A review on operational issues, maintenance strategies and OPEX-driven LCOE optimization in utility-scale PV systems

Utility-scale photovoltaic (PV) systems are central to renewable energy deployment, and while capital expenditure has historically dominated LCOE assessments, their long-term economic viability increasingly depends on optimizing operational expenditure (OPEX). OPEX accounts for up to 77 % of lifecycle costs and strongly affects the levelized cost of electricity (LCOE). This study provides an integrated assessment of the operational challenges, maintenance paradigms, and digitalization strategies that underpin effective OPEX management in utility-scale PV plants. Electrical faults, physical defects, and environmental stressors are identified as major performance constraints requiring timely mitigation. For each major operational fault, the study evaluates its severity and reviews the detection and mitigation strategies. These operational issues are then systematically linked to preventive, corrective, and predictive maintenance approaches, ranging from field inspection to ML-enabled diagnostics and digital twin-based forecasting, to assess their benefits, limitations, and regional applicability. Finally, the review presents a sensitivity based LCOE impact assessment that explicitly translates reported yield improvements and OPEX reductions from different O&M strategies to their resulting LCOE impacts. Together, these insights translate the technical and economic gains into measurable LCOE benefits, offering a practical decision framework for optimized PV plant maintenance. Furthermore, incorporating these advances within structured O&M frameworks improves system reliability, extends asset lifetime, and strengthens long term financial performance in utility-scale PV installations.