US Patent 8157533 Wind turbine blade with variable aerodynamic profile

A wind turbine blade comprising an active elastic member arranged with access to the surface of the wind turbine blade is provided. The active elastic member is deformable from a first shape to a second shape and the lift coefficient of the airfoil with the active elastic member in the first shape is larger than the lift coefficient of the airfoil with the active elastic member in the second shape. Furthermore, a wind turbine comprising such a wind turbine blade and a method of operating a wind turbine comprising such a wind turbine blade are provided.