PV Inverter Reliability Assessment: Methodology and Case Study

Reliable operation of photovoltaic (PV) inverters is critical for consistent power generation and minimizing maintenance costs in solar energy systems. An accurate reliability assessment plays a key role in optimizing system design, planning maintenance strategies, and enhancing operational efficiency. However, traditional assessment methods often rely on generic failure rates and simplified ambient conditions, limiting their accuracy by overlooking specific environmental stressors and mission profiles. To overcome these limitations, this paper introduces a comprehensive, application-oriented methodology that integrates tailored Physics-of-Failure (PoF) models with realistic, location-specific mission profiles. The proposed framework begins with a component-level evaluation of PV inverter reliability and is validated through a detailed case study using real-world field data. Results show a marked improvement in prediction accuracy over conventional approaches. Notably, the study underscores the importance of considering relative humidity—alongside temperature—as a critical factor in accelerating degradation, particularly in humid environments.