Photovoltaic system and methods for installing a photovoltaic system

Abstract

Photovoltaic system (1) with a supporting structure comprising a plurality of posts (2) anchorable in a ground (3) and at least one bifacial photovoltaic module (4) between two adjacent posts (2), wherein the at least one bifacial photovoltaic module (4) is held at four corners by a retaining element (5) and each retaining element (5) is fixed to one of the posts (2). The invention further relates to a method for mounting a photovoltaic system (1) that can be erected with minimal material and is easy to assemble.

Description

[0001] The present invention relates to a photovoltaic system having a supporting structure with a plurality of posts anchorable in a subsurface and at least one bifacial photovoltaic module between two adjacent posts and a method for assembling a photovoltaic system.

[0002] EP 3 742 602 A1 discloses a photovoltaic system with a supporting structure in which several posts are anchored in the ground and then connected to each other via crossbars. The posts and crossbars form a substantially rectangular mounting field, in each of which at least one photovoltaic module is arranged. This allows the photovoltaic module to be securely fixed to the crossbars and posts all the way around. The construction effort for such a supporting structure is comparatively high because the crossbars each bridge the distance between two adjacent posts, and therefore a large number of assembly steps are necessary to create the supporting structure.

[0003] It is therefore an object of the following invention to provide a photovoltaic system and a method for assembling a photovoltaic system which enable stable mounting of the photovoltaic modules with little use of material and which can be carried out effectively.

[0004] This object is achieved by a photovoltaic system having the features of claim 1 and a method having the features of claim 12.

[0005] The photovoltaic system according to the invention comprises a supporting structure with a plurality of posts anchorable in a subsurface and at least one bifacial photovoltaic module between two adjacent posts. The at least one bifacial photovoltaic module is held at four corners by a respective support element, and each support element is fixed to one of the posts. This allows the at least one bifacial photovoltaic module to be fixed to two posts via the four separate support elements, eliminating the need for additional crossbars or struts. This reduces the assembly effort and the material required to construct the supporting structure.

[0006] The at least one bifacial photovoltaic module is only secured at the four corners and can otherwise be arranged floating between the posts. Furthermore, the problem of shading on the top side of the photovoltaic module is reduced because the support elements are each arranged in only one corner area, allowing the solar radiation coming from above to be used on both sides of the at least one bifacial photovoltaic module to generate electricity.

[0007] Preferably, each holding element has a length in the direction of a longitudinal edge of the at least one photovoltaic module that is less than 20% of the distance between two adjacent posts, preferably between 5% and 15%. The bifacial photovoltaic modules are essentially plate-shaped and, for example, each have a length of between 1 m and 2.5 m on their longer horizontal side, for example 1.5 m to 2 m. Each holding element, on the other hand, has a significantly smaller extension in the horizontal direction, for example between 5 cm and 30 cm, in particular 10 cm to 20 cm, so that the majority of a longitudinal edge of the photovoltaic module is not covered by a holding element.

[0008] To compensate for temperature fluctuations, the at least one bifacial photovoltaic module is slidably mounted on the retaining elements. For this purpose, each retaining element can have a groove into which an edge is inserted, in particular an edge on a longitudinal edge of the at least one photovoltaic module, formed, for example, by a metal strip. This allows the photovoltaic module to expand longitudinally at high temperatures and is slidably held in the groove, preventing thermal stresses. Furthermore, tolerances can be better compensated.

[0009] The at least one photovoltaic module is preferably arranged at a distance from both posts, for example at a distance of at least 1 cm to 8 cm, preferably 2 cm to 6 cm. This allows a large-scale system to be designed to be less opaque.

[0010] To ensure stable fixation of the photovoltaic modules, each holding element is fixed to one of the posts via a threaded rod, which at least partially penetrates the post. Preferably, the threaded rod penetrates the post completely and is fixed on the side opposite the holding element by a nut. The nut can, for example, be cuboid-shaped, and at least one of the nuts forms a spacer for a photovoltaic module that is arranged on the side of the at least one nut. Drilling holes in the posts can be done after the posts have been erected, which simplifies assembly because the height of the individual photovoltaic modules can then be determined on site.

[0011] The at least one post and / or the retaining elements and / or the nut are preferably made from an extruded material comprising a mixture of plastic and natural fibers containing fillers. Such natural fibers can, in particular, be lignocellulose-containing fibers, which can be obtained from wood waste, straw, hay, rice husks, bamboo, grasses, or other natural fibers. A polymer or a mixture of polymers, for example with polypropylene, polyethylene, or other polyolefins, can be used as the plastic. Furthermore, other additives can be added as fillers, for example fibers made of plastic, glass, or other materials, or powdered additives, such as ground cement. The proportion of fillers can be more than 50%, for example between 50% and 80%.Despite the high proportion of natural materials and fillers, such extruded profiles can also be used in humid environments because they are weather-resistant and resistant to decay. The profiles can be cut to any length for the production of posts, support elements, or nuts. The use of lignocellulose-containing fibers in the supporting structure allows for the capture of CO2, which is beneficial from an ecological perspective.

[0012] To reduce material usage, the posts can be designed as a hollow profile, with one or more hollow chambers being provided. The hollow chamber is preferably rectangular in cross-section, as is an outer contour of the posts.

[0013] At least two bifacial photovoltaic modules can be arranged vertically on the posts to ensure effective use of the supporting structure. Crops can be planted between adjacent rows of posts, with the spacing between such rows of bifacial photovoltaic modules being, for example, between 2 m and 5 m.

[0014] In the method according to the invention for mounting a photovoltaic system, several posts are first erected and anchored to or in a substructure. Holding elements are then fixed to the posts, which protrude essentially vertically from a post, for example are aligned horizontally with their longitudinal extent, while the posts protrude essentially vertically. A bifacial photovoltaic module is then inserted into two lower holding elements, in particular into a groove or receptacle on the respective holding element. The bifacial photovoltaic module is subsequently fixed via two upper holding elements, each of which is fixed to a post. The upper holding elements can also have a groove or receptacle for securing the photovoltaic module. The holding elements can be of identical design, thus enabling effective installation.Each photovoltaic module on the supporting structure can be individually dismantled and replaced.

[0015] The invention will be explained in more detail below using an exemplary embodiment with reference to the accompanying drawings. They show: Fig. 1 a view of a photovoltaic system according to the invention; Fig. 2 a detailed view of a post between two photovoltaic modules; Fig. 3A and Fig. 3B two views of a part of a photovoltaic system with two posts, and Fig. 4A and Fig. 4B two detailed views of a holding element for a photovoltaic system.

[0016] A photovoltaic system 1 comprises a supporting structure with a plurality of posts 2, which are fixed in a schematically illustrated subsurface 3. The posts 2 have a vertical extension of, for example, 3 m to 5 m, with a portion of the vertical extension being arranged in the ground, for example, between 60 cm and 150 cm. In the area above the ground, two bifacial photovoltaic modules 4 are mounted between each post 2. These modules are rectangular in plan view and each have a surface for generating electricity on opposite sides.

[0017] In Fig. 2 shows a post 2 between two photovoltaic modules 4 in detail. On the post 2, strip-shaped holding elements 5 protrude on opposite sides, each of which encompasses a corner area of ​​the rectangular photovoltaic module 4 and holds it to the post 2. Each holding element 5 is fixed to the post 2 via a threaded rod that passes through the post 2 and is secured on the opposite side by a nut 8. The nut 8 can form a spacer to prevent a photovoltaic module 4 from coming into contact with the post 2. A distance b of the photovoltaic module 4 from the post 2 can, for example, be between 3 cm and 7 cm. The photovoltaic module 4 is arranged with play towards the nut 8 so that it can expand.

[0018] In the Fig. 3A and Fig. 3B shows two posts 2 of the photovoltaic system 1. Two photovoltaic modules 4 are arranged one above the other between the two posts, with each photovoltaic module 4 being held at a distance from the posts 2 and at a distance from one another. At all four corners of each photovoltaic module 4, holding elements 5 are provided, which have a groove 6 into which an edge 40 of a photovoltaic module 4 is partially inserted. The edge 40 can be formed, for example, by a metal profile of a frame of the photovoltaic module 4. The horizontal edge 40 is fixed to a holding element 5 on the top and bottom of the photovoltaic module 4.

[0019] Due to the fixation in the four corner areas of the photovoltaic module 4, no additional struts or bars are required between two posts 2, as the photovoltaic modules 4 have sufficient inherent stability and the fastening by the four holding elements 5 at the four corner areas is sufficient. The photovoltaic modules 4 are slidably held on the holding elements 5 and can thus expand or contract longitudinally without causing stress.

[0020] Each holding element 5 has an opening 7 into which a threaded rod can be inserted, which extends at least partially, preferably completely, through the post 2. On the side opposite the holding element 5, the threaded rod is fixed by a nut 8 so that the holding elements 5 can be easily installed. For this purpose, after the posts 2 have been erected, an opening is made in the posts 2 through which the threaded rod can then be pushed, so that a holding element 5 and a nut 8 are mounted on opposite sides of the post 2. This also enables subsequent replacement of individual photovoltaic modules 4, which can be mounted independently of one another on the posts 2. For example, two or three photovoltaic modules 4 can be fixed using the height of the posts 2.The photovoltaic modules 4 can be installed at different heights to take into account the contour of the substrate 3.

[0021] In the Fig. 4A and Fig. 4B shows a holding element 5 in detail. The holding element 5 has a length L which is, for example, between 10 cm and 20 cm and is thus significantly shorter than the distance between two posts 2. Each holding element 5 has a groove 6 into which an edge 40 of the photovoltaic module 4 is inserted. Adjacent to the groove 6, a through opening 7 is formed in the longitudinal direction, into which a threaded rod can be inserted. The width B of the holding element 5 can, for example, be in a range between 40 mm and 80 mm, while the height H is also in the range 40 mm to 80 mm. The width B and the height H are preferably less than the width of the posts on the side facing the photovoltaic modules 4.

[0022] The posts 2, the support elements 5, and / or the nuts 8 are preferably made of an extruded material containing a mixture of plastic and natural fibers, optionally also with additional fillers. The use of natural fibers gives the supporting structure a positive CO2 balance, and the embedding of the natural fibers in the plastic makes the posts, support elements, and nuts weather-resistant. List of reference symbols 1 photovoltaic system 2 posts 3 Underground 4 photovoltaic modules 5 Holding element 6 grooves 7 Opening 8 mother 40 Rand b distance B Width H Height L length QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 3 742 602 A1

[0002]

Claims

[1] Photovoltaic system (1) with a supporting structure with a plurality of posts (2) anchorable in a subsurface (3) and at least one bifacial photovoltaic module (4) between two adjacent posts (2), characterized by that the at least one bifacial photovoltaic module (4) is held at four corners on a holding element (5) each and each holding element (5) is fixed to one of the posts (2). [2] Photovoltaic system according to claim 1, characterized by that each holding element (5) has a length in the direction of a longitudinal edge of the at least one photovoltaic module (4) which is less than 20% of the distance between two adjacent posts (2), preferably between 5% - 15%. [3] Photovoltaic system according to claim 1 or 2, characterized by that at least one bifacial photovoltaic module (4) is slidably held on the holding element (5). [4] Photovoltaic system according to one of the preceding claims, characterized bythat each holding element (5) has a groove (6) into which an edge (40) of the at least one photovoltaic module (4) is inserted. [5] Photovoltaic system according to one of the preceding claims, characterized by that the at least one photovoltaic module (4) is arranged at a distance from both posts (2). [6] Photovoltaic system according to one of the preceding claims, characterized by that each holding element (5) is fixed to one of the posts (2) via a threaded rod which at least partially passes through the respective post (2). [7] Photovoltaic system according to claim 6, characterized by that the threaded rod is fixed by a nut (8) on the side opposite the holding element (5). [8] Photovoltaic system according to claim 7, characterized bythat the nut (8) is cuboid-shaped and at least one nut (8) forms a spacer for a photovoltaic module (4) arranged on the side of the at least one nut (8). [9] Photovoltaic system according to one of the preceding claims, characterized by that the at least one post (2) and / or the holding elements (5) and / or the nut (8) are made of an extruded material comprising a mixture of plastic and natural fibers containing fillers. [10] Photovoltaic system according to one of the preceding claims, characterized by that each post (2) is designed as a hollow profile. [11] Photovoltaic system according to one of the preceding claims, characterized by that in the vertical direction at least two bifarcial photovoltaic modules (4) are arranged one above the other between two posts (2). [12] Method for assembling a photovoltaic system (1) comprising the following steps: - erecting several posts (2) and anchoring the posts (2) to or in a subsoil (3); - fixing holding elements (5) to the posts (2) which protrude substantially perpendicularly from one of the posts (2); - Inserting a bifacial photovoltaic module (4) into two lower holding elements (5), and - Fixing the bifacial photovoltaic module (4) via two upper holding elements (5), each of which is fixed to a post (2).

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