In photovoltaic power station projects, corrosion of the supports is a common hazard. If the corrosion resistance is insufficient, the supports may fail prematurely within the 20-year design period, thereby affecting the revenue of the power station.
Currently, there are two commonly used processes:
Hot-dip galvanizing
This process is mature, has a low cost, and the coating thickness is generally 65-100 μm, which can last for more than 20 years. However, in coastal and high-salt-spray areas, "white rust" and "red rust" may occur within 5-8 years.
Aluminum-zinc plating
The aluminum layer can form a protective film, and its corrosion resistance is usually 2-3 times that of hot-dip galvanizing. It is more suitable for coastal or desert power stations. However, it requires higher processing and welding requirements, and the processing cost is also higher.
Application suggestions
Inland power stations: Hot-dip galvanizing is sufficient.
Coastal, islands: Prefer aluminum-zinc plating to extend the lifespan.
Desert environment: Focus on the coating thickness to avoid wind-sand abrasion.
When customers select the type, in addition to the steel thickness, they should also pay more attention to the coating process and salt spray tests. This often determines the actual lifespan of the supports more than "thickness".