The wind energy sector continues growing rapidly even under the pandemic, as an estimated 93GW wind capacity was installed in 2020 globally. After installation, wind turbines are expected to run around 20-25years, during which O&M (operation and maintenance) becomes crucial in maximising the economic and environmental benefits of wind assets. This project aims to develop a complete solution for robotic based inspection and repair of wind turbine blades (WTBs), both onshore and offshore. Firstly, we will integrate thermography and shearography with laser heating, so that advanced lock-in techniques will be achieved for in-situ inspection of both surface and subsurface defects within WTBs. (Current techniques including drone-based are limited to surface defects only). Secondly, a compact and efficient robotic deployment system will be developed which will hold the inspection unit and a robotic repair arm. The robotic system will be operated by engineers working on ground (for onshore wind farms) or on a vessel (for offshore wind farms). When defects are detected and deemed reparable, the repair arm of the whole system will be activated to rapidly repair the faulty area of composite components by resistance welding for joining and/or disassembly. Comparing to the traditional adhesively bonding for repair, the proposed resistance welding with optimised processing would significantly reduce the curing cycles/time with much fewer preparation for surface treatment steps while it will be more easily designed to integrate with robotic arm. The whole system will be operated remotely by engineers working on ground or on a vessel without risking their lives working in the sky on WTBs. Field trials on wind towers will be conducted to validate the system.