Valuation and Cost Optimization of the Proton Exchange Membrane Water Electrolyzer Technologies Considering the Degradation Phenomena

Abstract Polymer electrolyte membrane water electrolyzers (PEMWEs) have gained significant attention in the energy storing industry due to their suitable dynamic response to fluctuations. To minimize the overall hydrogen production cost over the life of the system, it is important to consider both the electricity pricing tariffs and the health of the system. The weakest component of a PEMWE for long term performance is the membrane which thins during operation and eventually no longer separates the reactants appropriately. Reported mechanisms of membrane thinning are conflicting with a wide range of failure rates, operating hours before failure, and differing estimates of efficiency impacts. Some degradation studies report significant reductions in ohmic losses as membranes thin leading to improved overall efficiency, while others predict increasing activation losses leading to declining efficiency over the life of the system. These conflicting reports make projecting long-term costs of PEMWE hydrogen production difficult at present. To provide a comprehensive valuation of hydrogen production cost, an optimal valuation algorithm for behind-the-meter hydrogen production is presented through a case study of hydrogen production at the Natural Energy Laboratory of the Hawaii Authority (NELHA). We include consideration of the various degradation mechanisms reported in literature to highlight which effects will be most important to understand for production planning. This is compared to estimations of production costs ignoring degradation, to highlight the impact of system degradation on long-term planning. Further, this paper suggests analyses to estimate renewable penetration levels for which PEMWE hydrogen production may be cost competitive with other fuel sources given the current membrane replacement costs.