Steel vs. Aluminum Structures in Solar (PV) Power Projects

Steel vs. Aluminum Mounting Structures in Solar Energy (PV) Projects?

 

1. The Backbone of a 25-Year Investment

Solar Power Plants (PV) are designed to generate energy for at least 25 years under scorching summer heat, heavy winter snow loads, and sometimes corrosive salty sea air. The mounting structure supporting the panels is the backbone of the plant. The two most common materials compared in this field are Galvanized Steel and Aluminum Alloys. Although steel may appear cheaper on a per-kilogram basis, when total project cost, installation speed, and Operations & Maintenance (O&M) expenses are calculated, the advantages of aluminum prevail.

2. Technical Comparison: Aluminum vs. Steel

2.1. Corrosion Resistance and Maintenance

The biggest enemy of PV projects is corrosion.

• Galvanized Steel: Steel is coated with hot-dip galvanization (approx. 80µm) to protect against rust. However, on-site cutting, drilling, or scratches during assembly compromise this coating, initiating rust. Especially in C4 and C5 class (coastal, industrial) corrosion zones, the galvanized layer thins over time, requiring annual maintenance and touch-ups. A rusting structure compromises the static safety of the plant.
• Aluminum: Aluminum naturally protects itself by forming an oxide layer upon contact with oxygen (passivation). The 10-12 micron Anodizing process applied to Mertcan Metal’s solar profiles elevates this resistance to perfection. An aluminum structure requires zero maintenance for 25+ years, even in coastal environments.

2.2. Weight, Static Load, and Installation Speed

• Weight: Steel density is 7.85 g/cm³, while aluminum is 2.7 g/cm³. Aluminum is approximately one-third the weight of steel. This is vital for Rooftop Solar projects. To minimize the dead load on the building's roof, aluminum is the only rational engineering choice.
• Installation Speed (Labor): Heavy steel profiles are difficult to transport and install, often requiring cranes or more manpower. Aluminum sigma profiles are lightweight, easily carried by workers, can be cut on-site, and are rapidly assembled with T-bolts/nuts thanks to their special channel designs. Using aluminum significantly reduces installation time and labor costs.

2.3. End-of-Life Value (Scrap)

Investors often overlook the end of the project, but when the plant is dismantled after 25-30 years, the material has residual value. The scrap value of aluminum is significantly higher than that of steel. When the plant completes its lifecycle, the revenue from aluminum scrap can recover a substantial portion of the initial investment.

3. Which Material for Which Project?

 

4. Conclusion

For massive land-based power plants (MW scale), steel construction might be preferred due to high strength and lower raw material costs. However, for rooftop projects, coastal areas with high corrosion risk, and all investments where Total Cost of Ownership (TCO) is prioritized, aluminum is the correct engineering choice. With rapid installation, minimal roof load, and zero maintenance costs, aluminum systems continue to generate profit for the investor throughout the operational process.