An economic assessment of tropical cyclone risk on offshore wind farms

Frequent tropical cyclones pose great risks and obstacles to the development of offshore wind farms in the coastal regions of China and other areas in the Pacific, where development of wind energy is gaining momentum. This paper aims to identify and evaluate the economic risks of tropical cyclones on offshore wind farms within the Economic Exclusive Zone (EEZ) of China and help improve decision-making for planners and investors. The risks of tropical cyclone impact in this paper are defined by the statistical extreme wind climate and the annual expected economic losses of offshore wind farms. A probabilistic tropical cyclone event model is applied to evaluate 20-year, 30-year, 50-year and 100-year recurrence of extreme wind speeds by geographical location. Combining a damage model derived from empirical loss data and an investment cost model within a Geographical Information System (GIS), the annual expected economic losses of offshore wind farms from tropical cyclones are evaluated and shown on a spatially continuous risk map. Results are given in terms of annual economic risks and damage losses based on occurrence of an average recurrence interval. Implications on identifying offshore wind potential and cost and setting design parameters for offshore wind turbines are then discussed. The impact of tropical cyclones on offshore wind farms likes a double-edged sword, which might be advantageous for some regions in terms of increasing full-loaded hours of turbines, but also disadvantageous for others due to its destructive effects. However, specific design standards and insurance of turbines would help reduce risks and economic losses of offshore wind farms in tropical cyclone-prone areas and expand exploitable locations for future offshore wind farms