Manufacturing Cost Analysis for Proton Exchange Membrane Water Electrolyzers

Abstract

Hydrogen is produced by several means including water electrolysis where water molecules are split into hydrogen and oxygen. While there are several commercial electrolysis systems, proton exchange membrane (PEM) technology has emerged as a technology of choice in the last decade or so because of the versatile properties it possesses. High current and power densities and high efficiency values are among the advantages of the PEM electrolyzer over other commercial or near-commercial electrolysis systems such as alkaline or solid oxide. This study attempts to study the impact of manufacturing economies of scale on the cost of the PEM electrolyzer and how this can be linked to reducing the cost of hydrogen production. We found that adoption of the high throughput, automated manufacturing processes that have high process yields such as roll-to-roll manufacturing of catalyst coated membrane and advanced coating processes for metal plates, could push the cost for the PEM electrolyzer stack to the $323/kW level for an overall production volume of 10MW (e.g. 1 MW systems x 10 units/year). The stack cost can be pushed as low as $165/kW at 10,000 systems/year. We do not expect to see same rate of the cost reduction in the balance of plant because most parts are outsourced from part suppliers who offer limited discounts on their products. System cost including stack and balance of plant, could also be pushed down with economies of scale. The uninstalled system cost can be reduced from $515/kW at 10 units/year to $230/kW at 10,000 units/year.