Wuxi Guoyin Metal Material Co., Ltd.

Application advantages and cost-effectiveness analysis of weathering steel in photovoltaic brackets

With the global photovoltaic installed capacity exceeding 1.5TW, the support system accounts for more than 15% of the total investment in power stations. Traditional galvanized steel supports face pain points such as high cost and high environmental pressure, while photovoltaic weathering steel, with its "rust-proof" characteristics, is becoming a disruptive solution in the field of new energy steel. This article will deeply analyze its technical principles, economic value and practical application cases.

1. Core technical advantages of weathering steel
1. Self-protective rust layer
By adding alloy elements such as copper, chromium, and nickel (typical composition: Corten-A), a dense rust layer of 50-100μm is formed on the surface of the steel, isolating water and oxygen erosion, and the corrosion resistance is more than 8 times that of ordinary carbon steel, which perfectly meets the 25-year life cycle requirements of photovoltaic power stations.

2. Paint-free environmentally friendly process
Compared with the hot-dip galvanizing process (zinc ingot consumption > 40kg/ton of steel), weathering steel is used directly, reducing:
✅ Carbon emissions from zinc smelting (1.8 tons of CO₂/ton of zinc)
✅ Pollution from pickling waste liquid
✅ VOC emissions from coating

3. Upgraded mechanical properties
Tensile strength ≥ 480MPa (30% higher than Q235), the material thickness can be reduced by 10%-15% under the same load, reducing the amount of steel used.

2. Cost competitiveness analysis of weathering steel brackets
Cost item Traditional galvanized steel brackets Weathering steel brackets Reduction
Material cost (yuan/ton) 5,200 5,800 +11.5%
Anti-corrosion treatment cost 600 0 -100%
Full-cycle maintenance cost* 3,150 900 -71%
Total cost for 25 years 8,950 6,700 -25%
*Note: Calculated based on a 30MW power station, including 3 times of coating repair and labor costs

Core conclusion: Although the unit price of weathering steel is 10%-15% higher, the full life cycle cost is reduced by more than 25% due to the elimination of galvanizing and maintenance costs.

3. Implementation of steel for new energy
▶ Scenario 1: Power station in high-corrosion environment (coastal/industrial area)

Case: Shandong Dongying fishery-photovoltaic complementary project

Solution: Use S450AW weathering steel (national standard GB/T 4171)

Results: The rust layer is stable after 5 years of operation, no local perforation occurs, and the maintenance cost is 62% lower than that of galvanized steel

▶ Scenario 2: Desert Gobi power station

Challenge: Wind and sand abrasion accelerates the loss of galvanized layer

Countermeasures: Weathering steel matrix + micro-arc oxidation sealing treatment

Measurement: Wind erosion resistance is increased by 300%, applicable to areas with wind speed > 15m/s

4. Progress of supporting industrial chain
Material certification: It has passed international standards such as UL2703 and IEC 62782

Design specification: "Technical Specifications for Weathering Steel Structures for Photovoltaic Brackets" (T/CECS 10188-2022) has been released

Capacity layout: Baosteel, Ansteel and other companies have built dedicated production lines with an annual supply capacity of over 2 million tons.

V. Application precautions
⚠️ Key control points

Rust activation period: 6-12 months after installation is the rust layer stabilization period, and contact with concrete alkaline substances must be avoided

Connection process: It is recommended to use aluminum bronze welding rods (to avoid electrochemical corrosion caused by carbon steel welding rods)

Geographical restrictions: Areas with an average annual humidity of <60% and a chloride ion concentration of >0.5mg/m³ require a closed coating

Conclusion:
Driven by the "dual carbon" goal, photovoltaic weathering steel has become the preferred material for large-scale ground power station brackets with its 25% comprehensive cost reduction capability and zero maintenance advantages. With the continuous optimization of metallurgical processes (such as thin strip continuous casting weathering steel), its cost is expected to further drop, accelerating the photovoltaic LCOE (levelized cost of electricity) to 0.2 yuan/kWh.