Techno-economic assessment with Monte Carlo analysis of high-pressure PEM water electrolysis and mechanical compression in ammonia production

Green ammonia from renewable-powered high-pressure electrolysis offers a pathway to decarbonize ammonia production. This study evaluates the techno-economic feasibility of integrating high-pressure proton exchange membrane water electrolysis (PEMWE) with the Haber–Bosch process to avoid mechanical hydrogen compression. Two configurations were analyzed: a 30-bar electrolyzer with mechanical compression and a 200-bar stack-only system, employing electrochemical compression. A detailed model estimates capital and operational costs of the electrolyzer and other components. The calculated levelized cost of hydrogen (LCOH) is $5.39 kg −1 for mechanical compression and $6.44 kg − 1 for electrochemical compression. The higher LCOH of the stack-only system mainly results from increased energy consumption driven by higher stack voltages at elevated pressures. Sensitivity analysis identifies electricity price, electrolyzer efficiency, cost, and lifetime as the most influential factors, while Monte Carlo simulations show greater variability and a higher median LCOH for the stack-only system. Improving electrolyzer efficiency, durability, and cost is essential to enable adoption of high-pressure electrolysis for green ammonia production. • Modeled and evaluated high-pressure PEMWE for green ammonia production. • 200-bar PEMWE eases integration but raises LCOH due to efficiency loss. • Sensitivity analysis reveals key LCOH drivers. • Monte Carlo simulation shows higher LCOH median and variability for the 200-bar system. • Improved efficiency and lower manufacturing cost are needed for high-pressure PEMWE to compete with mechanical compression.