Global assessment of spatiotemporal changes of frequency of terrestrial wind speed

Abstract

Wind energy, an important component of clean energy, is highly dictated by the disposable wind speed within the working regime of wind turbines (typically between 3 - 25 m s-1 at the hub height). Following a continuous reduction (“stilling”) of global annual mean surface wind speed (SWS) since the 1960s, recently, researchers have reported a “reversal” since 2011. However, little attention has been paid to the evolution of the effective wind speed for wind turbines. Since wind speed at hub height increases with SWS through power law, we focus on the wind speed frequency variations at various ranges of SWS through hourly in-situ observations and quantify their contributions to the average SWS changes over 1981-2021. We found that during the stilling period (here 1981-2010), the strong SWS (>= 5.0 m s-1, the 80th of global SWS) with decreasing frequency contributed 220.37% to the continuous weakening of mean SWS. During the reversal period of SWS (here 2011-2021), slight wind (0 m s-1< SWS <2.9 m s-1) contributed 64.07% to a strengthening of SWS. The strengthened strong wind (>= 5.0 m s-1) contributed 73.38% to the trend change of SWS from decrease to increase in 2010. Based on the synthetic capacity factor series calculated by considering commercial wind turbines (General Electric GE 2.5-120 model with rated power 2.5 MW) at the locations of the meteorological stations, the frequency changes resulted in a reduction of wind power energy (-10.02 TWh yr-1, p<0.001) from 1981 to 2010 and relatively weak recovery (2.67 TWh yr-1, p<0.05) during 2011-2021.

Effects of irrigation‐induced surface thermodynamics changes on wind speed in the Heihe River basin, Northwest China

“…This study highlights that irrigation may be a nonnegligible factor influencing global stilling. Previous studies have demonstrated that the global wind speed reduction, known as the "global stilling," has been a commonly accepted and ongoing phenomenon at the global and regional scales since the 1980s (Wu et al, 2018;Yang et al, 2021a;Zeng et al, 2019;Zhao et al, 2023). The global stilling can be mainly caused by the weakened pressure-gradient force (Lin et al, 2013), the large-scale atmospheric circulation anomaly (such as the North Atlantic Oscillation) (Minola et al, 2023), anthropogenic aerosols (Bichet et al, 2012), land use and cover changes (such as urbanization) (Chen et al, 2020).…”

Long-Term Assessment of Morocco’s Offshore Wind Energy Potential Using ERA5 and IFREMER Wind Data

“…It was discovered here for the first time that there have been instances of sustained negative wind anomalies in the area, including those that corresponded to the years 2000-2010. Although the seasonal characteristics of the long-term trends of wind speed have been pointed out in [39], and its effects on wind power potential were briefly discussed in [40], only terrestrial winds were considered.…”

“…The global decreasing trend was determined by those in Europe (−19%), South America (−16%), Australia (−14%) and Asia (−13%), while in North America an increasing trend (+3%) was found. The effects of this trend on terrestrial wind power potential and its association with wind frequency changes were briefly discussed in [40]. Based on the power wind curve of a specific turbine, it was estimated that wind energy had a continuous decline at a rate of 10.2 TW/year during 1981-2010, followed by a reversal, with a rate of 2.65 TW/year during 2011-2021.…”