Optimal supervisory operation of a solar-powered hydrogen and electricity co-generation system integrating SOEC, PEMFC, and dual-stage Rankine cycle

This study proposes a novel polygeneration energy system that operates independently of the grid, producing electricity, hydrogen, and heat as the primary outputs from solar energy. This system comprises the main components of a proton exchange membrane fuel cell (PEMFC), a solar dish collector (SDC), a solid oxide electrolyzer cell (SOEC), and a dual Rankine cycle (DRC). To address the intermittency of solar energy, three operational modes are implemented: Solar-DRC-SOEC, Solar-DRC-PEMFC, and PEMFC. The system is designed to provide a constant amount of electric power equal 110 kW during the year, and the excess produced hydrogen is stored for sale. Key design parameters are selected for multi-objective optimization using genetic algorithm, considering exergy efficiency and total system cost as objective functions. The optimized results show that in the three defined modes, the obtained exergy efficiencies at the optimum condition are 16.52%, 16.79%, and 55.74%, respectively. These findings demonstrate that the proposed configuration can achieve significantly improved exergy efficiency and economic performance, demonstrating its potential as a sustainable and cost-effective solution for multi-generation energy production. Additionally, the average cost rate, the levelized cost of produced electricity and hydrogen ( 114 kg / day ) are calculated 91.41 $ / hr , 0.31 $ / kW .hr , and 17.63 $ /kg H 2 , respectively with a $ 2.473 M total investment cost.