4.4.1 A System-of-Systems Framework for the Future Hydrogen-Based Transportation Economy

Today, almost 60% of the petroleum consumed in the United States is imported. The nation's current transportation system of systems (SoS) relies almost exclusively on refined petroleum products, accounting for over two-thirds of the oil used in the United States each day. As a nation, we must work to reduce our dependence on foreign sources of oil in a manner that is affordable, ensures national energy security, and preserves environmental quality. In the long term, a potential solution to the nation's transportation energy problems is an operational hydrogen-based transportation economy. Transitioning to any alternative transportation fuel on a national scale will require the creation of a robust and cost-effective system of systems that operates in concert with the dynamics of today's mature and highly-networked transportation infrastructure. Using a supply-chain point of view to trace the flow of transportation fuels through the necessary SoS, this paper addresses the current petroleum-based economy for transportation, the U.S. Department of Energy's (DOE's) vision for a future hydrogen-based transportation economy, and the significant challenges associated with such a massive market and infrastructure transformation.