Optimal Design of Alkaline Based Electrolysis Hydrogen Production Plants

Green hydrogen production from renewable energy sources using water electrolysis has recently attracted a significant attention to replace fossil fuel. Yet, improving the performance of green hydrogen production plants (GHPPs) and reducing the cost of hydrogen production require developing the necessary engineering design tools. This paper proposes a novel mathematical formulation to optimize the design of Alkaline electrolysis (AE) based GHPPs, where the objective is to minimize the levelized cost of hydrogen. The developed formulation concurrently determines the optimal sizing of the GHPP components (AE, power converter, and compressor), and the optimal internal parameters of the AE (operating pressures, temperature, effective area, separator thickness, and electrolyte concentration). The formulation takes into account the safety constraint on the limit of the hydrogen crossover in AE. Simulation results indicate that various input power profiles from renewable energy resources have a significant impact on the optimal internal parameters of the AE, specifically influencing the operating pressure and electrolyte concentration. This finding proves the significance of incorporating the optimization of the AE internal parameters as control variables in the design of GHPPs.