POWER DISCHARGE SYSTEM FOR A SHADING DEVICE AND SHADING DEVICE THEREFOR

Description

[0001] Power supply system for a shading device and shading device therefor.

[0002] The invention relates to a current dissipation system for a shading device, at least with a plurality of louvers with photovoltaic elements for generating electricity, and to a shading device with a current dissipation system.

[0003] Venetian blinds with slats on which photovoltaic elements (also called photovoltaic cells) are mounted are already known from the prior art. Reference is made, for example, to the publications DE 10 2007 031 236 A1 or DE 10 2014 200 359 A1.

[0004] Furthermore, it is known from publication DE 21 2019 000 358 U1 to connect the slats by means of a conductor wire for current conduction. However, this conductor wire is visually unappealing and has a negative impact on the handling and functionality of the external venetian blind.

[0005] A current-discharge system with busbars passing through cutouts in the louvers is known from publication CN 201071671 Y. The busbars are electrically contacted via an electrically conductive ring, which forms the cutout and is arranged around the busbar, and several wires or a type of electrically conductive brush that establish contact between the ring and the busbar. Furthermore, publication WO 2021 / 204358 A1 describes a generic current-discharge system for a shading device. Publication WO 2008 / 054145 A1 also describes a current-discharge system for a shading device with a series electrical connection of the louvers.

[0006] Further reference is made to the prior art documents DE 15 09 995 A, EP 3690176 A1, KR 102 152 986 B1 and WO 2018 / 216023 A1.

[0007] It is therefore an object of the invention to provide an improved current dissipation for a shading device with photovoltaic louvers and a shading device for this purpose.

[0008] This problem is solved by the features of independent claim 1. Advantageous embodiments of the invention are the subject of dependent claims.

[0009] The inventors have recognized that there is an improved way to transfer the electrical energy generated in the photovoltaic elements on the movable slats of a venetian blind or a roller shutter to a power grid or energy storage system, thus circumventing the disadvantages of the state of the art.

[0010] The invention therefore describes the possibility of conducting current via an electrically conductive rod, strip, or flat bar, which runs through the recesses in the lamellae, wherein electrically conductive sliding contacts are provided in the recesses and are electrically connected to the photovoltaic elements. Complex wiring of the individual lamellae is thus no longer necessary.

[0011] Different photovoltaic elements can be used on the lamellae. The various concepts for photovoltaic lamellae can be categorized according to the different technologies of the photovoltaic elements used. First-generation photovoltaic elements (wafer-based photovoltaic elements) and second-generation photovoltaic elements are characterized by the fact that they do not exceed the Shockley-Queisser (SQ) limit for single-band section devices. Third-generation photovoltaic elements, on the other hand, exhibit an efficiency potential above the SQ limit. The SQ limit describes the maximum achievable conversion efficiency of solar energy for a specific material. This limit is the benchmark against which new photovoltaic technologies are compared. A particular material has a specific band gap, which determines that only certain spectra of light can be absorbed.The remaining spectra cannot be absorbed and therefore cannot be used to convert light into electricity (first and second generation photovoltaic cells). Third generation photovoltaic cells overcome this limitation, for example, through so-called tandem photovoltaic cells, in which several materials are used in different layers to absorb the remaining spectra of light and convert them into electricity.

[0012] Conventional first-generation photovoltaic elements: This involves the use of first-generation photovoltaic elements, i.e., wafer-based photovoltaic elements. This technology is advantageous because, due to years of research and its large market share, it boasts a particularly high degree of long-term reliability, a very good price-performance ratio, and very high efficiency. However, a significant disadvantage is that mass-produced photovoltaic modules of this technology are only available in sizes that cannot be mounted directly onto the lamellae. Therefore, lamellae equipped with conventional photovoltaic elements must be manufactured in such a way that the photovoltaic elements are interconnected and laminated onto the raw lamellae themselves to form a module. Since individual standard photovoltaic elements are too large for the lamellae, they must be cut.

[0013] Second- and third-generation photovoltaic elements: These photovoltaic elements offer the advantage that, partly due to different manufacturing processes, they can be produced in almost any size with significantly fewer modifications to the manufacturing process. This allows the available surface area of ​​the lamella to be used more efficiently, without gaps. A significant disadvantage, however, is that, according to the current state of the art, second- and third-generation photovoltaic elements often cannot yet compete with first-generation photovoltaic elements in terms of efficiency. Some manufacturing processes allow the thin-film photovoltaic cell layer to be vapor-deposited directly onto the lamellae, which then serve as the substrate. It may be beneficial to pre-coat the lamellae so that they have more suitable properties for their role as a substrate.The processes used during the manufacturing process include thermal evaporation, sputtering deposition, laser deposition and metal-organic vapor phase epitaxy.

[0014] Adhesive photovoltaic elements of the second and third generation: These also utilize second- and third-generation photovoltaic elements, but instead of being produced directly on the lamella itself, they are manufactured on a film and then adhered to the lamellae. This concept offers the crucial advantage of allowing for a spatial separation between the production of the lamellae and the production of the photovoltaic elements. The photovoltaic film can be manufactured in lengths, stored in the correct width, and cut to size.

[0015] Furthermore, different types of lamellae can be used. Using lamellae with less curvature in the area where the photovoltaic elements are applied, such as flat lamellae, can have positive effects. Firstly, the photovoltaic elements only need to conform to a less pronounced bend, which simplifies the production process and reduces the demands placed on the photovoltaic elements themselves. Secondly, the photovoltaic elements can be more easily protected from external influences. It is crucial that the encapsulation of the photovoltaic cell layer adheres sufficiently strongly and reliably to the edges of the lamellae to ensure its encapsulating effect. Since expansion or contraction of the lamellae can cause delamination at weak points, such as the edges, it is advisable to take special precautions in these areas.For example, the encapsulation can be folded over one or more outer edges of the slats so that the film can also adhere to the underside of the slat. Since the flat slat has no hemming on its outer edges, folding the film over is easily accomplished. With a hemmed slat, the film would not fold over and laminate easily, and the package height would increase further because the film would extend over the hemming, thus thickening the thickest part of the slat. The film can then be securely attached to the underside using additional methods such as gluing.

[0016] Accordingly, the inventors propose to improve a current dissipation system for a shading device, in particular for a venetian blind or a Venetian blind, with at least a plurality of slats with photovoltaic elements for generating electricity, wherein at least one busbar is provided which runs through recesses in the slats and electrically connects them to each other in order to dissipate the current generated in the photovoltaic elements, wherein sliding contacts are arranged in the recesses of the slats which are electrically connected to the photovoltaic elements, and wherein the sliding contacts are designed as at least one electrically conductive contact pin and an electrically insulating insert is formed in the recesses, in such a way that at least two slats are repeatedly connected to each other in series to form a set of slats.the connection points between the lamellae are electrically coupled to each other in parallel via a busbar.

[0017] The current dissipation system according to the invention serves to feed the electricity generated in the photovoltaic elements of the louvers into a power grid or an electricity storage system. Depending on the design of the current dissipation system, an inverter is advantageously also provided. The shading device is preferably a venetian blind or a Venetian blind, in particular a venetian blind canopy. The invention is described below using a shading device designed as a venetian blind as an example.

[0018] The slats of the external venetian blind are movably mounted in lateral guide rails, similar to conventional external venetian blinds, by means of guide pins attached to their short ends. When the slats are raised, lowered, or tilted, the guide pins move within the guide rails. Furthermore, the shading device, particularly the external venetian blind, has at least one pull element for moving the slats. Advantageously, two pull elements in the form of cables, cords, or straps are provided, preferably located at the two ends of the slats. The pull cords allow the slats to be moved up and down as well as tilted around their longitudinal axis.

[0019] The current flow via busbars running through the lamellae can of course be combined with other ways of discharging the current generated in the photovoltaic elements, for example by means of busbars in the guide rails.

[0020] In a preferred embodiment with busbars arranged exclusively according to the invention, at least two busbars extending through the lamellae are formed.

[0021] Preferably, exactly two busbars run through each lamella, which are electrically connected to the photovoltaic elements. However, more busbars can also run through the lamellae, although not every lamella has an electrical connection. This allows for different types of series connection of the lamellae to increase the voltage. For example, a busbar is alternately electrically connected to the lamellae, or the lamellae are insulated from the busbar. According to the invention, however, the busbars run through all lamellae, even if there is not an electrical contact with every lamella. In an embodiment with two busbars, these are advantageously at the same potential.

[0022] In principle, it is also possible that more than one busbar runs through a recess and that the individual busbars are contacted differently and, for example, are also at different potentials.

[0023] The busbars are advantageously connected at their lower and upper ends to a power grid or a power storage unit.

[0024] The busbars are preferably stationary. In a particularly advantageous embodiment, to allow the busbars to pass through the lamellae, the lamellae each have recesses, openings, or holes through which the busbars are guided. These recesses can either contain electrical contacts to the busbars or be insulated from the busbars to prevent electrical contact. Advantageously, each lamella has at least two recesses, each with a busbar passing through it and in contact with all lamellae for current conduction. The recesses are preferably arranged near the longitudinal ends of the lamellae.

[0025] According to the invention, sliding contacts are arranged in the recesses of the lamellae, which are electrically connected to the photovoltaic elements. The sliding contacts move along the busbar when the lamellae are pulled up and down. Advantageously, the electrical contact between the movable lamellae or sliding contacts and the stationary busbars is also maintained when the lamellae are tilted or rotated.

[0026] The busbars are advantageously contacted from at least two opposite sides. This allows for better and more reliable contact by pressing down from both opposite sides.

[0027] One embodiment of the sliding contacts according to the invention provides that the sliding contacts are designed as at least one electrically conductive contact pin. Advantageously, two contact pins are provided, which establish electrical contact with a busbar in a recess from two opposite sides. Furthermore, the contact pins are advantageously spring-loaded, for example, designed as spring-loaded contact pins. Accordingly, in an advantageous embodiment, the contact pins have a spring mechanism to provide spring-loaded contact with the busbar.

[0028] A preferred embodiment provides two contact pins per recess, which contact the busbar from two opposite sides, perpendicular to the longitudinal orientation of the lamella. The contact pins preferably comprise an outer sleeve with an internally arranged, movably mounted piston. In a simple embodiment of the spring mechanism, the contact pin has a spring that resiliently mounts the piston within the sleeve. This corresponds to a conventional spring-loaded contact pin. The front end of the pin-like piston is designed as a widened head. The piston is advantageously made of an electrically insulating material. The movable, spring-loaded mounting of the piston allows for a telescopic change in the length of the contact pin.

[0029] In another embodiment of the spring mechanism, the entire contact pin is made of an elastic and flexible material, allowing it to bend flexibly. This enables the contact pin to adapt to tilting of the lamellae by bending up or down towards the busbar, as well as to lateral movement, such as that caused by temperature-related changes in the lamella's length, by bending sideways. Advantageously, in this design, the contact surface with the busbar is significantly wider to ensure optimal contact.

[0030] Another embodiment of the sliding contacts, not according to the invention, provides that the sliding contacts are designed as at least one electrically conductive brush, for example, a copper brush. Advantageously, an electrically conductive brush is arranged all around the recess. Alternatively, two individual brushes can also be arranged in the recess, at least on two opposite sides.

[0031] In another embodiment of the lamellae, an electrically insulating insert is formed in the recesses, so that the respective lamella has no contact with a busbar or only has no contact with a specific busbar out of several busbars.

[0032] The different designs of the recesses, with or without sliding contacts and with or without insulation, make it possible to implement more than two busbars or busbars at the same potential. Furthermore, the lamellae can be connected to the busbars in different series configurations; for example, two or three lamellae can be connected in series.

[0033] Preferably, the busbars are designed as an electrically conductive rod, flat strip, or cord. A flat and wide busbar is particularly suitable, as this facilitates contact. The busbars are generally made of a highly conductive material. In a preferred embodiment, a metal or alloy, for example, copper or aluminum, is suitable. Advantageously, one busbar extends over the entire height of the shading device.

[0034] Furthermore, the current dissipation system according to the invention is advantageously protected from weather influences such as rain, sunlight, etc., in order to ensure the longest possible service life with low wear.

[0035] One embodiment of the current dissipation system therefore provides that rubber seals and / or brush seals are inserted into at least sections of the longitudinal openings of the guide rails. These seals do not completely close the longitudinal opening, but allow the guide pins to slide up and down through the seals.

[0036] The advantages of brush seals, for example made of nylon or Perlon, are: The ease of implementation is due to prefabricated strips that can be applied along the longitudinal openings; brush seals are weather and water resistant; the replacement of slats is not affected; and protection in all positions of the slats.

[0037] However, individual bristles can come loose and thus contaminate the busbars. Furthermore, a brush seal does not offer complete protection against the ingress of moisture and dust.

[0038] The advantages of rubber seals, for example made of silicone rubber, are: Protection against splashing water and dirt; easy installation; the replacement of slats is not affected; protection in all slat positions.

[0039] However, there are high demands on the material of the

[0040] Rubber seals are preferred because they should remain permanently elastic and not become brittle. The friction between the guide pins and the seal is significantly greater with a rubber seal than with a brush seal.

[0041] Another embodiment of the current dissipation system provides that a fabric insert is arranged between the guide pins of adjacent louvers. This insert is stretched when the louvers are lowered and at least partially covers the openings of the guide rails. The fabric used is advantageously as flexible, weather-resistant, and breathable as possible, as well as waterproof and UV-resistant.

[0042] The advantages of using fabric include: The longitudinal openings are covered to be dustproof and waterproof; installation is possible with moderate effort; and any moisture that has penetrated can evaporate again.

[0043] However, the fabric insert only protects the longitudinal opening when the slats are lowered. Depending on the material, the individual fabric sections can fray at the edges. Replacing individual slats is made more difficult by the fabric inserts attached to the slats.

[0044] The inventive embodiment of the current dissipation system of a shading device with a plurality of louvers with photovoltaic elements provides that at least two louvers are connected to each other in series to form a set of louvers, wherein the connection points between the two louvers of a set of louvers are electrically coupled to each other in parallel via a busbar.

[0045] If several sets of louvers are used in the shading device, each consisting of two louvers connected in series, this can be achieved by having exactly two louvers connected in series in each set, wherein: The potential-equivalent connection points between the first and second slats of each slat set are electrically connected via a busbar on the first side of the shading device, and each slat set is electrically connected to a positive and a negative busbar on the second side of the shading device, opposite the first side. This results in the slats being arranged alternately from top to bottom with respect to their polarity.

[0046] If several sets of louvers are used in the shading device, each consisting of three louvers connected in series, this can be achieved by designing a current flow system such that each set of louvers has exactly three louvers connected in series, wherein: the potential-equal connection points between the first and second slats are electrically connected via a first busbar on a first side of the shading device, the potential-equal connection points between the second and third slats are electrically connected via a second busbar on a second side of the shading device opposite the first side, and each set of slats is electrically connected to a positive busbar and a negative busbar on one side of the shading device.

[0047] The invention further relates to a shading device, in particular a Venetian blind or a Venetian blind, according to claim 8.

[0048] The shading device is preferably a Venetian blind or a roller blind, in particular a roller blind canopy. The invention is further described using a shading device designed as a Venetian blind as an example.

[0049] The construction of the external venetian blind is the same as that of a conventional external venetian blind. Photovoltaic elements for power generation are attached to the slats, for example, as a complete coating of the slats or to individual sections of the slats. Both conventional first-generation photovoltaic elements and second- or third-generation photovoltaic elements can be used.

[0050] One embodiment of the shading device, particularly a Venetian blind, provides that the blind comprises at least a first slat assembly and a second slat assembly, wherein the slat assembly is tilted differently about its respective longitudinal axes. This type of blind is generally referred to as a two-part blind. Preferably, an upper slat assembly can be rotated or tilted separately from the remaining slats. For example, a lower section of the blind can be completely closed for power generation, while an upper section remains open or at least partially open to allow daylight to enter a room.

[0051] The invention is described in more detail below with reference to the preferred embodiments and the figures, whereby only the features necessary for understanding the invention are shown.

[0052] They show in detail: FIG 1: a schematic top view of two lamellae with the current flow system according to the invention, FIG 2: an enlarged section of one lamella according to the Figure 1 in the area of ​​a recess, FIG. 3: a schematic cross-sectional view through the lamellae according to the Figure 1 FIG. 4: a section of a cross-sectional view in the area of ​​a recess, FIG. 5: a schematic perspective view of two lamellae with the current flow system according to the invention, FIG. 6: an enlarged section of a lamella according to the Figure 5 in the area of ​​a recess, FIG. 7: a schematic top view of the cutout according to the Figure 6 FIG 8: a schematic cross-sectional view of the cutout according to the Figure 6 FIG 9: a schematic representation of a venetian blind with current flow system and a first series connection of the slats, FIG 10: schematically simplified representation of the electrical series connection of the venetian blind according to Figure 9FIG 11: a schematic representation of a venetian blind with current conduction system and a further series connection of the slats, and FIG 12: a schematically simplified representation of the electrical series connection of the venetian blind according to the Figure 11 .

[0053] In the Figure 1 Figure 1 shows a schematic top view of two slats 7 with the current flow system according to the invention. The slats 7 are part of a shading device designed as a venetian blind. For clarity, the guide pins at the lateral longitudinal ends of the slats 7, the pull cords for moving the slats 7, and the other components of the venetian blind are not shown. Each slat 7 has a planar photovoltaic element 7a for generating electricity.

[0054] The current dissipation system according to the invention comprises two busbars designed as electrically conductive rods 4. The rods 4 are connected at their upper and lower ends – not shown here – to a power grid or a power storage unit. Both rods 4 are at different potentials. When the lamellae 7 are moved, the rods 4 remain stationary and are not moved up and down. The lamellae 7 each have two laterally arranged recesses 2 through which the rods 4 are guided. The current generated in the photovoltaic elements 7a is dissipated to the rods 4 via sliding contacts in the recesses 2. For this purpose, the photovoltaic elements 7a have an electrical connection 6, for example, a cable, to the sliding contacts.

[0055] According to the invention, the sliding contacts are designed as two electrically conductive contact pins 10. Figure 2Figure 1 shows an enlarged section (Detail A) in the area of ​​a recess 2. The contact pins 10 each enclose an outer sleeve 11 in which a pin-like piston 12 is movably mounted in a telescopic manner by means of a spring 14. To ensure the best possible electrical contact with the rod 4 or the sliding contact to the rod 4, the front end of the piston 12 is designed as an enlarged or widened head 13. When the lamella 7 is moved up and down, the front ends of the contact pins 10 slide or rub along the rods 4.

[0056] The recesses 2 also contain an electrically insulating insert, which is not shown here. Furthermore, the sleeve 11 is made of an insulating material.

[0057] In the Figure 3 is a schematic cross-sectional view through the lamellae 7 according to the Figure 1The lamellae 7 are shown tilted about their longitudinal axis. The busbar or rod 4 runs through the lamellae 7.

[0058] The Figure 4 Figure 1 shows a section of a cross-sectional view in the area of ​​a recess 2, where the cross-sectional plane runs perpendicularly through the rod 4. The two contact pins 10 are arranged on two opposite sides of the recess 2 and project perpendicularly into the recess 2 to the longitudinal direction of the lamella 7, contacting the rod 4. Since the lamellae 7 are tilted, see Figure 1. Figure 3 The two contact pins 10 have different lengths. The front contact pin 10, shown on the left, is significantly longer than the rear contact pin 10, shown on the right.

[0059] The Figures 5 to 8 Each shows an alternative current discharge system with a non-inventive design of the sliding contacts.

[0060] In the Figure 5 Figure 1 shows a schematic perspective view of two lamellae 7 with the alternative current flow system. The lamellae 7 are shown tilted about their longitudinal axis. In the non-inventive embodiment shown here, see also Figure 2. Figure 6 , The sliding contacts are designed as brushes 5. In the Figure 7 A schematic top view of the lamella 7 in the area of ​​the recess 2 is shown again. The brush 5 is formed around the entire recess 2, so that the round rod 4 is contacted by the brush 5 on all sides. This allows temperature-related changes in the length of the lamellae 7 to be compensated for without the electrical contact being interrupted.

[0061] In the Figure 8 A schematic cross-sectional view through the lamella 7 in the area of ​​the recess 2 is shown. It can be clearly seen that the rods 4 are contacted evenly on both sides by the brush 5.

[0062] The Figure 9 Figure 1 shows an embodiment of the upper part of a venetian blind according to the invention, comprising a slat box 8 and a curtain, the slats of which 7.1 and 7.2 are provided with photovoltaic elements connected in series in sets, each forming a set of slats 7. The photovoltaic elements of the slats are connected in sets to the busbars 4+ and 4- for current dissipation, with each set having a connection of the photovoltaic elements to the busbar 4.z such that a series connection is established between the photovoltaic elements of each pair of slats 7.1 and 7.2 in each set of slats 7.1, thereby adding the voltages U1 and U2 generated by the photovoltaic elements to a total voltage Uges, ideally doubling it. As can be seen from the Figure 9As can be seen, the busbar for the intermediate potential 4z runs on the left side of one guide rail 1, while the two current discharge rails 4+ and 4- run in the right guide rail 1.

[0063] For a clearer illustration, the schematic electrical circuit of the photovoltaic elements mounted on lamellae 7.1 and 7.2 is shown in the Figure 9 again in the Figure 10The diagram shows the negative busbar 4-, which is grounded, on the left. From this busbar, leads extend to the first slat 7.1 of each slat set 7. The first and second slats 7.1 and 7.2 are connected together with reversed polarity to the busbar 4.z, where a common intermediate potential of voltage U1 exists between the first and second slats 7.1 and 7.2. The second slats 7.2 are then connected to the busbar 4+ via the positive side of their photovoltaic elements at their voltage U2, generating a total voltage Utotal = U1 + U2 between the busbars 4- and 4+. The two busbars 4+ and 4- serve to carry the current at the potential of the total voltage Utotal and combine the total power of the venetian blind according to the invention.

[0064] The venetian blind according to the invention therefore consists of a plurality of slat sets 7 connected in parallel connection of serially connected slats 7.1 and 7.2, wherein the intermediate potential between all first slats 7.1 and all second slats 7.2 is interconnected.

[0065] Another embodiment of the venetian blind according to the invention provides that three slats 7.1, 7.2 and 7.3 of a slat set 7 are connected in series, and that the slat sets 7 of the entire venetian blind are connected in parallel, and that the first, second and third slats 7.1, 7.2 and 7.3 are also connected in parallel to each other. Such an embodiment is exemplified in the Figure 11The figure shows the upper part of a venetian blind with a slat box 8, laterally arranged guide rails 1 designed according to the invention, and three slat sets 7. Each slat set 7 contains a first, second, and third slat 7.1, 7.2, and 7.3, each with a photovoltaic element mounted on it. A busbar 4+ and 4- are arranged on the right and left sides of the guide rails, respectively. These busbars are connected to an external power supply and electrically connect the slat sets 7. Additionally, a busbar 4.z is arranged in each of the lateral guide rails 1. This busbar connects the individual slats 7.1 and 7.2, and 7.2 and 7.3, in series and simultaneously connects all first slats 7.1, all second slats 7.2, and all third slats 7.3 in parallel.

[0066] A schematic representation of this electrical circuit from the Figure 11 is in the Figure 12As shown, there are four slat sets 7, each consisting of three slats 7.1 to 7.3. These three slats 7.1, 7.2, and 7.3 are connected in series within each slat set 7. Simultaneously, the slat sets are connected in parallel via busbars 4- and 4+. Furthermore, there is also a parallel connection at the same intermediate potentials of the individual slats 7.1 and 7.2 via the two busbars 4.z, which are each externally insulated. In this way, the resulting operating voltage Utotal can be increased to the sum of the individual voltages U1 + U2 + U3 of the first, second, and third slats 7.1, 7.2, and 7.3, respectively, in order to minimize transmission losses. At the same time, the current draw of the slat sets 7 is summed according to their number in the venetian blind.

[0067] Although the invention has been illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples and other variations can be derived by a person skilled in the art without departing from the scope of protection of the invention. The invention is defined by the claims. List of reference symbols

[0068] 1 Guide rail 2 Recess 4 Busbar / rod 4+ positive busbar 4- negative busbar 4.z Busbar for intermediate potential 5 Brush 6 Connection between sliding contact and photovoltaic element 7 Laminates with photovoltaic elements 7a Photovoltaic element 7.1 First lamination with photovoltaic element of a serial lamination set 7.2 Second lamination with photovoltaic element of a serial lamination set 7.3 Third lamination with photovoltaic element of a serial lamination set 8 Laminate box 9+ positive busbar 9- negative busbar 10 Contact pin 11 Sleeve 12 Piston 13 Head

Claims

1. Current discharge system for a shading installation, in particular for a Venetian blind or for a slatted blind, at least having a plurality of slats (7) having photovoltaic elements (7a) for power generation, wherein at least one busbar (4) is provided, which passes through recesses (2) in the slats (7) and electrically conductively connects said slats to one another in order to discharge the current generated in the photovoltaic elements (7a), wherein sliding contacts, which are electrically conductively connected to the photovoltaic elements (7a), are arranged in the recesses (2) of the slats (7), and wherein the sliding contacts are formed as at least one electrically conductive contact pin (10) and an electrically insulating insert is formed in the recesses (2), characterized in that in each case at least two slats (7.1, 7.2, 7.3) are electrically connected to one another in series repeatedly to form a respective set (7) of slats, wherein the connecting points (9) between the slats (7.1 to 7.2 and 7.2 to 7.3) are electrically coupled to one another in parallel via a respective busbar (4.z).

2. Current discharge system according to the preceding Claim 1, characterized in that at least two busbars (4) passing through the slats (7) are formed.

3. Current discharge system according to the preceding Claim 2, characterized in that exactly two busbars (4), which are electrically connected to the photovoltaic elements (7a), pass through each slat (7).

4. Current discharge system according to any one of the preceding Claims 1 to 3, characterized in that the contact pins (10) have a suspension in order to establish spring-loaded contact of the busbar (4).

5. Current discharge system according to any one of the preceding Claims 1 to 4, characterized in that the busbars (4) are formed as electrically conductive rods, ribbon cables or cords.

6. Current discharge system according to any one of the preceding Claims 1 to 5, characterized in that exactly two series-connected slats (7.1, 7.2) are provided for each set (7) of slats, wherein: - the equipotential connecting points (9) between the respective first slat (7.1) and the second slat (7.2) are electrically connected via a busbar (4.z) on a first side of the shading installation, and - each set of slats (7) is electrically connected to the positive and negative busbars (4+, 4-) on the second side of the shading installation opposite to the first side, wherein the polarity (+, -) of the slats in the shading installation alternates from top to bottom.

7. Current discharge system according to any one of the preceding Claims 1 to 5, characterized in that exactly three series-connected slats (7.1, 7.2, 7.3) are provided for each set (7) of slats, wherein: - the equipotential connecting points (9) between the respective first slat (7.1) and the second slat (7.2) are electrically connected via a first busbar (4.z) on a first side of the shading installation, - the equipotential connecting points (9) between the respective second slat (7.2) and the third slat (7.3) are electrically connected via a second busbar (4.z) on a second side of the shading installation opposite to the first side, - each set (7) of slats is electrically connected to a positive busbar (4+) and a negative busbar (4-) on each side of the shading installation.

8. Shading installation, in particular a Venetian blind or a slatted blind, having a current discharge system according to any one of the preceding Claims 1 to 7, wherein the plurality of slats (7) having the photovoltaic elements (7a) for generating current form a cover and wherein the current discharge system for discharging the generated current is provided.

9. Shading installation according to the preceding Claim 8, characterized in that the cover comprises at least a first package of slats and a second package of slats, wherein the packages of slats can be tilted differently about the respective longitudinal axes of the slats.