On the effectiveness of one-sided wake steering -A wind tunnel study with dynamic direction changes-

This paper has the goal of comparing one and two-sided wake steering, in terms of plant-level power capture and loading on the upstream and downstream turbines. Wind tunnel tests were conducted in a boundary layer wind tunnel in typical offshore conditions, using three scaled controlled and sensorized wind turbines, governed by an open-loop plant controller. Dynamic wind direction changes were obtained by rotating the wind tunnel turntable. Results indicate that one-sided steering achieves less than half the power gain of double-sided steering with respect to the uncontrolled greedy case. Additionally, although loading on the steering turbine is reduced, loading downstream is also significantly higher than for double-sided steering. On the other hand, actuator duty cycle is much reduced for one-sided steering, thanks to a reduced activity around the wind-aligned condition.