Understanding Reliability and Maintenance Concerns in Solar Energy Systems: State of the Art and Future Directions

Abstract

The global capacity of solar photovoltaic (PV) systems is increasing rapidly, necessitating robust reliability and maintenance (R&M) frameworks to ensure long-term economic viability and grid integration. Unlike conventional power plants, where fuel costs are distributed over the lifecycle, renewable energy systems incur high initial capital costs. Consequently, lowering lifecycle costs by enhancing system reliability and optimizing maintenance strategies has become a key research priority. This paper presents a comprehensive overview of existing literature on R&M for utility-scale grid-connected solar PV applications, with other solar configurations and technologies considered supporting extensions where relevant. Current research is categorized into major themes, including failure mechanisms, monitoring techniques, maintenance strategies, and operation and maintenance costs. Analyzing areas of agreement and divergence among studies reveals persistent research gaps, particularly in integrating probabilistic reliability modeling with cost-optimized maintenance planning. The conducted synthesis links reliability theory, maintenance decision-making, and economic considerations for solar PV systems, providing a consolidated reference to improve maintenance strategies, enhance system availability, and reduce long-term operating costs.