The impact of steel quality on solar panel durability

The impact of steel quality on solar panel durability 

Solar energy is often viewed through the lens of photovoltaic innovation, more efficient cells, lighter modules, and advanced inverters. Yet one of the less acknowledged, but critically important, components of a solar energy system lies beneath the panels: the steel support structure. As India and other emerging markets accelerate their solar ambitions, the quality of steel used in these foundations could well determine the true longevity and reliability of clean energy.

A strong foundation, or a silent failure 

At first glance, steel may appear secondary to solar panel technology. However, the structural backbone determines how long a solar array can stay functional under environmental duress. Poor-quality steel, often chosen to cut short-term costs, corrodes faster, weakens under load, and becomes a liability in a system designed for 25 years or more. By contrast, premium-grade, galvanised or coated steel can ensure mechanical stability and protect against corrosion, wind shear, and structural deformation. 

According to a 2023 report by the International Renewable Energy Agency (IRENA), structural failures including rust, warping and frame fatigue account for nearly 11% of premature solar system breakdowns worldwide. In humid or coastal zones, the risk is even higher, making material integrity non-negotiable.

Corrosion resistance: where longevity begins

Corrosion is perhaps the single greatest threat to the durability of solar panel supports. When steel oxidises in the presence of moisture, its structural capacity diminishes, leading to instability and misalignment. Galvanised steel, coated with zinc, offers a practical defence: the zinc corrodes sacrificially, preserving the integrity of the steel beneath. In harsher conditions such as saline zones or industrial sites, hot-dip galvanisation or stainless steel becomes a prudent upgrade.

A study by the Indian Institute of Technology, Bombay, found that solar installations using subpar structural steel showed visible corrosion in under five years, leading to increased maintenance costs and panel misalignments that lowered energy yield by 4–7%. 

Mechanical strength under real-world loads

Steel’s job is not just to stand still. It must bear static weight, withstand wind uplift and shear, and hold its shape through thermal expansion cycles. Inferior steel, especially that which lacks proper alloying or post-treatment, can buckle or deform under pressure, misaligning solar panels and reducing efficiency.

High-strength structural steel, compliant with IS 2062 or ASTM A36 standards, offers the tensile and yield strengths necessary for dependable support. Importantly, this strength enables thinner sections to be used, reducing overall weight and material costs while still enhancing performance.

Thermal behaviour: stability through seasons

Temperature swings can cause structural members to expand and contract. Steel with poor thermal stability can exacerbate stress at joints and mounts, leading to cracks or loosening over time. Consistent, high-quality steel offers predictable expansion coefficients, enabling design engineers to account for thermal movement and maintain long-term alignment.

This matters more than it seems. Even a one-degree tilt misalignment can reduce annual energy capture by as much as 2%, according to the Solar Energy Research Institute of Singapore. Over thousands of panels, the efficiency penalty compounds.

Compliance and traceability: not just box ticking 

Buying steel from reliable suppliers that provide mill test certificates and compliance with industry standards such as IS, ASTM or ISO 1461 for galvanisation is a baseline requirement. But savvy developers go further. They track the source of steel, verify the coating thickness, and inspect the weldability and formability of materials used.

Cheap imports or unlabelled steel often bypass these safeguards, posing hidden risks that only emerge years later in the form of higher insurance claims, retrofits, or reputational damage.

A systems-level decision for sustainable energy

Steel quality affects not just the panels it supports, but the entire solar ecosystem from installers who depend on ease of mounting, to investors looking at lifecycle costs, to regulators who seek safety compliance. Skimping on structural materials undermines the very promise of solar energy: that it is a long-term, low-maintenance source of sustainable power.

As solar becomes mainstream, the focus must expand beyond wattage per panel to include structure per square metre. Quality steel may be invisible once installed, but it is indispensable for the durability and credibility of solar infrastructure.

Conclusion

Solar panels may capture the sun’s energy, but steel captures the weight of responsibility -literally and figuratively. In the quest for cleaner, smarter energy systems, it is the unseen quality of support structures that will determine whether solar investments live up to their 25-year promise or fall short due to early failure.

For policymakers, manufacturers, and MSMEs investing in solar, one thing is clear: the cost of poor-quality steel will always exceed the cost of doing it right the first time.