Low Cost Large Scale PEM Electrolysis for Renewable Energy Storage

Solar and wind energy are the most likely candidates to meet our future energy needs based on the available capacity. The problem is that these renewable sources are not consistently accessible, and thus storage must be an integral part of the energy solution. Hydrogen generation via proton exchange membrane (PEM) water electrolysis is one attractive solution, but the life cycle cost of the electrolyzer must be reduced in order to meet the DOE targets. The membrane electrode assembly represents over 1/3 of the cell stack cost, while the membrane ionic resistance and oxygen evolution overpotential represent the majority of the efficiency losses. At high production volumes, the electricity cost can represent 2/3 of the total cost of hydrogen. The oxygen evolution catalyst and membrane materials are therefore key areas of focus for both operating and capital cost. In Phase 1, significant advancements were made in the oxygen evolution reaction, with an estimated order of magnitude improvement in the exchange current density. In parallel, membrane studies focused on thin, reinforced membranes obtained from W.L. Gore. During the period of performance, processing variables were modified to investigate their impact on stability and efficiency. Conditions were found which enabled durability surpassing 5-mil Nafion membrane, while providing a significant performance gain vs. commercial electrolysis cells. The proposed Phase 2 project will combine the effects of both efforts in single MEAs, as well as performing further optimization of the catalyst composition and performing substantial reductions in loading. Phase 2 will also focus on demonstration of scalability of the improved membranes to full size cell stacks, with fabrication of a 300 psi electrolyzer based on Protons 0.6 ft2 stack. This system will operate for at least 1000 hours, with a goal of demonstrating & gt;69% efficiency. Analysis of operation projected to 50,000 kg/day will be performed, including analysis of greenhouse gas and petroleum reductions that will occur with the successful implementation of the proposed technology. This research and development effort is designed to transform hydrogen-based energy storage into an enabling technology for the reduction of fossil fuel use by overcoming the present economic constraints preventing its widespread application. Protons electrolyzers already serve a wide variety of applications, including metals processing, chemical manufacturing, electronics manufacturing, hydrogenation, electrical generator cooling, fiber optic cable manufacturing, and argon purification. Next generation products currently under development include higher pressure systems for the fueling and energy storage markets as well as regenerative fuel cells for telecommunications backup power systems. All of these technologies are on pathways to commercialization and utilize various Government and internal sources of funding to advance their state of technical readiness. Protons mission is clearly to move advanced technology PEM products into hydrogen energy applications as those markets emerge.