Multi-objective techno-economic optimization of hybrid photovoltaic and battery energy storage systems for electric vehicle charging stations

The increasing adoption of electric vehicles (EVs) has led to a growing demand for cost-effective charging infrastructure. However, integrating renewable energy sources into EV charging stations (EVCSs) presents economic and operational challenges, mainly due to the high costs of battery energy storage systems (BESS) and the variability of photovoltaic (PV) generation. To address these challenges, this study proposes a methodology for the techno-economic assessment of EVCSs integrated with hybrid PV and BESS, using a multi-objective optimization framework. The approach combines detailed technical modeling of PV generation, BESS degradation, charge–discharge losses, charging demand profiles, and energy dispatch strategies, with an economic model that incorporates net metering regulations and taxation policies affecting EVCS operators. This integrated framework enables a comprehensive assessment of the economic viability of hybrid PV–BESS systems. Case study results for Goiânia, Brazil, emphasize the significant influence of tariff structures, BESS costs, and peak-hour energy export incentives on economic viability. Sensitivity analysis and optimization results show that BESS costs and peak tariffs are the most influential parameters. While reductions in BESS costs and increases in peak tariffs enhance economic returns, BESS integration is economically advantageous at lower peak tariffs (0.35 USD/kWh) only if costs drop to very low levels (100 USD/kWh). The optimization model also provides the optimal sizing of PV and BESS capacities, as well as the optimal BESS scheduling over a 24-hour period, ensuring cost-effectiveness while maximizing energy utilization and profitability.