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This paper investigates geothermal energy's potential for hydrogen production, addressing fossil fuel limitations, climate change, and the need for integrated simulations and financial assessments tailored to specific geological contexts. We compare the energy efficiency and economic feasibility of geothermal-driven hydrogen production systems through simulations of flash cycles, organic Rankine cycle (ORC), and hybrid flash-ORC systems. Optimal operational parameters for energy efficiency are identified under various geothermal conditions. Our analysis reveals that the system efficiency strongly depends on temperature and geofluid type. For dry steam over 200 °C, the energy efficiency of the system is estimated to be roughly 15 %. For wet steam in a fully liquid state, combining ORC with flash cycles can extract more than 10 % of energy from the geofluid. The levelized cost of hydrogen (LCOH) production using dry steam is estimated at 1.26 USD/kg, which is even lower than that of using natural gas. When feeding the hybrid flash systems with fully liquid wet geofluid, the lowest LCOH is 5.23 USD/kg. Economic viability depends on geological and technological variables, including well depth and pressure constraints. The results highlight the strategic potential of integrating geothermal energy into the clean energy matrix, balancing economic and environmental sustainability for carbon neutrality.
Cui et al. (Wed,) studied this question.