With the rising adoption of solar power globally, maintaining system reliability and performance is vital for a sustainable energy supply. Common faults discussed include panel degradation, electrical issues, inverter failures, and grid disturbances, all of which affect system efficiency and. This document, an annex to Task 13's Degradation and Failure Modes in New Photovoltaic Cell and Module Technologies report, summarises some of the most important aspects of single failures. Failure Modes and Effects Analysis (FMEA) and Risk Priority Number (RPN) are widely used methodologies to identify, assess, and prioritize potential failures in PV systems.