The Influence of Real‐World Wind Turbine Deployments on Local to Mesoscale Climate

Abstract

Paired simulations are conducted using the Weather Research and Forecasting model applied at convection permitting resolution in order to determine the impact of wind turbines (WTs) on the local to mesoscale climate. Using actual WT locations and a model of the effect of the WT rotor on the flow field, it is shown that while the presence of WT changes wind speeds (WSs) and near‐surface air temperature in 4‐km grid cells in which WTs are located, the impact at larger scales on near‐surface air temperature, specific humidity, the fluxes of latent and sensible heat, boundary layer heights, and precipitation is not significant in any season other than summer. During summer, the maximum pairwise difference in grid cell mean temperatures is 0.5 K and the maximum increase in near‐surface specific humidity is 0.4 g/kg. However, a spatial average of the mean seasonal perturbation of air temperature by WT gives a net impact of <0.1 K. Precipitation probability is also not significantly impacted in any season other than summer. In the summer the presence of WT is associated with a small decrease in precipitation probability and a decrease in season total precipitation of −2.6%. The finding of minor magnitude, but significant impacts, during summer should be used to contextualize results of substantial climate impacts from WT arrays deployed in the U.S. Central Plains based on short‐term simulations conducted for the summer season.

Automated Wind Turbine Wake Characterization in Complex Terrain

“…As the wake expands and higher momentum air is drawn into the wake the velocity deficit decreases such that practically, it is difficult to determine the presence and characteristics of wakes from individual wind turbines beyond about 10 D downwind, except in stable stratification and/or low surface roughness conditions when the expansion and meander are more limited. Large wind farm (multiple) wakes can be detected over longer 20 distances (Pryor et al, 2018), particularly in offshore conditions where the generally smooth surface and low turbulence intensity leads to both the deep array effect within arrays and highly persistent whole array wakes (Christiansen and Hasager, 2005; . Wakes are advected by the ambient flow and thus, in addition to expanding, they are also subject to both horizontal and vertical meander (Larsen et al, 2008).…”

Cluster wakes impact on a far-distant offshore wind farm's power

“…Siedersleben et al (2018b) used the same flight measurements as Platis et al (2018) to evaluate a wind farm parametrization (Fitch et al, 2012) in the numerical Weather Research and Forecasting model (WRF) that is well established in wind energy applications (e.g. Pryor et al, 2018b;Witha et al, 2019;Dörenkämper et al, 2015a). Additionally they presented an analysis of aircraft wake measurements in five different heights 5 km downwind of the cluster.…”

Simulated wind farm wake sensitivity to configuration choices in the Weather Research and Forecasting model version 3.8.1

“…Such findings have prompted additional studies using the WFP to address whether large-scale wind farms could alter regional climate (see Table 1 for an overview). Vautard et al (2014), who use WFP simulations of future European deployment at 50-km horizontal resolution and ∼30-m vertical resolution to find statistically significant temperature signals only in winter, constrained to ±0.3 K. Conversely, Pryor et al (2018) use the WRF WFP at 4-km horizontal resolution and ∼30-m vertical resolution to find that wind farm-induced surface warming (<0.1 K on average) around wind farms in Iowa is more significant during summer months. Miller and Keith (2018), using WFP simulations at 30-km horizontal resolution and 25-m vertical resolution, suggest that generating today's US electricity demand (which they estimate to be 0.46 TW e ) with only wind power would redistribute boundary-layer heat to warm the continental US (CONUS) surface temperatures by 0.24 K.…”