The Maritime Emissions Reduction Centre (MERC) has issued a publication on the role of advanced coatings in reducing emissions and improving vessel efficiency without requiring major structural modifications.
According to the report titled’ ‘An Overview of Silicone Based Antifouling Paints”, advanced coatings, including silicone-based antifouling, are a valuable tool for the decarbonisation of the existing fleet. While they require a significant investment, they offer notable emissions reduction potential without extensive structural modifications or retrofits. However, their effectiveness depends on vessel type and operating profile, necessitating careful assessment when selecting an optimal coating system.
Silicone-based coatings function as fouling release systems with low surface energies, enabling self-cleaning properties that reduce macro fouling and drag. Unlike traditional coatings, they maintain consistent performance over the docking cycle due to their non-polishing nature. This results in immediate fuel efficiency benefits and cumulative savings over time.
Costs and Application Challenges
Silicone and hard foul-release coatings are more expensive than traditional antifouling options, both in paint costs and application requirements. Full abrasive blasting to SA2.5 is necessary, unlike traditional systems where spot blasting is common.
Extended dry dock periods may be required due to stringent application conditions, potential contamination risks, and weather dependencies. These factors contribute to costs that are often three times higher than traditional SPC systems.
Considerations for System Selection
The suitability of a silicone-based system depends on vessel type, age, and operating profile. While offering advantages over SPC antifouling, these coatings require ongoing monitoring to maintain effectiveness between dockings. Mechanical damage can increase hull roughness and drag, impacting efficiency. A hybrid approach—combining silicone-based and traditional systems on different hull areas—can provide a balance between performance and cost-effectiveness.
Validation of Savings
Assessing the energy savings of silicone coatings remains challenging due to variables like main engine condition, weather, and hull roughness. Comparisons with new-build sea trials often involve assumptions that can either support or challenge reported performance improvements.
Conclusion
Silicone-based antifouling coatings present a promising solution for emissions reduction but require a tailored approach based on vessel-specific conditions. Hybrid AFS schemes may offer an optimal compromise, balancing efficiency benefits with operational constraints.
Performance monitoring and biofouling management remain critical to ensuring long-term effectiveness. Innovations such as autonomous hull grooming robots could further enhance coating performance, pending manufacturer approval.
The Maritime Emissions Reduction Centre (M-ER) continues to explore these advancements as part of ongoing efforts to enhance fleet sustainability.
