⚖️ Core Material Performance Comparison

⚙️ Key Dimensions for Material Selection

Material selection should consider four dimensions, not just a single indicator:

🛡️ Corrosion Resistance & Environmental Matching

C3 (inland, low pollution): Hot‑dip galvanized steel (coating ≥65 μm) – best cost‑performance.

C4 (industrial areas, general coastal): Upgrade to galvanized steel (≥85 μm) or choose aluminum alloy.

C5 (high salt spray, heavy industry): Must use Zn‑Al‑Mg coated steel or stainless steel. In C5 environments, conventional hot‑dip galvanizing requires 140 μm to achieve 25‑year life, while Zn‑Al‑Mg achieves the same or better corrosion resistance with a thinner coating, plus self‑healing cut edges.

💪 Strength & Structural Requirements

Ground‑mount / high‑load projects: Prioritise high‑strength steel (galvanized or Zn‑Al‑Mg).

Rooftop / lightweight projects: Aluminum alloy‘s light weight reduces building load.

💰 Cost & Economic Benefit

Initial investment: Hot‑dip galvanized steel is lowest, aluminum medium, stainless steel highest.

Life‑cycle cost: Although galvanized steel has lower upfront cost, aluminum‘s maintenance‑free nature gives it a better LCOE in high‑tariff regions over the long term.

🌿 Sustainability & Environmental Impact

Recyclability: Both aluminum and steel are 100% recyclable, meeting green building standards.

🎯 Scenario‑Specific Selection Strategies

🏞️ Ground‑mount Plants: Hot‑Dip Galvanized Steel – Economical and Reliable

For large‑scale ground‑mount plants, hot‑dip galvanized steel is the mainstream choice.

Deserts / gobi: “Precast concrete piles + galvanized steel mounts” – single pile cost RMB 80‑120, saving 15% on foundation costs.

Mountainous terrain: “Adjustable‑tilt steel mounts (±15°)” – increases generation by 5‑8%.

🏙️ Distributed Rooftops: Aluminum Alloy – Preferred for Lightweighting

For commercial and residential rooftops, aluminum alloy is the preferred material.

Commercial/industrial roofs: Aluminum rails reduce support points, increasing installation efficiency by 40%.

Residential: Lightweight design eliminates the need for roof reinforcement, reducing retrofit costs by about 30%.

🌊 Special Corrosive Environments: Upgraded Solutions for Long‑Term Service

Coastal plants: Galvanized steel requires upgraded 80 μm coating or aluminium‑magnesium alloy (e.g., 5052‑H32), increasing corrosion protection cost by 20% but reducing O&M frequency by 50%.

High‑altitude / cold regions: Steel must meet Charpy impact energy ≥27 J to avoid brittle fracture.

Offshore / chemical environments: Must use stainless steel or Zn‑Al‑Mg coated steel with a heavy‑duty anti‑corrosion coating system.

🔮 Industry Trends & Summary

Zn‑Al‑Mg coating accelerating adoption: With its superior corrosion resistance, self‑healing properties, and good workability, Zn‑Al‑Mg coated steel is rapidly becoming the mainstream material for PV mounts.

Continuous technological innovation: Materials science breakthroughs – such as lighter, stronger aluminium‑magnesium alloys partially replacing traditional steel mounts, and hot‑base high‑corrosion‑resistance medium‑aluminium Zn‑Al‑Mg coated steel – are driving cost reduction and efficiency improvement.

Site‑specific selection: Future material choices will become more refined, requiring customised designs based on local environment, loads, and budget.

Multi‑dimensional trade‑off: Material selection must balance corrosion resistance, strength, cost, life‑cycle economics, and sustainability.