In many project my colleagues from the wind and site department (the people who calculate the best wind turbine model and the optimal layout in a wind farm) are forced to put quite a lot of wind turbines in a reduced space.
Each of these wind turbines generate a “wake effect” – basically, they create turbulence in the wind.
These turbulences can affect other turbines nearby, increasing loads. This is not good, because higher loads usually means more problems due to component failures.
Wind sector management it’s a solution to this problem – basically, when the wind is blowing from a certain direction some turbines are automatically shut down.
There are basically 2 alternatives: you can shut down the turbine upstream (the one creating the turbulence) or the one downstream (the one suffering the increased loads).
Stopping one or more wind turbines will obviously result in a loss of production. However, the guys in wind and site often found that, even considering these losses, the global output of the wind farm is higher in a densely packed wind farm with wind sector management then in a configuration without it.
In the market there are also more advanced solutions that, instead of stopping completely the wind turbines, change only some parameters of the WTGs. For instance the optimization algorithm could decide to change the speed of the rotor or the pitch of the blade.
Wind sector management is one of the curtailment that a wind farm can have. Other typical restrictions are linked to environmental issues (noise, shadow flickering, birds or bats) or to requirements coming from the grid.