The aerodynamic design of wind turbine blades is carried out by means of evolutionary techniques within an automatic design environment based on evolution. A simple, fast, and robust aerodynamic simulator is embedded in the design environment to predict the performance of any turbine produced as intermediate individual of the evolutionary process. The aerodynamic simulator is based on blade element theory in which a panel method is combined with an integral boundary layer code to calculate blade airfoils' characteristics. In order to reduce computations some simplifications were contemplated and the results corrected by means of the application of neural network based approximations. Results of the simulations obtained using this technique, of the application of the automatic design procedure and of the operation of the wind turbines thus obtained are presented.