Comprehensive review of hydrogen generation utilizing geothermal energy

Hydrogen is an industrially significant gas and is considered a potential clean fuel. In the time of climate change; when the global impetus is towards reducing the reliance on fossil fuel, there is a need to go for other alternatives to secure the supply of this strategic gas as almost 95 % of Hydrogen is generated from fossil fuels. Geothermal energy is a reliable green energy source that harnesses crust thermal heat to generate power and is independent of physical weather processes. In this study, we outlined the different production techniques of hydrogen and evaluated the utilization of geothermal resources in the generation of green hydrogen. This study evaluated the different electrolyzers and geothermal energy-based green hydrogen production models and we concluded that cogeneration of hydrogen with the geothermal plant is strongly dependent on the temperature of the geothermal fluid, its flow rate, the cycle of the plant, and the ORC working fluid. Green hydrogen production utilizes the waste thermal energy of the plant thus increasing the plant efficiency and plant output diversification adds up to its economy. In this study, we also outlined the feasibility prospects of geothermal-based green hydrogen and concluded that geothermal energy-based green hydrogen can be a promising way to decarbonization. • Energy Efficiency and hydrogen production increased with geothermal temperature and mass flow. • The parametric factor like the working fluid of the binary cycle has a direct influence on the hydrogen generation rate. • The potential of the low-enthalpy geothermal resources is more favorable than that of high-enthalpy geothermal resources due to their availability at shallower depth.