Technical Concerns Regarding Low-Cost PV Mounting Systems: A Systematic Analysis from Wind Loads to Structural Reliability

In the design of photovoltaic (PV) power plants, the selection of the mounting system directly impacts overall power generation efficiency and structural safety. Tracking systems, for instance, can significantly increase energy yield compared to fixed-tilt systems, yet they impose more rigorous demands on structural design. In practical applications, rail-based mounting solutions-such as those utilizing solar panel rails and associated mounting hardware-come in various forms; however, their safety relies heavily on the scientific validity of wind load calculations and structural verification methods.

 

 

 

Wind load is a critical parameter determining structural dimensions and stability in PV mounting system design. Two primary calculation approaches currently exist in the engineering field: methods based on empirical coefficients from standards and refined methods based on wind tunnel testing.

 

Standardized designs-such as those employing aluminum rail profiles or racking rails-often rely on simplified wind load models. However, these methods frequently fail to fully capture aerodynamic interference between arrays and the complexities of three-dimensional wind fields.

 

In contrast, system-level designs-such as rooftop rail mounting systems-require greater consideration of factors like wind direction variability, module shielding effects, and coupled structural responses.

 

Furthermore, in actual engineering practice, localized components (e.g., aluminum rail connectors or short rails for roof mounts) are subject to complex stress states. If wind load values ​​are determined using overly conservative or purely empirical approaches, there is a risk of localized structural instability.

 

 

Regarding structural design, significant differences exist among various standards regarding the treatment of component stress modes, particularly concerning flexural-torsional coupling.

 

For example, in modular systems-such as universal rail brackets or mini-rail mounting kits-main beams and connectors are often subjected to simultaneous bending and torsional moments. However, some simplified design methods treat these components using only a single-axis bending model, which can lead to an underestimation of actual stress levels. Furthermore, for outdoor structures designed for long-term service-such as waterproof guide rails and aluminum roof mounting rails-it is essential to account for the impact of corrosion, temperature fluctuations, and long-term material creep on performance.

 

From a system perspective, the soundness of the roof mounting rail system design directly determines the continuity and stability of the load transfer path across the entire array.

 

 

Lightweight PV mounting systems are susceptible to vibration responses in high-wind environments, manifesting in forms such as vortex-induced vibration, buffeting, and aerodynamic instability.

 

Long-span rail systems-such as those utilizing connectors or modular long-rail configurations-exhibit higher structural flexibility, making them more prone to resonance amplification within specific wind speed ranges.

 

Additionally, for continuous load-bearing components like aluminum roof mounting rails, uneven stiffness distribution at connection points can lead to localized fatigue accumulation.

 

From an engineering standpoint, such vibrations not only compromise structural longevity but can also cause micro-cracks in modules and loosen connections, thereby reducing the system's overall reliability.

 

 

 

When selecting components for actual projects, the safety margin of the mounting structure must be evaluated systematically, rather than focusing solely on initial costs or isolated material parameters.

 

For instance, in applications involving mounting rails suitable for various roof types, differing roof conditions significantly alter load transfer paths, necessitating differentiated design strategies.

 

Regarding material selection, aluminum mounting rails must meet long-term outdoor service requirements concerning strength, stiffness, and corrosion resistance.

 

Moreover, in the integrated structural design, the geometric parameters and connection methods of the aluminum rails directly influence the system's overall stability and wind resistance.

 

 

 

The safety of a PV mounting system is not determined by a single factor but is the result of a combination of wind load calculations, structural verification methods, and vibration control capabilities. Over-reliance on empirical formulas or simplified models may reduce initial costs but introduce significant structural risks during long-term operation. Therefore, in engineering design, greater emphasis should be placed on aerodynamic test data, detailed structural analysis, and full-lifecycle reliability assessment to ensure that the photovoltaic system maintains stable, safe, and efficient operation in complex environments.