Performance analysis of hydrogen production systems using hot sedimentary aquifer geothermal resources

• Long-term performance of geothermal-based H 2 production systems is evaluated. • A 4.87 % geothermal temperature drop over 30 years significantly lowers H 2 output. • Long-term analysis prevents overestimation of system performance. • Advanced Organic Rankin Cycles consistently outperform the simple ones. • Advanced systems produced 496–419 kg/day H 2 at 5.52–5.58 AUD/kg over 30 years. Geothermal-based hydrogen production systems are receiving increasing attention due to the greater focus on renewable energy sources for sustainable hydrogen production. This study systematically assesses the long-term performance of hydrogen production systems using geothermal energy over 30 years, emphasizing the impact of geothermal temperature variations. Using a hybrid numerical model that integrates a hot sedimentary aquifer geothermal reservoir with Organic Rankine Cycle components, this study investigates, optimizes, and compares the long-term performance of three advanced power plant configurations against a simple one. Results show that hydrogen production is highly sensitive to temperature. A 4.87 % degradation in geothermal temperatures over the 30 years of operation leads to an average 14.3 % reduction in hydrogen production for all system configurations when both surface and underground processes are integrated into the model. However, the study reveals that advanced systems outperform the simple one in both hydrogen production rate and cost. Notably, the optimized closed regenerator system achieves the highest hydrogen production rates of 519 kg/day in the first year and 449 kg/day in the last year with minimal cost increases from 5.40 to 5.41 AUD/kg, respectively, over the 30-year period.