Unlocking the potential of vertically staggered wind farms through multi-dimensional misalignment and yaw control

Vertical staggering can enhance wind farm power output, yet its full potential remains incompletely characterized. This experimental study systematically evaluates the possibility of improving the efficacy of vertical staggering by integrating hub height distribution, horizontal alignment, rotor size arrangement and yaw control in a five-turbine array. Wake measurements via particle image velocimetry are conducted to elucidate the underlying mechanisms. The results show that adjusting the hub height distribution while maintaining a constant average height increases power production by 23%. Combining vertical and horizontal staggering yields up to 19% additional power gain relative to the purely horizontally staggered layout. The two selected yaw sets yield peak power gains of 17% in vertically staggered, horizontally aligned arrays, and 40% in vertically and horizontally staggered configurations. In multi-rotor-size configurations, altering hub height distribution—particularly through the placement of lower small-scale turbines—and applying yaw control further enhance power production, with small-scale turbines identified as the primary contributors to the observed gains under yawed conditions. Wake analysis reveals that in uniform-rotor-size farms, altering hub height redistributes wake velocity and turbulence intensity, which can enhance the vertical entrainment of kinetic energy, especially in checker height distributions. In multi-rotor-size farms, wake characteristics are dominated by the large-scale turbines; using low small-scale turbines enhances kinetic energy extraction in regions below the hub heights of large-scale ones. This study reveals the considerable, underexplored potential of vertical staggering, shedding new light on pathways to optimize wind farm configuration and thus power performance. This study identifies a significant potential for vertical staggering to enhance power performance through multi-dimensional misalignment and yaw control. • The synergy of multi-dimensional misalignment and yaw control shows great potential. • Staggering hub heights increases total power by 23% in a five-turbine wind farm. • Combining vertical and horizontal staggering can further boost power gains to 19%. • Yaw control unlocks the benefit from the vertical–horizontal staggering layout by 40%. • Lower small-rotor turbines and/or yaw yield higher power in multi-rotor-size farms.