Global trends of wind direction-dependent wind resource

Trends in wind resources are a decisive factor for wind turbine site selection. Past studies assessed the long-term wind resource trends independent of wind direction. They enable the selection of the wind farm site but not the optimum design of wind turbines within the wind farm. However, possible trends in the wind direction sector-dependent wind resource would influence the optimum wind farm design. Thus, the hypothesis that wind direction sector-dependent wind resource trends exist is tested. This study applies zonal and meridional wind vector components from 1973 to 2022 on a 0.25° × 0.25° global grid at 100 m above ground level. Directional wind speed and a generic wind turbine power curve were applied to assess the trends of (1) annual energy yield, (2) capacity factor, and (3) wind direction share. The results indicate remarkable differences between the various regions and wind direction sectors. In Western and Central Europe, annual energy yield related to seven wind direction sectors decreased within the investigation period. In South Asia, declines in annual energy yields of more than −0.20 GWh related to the southwest and west sectors were found. Thus, this study concludes that more attention should be paid to wind direction sector-dependent wind resource changes.