Solar element for windows or façades

Abstract

The invention relates to a solar element (1) having a body (10), which is composed of a transparent material, in particular a homogeneous transparent material, into which a multiplicity of photovoltaic lamellae (11), in particular non-transparent photovoltaic lamellae, for producing electric energy are embedded slanted at a lamella angle (ẟ) and / or integrated.

Description

[0001] Solar element for windows or facades

[0002] The invention relates to solar elements for windows and / or facades for building-integrated photovoltaics. The integration of solar-active surfaces into the building envelope is key to the development of climate-neutral buildings. Especially in large cities, where electricity demand is particularly high, the vast building surfaces offer plenty of space for photovoltaics. The sun, which is lower in the east and west, and in the south in winter, is used more optimally for energy generation. Compared to photovoltaic parks and rooftop systems, the modules deliver their peak values ​​not only at midday, but more widely throughout the day. Energy storage systems can therefore be designed smaller. Last but not least, the large-scale solar surfaces open up new aesthetic design possibilities for architects.

[0003] Modern architecture often features large windows and glass facades in everything from urban buildings and office buildings to private homes. Today, glass surfaces make up a large portion of the building envelope. Sunlight and daylight radiate through the windows into the rooms during the day, but thermal radiation also causes significant heat input into the rooms, especially in hotter regions of the world and during the hotter seasons. To keep rooms at a comfortable temperature, they are often air-conditioned (cooled). The more heat radiation, the more energy is required for cooling.

[0004] Direct sunlight through window elements also leads to unpleasant glare, which is particularly disruptive for office workplaces. Blinds, roller shades, or curtains are often used, either inside or outside the windows, to block glare from direct sunlight and reduce heat gain. This often darkens rooms to such an extent that artificial light must be switched on, thus consuming additional energy. Windows equipped with full-surface, partially transparent photovoltaic layers are known in the art. These photovoltaic layers can be made of various materials such as amorphous silicon (a-Si), cadmium telluride (CdTe), copper indium gallium diselenide (CIGS), or organic photovoltaic layers. Such windows typically achieve a transparency of 40–60%.However, a considerable proportion of the incident light is lost for photovoltaic generation, which leads to a comparatively low efficiency of these solutions.

[0005] Furthermore, transparent photovoltaic elements are known in the prior art that are largely transparent, especially in the visible spectral range, but absorb the infrared and / or UV portion of the incident light. This wavelength-selective approach is described in publication WO 2021 / 034713. However, with these photovoltaic elements, the entire visible portion of the incident light is lost for photovoltaic generation.

[0006] AT 512 678 A1 discloses a window and / or facade element with many photovoltaic elements, wherein the window and / or facade element is designed as a multi-layer composite panel having a smooth outer surface on both sides with two panes laminated to one another by means of light-transparent material, of which at least the light incidence pane has a structured surface only towards the laminating material binding the panes to one another.

[0007] The object of the invention is to create energy-efficient solar elements for windows and facades for building-integrated photovoltaics. On windows, the solar elements should shade the heat input and glare from direct sunlight, ensure clear visibility and plenty of daylight, and convert the shaded sunlight into solar power with high energy efficiency.

[0008] The above object is achieved by a solar element according to claim 1, wherein the solar element comprises a body made of a, in particular homogeneous, transparent material, into which a plurality of, in particular non-transparent, photovoltaic slats for generating electrical energy are embedded and / or integrated at an angle by which the slats are inclined. A solar element within the meaning of this disclosure is in particular planar. A solar element within the meaning of this disclosure is in particular a layer or a film or a plate. A solar element within the meaning of this disclosure has in particular a designated inner surface, a designated outer surface, a designated upper side and a designated underside. It can be provided that the designated inner surface and the designated outer surface run parallel or substantially parallel to one another.A designated inner surface of the solar element within the meaning of this disclosure is a space delimited by the solar element or a surface facing a facade structure.

[0009] A photovoltaic lamella can be designed as a micro-lamella and / or a thin layer with an approximately cuboid shape with a photovoltaic lamella length L, a photovoltaic lamella width w and a photovoltaic lamella layer thickness t.

[0010] An inclined photovoltaic slat within the meaning of this disclosure forms an incline relative to one or more of the surface normals of the intended outer surface of the solar element and / or the surface normals of the intended inner surface of the solar element. This incline runs downwards from the inner surface of the solar element ("top") toward the intended outer surface of the solar element ("bottom"). The edge of the approximately cuboid-shaped photovoltaic slat with edge length w encloses the slat angle by which the respective photovoltaic slat is inclined, along with the one or more of the surface normals of the intended outer surface and / or the surface normals of the intended inner surface of the solar element.

[0011] For the purposes of this disclosure, a photovoltaic slat surface is defined by the photovoltaic slat length L and the photovoltaic slat width w, or as the product of the photovoltaic slat length L and the photovoltaic slat width w. According to one embodiment, it is provided that the photovoltaic slat surfaces do not run, are not arranged, or are not aligned parallel to the intended inner surface and / or are not arranged or aligned parallel to the intended outer surface. The photovoltaic slats are arranged three-dimensionally in the depth of the planar solar element, in particular with a defined angular position. Alternatively, a photovoltaic slat can also be formed not as an approximately cuboid-shaped, thin layer, but as a curved or otherwise three-dimensionally shaped thin layer.

[0012] Transparent, as used in this disclosure, can optionally mean permeable to light with wavelengths in the visible range. Wavelengths in the visible range are the wavelengths that most people can perceive with the naked eye. Transparent, as used in this disclosure, can optionally mean permeable to light with a wavelength in the infrared range. Transparent, as used in this disclosure, can optionally mean permeable to light with a wavelength in the ultraviolet range.

[0013] Non-transparent within the meaning of this disclosure can optionally mean opaque to light in the visible range. Non-transparent within the meaning of this disclosure can optionally mean opaque to light with a wavelength in the infrared range. Non-transparent within the meaning of this disclosure can optionally mean opaque to light with a wavelength in the ultraviolet range.

[0014] Non-transparent material within the meaning of this disclosure may include or consist of light-absorbing material. Non-transparent material within the meaning of this disclosure may include or consist of photovoltaic material.

[0015] Photovoltaic lamellas within the meaning of this disclosure are, in particular, thin-film photovoltaic lamellas. A solar element within the meaning of this disclosure can be or comprise, in particular, a plate, a curved plate, or a film.

[0016] Photovoltaic slats within the meaning of this disclosure have, in particular, a photovoltaic slat width w, a photovoltaic slat thickness t, and a photovoltaic slat length L. The quotient of photovoltaic slat width w and photovoltaic slat thickness t, the so-called aspect ratio w / t, is, in particular, not less than 10. In one embodiment, the so-called aspect ratio w / t is less than 30, e.g., not more than 25.

[0017] The photovoltaic slats can be arranged adjacent to one another, from the bottom of the solar element to the top of the solar element. The photovoltaic slats can also be arranged adjacent to one another along the outer surface and / or the inner surface of the solar element. The spacing between the photovoltaic slats can be equidistant or different. Alternatively, the photovoltaic slats can have a different spacing and / or a different inclination and / or a different geometry in certain areas than in other areas.

[0018] The photovoltaic slat spacing d, i.e., the distance between two adjacent photovoltaic slats, is, for example, no more than 2.5 times the width w of the photovoltaic slats (photovoltaic slat width). The photovoltaic slat spacing d, i.e., the distance between two adjacent photovoltaic slats, is, for example, no less than 0.7 times the width of the photovoltaic slats (photovoltaic slat width). In particular, it is intended that the width w of the photovoltaic slats (photovoltaic slat width) is no more than 1000 μm, e.g., no more than 500 μm and / or no less than 10 μm.

[0019] In particular, it is provided that the thickness t of the photovoltaic slats (photovoltaic slat thickness) is not more than 10 pm, in particular not more than 5 pm, in particular not more than 3 pm. In particular, it is provided that the thickness t of the photovoltaic slats (photovoltaic slat thickness) is not less than 0.1 pm.

[0020] The solar element may include markings that identify the intended outer surface, the intended inner surface, the intended top side and / or the intended bottom side of the planar solar element.

[0021] In a further embodiment, it is provided that the amount of the slat angle is greater than 0° and less than 90°, in particular less than 45°, in particular not greater than 30°.

[0022] In a further embodiment, the amount of the slat angle is not less than 10° and not greater than 30°, in particular not greater than 20°.

[0023] In a further embodiment, it is provided that the transparent material of the solar element has a refractive index of not more than 1.45, in particular not more than 1.4, in particular not more than 1.35 and / or more than 1. In a further embodiment, it is provided that the body is designed as a plane-parallel layer.

[0024] In a further embodiment, it is provided that the solar element comprises a plurality of, in particular parallel, in particular wedge-shaped, microstructures on the intended outer side, wherein at least one photovoltaic lamella is arranged on a respective intended upper side of a microstructure. In a further embodiment, it is provided that a layer, in particular made of the transparent material, is arranged on each photovoltaic lamella. In a further embodiment, it is provided that the microstructures are covered by a cover layer, in particular made of the transparent material, in such a way that cavities are formed between the microstructures and / or the photovoltaic lamellas and the cover layer.

[0025] In a further embodiment, it is provided that conductor tracks are provided for the dissipation of electrical energy, which are arranged alternately and / or alternately above and below the photovoltaic slats.

[0026] The above-mentioned object is also achieved by a film composite with at least one film which is connected to an above-mentioned solar element.

[0027] The aforementioned object is also achieved by a solar window element comprising a glass pane on which an aforementioned solar element and / or an aforementioned film composite is arranged. A glass pane within the meaning of this disclosure can be a multi-pane and / or an insulating glass window.

[0028] Furthermore, a solar facade element can be provided which comprises an opaque facade structure on which an aforementioned solar element is arranged.

[0029] The aforementioned object is additionally achieved by a building comprising at least one aforementioned solar window element. The building can additionally comprise an aforementioned solar facade element. In one embodiment, the building is assigned a critical angle of the angle of incidence of directly incident sunlight, wherein directly incident sunlight above the critical angle is predominantly absorbed by the photovoltaic slats and below the critical angle is predominantly transmitted by the photovoltaic slats. In this context, predominantly means in particular more than 50%. In a further embodiment of the building, the absolute value of the critical angle is between 0° and 90°, preferably between 10° and 45°.

[0030] The aforementioned object is also achieved by a method for producing a solar element, in particular a solar element with one or more of the aforementioned features, wherein a basic structure or microstructure is produced from a transparent material, said microstructure comprising a plurality of, in particular, wedge-shaped, in particular (approximately) parallel microstructures, wherein material for forming photovoltaic lamellae is applied to a respective intended upper side or surface of the microstructures. In one embodiment, the material for forming photovoltaic lamellae 11 is applied to the intended upper sides or surfaces of the microstructures by means of a physical vacuum coating (PVD = Physical Vapor Deposition), for example in a sputtering or vapor deposition process.In a further embodiment, the material for forming photovoltaic slats is applied to the intended top sides or surfaces at an application angle. In a further embodiment, the base structure made of a transparent material with the photovoltaic slats is provided with a cover layer such that the photovoltaic slats are embedded between the base structure and the cover layer. The cover layer can be made of the same or approximately the same transparent material as the base structure.

[0031] In one embodiment, the base structure is created by embossing or hot stamping. In one embodiment, the base structure is made of plastic, for example, PET, PMMA, or PC. In one embodiment, the base structure consists of plastic, for example, PET, PMMA, or PC. In one embodiment, the material of the cover layer is the same as the material of the base structure. In another embodiment, the cover layer is a lacquer layer. The base structure can be created, for example, by UV embossing into a UV-curing lacquer layer, hot stamping, or extrusion. UV embossing is also possible directly on a glass pane.

[0032] The photovoltaic lamellae, or so-called thin-film photovoltaic lamellae, are applied using a sputtering or vapor deposition process, for example. This is achieved, for example, by oblique sputtering or evaporation. The direction of movement of the atoms in the respective PVD process is aligned, for example, at a defined angle to the microstructured surface. In this way, material is deposited in a thin film, for example, atom by atom, on certain areas of the microstructures, but almost no material is deposited on so-called shadow areas. Due to the geometry of the base structure 14, defined inclined photovoltaic lamellae can be deposited in the form of thin films in this way.

[0033] In a further embodiment, the material of the cover layer has a cover layer refractive index, and the material of the base structure has a base structure refractive index, wherein the base structure refractive index and the cover layer refractive index are the same or essentially the same. In this sense, "essentially the same" means that the refractive indices differ by no more than 0.05. This creates a virtually invisible interface between the microstructures. Thus, no reflections occur at the interface. Refractive index and refractive index are used synonymously here.

[0034] To conduct the electrical current generated by the photovoltaic slats, the photovoltaic slats must be equipped with electrical contacts. Various methods can be used to contact the photovoltaic slats, for example, conductor tracks made of transparent electrode materials such as TCO (Transparent Conductive Oxide). Alternatively, similar to silicon photovoltaics, contact fingers, usually made of silver or copper, are also possible. When contacting the photovoltaic slats with conductor tracks for electrical coupling, the conductor tracks can run alternately or alternately above and below the photovoltaic slats. For example, the conductor tracks running above the photovoltaic slats connect the p-doped side of the photovoltaic slats, while the conductor tracks running below the photovoltaic slats connect the n-doped side.A suitable arrangement of the p- and n-type conductors enables an optimal, tailored series connection of the pn junctions. This allows the overall voltage of the solar element to be increased and efficiency and performance to be optimized.

[0035] Wedge-shaped within the meaning of this disclosure means in particular in the shape of a wedge. A wedge within the meaning of this disclosure is in particular a body in which two side surfaces converge at an acute angle. In a preferred embodiment, the angular width of the wedge is more than twice, in particular not less than 2.5 times, the slat angle. In a preferred embodiment, the angular width of the wedge is not more than four times, in particular not more than three times, the slat angle. A wedge within the meaning of this disclosure can have a blunt tip. A wedge within the meaning of this disclosure can be a triangular prism. A wedge within the meaning of this disclosure can be a regular triangular prism.

[0036] The solar element or a corresponding solar window element can be used in buildings and other applications where angle-selective transparency is required, for example for glass surfaces in automobiles or other means of transport, such as trains, rail vehicles, aircraft or ships.

[0037] Further advantages and details are revealed in the following description of exemplary embodiments. These show:

[0038] Fig. 1A shows an embodiment of a flat solar element in a side view,

[0039] Fig. 1 B the solar element according to Fig. 1 A in a view from,

[0040] Fig. 1C the solar element according to Fig. 1A in a perspective view,

[0041] Fig. 2 shows an embodiment of the solar element according to Fig. 1A with different layers,

[0042] Fig. 3 shows an embodiment of the solar element according to Fig. 1A on a carrier,

[0043] Fig. 4 shows an embodiment of a solar window element with a solar element according to Fig. 1A,

[0044] Fig. 5 shows an embodiment of a solar facade element with a solar element according to Fig. 1A,

[0045] Fig. 6 exemplary transmission and solar absorption of a solar element as a function of the angle of incidence cp with w / d = 0.8 and |6| = 20° and a critical angle <pi_ gemäß Fig. 4 von 25°,

[0046] Fig. 7 shows an embodiment of an alternatively designed solar element,

[0047] Fig. 8 shows a further embodiment of an alternatively designed solar element, Fig. 9 shows an embodiment of trigonometric functions of the standardized power of solar elements with photovoltaic lamellas in comparison to vertically aligned full-surface solar modules, exemplified at the Frankfurt aM location with a south orientation,

[0048] Fig. 10 an example of trigonometric functions of the standardized power of solar elements with photovoltaic slats in comparison to vertically aligned full-surface solar modules, exemplified at the Frankfurt aM location with an east orientation,

[0049] Fig. 11 an example of trigonometric functions of the standardized power of solar elements with photovoltaic lamellas compared to vertically aligned full-surface solar modules, exemplified at the Madrid location with a south-facing orientation,

[0050] Fig. 12 an example of trigonometric functions of the standardized power of solar elements with photovoltaic lamellas compared to vertically aligned full-surface solar modules, exemplified at the Madrid location with an east orientation,

[0051] Fig. 13 an example of trigonometric functions of the standardized power of solar elements with photovoltaic lamellas compared to vertically aligned full-surface solar modules, exemplified at the Singapore location with an east orientation,

[0052] Fig. 14 standardized performance of a solar element with photovoltaic slats (w / d = 0.8 and |6| = 20°) at the Frankfurt aM location facing south with different refractive indices,

[0053] Fig. 15 an exemplary schematic cross-section through a solar element with photovoltaic lamellas and underlying transparent contact layers,

[0054] Fig. 16 an exemplary schematic cross-section through a solar element with photovoltaic lamellas and overlying transparent contact layers,

[0055] Fig. 17 is a schematic three-dimensional representation of an embodiment with conductor tracks for electrically coupling the photovoltaic slats. Fig. 18 is a schematic diagram of the embodiment according to Fig. 17.

[0056] Fig. 19A shows an embodiment of a building with a solar window element according to Fig. 4 and / or a solar facade element based on a solar element according to Fig. 7 and / or a solar facade element based on a solar element according to Fig. 8,

[0057] Fig. 19B schematic view of the building according to Fig. 19A,

[0058] Fig. 20 an embodiment of a ship with a solar window element according to Fig. 4,

[0059] Fig. 21 an embodiment of a train with a solar window element according to Fig. 4,

[0060] Fig. 22 an embodiment of a motor vehicle with a solar window element according to Fig. 4,

[0061] Fig. 23A shows an embodiment of a method step for producing the (flat) solar element according to Fig. 1A,

[0062] Fig. 23B shows an enlarged section of Fig. 23A,

[0063] Fig. 23C shows an embodiment of a further method step for producing the (flat) solar element according to Fig. 1A,

[0064] Fig. 23D shows an embodiment of a result of the method step according to Fig. 23C,

[0065] Fig. 23E shows an embodiment of a further method step for producing the (flat) solar element according to Fig. 1A, and

[0066] Fig. 23F shows an embodiment of a result of the method step according to Fig. 23E.

[0067] Fig. 1A shows - in a side view - an embodiment of a (flat) solar element 1 with photovoltaic slats 11 arranged obliquely in a transparent body 10 made of transparent material. Fig. 1B shows the solar element 1 in a view from the front, and Fig. 1C shows the solar element 1 in a perspective view. Reference number 2 denotes a designated outer surface and reference number 3 a designated inner surface of the solar element 1. Reference number w denotes a or the photovoltaic slat width, reference number t a or the photovoltaic slat thickness, reference number d a or the slat spacing of two adjacent (i.e. arranged adjacent to one another) photovoltaic slats, reference number L a or the photovoltaic slat length and reference number ö a or the slat angle.

[0068] The dimensions and proportions in Figures 1A, 1B and 1C are not to scale but serve solely to explain the basic structure of the planar solar element.

[0069] Due to the thin-film technology used, the thickness t of the photovoltaic lamellae (photovoltaic lamella thickness) is in a range below, for example, 10 pm, preferably below 5 pm, more preferably below 3 pm. The width w of the photovoltaic lamellae (photovoltaic lamella width), however, can be designed significantly above 10 pm, preferably above 50 pm. In this way, aspect ratios w / t above 10 are achieved. In this embodiment, the photovoltaic lamellae 11 are arranged parallel and equidistant from one another.

[0070] In an exemplary embodiment, the photovoltaic slats are each arranged at a slat angle of ö = -20°, which is measured counterclockwise (and therefore has a negative sign) from the surface normal 7 of the intended outer surface 2 of the solar element 1 to an edge of the respective photovoltaic slat with an edge length that has the length corresponding to the photovoltaic slat width w.

[0071] The solar element 1 can comprise markings 6 which identify the intended outer surface 2, the intended inner surface 3, a intended upper side 4 and / or a intended underside 8 of the (flat) solar element 1.

[0072] Fig. 2 shows a film composite 105 on a carrier 103, wherein the film composite 105 comprises a solar element 1 according to Fig. 1A as well as further film layers 101, 102. Fig. 3 shows an embodiment in which the solar element 1 is applied directly to the carrier 103 or arranged on the carrier 103.

[0073] Fig. 4 shows a solar window element 80 corresponding to the structure shown in Fig. 3, wherein the carrier 103 is designed as a glass pane 106. This results in a solar window element that converts direct solar radiation into electrical energy at higher angles of incidence while simultaneously allowing a clear view at lower angles of incidence. Fig. 4 shows light beams LS1 and LS2 entering the solar element 1 at different angles of incidence. The light beam LS2 is visible to an observer 5 on the inside. The light beam LS2 strikes a photovoltaic slat and is absorbed by it. At higher positions of the sun, i.e. at higher angles of incidence, the direct sunlight strikes the photovoltaic slats and is absorbed by them, whereby less heat reaches rooms on the inside of the solar element, and at the same time the absorbed sunlight is converted into electrical energy.This concept requires less energy in two ways. By absorbing direct solar radiation, interior spaces heat up less, and comparatively less air conditioning energy is required to cool them. Furthermore, the absorbed sunlight is used to generate electrical energy.

[0074] The angle of incidence range 71 for transmission or viewing (vertical hatching) and the angle of incidence range 70 for solar absorption (horizontal hatching) are defined by a critical angle <pL abgegrenzt, bei dem die Durchsicht bzw. Transmission durch das Solarelement 1 bei 50% liegt. Der Grenzwinkel <pi_ ist zudem von dem azimutalen Winkel 0 des jeweiligen Lichtstrahls LS1 bzw. LS2 abhängig.

[0075] Light rays, such as light beam LS1, that strike solar element 1 in the angle of incidence range 70 for solar absorption (horizontal hatching), are absorbed by the photovoltaic slats to an extent of more than 50%. Light rays, such as light beam LS2, that strike the solar element in the angle of incidence range for transmission, are transmitted by solar element 1 to an extent of more than 50%.

[0076] Fig. 5 shows an embodiment of a solar facade element, wherein the (transparent) solar element 1 is applied to an opaque facade structure 104 as a carrier 103. In Fig. 5, the angle of incidence range 71 of light reflected by the facade structure 104 (also referred to here as transmission), such as the light beam designated by reference symbol LS2', is marked by vertical hatching. The angle of incidence range 70 for solar absorption shown in Fig. 5 designates the area in which more than 50% of the sunlight entering the solar element 1 is absorbed by the photovoltaic slats. The critical angle ei can be specified by the ratio w / d and the angle of inclination of the photovoltaic slats 11, i.e., the slat angle θ. In this way, optimal product variants can be designed for different applications.

[0077] Fig. 6 shows, as an example, the angle of incidence ranges 71 and 70 for transmission and solar absorption of a solar element 1, for which a ratio w / d = 0.8 and an inclination angle of the photovoltaic slats of |6| = 20° were assumed. The solar element is designed for angles of incidence and viewing angles from -90° to the critical angle <pi_ = 25° sehr durchsichtig, während die solare Absorption für Sonnenstände oberhalb des Grenzwinkels von 25° ansteigt. Einfallswinkel und Sichtwinkel werden hier synonym verwendet, wobei streng genommen beim Sichtwinkel die Transmission im Vordergrund steht und beim Einfallswinkel die Absorption.

[0078] Fig. 7 shows an alternatively designed solar element T. This comprises a body 10' made of the transparent material. The body 10' comprises wedge-shaped microstructures 141 that form a microstructured surface 19. The photovoltaic lamellae 11 are arranged on the upper side of the wedge-shaped microstructures 141, i.e., on the microstructured surface 19. A cover layer 17 is arranged on the microstructured surface 19 to form cavities 15 between the cover layer 17 and the microstructured surface 19.

[0079] Fig. 8 shows another alternatively designed solar element 1". This has a body 10" made of the transparent material, which also includes wedge-shaped microstructures 141 that form a microstructured surface 19. The photovoltaic lamellae 11 are arranged on the upper side of the wedge-shaped microstructures 141, i.e., on the microstructured surface 19. A protective layer 16 is arranged on the upper side of the photovoltaic lamellae 11.

[0080] The photovoltaic slats 11 can be completely embedded in the transparent body 10 or a plastic film corresponding to the transparent body 10 (see Fig. 1A or Fig. 4). In another embodiment, the photovoltaic slats 11 can be enclosed by a cover layer 17 together with cavities 15 or air cavities (see Fig. 7). In yet another embodiment, photovoltaic slats 11 can be arranged in a microstructured surface beneath a protective layer 16 (see Fig. 8). The light beams LS1, LS3 and LS4 take different paths in the three variants. Due to the light refraction at the interface to the solar element 1, the light beam LS1 according to Fig. 4 hits a photovoltaic slat 11 at a flatter angle, while the light beam LS3 according to Fig.7 is refracted in the cover layer 17, but then re-impinges on a photovoltaic lamella 11 in a cavity / air cavity 15 at the original angle of incidence. The light beam LS4 according to Fig. 8 reaches a photovoltaic lamella without being affected by refraction.

[0081] The solar element 1 shown in Fig. 1A and Fig. 4 is particularly suitable for windows or solar window elements. It is transparent over a wide range of angles of incidence and solar-active at higher solar positions. However, due to the refraction of light by the transparent material with a refractive index of nB, the sun's rays hit the photovoltaic slats 11 at a somewhat flatter angle, which slightly reduces the energy yield.

[0082] The solar elements 1' and 1" according to Fig. 7 and Fig. 8, however, are not suitable for the see-through areas of glass surfaces, for example windows, since the view is distorted by the microstructures 141. With regard to use on opaque facade areas of the building envelope and on glass surfaces where no view is required, the solar elements 1' and 1" according to Fig. 7 and Fig. 8 are advantageous. By aligning the photovoltaic slats 11 towards the sun and providing a beam path without any change in angle, very high energy yields can be achieved with the solar elements 1' and 1".

[0083] Fig. 9 shows an exemplary embodiment of trigonometric functions of the normalized power of solar elements 1, 1', 1" with photovoltaic slats 11 in comparison to vertically oriented full-surface solar modules (conventional solar panels, however, are not slanted but vertically oriented), exemplarily at the Frankfurt aM location with a southerly orientation for w / d = 0.8 and |6| = 20°. Fig. 10 shows an exemplary embodiment of trigonometric functions of the normalized power of solar elements 1, 1', 1" with photovoltaic slats 11 in comparison to vertically oriented full-surface solar modules, exemplarily at the Frankfurt aM location with an easterly orientation for w / d = 0.8 and |6| = 20°. Frankfurt aM is located at a latitude of 50.1° North. Large cities such as London or Vancouver are also close to the 50N latitude and lead to a comparable result.

[0084] Fig. 9 shows the performance comparison for a south-facing orientation of solar elements 1, 1', 1". The solar element 1 with the photovoltaic slats 11 according to Fig. 9 achieves more than twice the performance P50S1 (integral over the standardized performance, 216%) compared to a vertically oriented, full-surface solar module, whose standardized performance is designated in Fig. 9 with reference symbol P50S0. A solar element 1' or 1" with photovoltaic slats 11 and direct or almost direct air interface according to Fig. 7 and Fig. 8, whose standardized performance is designated in Fig. 9 with reference symbol P50S2, achieves almost three times the performance (286%). The reason for this is that the photovoltaic slats 11 are aligned differently with respect to incoming sunlight than a vertically oriented full-surface solar element.

[0085] In the east orientation, as shown in Fig. 10, the solar element 1 with photovoltaic slats, whose standardized power is designated by reference symbol P50E1 in Fig. 10, achieves 63% and the solar element 1' or 1" with photovoltaic slats 11 and direct or almost direct air interface, whose standardized power is designated by reference symbol P50E2 in Fig. 10, achieves 88% of the power of the vertical solar module, whose standardized power is designated by reference symbol P50E0 in Fig. 10. With regard to the east orientation, vertically oriented full-surface solar modules are therefore advantageous in terms of power output. Due to the symmetry, an analogous result applies to a west orientation.

[0086] Fig. 11 shows an exemplary embodiment of trigonometric functions of the normalized power of solar elements 1, 1', 1" with photovoltaic slats 11 in comparison to vertically oriented full-area solar modules, exemplarily at the Madrid location with a southerly orientation for w / d = 0.8 and |6| = 20°. Fig. 12 shows an exemplary embodiment of trigonometric functions of the normalized power of solar elements 1, 1', 1" with photovoltaic slats 11 in comparison to vertically oriented full-area solar modules, exemplarily at the Madrid location with an easterly orientation for w / d = 0.8 and |6| = 20°. Madrid is located at the latitude 40.4°N. Other major cities close to the 40N latitude include New York and Beijing. When oriented south, the solar elements of this disclosure have significantly higher performance than a vertically oriented full-area solar module, the standardized performance of which is designated by reference symbol P40S0 in Fig. 11.Solar element 1 with photovoltaic slats 11, whose standardized power is designated by reference symbol P40S1 in Fig. 11, achieves 3.8 times the power. Solar elements 1' and 1" with photovoltaic slats 11 and a direct air boundary layer, whose standardized power is designated by reference symbol P40S2 in Fig. 11, achieve 4.5 times the power of a vertically oriented full-surface solar module.

[0087] In an east orientation, the solar elements 1 of this disclosure, whose standardized power is designated by reference symbol P40E1 in Fig. 12, or the solar elements 1' and 1", whose standardized power is designated by reference symbol P40E2 in Fig. 12, achieve 73% and 100% without and with air interface, respectively, compared to a vertically oriented full-area solar module, whose standardized power is designated by reference symbol P40E0 in Fig. 12.

[0088] Fig. 13 shows an example of trigonometric functions of the standardized performance of solar elements 1, 1', 1" with photovoltaic slats 11 in comparison to vertically oriented full-surface solar modules, exemplified at the Singapore location with an easterly orientation for w / d = 0.8 and θ = 20°. Singapore is close to the equator at 1.4°N. Similar performance curves can be expected, for example, in the cities of Nairobi in Kenya or Manaus in Brazil. Due to the high position of the sun, a south / north orientation of vertically oriented full-surface solar modules is not worthwhile. An east / west orientation produces the following results in the performance comparison of solar elements 1, 1', 1" (with photovoltaic slats 11) with vertically oriented full-surface solar modules: Solar modules 1 with photovoltaic slats 11, the standardized performance of which is shown in Fig.13 with reference symbol P1 E1, 89%, solar modules 1 ' and 1" with photovoltaic slats 11 with an air interface, the standardized power of which is designated in Fig. 13 with reference symbol P1 E2, 120%, vertically aligned full-surface solar modules, the standardized power of which is designated in Fig. 13 with reference symbol P1 E0, 100%. Fig. 14 shows the standardized power of a solar element 1 with photovoltaic slats 11 (w / d = 0.8 and 6 = 20°) at the Frankfurt aM location in a south-facing orientation with different refractive indices nB. The refractive index nB of the material of the fully embedded photovoltaic slats 11 has an influence on the power of the solar element 1. The lower the refractive index nB, the higher the energy yield.The refraction of the incident sunlight is lower for materials with a low refractive index nB, since a light beam hits the photovoltaic slats 11 at a steeper angle at the same angle of incidence and ensures a higher solar energy yield.

[0089] Fig. 15 shows a schematic cross-section through an exemplary solar element 1 or the exemplary solar element 1 with photovoltaic lamellae 11 and underlying transparent contact layers 24. Fig. 16 shows a schematic cross-section through an exemplary solar element 1 or the exemplary solar element 1 with photovoltaic lamellae 11 and overlying transparent contact layers 25.

[0090] Various methods can be used to contact the photovoltaic slats 11, for example conductor tracks made of transparent electrode material TCO (Transparent Conductive Oxide). Alternatively, analogous to silicon photovoltaics, contact fingers, usually made of silver or copper, are also possible. For example, Fig. 17 shows a schematic three-dimensional representation of an embodiment with conductor tracks 21 and 22 for electrically coupling the photovoltaic slats 11. The conductor tracks 21 and 22 run alternately or alternately above and below the photovoltaic slats 11. The conductor tracks 21 running above connect, for example, the p-doped side of the photovoltaic slats 11, while the conductor tracks 22 running below connect the n-doped side. A suitable arrangement of the p- and n-conductor tracks enables an optimal, customized series connection of the pn junctions, as shown schematically in Fig. 18.In this way, the total voltage of the solar element can be increased and the efficiency and performance can be optimized.

[0091] 19A and 19B show an embodiment of a building 30 with a solar window element 80 and with a solar facade element 81 and / or a solar facade element based on a solar element 1' according to FIG. 7 and / or a solar facade element based on a solar element 1" according to FIG. 8, wherein FIG. 19B shows a schematic diagram. Reference numeral 84 denotes a photovoltaic adapter, among other things, for interconnecting and wiring the solar window elements 80 and the solar facade elements 81. Reference numeral 31 denotes an accumulator, and reference numeral 32 denotes an accumulator controller. Reference numeral 33 denotes a transformer module, which includes, among other things, an inverter connected to an AC voltage network of the building 30. Furthermore, the transformer module 33 is connected to the accumulator controller 32.Reference numeral 34 denotes a cooling (possibly also a heating) system for rooms equipped with a solar window element 80. Furthermore, an output interface 35 is provided for connection to an AC power grid outside the building 30. In addition, conventional solar panels can be arranged on the roof of the building 30.

[0092] Fig. 20 shows an embodiment of a ship 40 with a solar window element 80, Fig. 21 shows an embodiment of a train 50 with a solar window element 80, and Fig. 22 shows an embodiment of an automobile 60 with a solar window element 80.

[0093] The solar elements 1 are manufactured using microstructuring and coating processes. The photovoltaic lamellae 11 can be built up, for example, by vacuum oblique coating on a microstructured layer. Various solar-active layer systems are possible here, for example (a) CIGS (copper indium gallium selenide), (b) CdTe (cadmium telluride), (c) a-Si (amorphous silicon), (d) CZTS / Se (copper zinc tin sulfide / selenide), (e) organic photovoltaic layers, or (f) perovskites.

[0094] Fig. 23A to Fig. 23F show an embodiment of a process chain for producing a solar element 1 with (three-dimensionally integrated photovoltaic lamellae). In the first process step according to Fig. 23A, a film or plate made of a plastic, for example PET, PMMA or PC, is provided with a basic structure 14 having microstructures. This can be done, for example, by UV embossing into a UV-curing lacquer layer, hot stamping or extrusion. UV embossing is also possible directly on a glass pane. Since the photovoltaic lamellae 11 are aligned parallel to one another, the microstructure is also aligned linearly. A typical structural geometry is micro-wedges or microprisms lying parallel to one another, which can have different side angles (i.e. δ and α - δ), where α denotes the angular width or angular dimension of the respective micro-wedge.Curved side surfaces are also possible, allowing curved photovoltaic slats to be produced. Fig. 23B shows an enlarged section of Fig. 23A, illustrating the angular width of a micro-wedge, designated by reference symbol a. Reference symbol h denotes the extension of a wedge-shaped structure in the orientation of the surface normal 7 of the intended inner surface 3 and / or the intended outer surface 2 of the planar solar element 1.

[0095] In the second process step (Fig. 23C), the photovoltaic lamellae 11 are applied to the surfaces of the microstructures using a sputtering or vapor deposition process (both PVD processes, physical vapor deposition). This is done by oblique sputtering or evaporation at a deposition angle β. The direction of movement of the atoms in the PVD process is aligned at a defined angle to the microstructured surface. In this way, a thin film of material is deposited atom by atom on specific areas of the respective microstructure, although no material is deposed in a thin film on so-called shadow areas. The geometry of the microstructures allows defined, inclined photovoltaic lamellae 11 to be produced in the form of thin films.

[0096] Fig. 23D shows the intermediate product with applied photovoltaic lamellae 11. In a further process step in Fig. 23E, a film or plate with an intermediate lacquer layer as a cover layer 12 is laminated onto the microstructure. The lacquer layer fills the microstructure, including the photovoltaic lamellae, completely and without air inclusions, and the film or plate ensures a flat surface. A UV-curing, highly transparent acrylic lacquer, for example, is used as the lacquer. Ideally, the same lacquer is used for the microstructuring and the subsequent filling of the microstructures. The refractive indices of the materials used for the basic structure with the microstructure and the cover layer are the same or almost the same in this embodiment. This way, no reflections occur at the boundary layer. As an alternative to Fig.23E, the microstructure can be filled with the transparent material of the base structure 14 to form a body of homogeneous material, as shown in Fig. 23F.

[0097] Further alternatively to Fig. 23E, the basic structure 14 having a microstructure with the photovoltaic lamellae 11 arranged thereon can be provided with a cover layer 17 in such a way that cavities, which can in particular be filled with air, are formed between the cover layer 17 and the photovoltaic lamellae.

[0098] The use of the described flat optical elements on windows and glass facades ensures pleasant daylight in rooms and prevents glare from direct sunlight. In the hot season, when the sun is high in the sky, the sun's rays are dimmed. This reduces the heat buildup in rooms, so less energy is needed to cool them. In the cooler season, when the sun is lower in the sky, more sunlight enters the rooms. The invention enables sustainable energy savings and more energy-efficient building technology.

[0099] The elements or objects in the figures are drawn for simplicity and clarity and are not necessarily to scale. For example, the sizes of some elements are exaggerated compared to others to improve understanding of the embodiments of the present invention. Fig. 1A, Fig. 1B, Fig. 1C, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 7, Fig. 8, Fig. 15, Fig. 16, Fig. 17, Fig. 19A, Fig. 20, Fig. 21, Fig. 22, Fig. 23A, Fig. 23B, Fig. 23C, Fig. 23D, Fig. 23E, and Fig. 23F are oriented, illustrated, or drawn with the intended top side at the top and the intended bottom side at the bottom. List of Reference Symbols

[0100] 1, 1', 1" solar element (solar lamella layer, solar-active microlamellae, microlamellae)

[0101] 2 intended exterior surface

[0102] 3 intended interior surface

[0103] 4 intended top side

[0104] 5 viewers

[0105] 6 Marking

[0106] 7 Surface normals

[0107] 8 intended subpage

[0108] 10, 10', 10" transparent body

[0109] 11 Photovoltaic slats

[0110] 12 Top coat (paint layer)

[0111] 14 Basic structure (microstructured film or plate, e.g. made of plastic)

[0112] 15 Cavity

[0113] 16 protective layer

[0114] 17 Top layer

[0115] 19 microstructured surface

[0116] 21 Conductor track (above photovoltaic slats)

[0117] 22 Conductor track (beneath photovoltaic slats)

[0118] 24 Contact layer (beneath photovoltaic slats)

[0119] 25 Contact layer (above photovoltaic slats)

[0120] 30 Building 31 Accumulator

[0121] 32 Accumulator control

[0122] 33 Transformer module

[0123] 34 Cooling (possibly also heating)

[0124] 35 Output interface

[0125] 40 Ship or watercraft

[0126] 50 train

[0127] 60 automobiles

[0128] 70 angle of incidence of solar absorption

[0129] 71 Angle of incidence range for transmission

[0130] 80 solar window elements

[0131] 81 Solar facade element

[0132] 84 photovoltaic adapters

[0133] 101 film layer

[0134] 102 film layer

[0135] 103 carriers

[0136] 104 (non-transparent) facade structure

[0137] 105 film composite

[0138] 106 glass pane

[0139] 141 wedge-shaped microstructure (wedge, triangular prism) d distance between two adjacent photovoltaic lamellas h extension of the wedge-shaped structure or microstructure

[0140] L Photovoltaic slat length

[0141] LS1 , LS2, LS2',

[0142] LS3, LS4 Light beam riB Refractive index

[0143] P50S0, P50S1, P50S2,

[0144] P50E0, P50E1, P50E2,

[0145] P40S0, P40S1, P40S2, P40E0, P40E1, P40E2,

[0146] P1E0, P1E1, P1E2 standardized power t photovoltaic slat thickness w photovoltaic slat width a angular width, angular dimension ß application angle

[0147] 0 azimuthal angle

[0148] 5 Slat angle P Angle of incidence (pi Critical angle (of the angle of incidence)

Claims

1. Solar element (1) with a body (10) made of a, in particular homogeneous, transparent material, in which a plurality of, in particular non-transparent, photovoltaic slats (11) for generating electrical energy are embedded and / or integrated at an angle by a slat angle (6).

2. Solar element (1) according to claim 1, characterized in that the photovoltaic slat width (w) of the photovoltaic slats is not more than 1000 pm and / or not less than 10 pm.

3. Solar element (1) according to claim 1 or 2, characterized in that the photovoltaic lamellae (11) are designed as thin-film photovoltaic lamellae with a photovoltaic lamella thickness (t) of less than 10 pm and / or less than 3 pm, in particular not less than 0.1 pm, and wherein the aspect ratio (w / t) is not less than 10.

4. Solar element (1) according to claim 1, 2 or 3, characterized in that the amount of the slat angle (6) is greater than 0° and less than 90°, in particular less than 45°, in particular not greater than 30°.

5. Solar element (1) according to one of the preceding claims, characterized in that the amount of the slat angle (6) is not less than 10° and not greater than 30°, in particular not greater than 20°.

6. Solar element (1) according to one of the preceding claims, characterized in that the transparent material has a refractive index of not more than 1.45, in particular not more than 1.4, in particular not more than 1.

35.

7. Solar element (1) according to one of the preceding claims, characterized in that the body is designed as a plane-parallel layer.

8. Solar element (1) according to one of claims 1 to 6, characterized in that the solar element (1) comprises on the intended outer side a plurality of, in particular parallel, in particular wedge-shaped, microstructures (141), wherein at least one photovoltaic lamella (11) is arranged on a respective intended upper side of a microstructure (141).

9. Solar element (1) according to claim 8, characterized in that a protective layer, in particular made of the transparent material, is arranged on each photovoltaic lamella.

10. Solar element (1) according to claim 8 or 9, characterized in that the microstructures (141) are covered by a cover layer, in particular made of the transparent material, in such a way that cavities are formed between the microstructures (141) and / or the photovoltaic lamellae (11) and the cover layer.

11. Solar element (1) according to one of the preceding claims, in which conductor tracks are provided for dissipating electrical energy, which are arranged alternately and / or alternately above and below the photovoltaic slats (11).

12. Film composite (105), characterized in that it comprises at least one film which is connected to a solar element (1) according to one of claims 1 to 6.

13. Solar window element (80), characterized in that it comprises a glass pane on which a solar element (1) according to one of claims 1 to 6 and / or a film composite (105) according to claim 12 is arranged.

14. Solar facade element (81), characterized in that the solar facade element (81) comprises an opaque facade structure (104) on which a solar element (1) according to one of claims 1 to 10 is arranged.

15. Building (30), characterized in that it comprises at least one solar window element (80) according to claim 13 and / or a solar facade element (81) according to claim 14.

16. Building (30) according to claim 15, characterized in that the building (30) has a limit angle ( <pi_) des einfallswinkels (cp) direkt einfallenden sonnenlichts zugeordnet ist, wobei einfallendes sonnenlicht oberhalb grenzwinkels (<pi_) überwiegend absorption unterliegt und unterhalb (< l) transmission unterliegt.

17. Building (30) according to claim 16, characterized in that the amount of the critical angle ( <pi_) zwischen 0° und 90°, bevorzugt 10° 45° liegt.

18. A method for producing a solar element (1), in particular a solar element (1) according to one of claims 1 to 11, wherein a basic structure or microstructure is produced from a transparent material, which comprises a plurality of, in particular wedge-shaped, in particular (approximately) parallel, microstructures, wherein material for forming photovoltaic lamellae (11) is applied to a respective intended upper side or surface of the microstructures.

19. The method according to claim 18, wherein the material for forming photovoltaic lamellae (11) is applied to the intended top sides or surfaces of the microstructures by means of a physical vacuum coating (PVD = Physical Vapor Deposition), for example in a sputtering or vapor deposition process.

20. Method according to claim 18 or 19, wherein the material for forming photovoltaic lamellae (11) is applied to the intended top sides or surfaces at an application angle.

21. Method according to one of claims 18 to 20, in which the basic structure made of a transparent material with the photovoltaic lamellae (11) is provided with a cover layer in such a way that the photovoltaic lamellae (11) are embedded between the basic structure and the cover layer.

22. Method according to one of claims 18-21, in which the basic structure made of a transparent material with the photovoltaic lamellae (11) is provided with a covering layer in such a way that cavities are formed between the basic structure with photovoltaic lamellas and the covering layer.

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