In solar mounting system design, material selection is not just a cost decision—it directly affects structural performance, durability, installation efficiency, and long-term return on investment.

Among all available options, aluminum alloy and steel (including galvanized steel and ZAM steel) are the two most widely used materials in photovoltaic mounting systems.

Each material has its own advantages and limitations. Choosing the wrong one may lead to:

  • Increased structural risk under wind and snow loads
  • Corrosion and reduced system lifespan
  • Higher installation and maintenance costs
  • Lower overall project profitability

This article provides a comprehensive comparison between aluminum and steel solar mounting systems, helping you select the most suitable material for your project.

Overview of Aluminum and Steel in Solar Mounting

Aluminum Alloy Mounting Systems

Aluminum is widely used in rooftop solar systems and is increasingly applied in ground-mounted structures.

Typical grades:

  • 6005-T5
  • 6061-T6
  • 6063-T6

Key characteristics:

  • Lightweight (about 1/3 the weight of steel)
  • Naturally corrosion-resistant due to oxide layer
  • Easy to transport and install

Steel Mounting Systems

Steel systems include hot-dip galvanized steel and ZAM-coated steel, commonly used in large-scale ground-mounted projects.

Key characteristics:

  • High strength and stiffness
  • Mature manufacturing process
  • Cost-effective for large projects

Mechanical Performance Comparison

PropertyAluminumSteel
Density (g/cm³)2.77.85
Yield Strength (MPa)200–260235–550
Elastic Modulus (GPa)70200
重量:LightweightHeavy
Structural RigidityLowerHigher

Insight:
Steel provides better stiffness and load-bearing capacity, while aluminum offers advantages in weight reduction and ease of installation.

Corrosion Resistance Comparison

材料Corrosion MechanismPerformance
AluminumNatural oxide layerExcellent
Galvanized SteelZinc coating protectionGood
ZAM SteelZn-Al-Mg coating + self-healingExcellent

Key takeaway:

  • Aluminum performs well in most environments
  • ZAM steel offers superior protection in harsh conditions
  • Galvanized steel is suitable for moderate environments

Installation and Processing

FactorAluminumSteel
InstallationFasterSlower
CuttingEasyRequires treatment
WeldingNot recommended常见
ConnectionBoltedBolted / welded
Labor CostLowerHigher

Cost Comparison

Cost AspectAluminumSteel
Material CostHighLow
Transport CostLowerHigher
Installation CostLowerHigher
Maintenance CostLowMedium
Lifecycle CostCompetitiveCompetitive

Environmental Suitability

EnvironmentRecommended Material
InlandSteel or Aluminum
CoastalAluminum or ZAM Steel
High humidityAluminum
Harsh industrialAluminum / ZAM Steel

应用场景

Aluminum Systems Are Ideal For:

  • Rooftop solar installations
  • Lightweight structure requirements
  • Corrosion-sensitive environments
  • Projects requiring fast installation

Steel Systems Are Ideal For:

  • Ground-mounted solar farms
  • High-load conditions (wind/snow)
  • Utility-scale projects
  • Cost-sensitive large installations

Advantages and Limitations

Aluminum Advantages

  • Lightweight and easy to handle
  • Excellent corrosion resistance
  • Faster installation

Aluminum Limitations

  • Higher material cost
  • Lower stiffness

Steel Advantages

  • High strength and rigidity
  • Lower material cost
  • Suitable for large-scale projects

Steel Limitations

  • Heavier weight
  • Corrosion risk if coating is damaged

Design Considerations

  • Match material strength with structural requirements
  • Consider environmental corrosion levels
  • Avoid galvanic corrosion between different metals
  • Use appropriate fasteners (SS304/316)

Common Mistakes

  1. Selecting material based only on price
  2. Ignoring environmental conditions
  3. Mixing materials without insulation
  4. Underestimating installation complexity

Conclusion: Aluminum vs Steel—Which One Is Better?

There is no universal answer. The best choice depends on project conditions, environment, and performance requirements.

Quick Selection Guide

ScenarioRecommended Material
Rooftop systemsAluminum
Utility-scale groundSteel
Coastal / corrosiveAluminum or ZAM Steel
Fast installation projectsAluminum

SOEASY Solar Mounting Solutions

SOEASY offers a full range of mounting systems using both aluminum and steel:

  • Aluminum mounting systems for rooftop and lightweight applications
  • Steel mounting systems for ground-mounted projects
  • ZAM steel solutions for enhanced corrosion resistance
  • Customized designs based on project conditions
  • Full technical support from design to installation

FAQ

Which is better, aluminum or steel for solar mounting?

It depends on the project. Aluminum is better for rooftops and corrosion resistance, while steel is preferred for strength and large-scale ground systems.

Is aluminum more durable than steel?

Aluminum has better corrosion resistance, but steel offers higher structural strength.

When should I choose ZAM steel?

ZAM steel is ideal for coastal or high-corrosion environments due to its self-healing coating.