High-Power electronics are a key in securing a renewable energy supply and advancing the digitization of our society. The liftetime and performance of state-of-the-art technologies are limited by degradation of the semiconductor device structure and the metallic interconnects. This long term proposal aims to characterize the breakdown mechanisms by a series of static and dynamic X-ray microscopy experiments at beamlines ID01 and ID03, supported by the Horizon Europe project ADDMOREPOWER. In operando X-ray microscopy techniques, such as Dark Field and Full-Field X-ray Microscopy, are applied during electrical stress and thermomechanical fatigue testing, to resolve structural changes in time and space. The results will advance the fundamental understanding of degradation mechanisms and provide important feedback for extending the lifetime and performance of high-power devices. The methodology and software will be developed for a future usage of the ESRF community.