How to Choose a Photovoltaic Support System?

La innovación es la base de todo lo que hacemos, pero nuestra verdadera motivación proviene del futuro. Trabajamos arduamente para eliminar las barreras a la energía limpia, haciéndola más práctica y accesible para todos. Para nosotros, esto no es solo un negocio: se trata de crear un mundo sostenible que nos enorgullezca legar a la próxima generación.

Shaw - Director ejecutivo de Future Green Technology Co., Ltd.

A Comprehensive Comparison of Corrosion Resistance and Service Life of Aluminum Alloy and Hot-Dip Galvanized Steel

Introduction

Photovoltaic support systems are the load-bearing foundation of the entire photovoltaic system. They are exposed to complex outdoor environments such as sunlight, rain, salt spray, acids, alkalis, and frost for extended periods. The material directly determines the stability of the power station, subsequent operation and maintenance costs, and overall service life. Currently, the mainstream support systems on the market are divided into two main categories: aluminum alloy support systems and hot-dip galvanized carbon steel support systems. Many owners and contractors are unclear about the differences in corrosion resistance and service life between the two when selecting models. This article provides a comprehensive breakdown to help you accurately match different photovoltaic projects.

I. Analysis of Corrosion Resistance Processes

1 Hot-Dip Galvanized Steel

Base material: Ordinary carbon steel.
Core method: Hot-dip galvanizing. Steel is immersed in molten zinc, forming a zinc-iron alloy layer + pure zinc layer (60–100μm).
Anti-corrosion principle: Sacrificial anode protection. Zinc oxidizes preferentially to protect the steel.
Shortcomings: Zinc layer is damaged at cutting/welding points. Long-term exposure leads to rust spots requiring paint repair.

2 Aluminum Alloy Supports

Base material: Mostly 6063-T5 industrial aluminum profiles.
Core method: Natural anti-corrosion properties. Automatically forms a dense aluminum oxide film upon air contact.
Processing advantages: Integral extrusion molding, minimal on-site welding. Cut surfaces automatically form an oxide film.
Enhancement: High-end supports undergo anodizing treatment to thicken the protective layer.

II. Comparison of Anti-corrosion Performance (By Environment)

Environment	Hot-Dip Galvanized Steel	Aluminum Alloy
Inland / Rural / Mountain	No significant rust after 5-8 years of normal use. Performance difference is minimal here.	Rarely shows visible rust; slight oxidation/whitening does not affect strength.
Coastal / High Salt Spray	Zinc layer bulges and peels within 3-5 years due to strong chloride ion penetration.	Stronger resistance to chloride ions. Anodized aluminum shows no structural corrosion for 10+ years.
Chemical / Acid Rain	Ammonia and acid/alkali exhaust consume zinc coating rapidly, large-scale rusting in 2-3 years.	Oxide layers resist weak acids/alkalis better. Much slower corrosion rate than steel.
Rainy / Humid / Freeze-thaw	Wet/dry cycles accelerate zinc peeling; joints and screws are prone to rust.	Does not rust. Bolt disassembly and later maintenance remain much easier.

III. Detailed Comparison of Service Life

Hot-dip Galvanized Steel

Standard Inland: 15–20 years

Coastal/Corrosive: 8–12 years (without reinforcement)

Maintenance: Requires overall inspection, rust repair, and replacement of rusted connectors every 5–8 years (high labor costs).

Aluminum Alloy

Standard Inland: 25–30+ years

Coastal/Corrosive: 20–25 years (no structural risk)

Maintenance: Minimal annual repairs; only periodic screw tightening needed. Covers the standard 25-year panel warranty easily.

IV. Advantages, Disadvantages & Scenarios

Hot-Dip Galvanized Steel

Pros: Lower raw material price, high load-bearing strength, high standardization.
Cons: Higher self-weight (60% heavier), lower corrosion resistance, difficult disassembly if rusted.
Ideal for: Large-scale ground-mounted plains, strong concrete roofs, short-term budgets.

Aluminum Alloy

Pros: Lightweight (reduces roof load), excellent corrosion resistance, high aesthetic appeal, good drainage.
Cons: Higher unit procurement cost, lower rigidity for ultra-high span ground stations.
Ideal for: Residential rooftops, coastal/islands, industrial roofs, BIPV, 20+ year operation stations.

V. Selection Summary & Recommendations

Inland Large-Scale, Budget Priority: Choose hot-dip galvanized steel, ensure proper zinc repair of welded sections, and conduct regular rust prevention inspections.

Rooftops, Coastal, Long-Term Stations: Prioritize aluminum alloy anodized brackets. A one-time investment reduces maintenance costs for over a decade.

Corrosion-Prone Farms & Chemical Parks: Avoid ordinary steel. Use aluminum alloy if budget allows, or steel with thickened zinc + anti-corrosion coating.

Conclusion

Photovoltaic bracket selection should not solely focus on initial purchase price. Corrosion resistance and service life directly impact long-term power generation safety and maintenance costs. Hot-dip galvanized steel excels in low price and high load-bearing capacity, while aluminum alloy excels in long-term corrosion resistance, lightweight design, and low maintenance. Select the right materials based on your project's specific site environment, roof load, and lifespan requirements to ensure stable operation for over 25 years.

Hot tags :

Blog

How to Choose a Photovoltaic Support System?

Introduction

I. Analysis of Corrosion Resistance Processes

1 Hot-Dip Galvanized Steel

2 Aluminum Alloy Supports

II. Comparison of Anti-corrosion Performance (By Environment)

III. Detailed Comparison of Service Life

Hot-dip Galvanized Steel

Aluminum Alloy

IV. Advantages, Disadvantages & Scenarios

Hot-Dip Galvanized Steel

Aluminum Alloy

V. Selection Summary & Recommendations

Conclusion

Photovoltaic Support System

Aluminum Alloy

Service Life

Rooftop Photovoltaics

Ground-Mounted Power Station

Hot-Dip Galvanized Steel

Ponte en contacto

Siempre estamos dispuestos a ayudarle y a responder a sus preguntas.