Lifecycle Optimization of Grid-connected Photovoltaic Energy Storage Systems

The increasing penetration of photovoltaic (PV) generation and battery energy storage systems (ESS) in grid-connected applications has intensified the need for design and operational strategies that simultaneously address technical performance, economic viability, and long-term system sustainability. Conventional multi-objective optimization frameworks for PV–ESS systems typically neglect component degradation or treat it as an exogenous post-processing factor, leading to solutions that are suboptimal over the system lifetime. This paper embeds physics-informed battery aging and grid constraints inside the NSGA-II optimization loop to co-optimize Net Present Cost (NPC), reliability (Energy Not Supplied and Loss of Power Supply Probability), curtailment, and battery State-of-Health. Across three regions (Nigeria, South Africa, India), the lifecycle-aware design reduces NPC by 12–15% and slows degradation by 38–41%, extending replacement intervals to 10–12 years while maintaining grid-code compliance. The framework integrates realistic battery aging models, energy balance constraints, and grid interaction limits, ensuring physical feasibility and long-term performance consistency. Validation across Nigeria, South Africa, and India under different climatic and tariff conditions demonstrates that integrating degradation awareness fundamentally alters optimal sizing and dispatch decisions, yielding solutions with improved lifecycle reliability and reduced total cost of ownership compared to conventional approaches. The results confirm that lifecycle-aware optimization is essential for the sustainable deployment of grid-connected PV–ESS systems and provide practical findings for system planners, utilities, and policymakers seeking to improve long-term grid resilience.