Active Wake Redirection Control to Improve Energy Yield

Matthew Churchfield, Elise DeGeorge, Paul Fleming, Bernard Bulder, Stanley White

Research output: NRELPoster


Wake effects can dramatically reduce the efficiency of waked turbines relative to the unwaked turbines. Wakes can be deflected, or 'redirected,' by applying yaw misalignment to the turbines. Yaw misalignment causes part of the rotor thrust vector to be pointed in the cross-stream direction, deflecting the flow and the wake. Yaw misalignment reduces power production, but the global increase in wind plant power due to decreased wake effect creates a net increase in power production. It is also a fairly simple control idea to implement at existing or new wind plants. We performed high-fidelity computational fluid dynamics simulations of the wake flow of the proposed Fishermen's Atlantic City Windfarm (FACW) that predict that under certain waking conditions, wake redirection can increase plant efficiency by 10%. This means that by applying wake redirection control, for a given watersheet area, a wind plant can either produce more power, or the same amount of power can be produced with a smaller watersheet area. With the power increase may come increased loads, though, due to the yaw misalignment. If misalignment is applied properly, or if layered with individual blade pitch control, though, the load increase can be mitigated. In this talk we will discuss the concept of wake redirection through yaw misalignment and present our CFD results of the FACW project. We will also discuss the implications of wake redirection control on annual energy production, and finally we will discuss plans to implement wake redirection control at FACW when it is operational.
Original languageAmerican English
StatePublished - 2014

Publication series

NamePresented at the 2014 AWEA Offshore WINDPOWER Conference & Exhibition, 7-8 October 2014, Atlantic City, New Jersey

NREL Publication Number

  • NREL/PO-5000-62763


  • controls
  • National Renewable Energy Laboratory (NREL)
  • NREL
  • wake effects
  • wakes
  • wind plants
  • yaw mislaignment


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