylene vinyl acetate (EVA), which adheres the two panes to each other. Alternatively or in addition, adhesion by an adhesive is also possible e.g. by means of a transparent silicone or casting resin. The thickness of the optically transparent layer is preferably 0.1 to 5 mm, preferably 0.2 to 4 mm, more preferably 0.4 to 2 mm.

[0025] In an assembled position, the at least one solar cell is typically at least partially embedded in an optically transparent layer (first optically transparent layer), which is typically attached to the second back face of the second pane. The thickness of the at least one solar cell is preferably 0.01 to 3.0 mm, more preferably 0.05 to 2.0 mm, most preferably 0.1 to 1.0 mm. The at least one solar cell can at least be partially arranged between the first optically transparent layer being attached to the second back face and a second optically transparent layer beingP29201 PCOO

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[0027] attached to the third front face of a third pane e.g. forming or being part of a back wall of the photovoltaic panel. While the first and the third layers should be as transparent as possible to not negatively influence the efficiency of the photovoltaic panel, the second optically transparent layer may be optically less or not transparent as it primarily forms the rear end of the photovoltaic panel. It may be relevant for hiding the solar cells arranged in front of it. The second optically transparent layer is preferably tinted in a dark color, preferably black or blue. Alternatively or in addition, - if present - the third front face of the third pane can be coated, e.g. by printing or the like, by a layer of color to shade the at least one solar cell, with the color being preferably equal to the color of the at least one solar cell.

[0028] The second layer may be foreseen to hide a cable which interconnects the at least one solar cell to the outside. Good results can be achieved when the first and second optically transparent layer are at least partially fused to each other and the at least one solar cell is thereby at least partially embedded hermetically sealed therebetween. The optically transparent layers are preferably made from a transparent material having an optical refractive index which is close to the refractive index of the material of the first, respectively the second pane.

[0029] Usually a photovoltaic panel comprises several rows and columns of solar cells, i.e. photovoltaic cells, electrically interconnected to each other. For visual appearance and improvement of efficiency the solar cells are preferably wired to each other on the back of the solar cells in form of back contacts. Back contact solar cells are characterized by the fact that both electrical polarities of the cell, n-con-tact and p-contact, are arranged on the rear side of the photovoltaic cells. ByP29201 PCOO

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[0031] relocating all electrical contacts to the back face of the solar cells, the light-facing surface remains free of metallization, which reduces optical shading losses and improves both efficiency and visual uniformity.

[0032] A practical challenge of this architecture is the reliable series interconnection of multiple back-contact cells without introducing complex crossovers or visible wiring. Good results can be achieved when the cells are wired according to the disclosure of W02023006632A1 of the same applicant, which describes a method and a device for wiring back-contact solar cells by arranging adjacent cells and electrically interconnecting them on their rear faces using elongated wiring elements placed in laterally offset positions. The document illustrates how back-con-tact cells can be assembled into strings and modules in an efficient, automated, and aesthetically unobtrusive manner, thereby enabling industrial-scale production of high-efficiency back-contact photovoltaic modules. In a further variation, back-contacted photovoltaic cells are implemented that are arranged in front of a PCB to which they are interconnected. A further layer of encapsulating or adhesive can be arranged between the photovoltaic cell and the PCB. In any case, the at least one solar cell is preferably electrically connected by at least one cable, which extends through an opening in the third pane out of the photo-voltaic panel.

[0033] For being able to modify the visual impression of the solar panel for a viewer’s eye, the solar panel usually comprises at least one color active material. The second back face can comprise the second surface texture with said second surface texture being at least partially plated with at least one color active material. The combination of the at least one color active material with the second surface texture can reduce or eliminate the angle dependence of the color impression.P29201 PCOO

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[0035] By applying the at least one color active material on the second back face with a second surface texture, the photovoltaic panel exhibits the identical color impression from several or all viewing angles.

[0036] In a preferred variation, the photovoltaic panel according to the disclosure has a front side that during operation is exposed to impacting radiation of the sun. It further has a back side in a mounted position facing away from the sun. The photovoltaic panel comprises, from the front side to the back side, an optically transparent first pane. The optically transparent first pane has a first front face facing towards the front side and comprising a first surface texture. The optically transparent first pane further has a first back face. An optically transparent second pane is arranged behind the first pane and has a second front face, interconnected to the first back face of the first pane. The optically transparent second pane has a second back face comprising a second surface texture. An optically transparent layer is arranged behind the optically transparent second pane in which at least one solar cell is at least partially embedded. The optically transparent layer is attached to the second surface texture of the second back face of the second pane. It usually reduces the roughness of the second surface texture by filling it up. Depending on the field of application, the second surface texture is at least partially plated with at least one color active material by which the visually apparent color at the front side of the photovoltaic panel is influenced. Alternatively or in addition, the optically transparent layer between the solar cell and the second surface texture comprises at least one color active material by which the visually apparent color at the front side of the photovoltaic panel is influenced.P29201 PCOO

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[0038] By combining a first pane, having a first front face facing towards the front side and comprising a first surface texture with a second pane having a second back face comprising a second surface texture, a laminated unit is created, providing both a degree of design flexibility as well as a high structural integrity. The first pane is preferably interconnected to the second pane by an optically transparent layer being arranged between the first back face and the second front face. The first pane with the first surface texture is typically arranged as the outermost layer of the photovoltaic panel, facing the environment. The second pane may serve as an intermediate layer, being arranged between the first pane and a third pane, with the third pane preferably being a substrate or a third glass or polymeric pane. With the first pane and the second pane being laminated together, the photovoltaic panel usually achieves a sufficient mechanical stability for application in a facade element. While the second surface texture is typically used as substrate for the at least one color active material, the first surface texture is used to influence the efficiency of the photovoltaic panel and its aesthetic impression of the overall photovoltaic panel and / or designed to provide a dirt-repellent surface and / or to influence the color impression. Depending on the first surface texture, the color impression can be intensified or weakened.

[0039] Good results can be achieved when the first surface texture comprises first indentations or first protrusions having a first height and / or the second surface texture comprises second indentations or second protrusions having a second height, wherein the first height of the first indentations or protrusions is larger than the second height of the second indentations or protrusions. The first surface texture of the first front face may have a regular texture and / or the second surfaceP29201 PCOO

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[0041] texture of the second back face may have a random texture. Alternatively or in addition, the first back face and / or the second front face may comprise a texture.

[0042] The second front face of the second pane can have a third surface texture and / or the second surface texture of the second back face may have a regular structure. Good results can be achieved, when the second back face has a regular structure in form of a pyramidal structure, being arranged in a matrix configuration. With the objective to achieve an angle independent visual impression, when looking at the front side of the photovoltaic panel, the regular structure may be arranged in a matrix configuration, comprising rows and columns. Pyramidal protrusions or indentations, preferably with pyramids, which are axially symmetrical to the pyramid height, i.e. the vertical line that runs through the pyramid apex and is arranged perpendicular with respect to the second back face, can be arranged in rows and columns. The rows and columns can be arranged with equal spacing between the individual rows and columns. The inclination of the side surfaces in relation to the base surface is preferably between 20 degrees and 70 degrees, particularly preferred between 30 degrees and 60 degrees. Good results can be achieved, when the first and / or second surface texture extends over the entire first front face of the first pane and / or over the entire surface of the second back face of the second pane, so that the entire facade element has a homogeneous color.

[0043] The second front face of the second pane can have a third surface texture. The third surface texture may be regular or irregular. Good results can be achieved when the third surface texture comprises third indentations or third protrusions, having a third height. The first height of the first indentations or protrusions isP29201 PCOO

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[0045] preferably larger than the third height of the third indentations or third protrusions and the third height is preferably larger than the second height of the second indentations or protrusions. This gradation of height and thereby surface roughness has advantages regarding the visual impression, mechanical integrity and the lamination. By having a comparatively small first surface texture, a uniform color gradient can be achieved, by keeping by the even color impression over a wide vision angle onto the front side of the photovoltaic panel. The second surface texture is preferably comparatively large, minimizing the notch effect and thereby limiting tension peaks which might cause the panel to mechanically fail under load. A third surface texture with third indentations or third protrusions, with a height being smaller than the first indentations or first protrusions but larger than the second indentations or second protrusions allows for a good compromise in increasing the surface area for the optically transparent layer without impacting the visual properties of the overall panel.

[0046] The at least one color active material may be configured to reflect light within a predetermined wavelength range, and / or configured to absorb light within a predetermined wavelength range. The at least one color active material may be an optical interference layer. The at least one optical interference layer is used to reflect light within a predetermined or predeterminable wavelength range. The at least one optical interference layer is preferably arranged directly, i.e. without any further intermediate layer, on the back face of the second pane. The at least one optical interference layer can be formed in one or more layers, i.e. can have one or more refractive layers. The optical interference layer serves to produce the color impression of the photovoltaic panel and thus of the facade element. The optical interference layer is designed such that constructive or destructiveP29201 PCOO

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[0048] interference of light reflected at the various boundary surfaces of the optical interference layer is possible. The color of the facade element results from the interference of the light reflected at the interfaces of the optical interference layer. When illuminated with (white) light, in particular sunlight, the optical interference layer acts as a color filter to produce a homogeneous color.

[0049] The at least one optical interference layer may include and particularly consist of one or more refractive layers. A refractive layer typically consists of a homogeneous material (composition) and exhibits a homogeneous (same) refractive index particularly across the layer thickness. When the optical interference layer contains several refractive layers, at least two refractive layers consist of a different material and have a different refractive index. Advantageously, at least one refractive layer has a refractive index n of greater than 1.7, preferably greater than 2.0 and particularly preferably greater than 2.3. In principle, the greater the refractive index, the lower the angular dependence of the reflected light, so that the angular dependence of the color impression can be further reduced.

[0050] The at least one color active material can comprise a first layer and at least one second layer with the material of the first layer and the at least one second layer being selected from the group of ZrO2, Nb2O5, TiO2, Si3N4, SiO2, AIN, SnO2, AI2 03, HfO2, Ta2O5, SiOxNy, AIOxNy, ZnO, Bi2O3, ln2O3, WO3 and MoO3. Advantageously, the optical interference layer contains at least one compound selected from TiOx, ZrOx, SiC and Si3N4, i.e. non-absorbing materials with a higher refractive index. If the optical interference layer has two, three or more layers, the optical interference layer preferably contains at least one compoundP29201 PCOO

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[0052] selected from MgF2, AI2O3, SiO2 and silicon oxynitride. These are non-absorbing compounds with a relatively low refractive index.

[0053] The color active material can alternatively or in addition comprise photonically active nanoparticles. A substrate my be applied to the second back face and comprise a sacrificial-release layer onto which a photonically active stack of layers is arranged. The sacrificial-release layer can be applied by detaching or releasing the sacrificial-release layer, laden with the photonically active stack of layers from a solid substrate and subjecting the detached sacrificial-release layer to a controlled crushing process to transform the photonically active stack of layers into nanoparticles. Preferably the photonically active stack of layers comprises at least a first layer having a first refractive index, a second layer having a second refractive index arranged adjacent to the first layer, wherein the first refractive index is lower than the second refractive index and a third layer having a third refractive index arranged adjacent to the second layer, wherein the third refractive index is lower than the second refractive index. Four or more layers are possible and in some cases even preferred. The at least one layer of the photonically active stack can be applied by a sputtering process, however other processes such as spray coating, inkjet printing, roll-to-roll coating, dip-coating, screen printing and aerosol jet printing, or a combination thereof are possible as well.

[0054] Alternatively or in addition, the at least one color active material may comprise colored particles, in particular colored inorganic particles. The optically transparent layer between the at least one solar cell and the second surface texture of the second back face may comprise colored particles, in particular coloredP29201 PCOO

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[0056] inorganic particles. The colored particles may be configured to absorb light at a certain spectrum. The colored particles may have a color different to the solar cell and / or the third pane. The colored particles may be in form of an enamel layer, in particular a glass enamel layer. For example, particles dispersed in liquid may be applied to the translucent pane and sintered to create the colorant layer. As another example, the colored particles may be manufactured from a liquid using an UV-hardening. The colored particles may also be embedded in a glass layer.

[0057] The colored particles may be embedded in a colorant layer. The colorant layer may be produced by manufacturing from two components, for example pigments and glass particles. The base material for manufacturing the colorant layer may be some powder or powder in a solvent or liquid medium. The powder can be baked onto the second back face onto the second surface texture. The colorant layer may be configured as a continuous layer. Manufacturing of a continuous layer may be particular easy and cost-effective. For example, the colorant layer may also be formed by discrete sections of the second back face. A resolution may be sufficiently high so that the colorant layer appears continuous from sufficiently far away, such as from 0,5 m, 1,0 m, 2,0 m or 5,0 m away. The discrete sections of the colorant layer may be completely opaque. Due to a spacing between the discrete sections, nevertheless light may pass through the colorant layer

[0058] The photovoltaic panel may further comprise a third pane being arranged behind the second pane and having a third front face, interconnected to the second back face, in particular by the optically transparent layer in which the at least one solar cell is at least partially embedded. The thickness of the back pane is preferablyP29201 PCOO

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[0060] 0.1 mm to 20 mm, more preferably 0.5 mm to 15 mm, most preferably 1 mm to 12 mm. The third front face of the third pane can have a coating and / or the third pane may be as dark as or even darker than the at least one solar cell. The color of the third pane or the coating may preferably be equal to the color of the at least one solar cell. This allows for a higher efficiency of panel and improves the visual impression. With the color being equal, the at least one solar cell cannot be seen from the outside when looking at the panel.

[0061] The present disclosure further relates to a method for manufacturing a photovoltaic panel, in particular a photovoltaic panel as described above. The method relates to a manufacturing a photovoltaic panel, having a front side, during operation being exposed to impacting radiation of the sun, and having a back side. The method typically comprises the steps of:

[0062] • Providing an optically transparent first pane which has a first front face facing towards the front side and comprising a first surface texture and has a first back face;

[0063] • Arranging an optically transparent second pane, having a second front face and a second back face comprising a second surface texture, behind the first pane by interconnecting the second front face to the first back face of the first pane;

[0064] • Arranging an optically transparent layer in which at least one solar cell is at least partially embedded, by attaching said optically transparent layer to the second back face of the second pane.P29201 PCOO

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[0066] The second surface texture of the second back face may be plated with at least one color active material before the optically transparent layer, in which at least one solar cell is typically at least partially embedded, may be attached to the second back face of the second pane.

[0067] The optically transparent layer can comprise colored particles, in particular colored inorganic particles. The optically transparent layer may be in form of a liquid, which is applied to the second surface texture of the second back face before the at least one solar cell is at least partially embedded in the optically transparent layer.

[0068] Alternatively, the optically transparent layer may be in form of a sheet which is applied to the second surface texture of the second back face with the at least one solar cell preferably being at least partially embedded in the optically transparent layer.

[0069] The optically transparent layer may be molten and at least partially deformed into the second surface texture of the second back face.

[0070] After arranging the optically transparent layer, with the at least one solar cell being at least partially embedded therein, is attached to the second back face of the second pane, a third pane may be arranged behind the second pane.

[0071] The third pane can via a third front face be interconnected to the second back face by the optically transparent layer, in which the at least one solar cell is at least partially embedded, or the optically transparent layer can be attached to the second back face and an optically transparent layer may be attached to a thirdP29201 PCOO

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[0073] front face of the third pane, whereby the two optically transparent layers are at least partially fused to each other. The two optically transparent layers may be fused through the at least one solar cell, thereby forming bridges across voids in the at least one solar cell.

[0074] The first pane can be interconnected to the second pane by an optically transparent layer being arranged between the first back face and the second front face and can have a refractive index which is higher than the refractive index of the first pane and the second pane.

[0075] The present disclosure further relates to a facade element or roof tile, comprising a photovoltaic panel as described above noted. The facade element or roof tile may comprise first fastening means to fasten the facade element to second fastening means arranged at a facade. The first fastening means can be configured to adjust the facade element with respect to the facade.

[0076] It is to be understood that both the foregoing general description and the following detailed description present embodiments, and are intended to provide an overview or framework for understanding the nature and character of the disclosure. The accompanying drawings are included to provide a further understanding, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments, and together with the description serve to explain the principles and operation of the concepts disclosed.P29201 PC00

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[0078] BRIEF DESCRIPTION OF THE DRAWINGS

[0079] The herein described disclosure will be more fully understood from the detailed description given herein below and the accompanying drawings which should not be considered limiting to the disclosure described in the appended claims. The drawings are showing:

[0080] Fig. 1 an exploded view of a first embodiment of a facade element;

[0081] Fig. 2 a perspective view onto a first embodiment of the photovoltaic panel being part of the facade element according to Fig. 1 ;

[0082] Fig. 3 a perspective view onto the first embodiment of the photovoltaic panel according to Fig. 2 with the first and second pane being unfolded;

[0083] Fig. 4 a lateral view onto the first embodiment of the photovoltaic panel according to Fig. 3;

[0084] Fig. 5 a perspective view onto a second embodiment of the photovoltaic panel;

[0085] Fig. 6 a perspective view onto a third embodiment of the photovoltaic panel;

[0086] Fig. 7 a lateral view onto a fourth embodiment of the photovoltaic panel.P29201 PCOO

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[0088] DESCRIPTION OF THE EMBODIMENTS

[0089] Reference will now be made in detail to certain embodiments, examples of which are illustrated in the accompanying drawings, in which some, but not all features are shown. Indeed, embodiments disclosed herein may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Whenever possible, reference numbers will be used to refer to like components or parts.

[0090] Figure 1 shows a facade element 100, comprising a photovoltaic panel 1 as described below noted with respect to Figures 2 to 7. The facade element 100 comprises first fastening means 101 to fasten the facade element 100 to second fastening means arranged at a fagade (not shown in detail). The first fastening means 101 are configured to adjust the facade element 100 with respect to the facade.

[0091] The facade element 100 comprises an embodiment of the photovoltaic panel 1. The shown photovoltaic panel 1 has a front side 11 which during operation is exposed to impacting radiation of the sun and has a back side 12 being opposite to the front side 11. The photovoltaic panel 1 is assembled by providing an optically transparent first pane 2 which has a first front face 21 facing towards the front side 11 and comprising a first surface texture 22 and has a first back face 23. An optically transparent second pane 3 having a second front face 31 and a second back face 32 comprising a second surface texture is arranged behind the first pane 2 by interconnecting the second front face 31 to the first back face 23 of the first pane 2. The first pane 2 and second pane 3 are connected to eachP29201 PCOO

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[0093] other by a first optically transparent layer 4, which is in the shown variation in form of a transparent foil. The first pane 2 and the second pane 3 are laminated by melting the optically transparent layer 4 and baking the first pane 2 and second pane 3 together. In the optically transparent layer 4 a solar cell 5 is embedded and is attached to the second back face 32 of the second pane 3.

[0094] For increasing the structural integrity of the shown photovoltaic panel 1 , a third pane 7 is arranged behind the first optically transparent layer 4 in which the solar cell 5 is embedded. The second pane 2 and the third pane 3 are also laminated together, thereby sandwiching the solar cell 5 between them. The third front face 71 of the third pane 7 is baked to the second back face 32 of the second pane 3 by the optically transparent layer 4 in which the solar cell 5 is embedded. The at least one solar cell 5 is electrically connected by at least one cable 10, which extends through an opening 11 in the third pane 7 out of the photovoltaic panel 1. The optically transparent layer 4 is therefore molten and partially deformed into the second surface texture of the second back face 32. The second surface texture of the second back face 32 is plated with color active materials before the optically transparent layer 4 and the therein embedded solar cell 5 is attached to the second back face 32 of the second pane 3. For increasing the visual color impression of the color active materials 6, the third front face 71 of the shown embodiment is coated with a black coating 72, e.g. by printing.

[0095] The optically transparent first pane 2 has a first front face 21 facing towards the front side 11 and comprising a first surface texture 22. The optically transparent first pane 2 further has a first back face 23. An optically transparent second pane 3 is arranged behind the first pane 2 and is having a second front face 31,P29201 PCOO

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[0097] interconnected to the first back face 23 of the first pane 2. The optically transparent second pane 3 has a second back face 32 comprising a second surface texture 33. An optically transparent layer 4 is arranged behind the optically transparent second pane 3 in which at least one solar cell 5 is at least partially embedded. The optically transparent layer 4 is attached to the second surface texture 33 of the second back face 32 of the second pane 3. It usually reduces the roughness of the second surface texture by filling it up. Depending on the field of application, the second surface texture 33 is at least partially plated with at least one color active material 6 by which the visually apparent color at the front side 11 of the photovoltaic panel 1 is influenced. Alternatively or in addition, the optically transparent layer 4 between the solar cell 5 and the second surface texture 33 comprises at least one color active material 6 by which the visually apparent color at the front side 11 of the photovoltaic panel 1 is influenced.

[0098] Figure 2 shows a perspective view onto the front side 11 of the first embodiment of the photovoltaic panel 1 according to Fig. 1. The shown front side 11 which during operation is exposed to impacting radiation of the sun is defined by the first front face 21 of the first pane 2. From the front side 11 to the back side 12 the photovoltaic panel 1 comprises an optically transparent first pane 2, having a first front face 21 facing towards the front side 11 and comprises a first surface texture 22 and a first back face 23. The shown first pane 2 is a glass pane made from a tempered glass. The thickness of the first pane 2 is between 3 mm to 12 mm.

[0099] Interconnected to the first pane 2 is a second pane 3 having a second back face 31 comprising a second surface texture. The laminated unit provides a degree ofP29201 PCOO

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[0101] design flexibility as well as a high structural integrity. The shown first pane 2 is interconnected to the second pane 3 by the third optically transparent layer 9 being arranged between the first back face 23 and the second front face 31. The first pane 2 with the first surface texture 22 is typically arranged as the outermost layer of the photovoltaic panel 1 , facing the environment. The second pane 3 serves as an intermediate layer, being arranged between the first pane 2 and the third pane 7, with the third pane 71 a third glass or polymeric pane. With the first pane 2 and the second pane 3 being laminated together, the photovoltaic panel already has sufficient mechanical stability.

[0102] Figure 3 shows a perspective view onto the first embodiment of the photovoltaic panel 1 according to Fig. 2 with the first pane 2 and second pane 3 being unfolded. As can be obtained, the shown second pane 3 comprises a second surface texture 33 on the second back face 32. The shown second surface texture 33 is in form of a pyramidal structure made by a rolling process. The second surface texture 33 is used as substrate for the color active material 6. The second back face 32 has a regular structure in form of a pyramidal structure, being arranged in a matrix configuration. The regular structure is arranged in a matrix configuration, comprising rows R and columns C.

[0103] As can be seen best in Figure 4, the first surface texture 22 comprises first indentations or first protrusions 24 having a first height hi and the second surface texture 33 comprises second indentations or second protrusions 34 having a second height h2. In the shown embodiment, the first height hi of the first indentations or protrusions 24 is larger than the second height h2 of the second indentations or protrusions 34 (not shown to scale). The first surface texture 22 of theP29201 PCOO

[0104] 23 / 32

[0105] first front face 21 has a regular texture with a segment spacing which is significantly larger than the segment spacing of the second surface texture 33 of the second back face 32.

[0106] Figure 5 shows an alternative embodiment in a perspective view onto the photovoltaic panel 1. The shown embodiment comprises a first pane 2 and a second pane 3 which are made in an integral manner. The first front face 21 and the second back face 32 comprise a texture each. The first 22 and second 33 surface texture extend over the entire first front face 21 of the first pane 2 and over the entire surface of the second back face 32 of the second pane 3, so that the entire facade element has a homogeneous color impression.

[0107] Figure 6 shows a third embodiment of the photovoltaic panel 1 , being similar to the first embodiment and comprises a first pane 2, second pane 3 and third pane 7. The second pane 2 and the third pane 3 are also laminated together, thereby sandwiching the solar cell between them. The third front face 71 of the third pane 7 is baked to the second back face 32 of the second pane 3 by the optically transparent layer 4 in which the solar cell is embedded. The first optically transparent layer 4 is attached to the second back face 32 and a second optically transparent layer 8 is attached to the third front face 71 of the third pane 7. The first 4 and second 8 optically transparent layers are at least partially fused to each other. The two optically transparent layers 4, 8 are fused through the solar cell 5, thereby forming bridges across voids in the solar cell 5.

[0108] Figure 7 shows a fourth embodiment, wherein the first surface texture 22 comprises first indentations or first protrusions 24 having a first height hi and theP29201 PC00

[0109] 24 / 32

[0110] second surface texture 33 comprises second indentations or second protrusions 34 having a second height h2. In the shown embodiment, the first height hi of the first indentations or protrusions 24 is larger than the second height h2 of the second indentations or protrusions 34. The first surface texture 22 of the first front face 21 has a regular texture with a segment spacing which is significantly larger than the segment spacing of the second surface texture 33 of the second back face 32. The second front face 31 of the second pane 3 has a third surface texture 35. The shown third surface texture 35 is regular and comprises third protrusions 36, having a third height h3. The first height hi of the first protrusions 24 is larger than the third height h3 of the third protrusions 36 and the third height h3 is larger than the second height h2 of the second protrusions 34 (not shown to scale). This gradation of height and thereby surface roughness is advantages regarding the visual impression, mechanical integrity and the lamination.

[0111] Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the Spirit and scope of the disclosure.P29201 PCOO

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[0113] LIST OF DESIGNATIONS

[0114] 1 Photovoltaic panel 5 Solar cell

[0115] 11 Front side 6 Color active material 12 Back side 61 Particles

[0116] 2 First pane 25 7 Third pane

[0117] 21 First front face 71 Third front face

[0118] 22 First surface texture 72 Coating

[0119] 23 First back face 8 Second optically transpar24 First Indentations / protru- ent layer

[0120] sions 30 9 Third optically transparent 3 Second pane layer

[0121] 31 Second front face 10 Cable

[0122] 32 Second back face 11 Opening

[0123] 33 Second surface texture hi First height

[0124] 34 Second indentations / pro- 35 h2 Second height trusions R Row

[0125] 35 Third surface texture C Column

[0126] 36 Third indentations / protru- 100 Facade element sions 101 First fastening means 4 First optically transparent 40

[0127] layer

Claims

1. P29201 PC0026 / 32PATENT CLAIMS1. A photovoltaic panel (1 ) having a front side (11 ), during operation being exposed to impacting radiation of the sun, and having a back side (12), wherein from the front side (11 ) to the back side (12) the photovoltaic panel (1) comprises:a. an optically transparent first pane (2) havingi. a first front face (21 ) facing towards the front side (11 ) and comprising a first surface texture (22) andii. a first back face (23);b. an optically transparent second pane (3) being arranged behind the first pane (2) and havingi. a second front face (31 ), interconnected to the first back face (23) of the first pane (2), andii. a second back face (32) comprising a second surface texture (33);c. an optically transparent layer (4) in which at least one solar cell (5) is at least partially embedded, said optically transparent layer (4) being attached to the second surface texture (33) of the second back face (32) of the second pane (3); whereinP29201 PCOO27 / 32i. the second surface texture (33) is at least partially plated with at least one color active material (6) by which the visually apparent color at the front side (11) of the photovoltaic panel (1) is influenced and / orii. the optically transparent layer (4) between the solar cell (5) and the second surface texture (33) comprises at least one color active material (6) by which the visually apparent color at the front side (11) of the photovoltaic panel (1) is influenced.

2. The photovoltaic panel (1) according to claim 1, wherein the at least one color active material (6)a. is configured to reflect light within a predetermined wavelength range, and / orb. configured to absorb light within a predetermined wavelength range.

3. The photovoltaic panel (1) according to claim 2, whereina. the color active material (6) being selected from at least one out of the group of the following materials ZrO2, Nb2O5, TiO2, Si3N4, SiO2, AIN, SnO2, AI2 03, HfO2, Ta2O5, SiOxNy, AIOxNy, ZnO, Bi2O3, ln2O3, W03 and MoO3 or a combination thereof and / orP29201 PCOO28 / 32b. the color active material (6) comprises colored particles (61 ), in particular colored inorganic particles.

4. The photovoltaic panel (1 ) according to at least one of the preceding claims, wherein the first surface texture (22) comprises first indentations or first protrusions (24) having a first height (hi ) and / or the second surface texture (33) comprises second indentations or second protrusions (34) having a second height (h2), wherein the first height (hi) of the first indentations or protrusions (24) is larger than the second height (h2) of the second indentations or protrusions (34).

5. The photovoltaic panel (1 ) according to at least one of the preceding claims, wherein the first surface texture (22) of the first front face (21 ) has a regular texture and / or the second surface texture (33) of the second back face (32) has a random texture.

6. The photovoltaic panel (1) according to at least one of claims 1 to 4, wherein the second front face (31) has a third surface texture (35) and / or the second surface texture (33) of the second back face (32) has a regular structure, preferably in form of a pyramidal structure being arranged in a matrix structure.

7. The photovoltaic panel (1) according to claims 4 and 6, wherein the third surface texture (35) comprises third indentations or third protrusions (36) having a third height (h3), wherein the first height (hi) of the first indentations or protrusions (24) is larger than the third height (h3) of the thirdP29201 PCOO29 / 32indentations or third protrusions (36) and the third height (h3) is larger than the second height (h2) of the second indentations or protrusions (34).

8. The photovoltaic panel (1 ) according to at least one of the preceding claims, wherein the photovoltaic panel (1) further comprises a third pane (7) being arranged behind the second pane (3) and having a third front face (71), interconnected to the second back face (32), in particular at least partially by the optically transparent layer (4) in which the at least one solar cell (5) is at least partially embedded.

9. The photovoltaic panel (1) according to claim 8, wherein the third pane (7) is at least partially colored and / or the third front face (71) of the third pane (7) is coated by a layer of color to shade the at least one solar cell (5), with the color being preferably equal to the color of the at least one solar cell (5).

10. The photovoltaic panel (1 ) according to at least one of the preceding claims, wherein the at least one solar cell (5) is at least partially arranged between the optically transparent layer (4) being attached to the second back face (32) and an optically transparent layer (8) being attached to the third front face (71) of the third pane (7), with the optically transparent layer (8) being attached to the third front face (71) preferably being colored with the color being equal to the color of the at least one solar cell (5).

11. The photovoltaic panel (1) according to claim 10, wherein the optically transparent layer (4) attached to the second back face (32) and the optically transparent layer (8) attached to the third front face (71 ) are at least partiallyP29201 PCOO30 / 32fused with each other around the at least one solar cell (5) arranged therebetween.

12. The photovoltaic panel (1) according to at least one of claims 8 to 11, wherein the at least one solar cell (5) is electrically connected by at least one cable (10), which at least one cable (10) extends through an opening (11 ) in the third pane (7) out of the photovoltaic panel (1 ).

13. The photovoltaic panel (1) according to at least one of claims 8 to 12, wherein the comprises at least one row and / or column of solar cell (5) that are electrically interconnected to each other, in particular wherein the solar cells (5) are of the type of back-contact solar cells (5) no visible wiring at the front of the solar cell (5), in particular wherein the solar cells (5) are arranged in front of a printed circuit board to which they are interconnected, wherein the wiring is arranged in the printed circuit board.

14. The photovoltaic panel (1 ) according to at least one of the preceding claims, wherein the first pane (2) is interconnected to the second pane (3) by an optically transparent layer (9) being arranged between the first back face (23) and the second front face (31 ).

15. Facade element (100) or roof tile comprising a photovoltaic panel (1) according to any of the preceding claims.

16. The facade element (100) or roof tile according to claim 14, wherein the facade element (100) comprises first fastening means (101) to fasten theP29201 PC0031 / 32facade element (100) to second fastening means (102) arranged at a facade.

17. The fagade element (100) or roof tile according to claim 15, wherein the first fastening means (101) are configured to adjust the facade element (100) with respect to the facade.

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