The subject of the solution is a support structure for photovoltaic panels. The disclosed solution relates to support structures designed for flat roofs or roofs with insignificant slope angles, in particular for double-sided photovoltaic panels.

Photovoltaic installations are currently regarded as a multi-year investment with an estimated payback of 6 to 10 years, where the lifetime of photovoltaic panels reaches up to 30 years. Photovoltaic panels still only utilise a small part of the sun's energy. Various solutions are being sought to increase the efficiency of the panels. A relatively new solution is bifacial modules, where both sides of the panel cells absorb sunlight. The other side of the panel acquires energy from reflected rays, so the mounting location becomes extremely important, as does the supporting structure, which contributes to reducing the access of light. Numerous studies have shown that, under reference conditions (panel without restricted light access) in an analogous position to a photovoltaic panel mounted on support structures, with a reflectance of 90%, the production of the back side of the module reaches 40% of the front side.

Known from the state of the art are free-standing support structures designed for double-sided panels.

Utility model CN213094111U discloses a solution for a support structure, where a photovoltaic panel is set with its side edges on brackets and the brackets are connected to supports. The supports shown in the example are longer than the length of the side edges of the panel. The upper support is at right angles to the brackets and the lower support is inclined towards the upper support. The supports are mounted on two mounting rails, parallel to the brackets, by means of movable connectors. In one variant, the rails are connected to each other. The angle of inclination of the solar support can be adjusted manually, thanks to the movable connectors.

A method and assembly for attaching strip to photovoltaic and/or solar panels on flat roofs is known, as described in patent EP2362428B1. The arrangement has a laminate strip provided with a fiber reinforcement and a matrix material that encloses the fiber reinforcement and comprising sufficient width. The laminate strip is arranged on a flat roof, and profile rails are fitted at the laminate strip and pasted with each other by the matrix material of the laminate strip. The profile rails comprise openings located in a support surface that points to the flat roof. The matrix material fills the openings with or without the fiber reinforcement that is made of textile fabric or polyester grid fleece.

The purpose of the solution is therefore to provide a photovoltaic module support structure that will provide the highest performance of double-sided photovoltaic modules possible in a fixed panel position, taking into account the light access to both sides of the module resulting from the positioning of the photovoltaic module and the shading resulting from the support structure itself.

According to the solution, a support structure for photovoltaic panels including mounting rails, brackets, supports, characterised in that a bottom bracket supports a photovoltaic panel A along a bottom edge A located more than 30cm above the ground, to which a mounting rail is attached, and an top bracket supports a photovoltaic panel B along a top edge B, where a photovoltaic panel A and a photovoltaic panel B are inclined at an angle between 10 and 30 degrees to the horizontal. The bottom bracket is supported on and connected to two bottom supports, and the top bracket is supported on and connected to two top supports. The bottom supports and the top supports are attached to mounting rails fixed to the building structure and facing outwards of the photovoltaic panel A and the photovoltaic panel B, respectively, inclined at an angle of not more than 80 degrees to the mounting rails. As well as providing optimum solar exposure to the upper surface of the panel, the design does not restrict light from reaching the side edges (it does not create shading). This is due to the fact that the panels face south, with the sun rising and setting to cast light precisely on the side edges of the panel. When the sun is in its zenithal position it illuminates the panel centrally. By electrically connecting solar cells in series, all the solar cells in the area of one panel act as the weakest of the cells. In the area of the lower part of the panel, none of the cells are shaded by its elements, the supports are adjacent to the panel frame and the supports, which are inclined vertically towards the supported panels, are moved away from the area where the rays illuminating the lower part of the panel are scattered. This has the effect of increasing the efficiency of each cell of the lower panel surface. In previous designs, this effect was not taken into account. Supporting structures were created under the panels and not, as in the solution presented, between them. In addition, uniform illumination of all cells increases the service life of the entire panel by eliminating the "hot spot" effect, which arises to a greater or lesser extent in the area of cells that are less well illuminated than others.

Preferably, the bottom bracket and the top bracket are no wider than the photovoltaic panel frame, they are thin- walled sections with an open, L- shaped profile, clinging to the photovoltaic panel frame. The illumination of the outer cells of the panel is very close around the entire perimeter of the panel - the brackets have no effect on the operation of the system.

Preferably, the length of the bottom bracket and the top bracket is not greater than the length of the bottom edge A and the top edge B.

Preferably, the mounting rail has side walls and a base containing numerous holes. The design of the rail enables it to be fixed to the building structure by means of anchors and also by bonding with adhesive or sealing the joints by flooding with adhesive, so that there is no leakage of the building structure in the anchoring area.

Preferably, the bottom supports and top supports are C-shaped open profile sections. Preferably, the bottom supports and the top supports are connected to the bottom bracket, the top bracket and the mounting rail respectively with a screw connection, and in the C- connection areas the bottom supports and the top supports fill cores. The cores are designed to increase torsional and crushing strength in the connection area between the two components ensuring stable connections.

Preferably, the cores extend along the entire length of the bottom support and the top support. Filling the supports with cores increases their resistance to bending and torsional loads on the structure, allowing narrower supports to be used and therefore allowing more light into the underside of the panel.

The subject matter of the invention is illustrated by examples which do not limit its scope. The invention is illustrated in the figures:

• fig. 1. - support structure in axonometric view

• fig. 2. - application of support structures in multi-panel photovoltaic installations

• fig. 3. - supporting structure in side view

• fig. 4. - axonometric view of support structure with long core

• fig. 5. - degree of illumination of the underside of the panel

• fig. 6. - state of the art: degree of illumination of the underside of the panel

In the example solution shown in fig. 1 a support structure for photovoltaic panels comprising two mounting rails 8, a bottom bracket 2, a top bracket 4, two bottom supports 6 and two top supports 7. The bottom bracket 2 and the top bracket 4 are narrower than the frame of the photovoltaic panel 12, they are thin-walled sections with an open profile, L-shaped, adhering to the frame of the photovoltaic panel 12. The L-shaped profiles of the bottom bracket 2 and the top bracket 4 are parallel to each other and directed by the inner angle of the L-shaped profile in opposite directions towards the outside of the structure. The bases of the L-shaped profiles of the bottom bracket 2 and the top bracket 4 are both inclined from the horizontal at an angle of 20 degrees. In alternative variants, the bases of the L- shaped profiles of the bottom bracket 2 and the top bracket 4 can be inclined from the horizontal at an angle of 10 to 30 degrees, analogous to the inclination range of the photovoltaic panels 1 A and IB. The bottom bracket 2 supports a photovoltaic panel A 1 A along the bottom edge A 3 A located 40cm above the ground to which the mounting rail 8 is attached. The top bracket 4 supports the photovoltaic panel B IB along the top edge B 5B, where the photovoltaic panel A 1A and the photovoltaic panel B IB are inclined at an angle of 20 degrees to the horizontal. The bottom bracket 2 is supported by and connected to two bottom supports 6 by a screw connection, and the top bracket 4 is supported by and connected to two top supports 7 by a screw connection. The bottom supports 6 and the top supports 7 are bolted to mounting rails 8 fixed to the building structure. Alternatively, parts can be welded instead of bolted connections. The bottom supports 6 and the top supports 7 face outwards of the photovoltaic panel A 1 A and the photovoltaic panel B IB, respectively, i.e. they are inclined in opposite directions towards each other at an angle of no more than 80 degrees. In the example shown in fig. 1 they are inclined at an angle of 75 degrees to the mounting rails 8. The length of the bottom support 2 and the top support 4 is no longer than the length of the bottom edge A 3A and the top edge B 5B. The mounting rail 8 has side walls 9 and a base 10 containing numerous holes 11. The bottom supports 6 and the top supports 7 are C-shaped open profile sections. The C-shaped bottom supports 6 and top supports 7 are filled with a total of eight cores 13 in the connection areas to the rest of the structure. The cores 13 are made of plastic.

Fig. 2 shows how the photovoltaic panels are mounted on the support structures described above.

Fig. 3 shows the extent and direction in which the individual elements are inclined.

Fig. 4 shows a support structure whose top supports 7 are filled with cores 13 along their entire length.

Figs. 5 and 6 show the degree of illumination of the underside of the photovoltaic panel with identical exposure for the supports according to the proposed support structure (fig.5) and for the supports known from the state of the art, where the dimension of the profile supporting the panel frame significantly exceeds it. In extreme cases, the power of the underside drops by up to more than 50% as a result of the shading of the extreme cells by the brackets, and these, connected in series in the installation, limit the power of the other cells.