Overview - ISO 24656:2022 (Cathodic protection of offshore wind structures)
ISO 24656:2022 specifies requirements for external and internal cathodic protection (CP) of offshore wind farm structures and appurtenances that are in contact with seawater or the seabed. The standard covers design, installation, commissioning, inspection, performance monitoring, retrofit solutions, assessment of residual life and guidance for CP of steel and reinforced concrete offshore structures.
Key topics and technical requirements
ISO 24656 organizes technical guidance across the full CP lifecycle. Major topics include:
- Scope and personnel competence - definitions, required skills and qualifications for CP designers, installers and surveyors.
- Structural and material considerations - identification of structures to be protected, materials and corrosion protection strategy.
- Cathodic protection criteria - acceptance criteria for temporary and permanent protection of steel and reinforced concrete.
- Design of CP systems - objectives, design life, surface area and structure subdivision, environmental factors (e.g., seawater resistivity, flow), current demand calculations, electrical continuity and interaction management.
- Galvanic anode systems - alloy selection, current availability, anode distribution and installation considerations.
- Impressed current systems - system resilience, DC power sources, impressed anodes, reference electrodes and dielectric shielding.
- Cable systems - CP DC cable requirements and consideration of inter-array/export AC cables.
- Commissioning, surveying and monitoring - commissioning objectives, detailed internal/external surveys, permanent monitoring systems, reference electrode use and survey frequency.
- Retrofit and life-extension - survey-led retrofits for inadequate protection or life extension of existing CP.
- Documentation and safety - design reports, material specifications, as-built records, operation & maintenance requirements, and electrical and physical safety considerations.
Practical applications - Who uses ISO 24656
ISO 24656 is intended for professionals involved in the design, construction, operation and maintenance of offshore wind farms:
- Corrosion engineers and CP designers planning galvanic or impressed current systems
- Offshore structural and marine engineers specifying corrosion protection strategies for steel and reinforced concrete foundations, jackets, monopiles and subsea appurtenances
- Asset owners and operators conducting residual-life assessments, monitoring and retrofit planning
- Installation contractors, inspection and survey teams performing commissioning, periodic CP surveys and maintenance
- Regulators and certificatio n bodies referencing CP requirements in permits and technical assessments
Related standards (if applicable)
ISO 24656 should be used alongside other relevant international standards on offshore structures, corrosion management and wind turbines (e.g., ISO and IEC standards covering offshore structural design, corrosion control best practice and the IEC 61400 series for wind turbine systems).
Keywords: ISO 24656, cathodic protection, offshore wind, galvanic anode, impressed current, corrosion protection, CP monitoring, retrofit cathodic protection.
