The transportation sector has traditionally had little integration with the electricity sector except for a brief and unsuccessful experiment with battery electric vehicles. A possible transition to hydrogen fuel cell vehicles for transportation would replace petroleum-fueled internal combustion engine vehicles with electric vehicles that use hydrogen fuel cells to supply the electricity. A common view of hydrogen is that it is merely a replacement for gasoline, with an analogous process chain and infrastructure. A more integrated and holistic analysis of the energy system would imply that hydrogen and electricity would converge towards a tightly coupled set of energy carriers that will have interactions at many different scales and locations along the infrastructure chain. We will describe and provide preliminary analysis of these crucial interactions that would more closely integrate the transportation fuel and electricity sectors in a hydrogen economy. This paper will provide a high-level framework for understanding the economic and environmental impacts of a transition to a hydrogen and electricity economy. An obvious but important interaction between these two sectors is the additional electricity demands for hydrogen pathways steps such as electrolysis, compression or liquefaction. Determining the true life-cycle emissions of these hydrogen pathways requires a detailed analysis of how these additional demands would impact the load shape, generation capacity additions and dispatch of generation resources (McCarthy, 2006). Another important set of interactions relate to production. The H2 and electricity sectors will interact because they can be produced from the same primary energy feedstocks, such as coal, natural gas and biomass. The timing of the demands for these energy carriers and possible competition for these primary energy feedstocks are important issues for analysis. In addition, the co-production of H2 and electricity in thermochemical plants utilizing coal or other fossil resources provides a method for producing small amounts of low-cost hydrogen for early markets (Chiesa, 2005). Co-product strategies can improve the overall economics, and coupled with carbon capture and sequestration (CCS), these plants can produce both energy carriers with near-zero carbon emissions. Also, the two energy carriers can be inter-converted as grid and renewable electricity can be used to generate hydrogen via electrolysis and hydrogen is converted to electricity in vehicle and stationary power plants. This study will identify the design issues, costs and benefits associated with these co-production and inter-conversion strategies. By analyzing the potential for these options, the we hope to address many of the questions that have been posed as to what resources can and should be used to produce each energy carrier when considering economic and environmental attributes. Our goal is to improve our understanding of how a future hydrogen/electric economy may best be organized and identify and explore potential opportunities and challenges for hydrogen within the larger energy system (McCarthy, 2006, Sperling, 2004 and Romm, 2004).