Solar panel racking systems should last decades, even in coastal regions with high salinity and industrial areas with elevated air pollution. However, even with proper maintenance and cleaning, their lifespans reach an upper limit of 25 to 30 years. Rather than attempting to increase longevity with timely repairs, professionals should prioritize resilience by design.

What Cuts a Solar Racking System’s Lifespan Short?

To truly understand the factors that diminish a system’s service life, professionals must know how long solar panels typically last. Photovoltaic (PV) modules degrade slowly, normally losing less than 1% of their performance yearly. This degradation remains virtually undetectable for several years. Therefore, solar racking systems are fundamentally reliable.

Given that the modules lose less than 1% of their performance annually, a 20-year-old system can still generate around 90% of its original capacity. A solar panel should last 25 to 30 years before it reaches a point where users consider replacing it due to sufficient degradation. However, harsh environmental conditions can accelerate this performance decline, threatening system integrity and longevity.

Thermal Expansion Creates Stress at Key Points

Dissimilar materials expand and contract at differing rates as temperatures change. When components with vastly different coefficients of thermal expansion (CTEs) are joined, thermal stress builds up at the connection point. Over time, accelerated wear can cause equipment failure.

Galvanic Corrosion Weakens the Entire Structure

Environmental contaminants, moisture ingress and the joining of dissimilar metals are common causes of corrosion in PV racking systems. The latter is among the most aggressive forms because it occurs regardless of environmental conditions.

When one metal comes into electrical contact with another in the presence of an electrolyte, it corrodes faster. This electrochemical process is known as galvanic corrosion. It typically happens at a much higher rate than the corrosion of a single material, but the reaction’s speed depends on the reactivity between the dissimilar metals.

Environmental Factors Create Mechanical Stress

Mechanical stresses from ice formation, wind gusts and snow accumulation create heavy, uneven bending forces and cyclic loads. At low temperatures, solar panel racking systems are stiff, making them unable to absorb deformation. Stress is more likely to transfer directly to silicon cells, cracking PV modules.

Material Selection Reduces Long-Term O&M Costs

A solar panel racking system’s lifespan is primarily determined in the design stage, which influences durability and repairability. As such, it stands to reason that informed material pairing could be the key to creating sturdy solar racking that outlives its conventional counterparts.

Carefully selecting metals prevents galvanic corrosion. For unavoidable dissimilar pairings, durable isolators and specialized coatings can help, lowering operations and maintenance (O&M) costs.

This method also reduces thermal stress. Aluminum’s creep strength — its tendency to deform under a constant load — is poor, and it has a very high CTE. Consequently, it expands nearly twice as much as steel for the exact temperature change. Over thousands of cycles, the racking system creates substantial stress. Strategically pairing structural and fastening materials is vital.

Targeted reinforcement resists environment-related degradation. By pairing a robust base material with a specialized protective coating and carefully selected metals, professionals can create a durable solar installation that far surpasses its conventional counterparts.

Strategic material pairing helps prevent galvanic corrosion, mitigate thermal stress and resist the buildup of environmental pollutants, which are among the most common sources of premature material degradation. This technique creates a multilayered defense against the environment by providing targeted reinforcement to critical components.

The Science Behind Solar Racking Material Selection

Smart material pairing affects how long solar panels last. It can increase their endurance and longevity, improving the general public’s opinion of renewables and accelerating the clean energy transition.

Isolate Dissimilar Metals to Prevent Galvanic Corrosion

Electrically isolating the two metals in contact using nonconductive barriers, adhesives or coatings mitigates the electrochemical activity that causes corrosion in PV racking systems. In layperson’s terms, it breaks the electrical path, stopping corrosion from forming.

Use Sacrificial Material in Highly Corrosive Zones

A sacrificial anode corrodes first because it is made from highly active materials. By diverting corrosion away from critical components, it provides reliable cathodic protection, effectively safeguarding the racking system. 

Sacrificial coatings operate on the same scientific principle. By intentionally introducing a more electrochemically active material — one willing to give up its electrons and corrode — it protects the less active, more important base metals.

Match Thermal Expansion Rates to Reduce Fatigue

The best way to prevent thermal expansion from creating immense stress is to use similar metals with the same CTE. However, that is often not possible due to application demands. When using dissimilar materials is necessary, engineers should use specialized connection techniques such as slip joints or expansion joints.

Apply Advanced Functional Coatings Over Base Materials

Multifunctional solar panel coatings include antifogging, self-healing and self-cleaning options. Their purpose is to prevent wear and damage while improving light absorption, reducing soiling and preventing hot spots from forming. Increasing the transmission of light into the PV cell passively enhances the solar panel’s lifetime efficiency without increasing maintenance needs.

Next Generation Solutions for Extreme Environments

While smart material pairing is not a new concept, it has seen increased attention in recent years. As a result, researchers have developed state-of-the-art solutions to enhance solar panel lifetime efficiency.

Phase-change materials are among the most promising developments. They melt and solidify at specific temperatures. While changing phases, they absorb and release thermal energy without noticeably increasing the PV modules’ temperature. Studies show these materials can increase panels’ power output by providing passive cooling.

For saltwater protection, researchers have created specialized coatings that resist salt buildup. When combined with mounting systems made from marine-grade aluminum or stainless steel, they resist salt-induced corrosion.

Because many industries have the ultimate goal of transitioning to clean energy, avoiding solar installations in these harsh and coastal environments is not a sustainable long-term solution. In fact, harsh environments can offer unique benefits. For instance, floating solar installations generate 15% more energy than ground-mounted systems because water has a cooling effect and enhances light reflection. Meanwhile, they shade water bodies — reducing evaporation — and minimize land use. In addition to improving efficiency, rethinking material selection introduces novel implementation opportunities.

Designing Racking for Decades of Peak Performance

Whether engineers use sacrificial anodes, hybrid materials or specialized coatings, these materials extend solar panel racking systems’ lifespans. This change has far-reaching implications on the renewable energy sector and related fields, as it increases installation accessibility and lowers the total cost of ownership.