Techno‑Economic Benchmarking of Proton Exchange Membrane Water Electrolysis Against Alkaline Electrolysis: Cost Drivers and LCOH Sensitivities

Abstract

This research provides an in-depth techno-economic analysis (TEA) of the proton exchange membrane electrolysis (PEME) using the alkaline water electrolysis (AWE) as the benchmark technology. The primary aim is to identify the cost drivers associated with these technologies. The study includes Aspen HYSYS simulations of PEME and AWE plants, base case scenarios, and sensitivity studies to determine levelized cost of H₂ production ($/kg H₂) for both technologies based on key plant operating parameters. Analysis results show that capital expenditures (CAPEX) are largely influenced by the stack cost, whereas operating expenditures (OPEX) are primarily affected by the cost of electricity for the stacks. Additionally, the plant capacity factor (CF) is a significant contributor in reducing LCOH. For the 50-MW PEME plant base case scenario, the lower-bound (5^th percentile) LCOH is $6.56/kg H₂, and the upper-bound (95^th percentile) value is $11.60/kg H₂. For the 50-MW AWE plant base case scenario, the lower-bound LCOH is calculated at $4.68/kg H₂, while the upper-bound value is $9.78/kg H₂. A total of 60 sensitivity studies were conducted to evaluate the impact on LCOH of key operating parameters for the PEME and AWE plants. Despite ongoing improvements in stack efficiency and efforts to reduce other cost drivers such as material costs, LCOH from water electrolysis remains above the U.S. Department of Energy’s target of $1/kg H₂ by 2030.