Comprehensive 4E analysis and optimized performance evaluation of grid-connected renewable hydrogen production systems integrated with PEMFC-ORC using solar, biomass, geothermal, and wind energy

This study highlights the significance of coupling solar, biomass, geothermal, and wind energy power sources with a proton exchange membrane fuel cell (PEMFC) for green and reliable grid-connected power production. By integrating these four renewable power sources, a proton exchange membrane electrolyzer (PEME) efficiently generates hydrogen, which is then stored and later utilized in a PEMFC, ensuring a continuous and reliable supply of clean energy. This approach not only maximizes the use of diverse renewable resources but also enhances energy security and reduces greenhouse gas emissions, contributing to a sustainable energy future. In the present research, a 4E study is done on the proposed configurations. In considered layouts, the four different types of renewable power produce green hydrogen in a PEME, and the hydrogen is injected into a PEMFC for power generation. Furthermore, the waste energy of the PEMFC is recovered by a bottoming organic Rankine cycle (ORC). Results demonstrates that in the optimal output performance mode, the biomass-based system achieves the highest exergy efficiency (6.25%), while the geothermal-based system achieves the lowest values for total cost rate and output unit cost (25.89 $/h and 45.77 $/GJ, respectively). In the optimal case of the geothermal-based system, the topping system produces 3.167 kg/h of green hydrogen with a unit cost of 29.98 $/GJ (4.25 $/kg). The produced hydrogen is then supplied to the bottoming PEMFC–ORC system, which generates 49.2 kW of electrical power. In this configuration, the unit cost of the produced electricity is calculated as 45.77 $/GJ.