A 13.5 meters prototype of blade designed by Cener for a 150 kW wind turbine machine, made with glass fiber and vinylester resin doped with carbon nanofibers, was manufactured by Grupo Antolín using a new technique called Light RTM. The blade was done as a monocoque structure with a PVC foam core. Indra and UPM have developed a methodology for instrumenting the blade with fiber optic sensors embedded into the structure during the manufacturing process. Two different sensing techniques were embedded into the blade: Fiber Bragg Gratings (FBG) and a plain fiber optic for Distributed Sensing using an Optical Backscatter Reflectometer (OBR). By means of a novel and robust automated technique based in strain field pattern recognition, a study of detectability of defects was performed for the blade under different load scenarios. Several static tests were conducted, including a test campaign with known artificial damages induced into the structure and the sensitivity of the technique was evaluated. The results showed that every damages could be detected by using both sensing techniques.