In this study, thermodynamic and economic analysis of a hybrid renewable system based on solar, wind, and geothermal energy for simultaneous production of hydrogen, oxygen, fresh water, and clean electricity is presented. System modeling, including parabolic trough solar collector, wind turbine, steam and organic Rankine cycles, reverse osmosis, and proton exchange membrane electrolyzer, was performed using EES software. For multi-objective optimization, a hybrid method combining neural networks and genetic algorithm was employed. Two objective functions, exergy efficiency and cost rate, were optimized with nine decision variables: number of wind turbines, geothermal temperature, inlet pressure to turbine and steam pump, pump and turbine efficiencies, geothermal mass flow rate, evaporator inlet temperature, and evaporator pinch-point temperature. Based on the optimization output, the optimal system point achieves an exergy efficiency of 22.6% and an hourly cost rate of $238. Subsequently, the performance of the proposed system was comparatively evaluated in four Iranian cities—Tehran, Ahvaz, Isfahan, and Shiraz—using hourly weather data, including solar radiation, wind speed, and ambient temperature. Results showed that the system can generate between 38 to 44 million kWh of electricity annually in these cities. Under the assumed identical geothermal conditions, Isfahan showed the highest system performance among the four climatic cases, mainly due to its comparatively favorable solar radiation and wind conditions. Environmental analysis revealed that system deployment in Isfahan could prevent approximately 9,000 tons of CO₂ emissions, resulting in $215,000 environmental cost savings and contributing to 43 hectares of green space expansion.