Optimizing Sustainable Energy Systems: A Comparative Study of Geothermal-powered Desalination for Green Hydrogen Production

The synergy between hydrogen and water is crucial in moving towards a sustainable energy future. This study explores the integration of geothermal energy with desalination and hydrogen production systems to address water and clean energy demands. Two configurations, one using multi-effect distillation (MED) and the other reverse osmosis (RO), were designed and compared. Both configurations utilized geothermal energy, with MED directly using geothermal heat and RO converting geothermal energy into electricity to power desalination. The systems are evaluated based on various performance indicators, including net power output, desalinated water production, hydrogen production, exergy efficiency, and levelized costs. Multi-objective optimization using an artificial neural network (ANN) and genetic algorithm (GA) was conducted to identify optimal operational conditions. Results highlighted that the RO-based system demonstrated higher water production efficiency, achieving a broader range of optimal solutions and lower levelized costs of water (LCOW) and hydrogen production, while the MED-based system offered economic advantages under specific conditions. A case study focused on Canada illustrated the potential benefits of these systems in supporting hydrogen-powered vehicles and residential water needs, emphasizing the significant impact of using high-quality desalinated water to enhance the longevity and efficiency of proton exchange membrane electrolyzers (PEME). This research provides valuable insights into the optimal use of geothermal energy for sustainable water and hydrogen production.