Multi-objective optimization of hybrid renewable energy systems for sustainable resource management and emission mitigation in climate-sensitive regions

A multi-objective optimization framework is developed for designing a hybrid renewable energy system (HRES) for Hormuz Island, integrating photovoltaic, wind, lithium-ion battery, proton-exchange-membrane electrolyzer-tank-fuel-cell, and a standby diesel generator. Real meteorological and demand data are employed to minimize the Levelized Cost of Energy (LCOE) and Net Present Cost (NPC) while maximizing the Renewable Energy Fraction (REF) and system resilience. The optimization integrates multiple conflicting techno-economic and environmental objectives through a TOPSIS-guided multi-criteria framework, where a scalar closeness coefficient is used as the fitness function within the search process, without explicit Pareto-front construction. Results indicate that, compared with the diesel baseline, the optimized configuration achieves an LCOE of 0.139 USD kWh −1 , a 38.6 % reduction in NPC, a REF of 87 %, and nearly 89 % GHG mitigation. The discount rate exhibits the highest sensitivity, inducing ± 14.8 % variability in NPC and ± 9.2 % in LCOE, followed by battery CAPEX (±9.5 % NPC) and PV CAPEX (±7.1 %). Resilience evaluation under 10 % PV and 20 % hydrogen-storage perturbations confine the Loss-of-Load Probability to ≤ 2 %, confirming robust operation under adverse climatic fluctuations. Life-cycle assessment demonstrates approximately 20 % reduction in CO 2 -equivalent emissions, while techno-economic analysis indicates about 15 % reduction in total energy cost relative to conventional diesel supply. The proposed configuration provides a replicable blueprint for off-grid, climate-vulnerable islands seeking reliable and low-carbon electrification pathways.