Rigorous modeling and wind energy integrated simulation of an alkaline water electrolysis system

Alkaline water electrolysis (AWE) has been widely demonstrated, particularly for large-scale hydrogen production. However, its underlying electrochemical phenomena are complex; therefore, rigorous modeling is required to better predict system performance and accurately estimate hydrogen production. This study proposed a rigorous electrochemical model of a zero-gap-type AWE, incorporating electrode-specific bubble effects reflecting the differing gas-production rates, effective electrolyte thickness calibrated through impedance measurements, and interfacial contact resistance. The model was validated using experimental data and extended to simulate a large-scale green hydrogen production system. The validated AWE model was applied to quantify green hydrogen production using real-time wind-power data from a 2.3 MW wind turbine located in Yeonggwang Baeksu, South Korea. Case 1, a standalone AWE system coupled with wind-power, yielded an annual hydrogen production of 85,863 kg with a storage-based efficiency of 81.5%. In Case 2, an integrated AWE–proton-exchange membrane fuel cell (PEMFC) configuration maintained the minimum AWE operating load, resulting in a net annual hydrogen storage of 69,500 kg with a reduced storage-based efficiency of 62.5% owing to hydrogen consumption by the PEMFC. Case 3 focused on stabilizing intermittent renewable electricity, where the AWE–PEMFC system balanced wind-power fluctuations using hydrogen as an intermediate energy carrier, achieving a constant annual power output of 300.12 kW. Additionally, a case-study-based economic analysis evaluated the levelized cost of hydrogen for different system configurations.