Optimization of waste heat utilization from green hydrogen PEM electrolyzers for enhanced energy efficiency in hot climates: A Persian Gulf region airport study

This paper proposes an optimized approach to waste heat recovery and thermal management in green hydrogen proton exchange membrane (PEM) electrolyzers, aiming to significantly enhance both energy efficiency and overall system reliability in hot climate conditions. The integrated system utilizes thermal storage tanks, carefully optimized heat exchangers, and advanced control strategies to effectively repurpose excess heat for useful applications, such as domestic hot water heating and preheating of make-up water. The methodology involves developing a dynamic thermal model of the integrated system, simulating heat flows, storage dynamics, and cooling loads under representative Persian Gulf-region airport conditions. The model integrates heat recovery, thermal storage, and cooling systems, optimized to minimize energy use and CO₂ emissions while maintaining stable electrolyzer operation. A smart control strategy adjusts chiller operation and pump speeds in real time to minimize energy use, shift peak loads to off-peak periods, and maintain optimal operating temperatures for the electrolyzers. Novel chiller scheduling and pump operation strategies further reduce overall energy consumption and improve system performance. Analytical results obtained from simulations show that the proposed optimization reduces air-cooled chiller energy consumption by 28 %, circulation pump energy by up to 56 %, total power cost by 33 %, and CO₂ emissions by 33 % (∼94 tonnes/year). These promising findings highlight not only the technical viability but also the economic feasibility of implementing waste heat recovery systems, ultimately offering a sustainable and practical solution for renewable energy applications specifically tailored for hot climate regions.