Extreme wind speed projections from km-scale climate model simulations : Implications for future wind turbine design classes

Extreme wind speeds threaten the structural integrity of wind turbines. As climate change is projected to alter global circulation patterns, it is crucial to understand its impact on extreme winds to ensure safe turbine operation. General Circulation Models (GCMs) and Regional Climate Models (RCMs) are standard tools for assessing future climate parameters. However, they often lack the temporal and spatial resolution necessary to simulate the wind speed variability at sub-daily and sub-hourly scales important for capturing extreme wind events relevant to structural safety.

Convection permitting climate models (CPMs) unlike conventional climate models represent wind spectra accurately when compared to observations, up to their temporal resolution limits (Correa-Sánchez et al., 2025) . Therefore, we utilize an ensemble of CPMs from CORDEX-Flagship Pilot Study on Convective Phenomena over Europe and the Mediterranean (CORDEX-FPS Conv) project. They have a horizontal resolution of 2-3 km and hourly temporal resolution. The CPM domain cover central-southern Europe. The 100 m wind speed from the CPM ensemble is utilised to assess changes in 50-year return period winds at a 10-minute effective temporal resolution, U50_10min.  U50_10min is a key design parameter mandated by International Electrotechnical Commission (IEC) standards for selecting wind turbine classes (I, II, III, and S/T). The spectral correction method (Larsén et al., 2012) is used to estimate U50_10min from the hourly CPM outputs.

Future CPM projections suggest large spatial variability in U50_10min changes. Most parts show an increase in U50_10min, necessitating a higher turbine class requirement in ~7% of the area covered by the CPM domain. While, ~1% will experience a decrease in class requirement. The increases are primarily concentrated along the Ligurian and Adriatic coasts and in areas of complex orography. Moving forward, we plan to determine if existing wind farms are located in regions where a change in turbine class is anticipated. Furthermore, we intend to investigate the added value of CPMs compared to conventional models in capturing extreme wind events.

Correa-Sánchez, N., Larsén, X. G., Fosser, G., Dallan, E., Borga, M., & Marra, F. (2025). Brief communication: Enhanced representation of the power spectra of wind speed in convection-permitting models. Wind Energy Science, 10(11), 2551–2561. https://doi.org/10.5194/wes-10-2551-2025

Larsén, X. G., Ott, S., Badger, J., Hahmann, A. N., & Mann, J. (2012). Recipes for Correcting the Impact of Effective Mesoscale Resolution on the Estimation of Extreme Winds. Journal of Applied Meteorology and Climatology, 51(3), 521–533. https://doi.org/10.1175/JAMC-D-11-090.1