Surface erosion damage in mounting structures of large-scale photovoltaic systems

A large-scale photovoltaic (PV) plant is a complex infrastructure composed of PV modules supported by metallic mounting structures, which may include motors for module tracking, inverters, cabling, and control systems. While the degradation of PV panels and the corrosion of structural elements are well-studied, limited research has addressed the specific impact of sand erosion on metallic structures in desert and semi-desert environments. This study investigates the erosion resistance of three commonly used galvanized coatings in PV mounting systems: continuous galvanized steel (Z275), Zn-Mg-Al alloy (ZM310), and hot-dip galvanized steel (HDG). Additionally, a representative sample of the aluminum-based motion components, protected by an organic coating, was included. The organic coating was evaluated using ASTM D968-22 and met the AAMA 2604-05 abrasion resistance requirements. Metallic coatings were tested following both ASTM D968-22 and a modified ASTM G76-18 standard adapted to simulate desert conditions. Among the materials tested, the Z275 coating exhibited the lowest erosion rate, outperforming both HDG and ZM310. The findings highlight the importance of considering ductility and mechanical toughness -beyond hardness-when assessing erosion resistance for solar plant structures.