(Invited) Critical Metrics and Fundamental Challenges for Hydrogen and Fuel Cell Technologies

Abstract

Research and development investments by the US Department of Energy’s (DOE) Fuel Cell Technologies Office have contributed to significant technological advancements leading to the cost reductions witnessed in hydrogen and fuel cell technologies over the past decade. The long-anticipated rollouts of fuel-cell electric vehicles (FCEVs) by major automotive manufacturers over the next several years provide clear evidence of this progress. At this tipping point when FCEVs are just entering the market, continued cost reductions sustained by ongoing scientific advances remain critical. Consumer acceptance will hinge not only on affordable cars, but also on the widespread availability of low-cost hydrogen. In the near term, hydrogen demand for early FCEV markets can be supplied through standard reforming of natural gas and biomass feedstocks. Emerging commercial technologies based on water electrolysis can also contribute. In the DOE’s longer term vision, a significant penetration of FCEVs into transportation markets coupled with an industrial-scale supply of renewable hydrogen could help the U.S. achieve its clean-energy and environmental goals. The continued development of enabling technologies for the widespread and affordable production, delivery, storage and utilization of renewable hydrogen is essential. Materials costs as well as system-level performance and durability issues all contribute to the cost barriers in these technologies. Quantifying these barriers and tying them to specific scientific and engineering metrics provides a powerful tool toward achieving needed performance enhancements and cost reductions. In the hydrogen and fuel cell space, DOE utilizes technoeconomic analyses to quantify key materials- and system-level cost drivers over a broad technology portfolio including fuel cells, hydrogen storage and compression, and hydrogen production by electrolytic, solar-thermochemical and photoelectrochemical water splitting, among others. In these technologies, the ultimate technical and economic viability can be linked to capital and operations costs, which are in turn impacted by fundamental materials properties, including thermodynamic and kinetic limitations. As discussed in this talk, technoeconomic sensitivity studies are invaluable in linking technology-dependent cost reduction targets with specific scientific and engineering metrics and goals. They also provide vital information for establishing research priorities for addressing the key cost drivers across all hydrogen and fuel cell technologies. Opportunities to exploit research synergies among these technologies in cross-cutting functionalities such as catalysis and separations will also be discussed.