A research team from the University of New South Wales recently published findings analyzing the “long tail” phenomenon observed in large-scale photovoltaic power plants.

The study discovered that approximately 20% of solar components in field applications exhibit significantly faster-than-expected performance degradation. This phenomenon implies that asset owners may face risks of reduced power generation and extended investment payback periods.

“Our findings indicate that the long-tail effect of extreme degradation in PV systems is an inherent characteristic of solar power plants, occurring across all climatic conditions and project types—not confined to specific regions or technologies,” stated Shukla Poddar, the study\’s corresponding author. She further noted: “Climate and project environment influence the severity of the long-tail effect. Hot, dry, or humid regions typically exhibit higher average degradation rates and more pronounced long-tail effects.”

The factors contributing to this phenomenon are complex and diverse, including potential-induced degradation, light-induced degradation, thermohygric stress, and UV-induced material aging.

The study found that the most severe performance degradation often occurs when multiple degradation mechanisms coexist and reinforce each other.

The study recommends adopting a systematic response strategy. Poddar explained: “In our research context, a holistic approach means moving beyond treating individual failure modes in isolation. Instead, it involves preventing cascading or interacting degradation mechanisms starting from the design, manufacturing, and operation of PV systems.”

Key mitigation strategies proposed by the research team include: disrupting correlations between different degradation pathways through robust system design, adopting more reliable module structures, and implementing stricter manufacturing quality control alongside proactive field monitoring.

The study highlights that understanding and preventing interactions between degradation modes, alongside adopting module designs with greater tolerance for cell performance variations, represent critical future directions for industry efforts.