Optimal Sizing and Operation of PV–Diesel–Battery Hybrid Energy Systems for Electric Vehicle Charging Using Homer Grid

The rapid adoption of electric vehicles (EVs) has intensified the demand for reliable and low carbon charging infrastructure, especially in regions with weak or unstable electricity grids. This study presents a techno-economic optimization of a hybrid photovoltaic (PV)–diesel–battery energy system for EV charging applications at Agric Village, Ogbomoso, Nigeria, using the HOMER Grid simulation platform. The objective was to minimize the system’s Net Present Cost (NPC) and Levelized Cost of Energy (LCOE) while ensuring uninterrupted power supply to meet charging demand. Three configurations were modeled and compared: diesel-only, PV + diesel, and PV + diesel + battery. Results indicate that the integrated hybrid system significantly reduces both operating costs and emissions, achieving an LCOE of 0.227 USD/kWh and a 67.8% reduction in fuel consumption compared to the diesel-only system. The inclusion of battery storage improved reliability by balancing intermittent solar output and evening load peaks. Sensitivity analysis further showed the system’s robustness under varying diesel and battery cost conditions. Overall, the optimized PV–diesel–battery configuration demonstrates a sustainable and economically viable pathway for powering EV charging infrastructure in semi-urban communities, supporting Nigeria’s renewable energy transition and sustainable mobility goals.