A methodology to revise wind speed maps considering the wake effect: An assessment of wind turbines in the western region of Türkiye

Wind resource maps used in turbine siting and regional energy planning are typically derived from reanalysis or mesoscale modelling and do not account for wake-induced wind speed deficits. This study proposes a GIS-based methodology that directly incorporates the wake effect into the background wind speed map, producing a pixel-resolution revised resource map reflecting the cumulative wake influence of all installed turbines across a region. Implemented in MATLAB using Jensen's wake model, the methodology is applied to the western region of Türkiye, encompassing 932 active wind turbines. The revised map demonstrates substantial downstream wind speed reductions; 384 turbines (41%) lie within the wake zone of at least one upstream neighbour, with local speed deficits reaching up to 50% in the most adversely positioned cases. Total energy loss is estimated at 4.9%, equivalent to the annual output of approximately 46 turbines. Regional analysis reveals pronounced differences in wake exposure: Karaburun peninsula, where turbines are predominantly aligned with the prevailing wind, exhibits comparatively low losses, whereas certain clusters in Çeşme-Urla region display avoidable back-to-back configurations that severely reduce energy output. A Monte Carlo uncertainty analysis (N=1000 simulations) is performed, independently sampling the Jensen wake decay constant (α) and wind direction perturbations. The analysis yields a 95% empirical confidence interval of [4.12%, 6.65%] for total energy loss, confirming 4.9% as a robust central estimate, with α identified as the dominant source of output variability (r = −0.763). The revised map provides a practical tool for wake-aware siting of future turbines near existing installations.