A number of numerical and experimental studies over the last more than 10 years have shown that active flap systems can provide an interesting perspective for control of aerodynamic loads along wind turbine blades. In the state of the art technology control is done by pitching the blades and by variable rotor speed. With an active flap system a third control option is present which has the big advantage that the load control can vary along the blade span which can increase Annual Energy Production (AEP), reduce noise and significantly reduce overall turbine loading. With a successful implementation of active flap technology it can be a quantum leap reducing the overall cost of energy for wind turbines.