Corrosion prevention technologies in renewable energies

The renewable energy sector is expanding rapidly, driven by the global need to mitigate climate change and reduce dependence on fossil fuels. Technologies such as wind, solar, hydro and tidal power require metallic infrastructures exposed to highly aggressive environments, such as marine environments, areas with high ultraviolet radiation, and atmospheres with high levels of humidity and pollutants. These factors accelerate electrochemical corrosion mechanisms, jeopardizing the structural integrity, operational safety and economic viability of the projects.

In this context, the implementation of advanced corrosion prevention and control technologies is essential to maximize the useful life of assets and minimize costs associated with premature failures, frequent repairs and unscheduled shutdowns. The application of high-tech anti-corrosion coatings, together with specialized inhibitors and predictive monitoring systems, form the basis of modern strategies to ensure durability in clean energy infrastructures¹.

What is performance-based corrosion protection?

Corrosion protection has traditionally been based on prescriptive specifications that dictate the chemical composition, quantity, and sequence of paint or coating layers, as well as application and curing parameters. Although this method has been effective in controlled scenarios, its rigidity limits its adaptability to variable and real operating conditions, generating discrepancies between the expected performance and that observed in service.

The performance-based approach represents an innovative paradigm that shifts the focus from prescriptive characteristics to measurable functional outcomes, focusing the evaluation on specific functional failure criteria. This includes loss of adhesion, visible surface degradation, loss of dry film thickness (DFT), and occurrence of structural coating defects. The validation of these criteria is performed through standardized laboratory tests and field evaluations that replicate the environmental and mechanical conditions to which the asset will be subjected².

This model is supported by recognized international standards, such as ISO 12944-9, which specifies methods for the selection and evaluation of paint systems for offshore structures and highly corrosive environments, and NACE SP 21412‑2016, which establishes guidelines for the development of performance-based specifications, promoting technical flexibility and stringency in the objective testing of corrosion performance³.

Determining factors for the coating life cycle (CLC)

Coating Life Cycle (CLC) is a comprehensive concept that covers from the correct selection and formulation of the protective system, to the application, quality control and continuous evaluation during operation. Its objective is to ensure that the surface protection system maintains its functional properties without requiring corrective maintenance during the expected period.

Variables influencing the extent of CLC include:

• Site-specific environmental conditions: Exposure to high UV radiation, salt spray and high relative humidity accelerate the degradation of coatings⁴. In marine or coastal environments, chloride concentration is a critical factor determining the need for galvanized protection and highly resistant coatings.
• Coating system design: The optimal combination of zinc-rich primers, low permeability epoxy interlayers and polyurethane or polysiloxane topcoats with high UV and abrasion resistance helps to maximize protection. Chemical and mechanical compatibility between coats is essential to avoid premature failure.
• Quality in surface preparation and application: The degree of cleanliness (preparation type Sa2.5 or higher), homogeneity of dry film thickness (DFT) and strict control of parameters during application have a decisive influence on adhesion and durability. Continuous measurement of DFT by non-destructive techniques is a recommended practice to ensure uniformity².
• Field evaluation and monitoring: The implementation of scheduled inspections using standardized visual evaluation techniques and destructive tests (pull-off tests) allows detecting early signs of deterioration and planning predictive maintenance.

Coating and protection technologies for renewable energies

In the renewable energy industry, the selection and implementation of advanced corrosion protection systems has evolved into multi-layered and multi-functional solutions that offer both galvanic and barrier protection. Key technologies include:

• High-performance multilayer systems combine zinc-rich primers, which provide passive cathodic protection; epoxy interlayers with high impermeability to moisture; and polyurethane- or polysiloxane-based topcoats, which guarantee resistance to ultraviolet radiation, mechanical abrasion and color stability. These systems are validated by accelerated salt spray tests and QUV exposure, demonstrating a useful life of more than 25 years in environments classified C5-M⁴.
• Thermosetting powder coatings have gained acceptance in specific applications, such as racks and electrical components of photovoltaic systems, due to their excellent adhesion, mechanical strength and absence of volatile organic compound (VOC) emissions. Their controlled dry film thickness (DFT) typically ranges between 70 and 120 µm, with estimated durability between 10 and 15 years under moderate environmental conditions⁴.
• Smart corrosion inhibitors, including volatile corrosion inhibitors (VCI) and controlled-release formulations, complement protection in cavities and areas inaccessible to conventional coatings. The trend toward biodegradable and nontoxic compounds ensures environmental compatibility and compatibility with polymeric materials integrated into composite systems⁶.
• Finally, innovation in self-healing coatings incorporates microcapsules or encapsulated particles that release healing agents upon detection of damage or cracks in the coating matrix, promoting autonomous regeneration and extending functional life. Although still under development for large-scale infrastructure, it is already being applied in critical energy storage components⁶.

From prescriptive standards to a performance based approach

For decades, the selection of corrosion protection systems has been guided by prescriptive specifications that strictly detail acceptable materials, coatings and application methods. These specifications, while useful for establishing a minimum standard and ensuring uniformity in traditional operating environments, often limit innovation and adaptation to particular service conditions. In a scenario of increasing operational complexity, such as that posed by the energy transition, these limitations become evident.

The transition to performance-based specifications responds to the need to align technical criteria with the functional objectives of the system over its lifetime. Rather than defining how a system should be designed, these specifications establish what it must achieve: corrosion resistance under specific conditions, durability in highly aggressive environments, compatibility with cathodic or hybrid systems, or behavior in the face of varying thermal or chemical cycles.

This approach allows suppliers to select more efficient and innovative technologies such as advanced high-performance coatings, hybrid solutions with vapor corrosion inhibitors (VCI) or intelligent monitoring systems, as long as they meet defined performance criteria. This promotes technical adaptability and optimizes the cost-benefit ratio without compromising the integrity of the asset.

Standards such as ISO 12944-9, which introduces specific performance criteria for coatings in offshore or highly corrosive environments, or NACE/AMPP initiatives aimed at operational reliability, are key examples of this regulatory evolution. Consequently, engineering professionals must develop competencies not only in interpreting traditional standards, but also in evaluating actual performance through accelerated testing, field monitoring and coating life cycle analysis.

The transition from prescriptive to functional represents a methodological shift, towards a cultural change in the way corrosion protection is conceived: not as a technical prescription, but as a comprehensive engineering strategy adapted to the environment and operational goals of the 21st century.

Performance evaluation and field monitoring

Corrosion performance assurance is based on rigorous evaluation protocols combining laboratory techniques and in-situ methods. Tests include dry film thickness (DFT) measurement by non-destructive methods, pull-off adhesion tests, visual inspection under ISO 4628 to evaluate blister, chalk and surface corrosion degradation, as well as accelerated salt spray (ISO 9227) and UV-condensation cycling (ISO 16474).

The incorporation of digital monitoring technologies, such as embedded sensors, inspection drones equipped with high-resolution cameras and predictive analytics platforms based on artificial intelligence, facilitates the early detection of conditions that portend functional failure. These tools help optimize maintenance management and extend the useful life of systems⁵.

Towards a new culture of corrosion protection

In the context of renewable energies, where materials are exposed to variable, aggressive and sometimes unpredictable environmental conditions, corrosion prevention can no longer be limited only to compliance with prescriptive standards. While these have been instrumental in establishing minimum protection guidelines, they do not always reflect actual operating conditions or ensure optimized long-term durability.

Adopting a performance-based approach means designing, selecting and implementing corrosion protection solutions that respond to specific project requirements, considering factors such as climate, location, type of structure, maintenance cycles and expected service life. This paradigm shift enables more accurate, reliable and cost-efficient engineering, in addition to boosting the sustainability and resilience of renewable assets. Moving towards this vision is key to consolidating a technical culture focused on real results, not just formal compliance with standards.

Conclusions

The development and application of corrosion prevention technologies in renewable energy is essential to ensure the reliability, safety and financial sustainability of projects. The implementation of advanced corrosion prevention systems, supported by international standards and evaluated through performance-based specifications, maximizes the useful life of assets and reduces the environmental impact associated with frequent repairs and replacements.

The synergy between high-performance coatings, smart inhibitors, advanced monitoring techniques and a comprehensive preventive approach strengthens the energy infrastructure, consolidating clean energies not only as an environmental alternative but also as a technologically robust and economically viable option in the medium and long term.

References

1. Revie, R. W., & Uhlig, H. H. (2008). Corrosion and Corrosion Control: An Introduction to Corrosion Science and Engineering (4th ed.). John Wiley & Sons.
2. ISO. (2018). ISO 12944-9: Paints and varnishes — Corrosion protection of steel structures by protective paint systems — Part 9: Protective paint systems and laboratory performance test methods for offshore and related structures. International Organization for Standardization. https://www.iso.org/standard/74748.html
3. NACE International. (2016). SP 21412‑2016/SSPC‑CPC 1: Corrosion prevention and control planning standard practice. NACE International.
4. Funke, W. (2015). High-Performance Anti-Corrosion Coatings for Renewable Energy Applications. Progress in Organic Coatings, 78, 273–281. https://doi.org/10.1016/j.porgcoat.2014.06.017
5. AkzoNobel. (2022). ISO 12944-6: Protective paint systems—Performance requirements for systems for corrosive environments. AkzoNobel Protective Coatings.
6. Sika Group. (2023). Performance-Based Coating Systems in Renewable Energy Applications. Recuperado de https://www.sika.com