A method for operating a wind energy system (100) is provided comprising the steps of setting the value of an operational parameter of the wind energy system (400), measuring a yield parameter of the wind energy system (410), and measuring a condition parameter. Further, the method comprises the step of calculating an optimized value of the operational parameter based on historical data and the outcome of the measurements (420). The method further comprises the step of resetting the operational parameter to the optimized value of the operational parameter (430) wherein the resetting is such that the yield parameter is optimized. Further, a wind energy system is provided having a sensor unit (215) for measuring a yield parameter of the wind energy system and a sensor for measuring a condition parameter, an actuator (225) for adjustment of at least one adjustable part (140) of the wind energy system, and a self-learning controller (200). The self-learning controller is connected to the sensor unit and the actuator and receives measurement data from the sensor unit. The self-learning controller performs optimization calculations based on the measurement data and sends instruction signals to the actuator based on the outcome of the optimization calculations for the adjustment of the adjustable part of the wind energy system. The instruction signals are such that the yield parameter is optimized.