Optimal PV-BESS Sizing for Car-Sharing EV Charging Stations considering Different Electricity Prices

Nowadays, the rise of electric vehicle (EV) carsharing services presents both opportunities and challenges for sustainable urban mobility. However, the volatility in energy prices over recent years has made it increasingly crucial for carsharing stakeholders to keep operational costs under control. To increase the economic returns of car-sharing services, integrating photovoltaic (PV) systems and battery energy storage systems (BESS) with charging stations offers a promising solution to mitigate energy costs and increase the share of green energy used. In this context, this paper presents a PV-BESS sizing optimization model based on a genetic algorithm for car-sharing EV charging stations, aiming to determine the optimal system size by minimizing the annual total cost. The analysis is performed using real electricity price data from 2019 to 2023 to evaluate the impact of price variations. The results demonstrates that integrating a PV-BESS system results in significant cost reductions particularly in years with high electricity prices, with savings reaching up to $\mathbf{4 2. 2 \%}$. Additionally, the PV-BESS system stabilizes costs by reducing the maximum annual cost variation between the years considered, from 101.3% to 42.3%, thereby enhancing the economic sustainability of car-sharing operations.