Overview
IEC TS 61400-31:2023 - Wind energy generation systems, Part 31: Siting risk assessment - is an IEC Technical Specification (Edition 1.0, 2023-11) that provides guidelines for assessing the risks a wind turbine may pose to the general public. The standard focuses on onshore, horizontal-axis wind turbines with a swept area greater than 200 m² and covers risks during operation (including maintenance, idling and standstill). Substations and external structures are excluded. The document supports a uniform scope and consistent methods for wind turbine risk assessment, addressing internal and external causes such as technical failures, human error, extreme wind, icing, lightning, earthquakes, flooding, landslides and fire.
Key Topics
- Risk assessment process: documented workflow, stakeholder involvement and lifecycle risk management.
- Hazard identification: turbine failure modes (tower collapse, hub/nacelle shedding, blade failure), ice fall/throw, fire and domino effects.
- Risk estimation methods: prescriptive, qualitative, semi‑quantitative and quantitative approaches; selection flowcharts for method fidelity.
- Risk acceptance criteria: individual and societal risk regions, f–N plots and policy factors - options for applying prescriptive or risk‑based thresholds.
- Risk treatment and reduction: selection and documentation of measures (e.g., exclusion zones, ice detection/rotor heating systems), plus examples and guidance.
- Uncertainty and reporting: guidance on documenting assumptions, models and uncertainty sources.
- Informative annexes: failure frequency summaries, international risk-criteria overview and blade/fragment trajectory modeling.
Applications
IEC TS 61400-31 is practical for activities that require documented, repeatable siting risk assessment for onshore wind projects:
- Project developers and site assessors: informing site selection, layout and setback distances to meet tolerable risk targets.
- OEMs and safety engineers: evaluating design-related failure consequences and mitigation needs.
- Consultants and risk analysts: conducting hazard identification, quantitative risk modelling and reporting to regulators.
- Regulators, permitting authorities and insurers: using standardized risk assessments for approvals, compliance checks and underwriting decisions.
- Operations and maintenance teams: integrating operational risk controls and emergency response planning.
Related standards
IEC TS 61400‑31 complements other IEC 61400 series parts (wind turbine design, testing and safety) and aligns with general risk-management guidance (ISO/IEC guides referenced in the document). For practical compliance, users typically combine this Technical Specification with site‑specific meteorological, geotechnical and land‑use regulations.
Keywords: IEC TS 61400-31:2023, siting risk assessment, wind turbine risk assessment, onshore wind turbines, risk-based methods, prescriptive risk criteria, ice throw, blade failure, tower collapse.