The sizing of photovoltaic structures is a strategic step to ensure the safety, performance, and economic viability of projects. Far beyond the simple definition of metal supports, the process involves advanced structural analyses, computer simulations, and strict compliance with Brazilian technical standards.
From initial design to laboratory testing, each phase is crucial to ensuring the structure can withstand real-world operating conditions, especially wind loads and mechanical stresses.
During the design phase of a photovoltaic structure, a basic drawing is created that defines all the structural and commercial parameters to be met, such as wind speed, terrain slope, distance between stakes, panel height, latitude where the structure will operate, among others.
Based on this basic design, a preliminary assessment of the thicknesses, materials, and profiles to be implemented is carried out, and with this information, the 3D modeling of the structure will be performed to begin the structural design.
3D allows us to apply structural analyses such as FEA and CFD, with FEA being the finite element analysis that simulates the maximum deformations and stresses of individual components when a force, vibration, and other physical effects are applied.
CFD is computer-aided fluid dynamics analysis, where we can calculate, using wind speeds and angles of attack, what the wind pressure and turbulence will be, allowing us to optimize the points of greatest impact.
I emphasize that all analyses and designs must comply with current Brazilian standards (NBRs). For CFD design, the premises of ABNT NBR 6123 are used, which, through its factors S1, S2, and S3, allows for the calculation of the standard wind that will be analyzed in the simulation.
In the preliminary and final design phases, certain principles must be used, such as those applied in ABNT NBR 6355, which defines the main types of cold-formed steel structural profiles. After analysis, deformations must comply with the parameters of ABNT NBR 8800, which addresses structural deformations. Currently, there is no specific standard for the design of photovoltaic structures.
With the initial analyses carried out, the results are used to optimize the structures, for example, using profiles with less thickness where there is no accumulated stress, reducing or increasing the hardness of the structural material, using profiles that consume less steel such as the U-profile, and thus arriving at a robust and commercially viable result, given that the solar market today is very specialized and competitive.
After all the virtual analyses and optimizations, the structure is tested in the laboratory, where the stresses and resistances of each piece are measured individually, in addition to being tested in a wind tunnel to analyze real loads, thus validating all the studies and releasing the structure for commercial sale.
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