A Framework for Hurricane Risk Assessment of Offshore Wind Farms

We present a framework aimed at estimating the potential damage to an offshore wind farm from hurricanes. Our approach is related to assessing risks that are assumed to be fundamentally related to the estimation of wind speed exceedance probabilities at selected hub heights of wind turbines in the farm and of associated wind turbine loads. As part of this preliminary framework for risk assessment, synthetic storm tracks are first simulated over the ocean using available historical tropical storm data; then, a hurricane intensity evolution model based on thermodynamic and atmospheric environmental variables is developed for each of the tracks as they get to regions within the proximity of the chosen wind farm site. Based on this intensity model, a turbulent wind field can be simulated at locations of interest along the hurricane track. The simulated turbulent wind field may then be used to estimate wind speed exceedance probability distributions and, when combined with correlated waves, it can also be used in analysis of the response of individual turbines in a wind farm. The framework for the overall risk assessment is presented; the individual components that comprise such an assessment are described briefly in illustrative applications.