A method for controlling a renewable energy farm comprising a plurality of wind turbines and at least one central control unit is disclosed. The wind turbines of the renewable energy farm are connected to a power grid. The central control unit receives a request for change in operation of at least one of the wind turbines, where execution of the change in operation causes a change in power output of the wind turbine. The central control unit checks whether or not the change in power output is in conflict with at least one obligation of the renewable energy farm towards the power grid. In the case that the change in power output is in conflict with at least one obligation of the renewable energy farm towards the power grid, execution of the change in operation is deferred.