This article details analysis of hydrogen (H2) production based on polymer electrolyte membrane (PEM) electrolysis. This work identifies primary constraints to the success of this production pathway, primary cost drivers, and remaining Research and Development (R&D) challenges. This research assesses the potential to meet U.S. Department of Energy (DOE) H2 production and delivery (P&D) cost goals of $2 to $4/gasoline gallon equivalent (dispensed, untaxed) by 2020. Pathway analysis is performed using the DOE’s main H2A modeling tool, namely, the H2A Production model, which encapsulates the standard methods of energy, emissions, and cost analysis developed by DOE’s H2 and fuel cell technology teams. PEM electrolysis production pathways are analyzed for a distributed, forecourt H2 production system of 1,500 kilograms (kg) of H2 per day, and for a central, large, plant size H2 production system of 50,000 kg H2/day, for both current and future cases. The analysis is based in part on data from a technical and economic survey completed by four different PEM electrolyzer companies.
Model results indicate that, for PEM electrolysis, the primary cost drivers are the electricity expenditures to run the electrolyzer and the capital cost of the electrolyzer. In the future within the electrolyzer system, the balance of plant is expected to be a greater source of cost than the electrolyzer stack due to stack reductions facilitated by operation at higher current densities whereas the balance of plant remains similarly sized for the given flow. This balance between size and cost of the stack versus balance of plant could also increase difficulties in meeting efficiency improvements in the future. The H2 cost reduction is estimated to be greater moving from a Current case to a Future case, compared with moving from a Forecourt case to a Central case.