Choosing the right material for solar mounting systems is a crucial decision that affects durability, cost, and performance. The question of whether to use steel or aluminum often arises, and each option has its unique advantages and limitations. This document provides a detailed analysis of these two materials, helping industry professionals and decision-makers choose the most suitable option for their specific requirements.

1. Material Strength

Solar mounting structures typically use Q235B steel and 6005-T5 aluminum alloy extrusions. A comparison of the design strength is shown below:

Table 1: Strength Comparison (N/mm²)

In terms of strength, 6005- T5 aluminum alloy provides approximately 68-69% of the strength of Q235B steel. Therefore, steel is preferred in regions with strong winds, larger spans, or other high-stress scenarios.

2. Deflection and Deformation

Structural deflection and deformation depend on the profile dimensions, shape, and the material’s modulus of elasticity (a material-specific parameter) rather than its strength.

Table 2: Comparative Analysis of Deflection

Under the same conditions, aluminum alloy structures experience 2.9 times more deformation than steel, weigh only 35% as much, and cost three times as much per unit weight. For applications in high-wind areas, larger spans, or cost-sensitive scenarios, steel is a more favorable choice.

3. Corrosion Resistance

Current anti-corrosion methods for mounting systems include hot-dip galvanization (55-80 μm) for steel and anodizing (5-10 μm) for aluminum.

• Aluminum: In atmospheric conditions, aluminum forms a dense oxide layer that passivates the surface, offering excellent corrosion resistance. Its corrosion rate decreases over time, making it ideal for long-term use.
• Steel: Galvanized coatings of 80 μm can ensure over 20 years of service life in standard environments (C1-C4). However, in high-humidity industrial zones or coastal/marine environments, corrosion accelerates, requiring 100 μm galvanization and annual maintenance.

In terms of corrosion resistance, aluminum significantly outperforms steel.

4. Other Comparisons

(1)Appearance:

Aluminum: Various surface treatments, such as anodizing, chemical polishing, fluorocarbon coating, and electrophoretic painting, offer a visually appealing finish suitable for diverse environments.

Steel: Typically treated with hot-dip galvanization, surface spraying, or painting. Its aesthetic and corrosion resistance are inferior to aluminum.

(2)Cross-sectional Versatility:

Aluminum: Extrusion allows for nearly unlimited cross-sectional profiles, making production flexible and fast.

Steel: Roll forming is the primary method for cold-formed sections. While efficient for consistent profiles like C and Z sections, it lacks flexibility compared to aluminum extrusion.

5. Comprehensive Performance Comparison

Aluminum:

Lightweight, aesthetically superior, and highly corrosion-resistant.

Best suited for rooftop installations or corrosive environments like chemical plants.

Steel:

High strength and minimal deflection under load.Ideal for large-span structures and cost-effective for standard installations.

Cost:

In regions with a basic wind pressure of 0.6 kN/m² and spans below 2 meters, aluminum structures are 1.3-1.5 times the cost of steel. For small-span systems, such as rooftop installations, aluminum’s lightweight nature makes it competitive despite the cost difference.

For high-wind regions and larger spans, steel structures offer clear economic benefits.

Conclusion

When selecting between steel and aluminum for solar mounting systems, the choice depends on factors like load requirements, environmental conditions, and cost considerations. Aluminum excels in lightweight and corrosive environments, while steel is preferred for high-strength and cost-sensitive applications.

Leon Solar’s Advantage

At Leon Solar, we specialize in designing and providing high-quality solar mounting solutions tailored to diverse needs. Our team leverages expertise in both steel and aluminum structures, offering:

• Customizable designs to maximize efficiency and durability.
• Solutions optimized for different climates and installation environments.
• Advanced surface treatment technologies ensuring long-lasting performance.

Whether you need rooftop systems, ground-mounted solutions, or specialized designs for harsh conditions, Leon Solar delivers unmatched quality and innovation.