Stand for use with an associated photovoltaic module and associated photovoltaic device

Abstract

Base (1) for use as a support for a photovoltaic module (2) and designed for mounting on a flat roof, comprising: - a base body (3), preferably cast or produced by pressing, which - two stands (4a, 4b) and - forms two support surfaces (5a, 5b), - wherein the two standing surfaces (4a, 4b) lie in a common horizontal standing plane (6) and - wherein the two support surfaces (5a, 5b) lie in a common module plane (7) and - wherein the module plane (7) forms an angle α with the standing plane (6), preferably of at least 20° and / or of at most 80°, and thus runs obliquely to the standing plane (6).

Description

The invention relates to a stand which is provided and designed for use as a support for a photovoltaic (PV) module. The stand is designed for mounting on a flat roof and comprises a base body. This base body can preferably be designed as a cast base body, in particular made of concrete, or else be produced by means of a pressing method, for example from old plastic pressed under pressure and temperature. In any case, however, the stand is preferably configured in one piece, because this substantially simplifies the assembly.The invention also relates to a PV device which is based on two such feet.In the field of energy reversals, the removal of renewable energies has been rapidly beginning to travel, in particular the area of photovoltaic (PV) modules which are mounted on roofs has been increasing for years. While this is now legally prescribed in residential houses, especially new buildings, even in individual federal countries, there is still very great unused potential with respect to flat roofs, as are frequently encountered especially in industrial or commercial buildings.The use of PV modules on a flat roof which has just been remanaged has the advantage, for example, that the otherwise customary gravel, which is typically applied to the welded bitumen panels of the flat roof in order to avoid excessive heating of the bitumen panels and to ensure protection against solar radiation, can be dispensed with, because the PV modules substantially take over this shading. This allows further costs to be saved.In addition, the PV modules also provide protection against damage to the tile for the sealing of the flat roof located underneath.Proceeding from this, the invention addresses the problem of how PV modules can be erected cost-effectively on flat roofs.Rectangular concrete feet have already been used on the market on flat roofs, a metallic supporting structure which carries the respective PV module, oriented toward the south, in an inclined position, then being screwed to the concrete foot. The PV module is held and aligned by the complex metallic supporting structure and the concrete foot merely serves for weighting in order to ensure the stability. However, in this approach, holes must first be drilled in the concrete in a complicated manner and the corresponding screws inserted in order to connect the metal construction securely to the concrete foot. In addition, these metallic support structures typically consist of more than twenty individual parts, which first have to be assembled in a complicated manner and finally mounted on the respective concrete foot together with the PV module in situ.Proceeding from this technical background, the object of the invention is to provide an improved technical solution with which PV modules can be erected on flat roofs with as little installation effort as possible and thus in a time-saving and cost-saving manner.To achieve this object, the features of the two independent claims are provided according to the invention. In particular, it is thus proposed according to the invention for achieving the object in a platform of the type mentioned at the beginning that the basic body mentioned forms two platform surfaces and two support surfaces, wherein the two platform surfaces lie in a common horizontal platform plane and the two support surfaces lie in a common module plane. Furthermore, to achieve the object and in particular to avoid the otherwise customary metallic supporting structure, it is provided that the module plane encloses an angle α with the standing plane. Thus, the module plane extends obliquely to the base plane. If a PV module is accordingly held in the module plane by the stand, this PV module (more precisely the module plane taken by it) is thus aligned obliquely to the stand, as is advantageous for optimum solar energy generation.Depending on the configuration, the angle α can preferably be at least 20° and / or at most 80°. The angle α can preferably be in the range 30°≤α≤70°. In addition to the geographical latitude of the location, the selection of the angle α also depends on the inclination of the surface on which the foot is to be placed finally. In the case of a flat roof with a roof surface running as far as possible horizontally, the angle α thus corresponds to the angle of inclination between the module plane and the horizontal. Typical of installation locations in Germany (for example at a latitude of 50°) would be an angle of approximately 45°+ / -15°, for example. Thus, depending on the geographic installation location, different types of feet according to the invention can be produced in order to always ensure optimum alignment of the PV module with respect to the sun.What is advantageous with this embodiment is above all that a complex metallic supporting structure, which conveys between the stand and the PV module and is arranged therebetween, can be completely dispensed with, as a result of which considerable outlay on material and assembly and thus costs can be saved. In other words, an associated PV module can thus be mounted directly (i.e. without a mechanical substructure lying therebetween) on the respective supporting surface which the respective foot according to the invention provides.A further advantage consists in mass-compatible and thus cost-effective production of the stand with the aid of a casting or press mold. In this case, it is also possible very easily to produce different shapes in order to service different customer desires, for example with respect to the size, shape or angle α of the foot. Furthermore, with the concept according to the invention, just-in-time production of the feet is possible very easily, which saves storage costs.The respective bearing surface can offer at least three defined bearing points, whereby a tilt-free placement is simplified.According to the invention, the object can also be achieved by further advantageous embodiments according to the dependent claims, which we describe below:The said base body of the foot can preferably exhibit an H-shape. For example, the base body may form (together) a rear pillar, a front pillar, and a bridge connecting the rear pillar to the front pillar in a longitudinal direction. In this case, the front pillar is situated opposite the rear pillar with respect to a longitudinal direction and is configured to be shorter than the rear pillar (in a vertical direction which runs perpendicular to the standing surface).The pillars form one of the two support surfaces of the foot at their lower end and one of the two support surfaces at their upper end. The pillars thus absorb the weight load of the module via the bearing surfaces and conduct it into the standing surface. The bridge positions the two pillars at a defined distance from each other and provides additional weight, which increases durability and is advantageous in particular at high wind loads acting on the PV module.A preferred embodiment provides that the bridge forms a depression in its center, which is designed to accommodate a cross strut. By means of such a cross strut, two identical feet according to the invention can be mechanically connected to one another, as a result of which, on the one hand, their transverse spacing can be fixed and, on the other hand, the stability of the entire supporting structure (comprising the two feet and the cross strut) is increased. The cross strut can be firmly connected to the respective foot by means of corresponding connecting means such as a screw connection, or can be positively connected to the foot merely by positive locking with the respective trough.A further advantageous embodiment provides that the rear pillar (preferably on an outer surface facing away from the opposite front pillar) forms a recessed grip. Alternatively or additionally, such a recessed grip can also be formed on the front pillar, then preferably in that outer surface of the front pillar which is facing away from the rear, opposite pillar. It is particularly preferred in this case if a rear grip recess is arranged within an upper half of the rear pillar and / or if a front grip recess is arranged approximately at the height of the center of the front pillar. The design of the two opposing front and rear depressions is advantageous because the foot can thus be securely carried around by two persons. Thus, in this way, the ergonomy and the work safety can be improved, so that the placement of the concrete feet is much easier to manipulate.According to a further embodiment, it can be provided that the rear pillar tapers upwards in a transverse direction running transversely to the longitudinal direction (i.e. in the direction of the mentioned vertical direction). This taper may be at least 20% or even at least 30% if, for example, the lateral extent in the transverse direction at the lower and upper ends of the pillar is compared with one another. This has the result that, in the case of such a configuration, a lateral extent of the bearing surface formed by the rear pillar in the transverse direction can be correspondingly smaller (at least 20% or even 30% smaller) than a lateral extent of the bearing surface formed by the rear pillar.As already mentioned, the base body can be manufactured / cast from a casting material. This casting material can be concrete in particular.An alternative embodiment to this, however, provides that the base body is produced from a material which has been pressed under pressure and temperature (within a press mold), in order in this way to define the shape of the base body. Suitable materials for this batch are, in particular, used plastics which have been recycled.A further preferred embodiment provides that in the respective bearing surface at least one receiving body is cast into a material of the base body or pressed therein. In this case, the receiving body, which can be designed, for example, in the form of a plastic dowel, is provided for screwing in a fastening screw and is designed for this purpose. By screwing a fastening screw into the respective receiving body (which is already firmly integrated into the base body and therefore does not first have to be introduced manually laboriously at the installation site), it is possible to connect a PV module directly to the support surface, wherein a fastening element (hook element or the like) can be used in this case, which transmits fastening forces to a frame of the PV module.Alternatively, at least receiving holes can already be formed in the respective bearing surface during the shaping / production of the base body (e.g. by "casting" the respective hole in concrete), so that at least no holes have to be drilled. In this case, separate receiving bodies such as commercially available dowels can be introduced into the receiving holes placed in front in this way in order subsequently to screw the fastening screws into these receiving bodies. This solution is technically equivalent with respect to the fastening forces that can be achieved, but requires a higher installation effort on site.The two said bearing surfaces, which are formed at the upper end by the base body, can each be provided with a rubber-elastic mat which is firmly connected to the respective bearing surface. For example, the mat can be cast into the base body, i.e. connected to the base body by casting. Or the mat was glued onto the support surface. It is advantageous in such embodiments that when the PV module is mounted on the stand, the underside of the PV module can be pressed into the respective rubber-elastic mat of the support, whereby a very secure and at the same time non-destructive mounting can be ensured. Neoprene, for example, is suitable as the material for the rubber-elastic mat.It is furthermore advantageous if the two footprints of the foot are each provided with a rubber-elastic mat which is firmly connected to the respective footprint. This connection can also be achieved, for example, by casting with a material of the base body or by means of adhesive bonding. The technical advantage of such a "rubber coating" (e.g. made of neoprene) of the stand surfaces of the stand is that the stand can be placed on the flat roof in a slip-proof manner. Therefore, a separate rubber mat below the foot must then also not be designed beforehand in a complicated manner, which often forms folds and therefore produces considerable effort. Furthermore, such a configuration is advantageous because no anchoring / connection / screw connection between the stand and the flat roof has to take place in this way, which is why the position of the PV modules on the flat roof can also be adapted relatively easily and the sealing of the flat roof is not impaired.One embodiment provides that the respective mat provides a fiberized surface (similar to a hook and loop fastener) on its upper side. This fiberized surface can then be pressed into the liquid casting material of the concrete foot, so that the mat irreversibly bonds to the casting material during curing (which can be used both on the standing surfaces and on the supporting surfaces). As a result, the mats which are integrated in the standing surfaces no longer have to be placed on site at the correct location on the flat roof in a complicated manner, but instead land directly at the correct location when the concrete feet are placed on. The same applies to the mats in the region of the bearing surfaces.In addition, it is advantageous if the two footprints have an added-up overall length L 1+L 2 in a longitudinal direction of the foot of at least L 1+L 2=20 cm. This minimum length leads to sufficient stability due to sufficient static friction, wherein the bearing surfaces can have a minimum width in the lateral transverse direction of at least 5 cm, preferably of at least 8 cm.By means of shaping and material selection, the weight of the foot can be selected such that it is preferably less than 45 kg, particularly preferably even less than 40 kg. Such a configuration has the advantage that the physical work when depositing the feet on the flat roof is facilitated and the resulting roof load also remains limited.With regard to a preferred geometry of the foot, it can be provided, for example, that the rear pillar has a maximum height of 60-90 cm, ideally of 65-75 cm. The front pillar, on the other hand, can have a minimum height of 10-30 cm, ideally 15-25 cm. And finally, the stand can have an overall length of 80-100 cm, ideally of 85-95 cm, in the longitudinal direction.To achieve the object mentioned, the invention furthermore provides the features of the independent claim, which is directed to a PV device. This device can be used to efficiently convert sunlight into electrical current using the PV module. This (PV) device according to the invention comprises a PV module (which is preferably embodied in a framed manner, i.e. equipped with a module frame) and two feet according to the invention, as have been described above and are claimed herein. According to the invention, it is now provided that the two feet are aligned with respect to one another in such a way that their two longitudinal axes run (approximately) parallel to one another. In order to produce additional stability, the two parallel feet can preferably be connected to one another by means of a cross strut. This cross strut can be inserted into a respective trough formed in the mentioned bridge of the respective foot and there connected to the foot in a positive or non-positive manner (e.g. by means of a screw connection), for example.The PV module can preferably be of monofacial or else bifacial design and is oriented obliquely to the horizontal by the module plane which is predefined by the two bearing surfaces of the respective stand, in order thus to achieve optimum energy yield.According to the invention, it is further provided that the PV module rests with its underside on the support surfaces of the respective stand or is supported there. This can preferably be realized by a rubber-elastic mat (in particular integrated into the said bearing surface of the stand, as already described above) and / or by a fastening element (designed as a separate component).The two feet (and optionally the optional cross strut) thus form a supporting structure which is already designed such that the PV module can be mounted directly on the two feet, in particular without complex metallic substructure lying therebetween. For this purpose, it is decisive that the support surfaces of the two feet (provided they are set up with their respective support surfaces on a plane, for example a flat roof) already lie in the later module plane, in which the active surface of the PV module is also intended to be oriented toward the sun, in order to provide an optimum power output. The fastening elements can also be configured in a correspondingly simple manner, namely in particular without joints, because the underside of the PV module and the bearing surfaces of the respective stand already extend parallel to one another in the final assembly position. In the simplest case, the fastening elements can be designed, for example, in the form of retaining clips made of bent sheet metal, each of which has a receptacle / a through hole for a fastening screw.One configuration provides that the fastening elements each form small barbs, which dig into the frame of the PV module in a tooth-like manner in order to enable improved mounting.The respective mechanical connection between the PV module and the respective foot is preferably configured exclusively in the region of a frame surrounding the PV module (and belonging to the PV module) with the aid of a respective fastening element. The respective fastening element is screwed here with a fastening screw directly into the base body of the concrete foot, preferably into the mentioned receiving bodies integrated therein. As a result, a respective holding force, mediated by the fastening element, can be introduced onto the PV module (preferably onto the upper side of the module frame), wherein preferably only four such fastening points per PV module (or two per foot) can be provided. Alternatively, bracket closures with a snap mechanism can also be used as fastening elements, which, however, are / are preferably likewise directly connected to the base body by means of a fastening screw.A preferred embodiment provides that the PV module, in particular the aforementioned frame of this PV module, is fixedly mounted on the respective one of the total of four support surfaces (which provide the two feet) by means of a respective fastening element (in particular the aforementioned). In this case, the fastening element can be designed, for example, in the form of a simple bent sheet metal part. It is furthermore preferred if the respective fastening element / the sheet metal part is fixedly mounted on the respective bearing surface of the respective stand by means of only one single fastening screw (per fastening element). In other words, it can thus be provided that the PV module is supported by the two feet at four support points, wherein these four support points define a rectangle.Almost all PV modules available on the market have a rectangular format, with a long side and a short side. According to the invention, it can therefore be provided that a long side of the PV module of the PV device runs in the longitudinal direction of the respective foot. In this case, the short side of the PV module is thus oriented along the transverse direction, which also corresponds to the longitudinal direction of the optionally usable transverse strut. In such a configuration, the respective foot can be selected to be so short in its longitudinal direction that the PV module (relative to the longitudinal direction of the foot) protrudes beyond the respective foot on the front and rear sides. As a result, the usable roof surface can be optimally used for the installation of the PV modules.The invention will now be described in more detail with reference to exemplary embodiments, but is not limited to these exemplary embodiments. Further embodiments of the invention may be obtained from the following description of a preferred embodiment in conjunction with the general description, the claims and the drawings.It shows: FIG. 1 shows a side view of a stand according to the invention, FIG. 2 is a rear view of the foot of FIG. 1, FIG. 3 shows a perspective illustration of a fastening element, and finally FIG. 4 shows a side view of a further foot according to the invention.FIG. 1 shows a foot 1 cast from concrete, which can be placed on a flat roof in order to support a photovoltaic (PV) module 2, as illustrated in FIG. 4. The stand 1 is formed by a base body 3 which forms two planar stand surfaces 4 aand 4 bon its underside and two support surfaces 5 aand 5 baligned obliquely to the stand surfaces in the upper region. While the two support surfaces 4 aand 4 bare thus located in the illustrated horizontal support plane 6 (which can coincide, for example, with the plane of the flat roof), the two support surfaces 5 aand 5 bare, on the other hand, arranged in a common module plane 7, in which the PV module 2 is intended to be located later (compare FIG. 4 ). The module plane 7 encloses an angle α of somewhat less than 45° with the standing plane 6.It can likewise be seen well in FIG. 1 that the base body 3 has an H-shape in the side view. This is because the base body 3 forms both a long rear pillar 8, a shorter front pillar 9 and a bridge 10 which connects the two pillars 8, 9 to one another in the illustrated longitudinal direction 12. In the center of the bridge 10 there can be seen a trough 17 which, as illustrated in FIG. 4, is designed to receive a cross strut 28 by means of which two feet 1 according to the invention can be connected to one another transversely. By means of the two recessed grips 11 aand 11 b, which are formed in the outer surfaces 18 of the respective pillar 8, 9, the foot 1 can be safely carried around and placed down by 2 persons.In order to prevent the foot 1 from slipping on the surface of the flat roof as far as possible, rubber-elastic mats 16 a, 16 bare integrated into the respective standing surfaces 4 a, 4 b,by means of which the foot 1 stands on the standing plane 6.In the example of FIG. 4, such rubber coverings 16 cand 16 dare also each formed in the region of the bearing surfaces 5 a, 5 b,so that the PV module 2 located there can rest with its underside 14 on the bearing surfaces 5, but mediated by the two mats 16 c, 16 d. Instead of being designed as mats, these rubber coverings 16 cand 16 dmay also be designed, for example, in the form of rubber-elastic washers. In all these cases, these rubber coverings 16 c, 16 d avoided the occurrence of mechanical stresses between the PV module 2 and the concrete foot 1 when the PV module is fixedly mounted directly on the foot 1 (cf. FIG. 4 ).The PV module 2 is fastened to the stand 1 by means of separate fastening elements 23, which can be designed, for example, as bent sheet metal parts as shown in FIG. 3. These fastening elements 23 are each screwed directly to the stand 1 by means of a fastening screw 25 (the fastening elements 23 have corresponding through-holes for the respective screw 25); a substructure lying therebetween can thus be dispensed with. For this purpose, in the region of the two bearing surfaces 5 aand 5 b, respective receiving bodies 24 with an internal thread are cast into the base body 3, so that the respective fastening screw 25 can be screwed into the respective receiving body 24.After mounting the PV module 2 in the orientation shown in FIG. 4, a PV device 13 can thus be obtained with greatly reduced mounting effort, which converts sunlight efficiently into electrical current. The otherwise customary complex substructure made of various metal parts in order to produce a connection between a stand weight and the PV module 2 and in particular align it around the PV module 2 obliquely to the sun can thus be dispensed with.In summary, a novel stand 1 is thus proposed, which can be used to directly support a photovoltaic (PV) module 2 without using a complex substructure and thereby to align it in a robust and secure manner on a flat roof in a desired oblique position with respect to the sun. For this purpose, a base body 3 of the stand 1 forms two support surfaces 5 a, 5 bwhich specify a module plane 7 and thus the orientation of the PV module 2 (cf. FIG. 1 ).The essential advantages of the invention are: a) a greatly simplified assembly and thus a saving in time and costs; b) a saving in weight compared to previously known cast feet; c) an increased stability, in particular against tilting; d) the possibility of being able to produce the feet 1 just-in-time in a suitable quantity as required by means of a casting method--for only the casting mold, the casting material and, if appropriate, the receiving bodies 24 to be introduced have to be stored.List of reference characters1 Stand 2 photovoltaic (PV) module (for use with / mounting on 1) 3 base body 4 stand surface (of 1) 5 support surface (formed by 1, serves as a support for 2) 6 stand plane (can coincide, for example, with the plane of a flat roof; runs through 4) 7 module plane (runs through 5) 8 rear pillars 9 front pillar 10 bridge (connects 8 to 9 in the longitudinal direction) 11 grip well 12 longitudinal direction (of 3; for example connecting line of 8 to 9 running through 10) 13 photovoltaic device (comprises twice 1 and once 2) 14 underside (of 2) 15 upper side (of 2) 16 rubber-elastic mat / rubber covering (preferred minimum thickness: 2 mm) 17 well (formed by 10; for receiving a cross strut which connects 1 to 1 transversely) 18 outer surface (of 8 / 9) 19 transverse direction (extends transversely to 12) 20 vertical direction (extends normally to 4) 21 long side (of 2) 22 short side (of 2) 23 fastening element 24 receiving body (in particular in the form of a plastics material sheet) 25 fastening screw 26 washer 27 active surface (of 2) 28 cross strut

Claims

Stand (1) for use as a support for a photovoltaic module (2) and designed for mounting on a flat roof, comprising: - a base body (3) which is preferably cast or produced by pressing and which - forms two stand surfaces (4a, 4b) and - two support surfaces (5a, 5b), - wherein the two stand surfaces (4a, 4b) lie in a common horizontal stand plane (6) and - wherein the two support surfaces (5a, 5b) lie in a common module plane (7) and - wherein the module plane (7) encloses an angle α, preferably of at least 20° and / or of at most 80°, with the stand plane (6) and thus extends obliquely with respect to the stand plane (6).The stand (1) according to claim 1, - wherein the base body (3) exhibits an H-shape and / or - wherein the base body (3) forms - a rear pillar (8), - a front pillar (9) which is opposite the rear pillar (8) in a longitudinal direction (12) and is configured shorter than the rear pillar (9), and - a bridge (10) which connects the rear pillar (8) to the front pillar (9) in the longitudinal direction (12).The stand (1) according to claim 2, - wherein the bridge (10) forms a depression (17) in its center for receiving a cross strut (28).Stand (1) according to claim 2 or 3, - wherein the rear pillar (8) and / or the front pillar (9), preferably on respective outer surfaces (18) facing away from the opposite pillar (9 / 8), forms / form a grip recess (11a, 11b), - preferably wherein a rear grip recess (11a) is arranged within an upper half of the rear pillar (8) and / or wherein a front grip recess (11b) is arranged approximately at the height of the center of the front pillar (9).The stand (1) according to any one of claims 2 to 4, - wherein the rear pillar (8) tapers upwards in a transverse direction (19) running transversely to the longitudinal direction (12), preferably by at least 20%, particularly preferably by at least 30%.The stand (1) according to one of the preceding claims, - wherein the base body is cast from a casting material, preferably from concrete.Stand (1) according to one of Claims 1 to 5, - wherein the base body (3) is produced from a material which is pressed under pressure and temperature, in particular from old plastic.Stand (1) according to one of the preceding claims, - wherein in the respective bearing surface (5a, 5b) at least one receiving body (24), in particular in the form of a plastic dowel, is cast into a material of the base body (3) or pressed therein, wherein the receiving body (24) is configured for screwing in a fastening screw (25).Stand (1) according to one of the preceding claims, - wherein the two bearing surfaces (5a, 5b) are each provided with a rubber-elastic mat (16) which is firmly connected to the respective bearing surface (5a, 5b), for example by casting with a material of the base body (3) or by means of adhesive bonding.Stand (1) according to one of the preceding claims, - wherein the two stand surfaces (4a, 4b) are each provided with a rubber-elastic mat (16) which is firmly connected to the respective stand surface (4a, 4b), for example by casting with a material of the base body (3) or by means of an adhesive bond, and / or - wherein the two stand surfaces (4a, 4b) have an added-up total length L1 + L2 in a longitudinal direction (12) of the stand (1) of at least L1 + L2 = 20 cm.The foot (1) according to any one of the preceding claims, wherein a weight of the foot (1) is less than 45 kg, preferably less than 40 kg.The stand (1) according to claim 2, - wherein the rear pillar (8) has a maximum height of 60-90 cm, preferably of 65-75 cm, and / or - wherein the front pillar (9) has a minimum height of 10-30 cm, preferably of 15-25 cm, and / or - wherein the stand (1) has an overall length of 80-100 cm, preferably of 85-95 cm, in the longitudinal direction (12).Photovoltaic device (13) comprising - a, preferably framed, photovoltaic module (2) and - two feet (1), each configured according to one of the preceding claims, - wherein the two feet (1) are arranged running parallel to one another and are preferably connected to one another by means of a cross strut, - wherein the photovoltaic module (2) rests with its underside (14) on the support surfaces (5a, 5b) of the respective foot (1), preferably mediated by a rubber-elastic mat (16) and / or a fastening element (23).Photovoltaic device (13) according to the preceding claim, wherein the photovoltaic module (2), in particular a frame of the photovoltaic module (2), is fixedly mounted on the respective one of the total of four support surfaces (5) by means of a / the respective fastening element (23), preferably in the form of a bent sheet metal part, and namely preferably by means of only one single fastening screw (25) per fastening element (23), - in particular so that the photovoltaic module (2) is supported by the two feet (1) at four support points defining a rectangle.Photovoltaic device (13) according to one of the two preceding claims, wherein the photovoltaic module (2) has a rectangular format with a long side (21) and a short side (22) and wherein the long side (21) runs in the longitudinal direction (12) of the respective stand (1), - in particular wherein the photovoltaic module (2) projects beyond the respective stand (1) on the front and rear side, with respect to the longitudinal direction (12).

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