This thesis analyses and optimizes the repair processes of wind turbine blades, focusing on onshore maintenance and its impact on technical performance, cost reduction, and environmental sustainability. Wind energy is a key pillar of the energy transition, yet blade deterioration remains a major challenge for reliability and lifecycle efficiency. The study examines damage typologies, repair methods, and material choices to define a structured approach to blade restoration that combines engineering accuracy and sustainability metrics. Structural repairs—such as scarf joints, core replacements, and trailing-edge restorations—restore up to 95% of the original mechanical strength, provided that surface preparation, adhesive selection, and curing parameters are rigorously controlled.