This deliverable evaluates the operational stability and reliability of perovskite/Si tandem solar cells under relevant stress conditions, including spectral variations, potential-induced stress, and reverse-bias operation. A dedicated light-soaking and characterization setup was used to emulate realistic operating conditions and monitor device behaviour over time. The results indicate that device performance is influenced by operating conditions that differ from ideal current-matched operation, highlighting the importance of spectral effects under real-world illumination. In addition, the tandem devices showed strong resilience against high-voltage stress and maintained stable operation under reverse-bias conditions relevant to partial shading scenarios. Overall, the findings confirm the robustness of the developed tandem technology under a range of application-relevant conditions