Suggested Citation: J. M. Ogden and M. A. DeLuchi, “Solar Hydrogen Transportation Fuels,” Chapter 8 of Transportation and Global Climate Change, ed. by D. L. Greene and D. J. Santini, American Council for an Energy Efficient Economy, Washington, D. C., pp. 189-241 (1993).
Concerns about global warming, urban air quality, acid deposition, and energy supply security are motivating increased interest in low-polluting alternative transportation fuels. Hydrogen is a high-quality, exceptionally clean fuel that has been demonstrated in experimental cars, buses, trucks, and airplanes. With today's hydrogen internal-combustion engine vehicles, the only pollutants are nitrogen oxides (NOx, which can be controlled to low levels). With hydrogen fuel cell vehicles, which could be developed over the next several years, even NOx emissions would be eliminated. If hydrogen is produced from renewable resources, via water electrolysis using solar, wind, or hydroelectric power or via gasification of renewably grown biomass, it would be possible in principle to produce and use transport fuel on a large scale with greatly reduced greenhouse gas emissions and very little local pollution.
In this chapter we analyze the prospects for producing hydrogen transportation fuel from renewable resources. We first review the technologies for producing hydrogen from renewables and describe several base case renewable hydrogen production systems. We then estimate hydrogen production costs, based on current technology and projections for the near term (1990s) and the long term (post 2000 with mature technologies widely employed so that economies of scale are fully exploited). Potential resources for producing hydrogen from solar, wind, hydropower, and biomass are estimated, and environmental aspects of renewable hydrogen systems are considered. We discuss hydrogen transportation technologies, with an emphasis on fuel cell vehicles now under development. Hydrogen fuel cell vehicles are particularly interesting because they could combine the best features of electric-battery vehicles (zero emissions, high efficiency, quiet, long life) with the convenience and flexibility of gasoline vehicles (fast refueling time, long range) and could potentially serve a larger fraction of the market than battery-powered electric vehicles. The life-cycle cost of automotive transportation for a fuel cell vehicle fueled with solar hydrogen is compared with other alternatives, such as gasoline internal-combustion engine vehicles, methanol fuel cell vehicles, and battery-powered electric vehicles. Emissions of greenhouse gases and other pollutants are estimated for various alternatives. Finally, we discuss a strategy for developing renewable hydrogen transportation systems.