Sustainable Transportation Energy Pathways (STEPS)
Ogden, Joan M., Christopher Yang, Joshua M. Cunningham, Nils Johnson, Xuping Li, Michael A. Nicholas, Nathan C. Parker, Yongling Sun (2011) "The Hydrogen Fuel Pathway" chapter 3 in Sustainable Transportation Energy Pathways: A Research Summary for Decision Makers. Institute of Transportation Studies, University of California, Davis, 64 - 93
We turn now from biofuels and electricity to a fuel pathway that holds out promise farther in the future. Hydrogen has been widely discussed as a long-term fuel option to address environmental and energy security problems posed by current transportation fuels. Hydrogen fuel cell cars are several times more efficient than today’s conventional gasoline cars, and they produce zero tailpipe emissions. They offer good performance, a range of 270-430 miles,1 and can be refueled in a few minutes. Hydrogen can be made with zero or near-zero emissions from widely available resources, including renewables (like biomass, solar, wind, hydropower, and geothermal), fossil fuels (such
as natural gas or coal with carbon capture and sequestration), and nuclear energy. In principle, it should be possible to produce and use hydrogen transportation fuel with near-zero well-to-wheels emissions of greenhouse gases and greatly reduced emissions of air pollutants while simultaneously diversifying away from our current dependence on petroleum.
To reach stringent long term goals for cutting greenhouse gas emissions from transportation, it appears likely that the light duty fleet will be largely electrified by 2050 (see Chapter 8). Hydrogen fuel cells are an important enabling technology for this vision. Automakers foresee a future electrified light duty fleet with batteries powering smaller, shorter range cars and hydrogen fuel cells powering larger vehicles with longer range. To electrify all segments of the light duty market, fuel cells are a necessary complement to batteries.
Recent assessments affirm the long-term potential of hydrogen to greatly reduce oil dependence as well as transportation emissions of greenhouse gases and air pollutants—far beyond what might be achieved by energy efficiency alone. They also highlight the complex technical and logistical challenges that must be addressed before a hydrogen-based transportation system can become a reality. This chapter discusses some of the major questions regarding future use of hydrogen in the transportation sector and highlights STEPS research on these issues.
• What is the technical outlook for hydrogen vehicles and hydrogen supply?
• What are the environmental impacts of hydrogen fuel compared to alternatives?
• What would a hydrogen infrastructure look like, and how could we make a transition to hydrogen?
• What policies and business strategies are needed to support hydrogen in both the near and long terms?