The mounting structure is the backbone of any solar photovoltaic (PV) system, tasked with supporting panels for 25 years or more under diverse weather conditions. But not all materials are created equal when it comes to weather resistance and long-term durability.

In this article, we compare the weather performance and lifespan of the four most commonly used materials in solar mounting systems: Hot-Dip Galvanized (HDG) steel, Zinc-Aluminum-Magnesium (ZAM) coated steel, aluminum alloy, and carbon steel.

 

solar panel structure design calculations

 

What Is Weather Resistance in Solar Mounting?

Weather resistance refers to a material’s ability to withstand:

UV radiation and temperature changes

Moisture, rain, and humidity

Salt spray (in coastal areas)

Wind and snow loads

Airborne pollutants or acid rain (in industrial zones)

Material selection plays a major role in minimizing corrosion, deformation, and mechanical fatigue over decades of exposure.

 

 

Material-by-Material Comparison

1. Hot-Dip Galvanized (HDG) Steel

Weather Resistance: ★★★☆☆
Zinc coating provides moderate protection against corrosion, especially in inland areas.

Expected Lifespan: 20–30 years (depending on coating thickness and environment)

Best Use: Ground-mount systems in dry or temperate zones

Note: Requires thicker coating (≥ 85 μm) in high-humidity or coastal areas to meet durability standards.

 

pv racking 

 

2. ZAM (Zinc-Aluminum-Magnesium) Coated Steel

Weather Resistance: ★★★★★
Superior protection against corrosion in salt-rich, humid, and polluted environments.

Expected Lifespan: 30–35 years, even in harsh climates

Best Use: Coastal projects, desert solar farms, tropical installations

Fact: ZAM outperforms HDG by 2–5 times in salt spray corrosion tests (over 1,000+ hours).

 

3. Aluminum Alloy (e.g., 6005-T5)

Weather Resistance: ★★★★☆
Naturally forms a protective oxide layer; highly resistant to rust and UV.

Expected Lifespan: 25–35 years with minimal degradation

Best Use: Rooftop systems, carports, lightweight elevated structures

Bonus: Aluminum does not require additional surface treatment and performs well in humid environments.

 

4. Carbon Steel (Painted or Untreated)

Weather Resistance: ★☆☆☆☆
Susceptible to rapid corrosion if exposed to moisture without coating.

Expected Lifespan: 5–15 years, depending on coating quality and site conditions

Best Use: Budget-sensitive indoor applications or dry regions with low rainfall

Warning: Not suitable for long-term outdoor exposure without galvanizing or protective layers.

 

aluminum ground mounting system

 

Summary Comparison Table

Material

Corrosion Resistance

UV & Humidity Resistance

Lifespan (Years)

Ideal Environment

HDG Steel

Moderate (★★★☆☆)

Good

20–30

Inland, moderate climates

ZAM Steel

Excellent (★★★★★)

Excellent

30–35

Coastal, humid, desert regions

Aluminum Alloy

Very Good (★★★★☆)

Excellent

25–35

Rooftops, high humidity, urban zones

Carbon Steel

Low (★☆☆☆☆)

Poor

5–15

Indoor or dry rural areas

 

 

Conclusion

When it comes to solar mounting systems, material durability isn’t just a nice-to-have—it’s essential for long-term performance and return on investment. If you're working in a high-risk weather environment like the coast, mountains, or tropics, upgrading to ZAM or aluminum structures may significantly extend your system’s life with minimal maintenance. For dry, low-impact environments, HDG steel can offer solid value, while carbon steel is best reserved for short-term or controlled settings.

At Xiamen TopFence, we offer all four material options to match your unique site conditions and budget. Our engineering team ensures every system is designed for structural integrity and environmental resilience, no matter the location.

Would you like us to help you select the right material for your next solar project? Contact our team for a free consultation and technical datasheet comparison.