global climate change of hydrogen leakage or of changes in the quantities of other greenhouse gases released into the atmosphere, nor does it examine the impacts on emissions of criteria pollutants2 from vehicles.
The economic impacts examined are the costs to the United States as a whole from fueling the fleet of light-duty vehicles. Under the committee’s maintained assumption that the costs of the vehicles themselves are equivalent to the costs of the vehicles for which they substitute, differences in the costs of fueling the fleet will translate into differences in the total costs of driving the fleet of light-duty vehicles. Costs of the infrastructure to fuel the vehicles are included in the supply costs for hydrogen. Therefore, although the committee does not explicitly separate the infrastructure costs from the fuel costs, the infrastructure costs are part of the total. However, because the development of infrastructure may involve large investments concentrated over a small number of years, calculations should not be interpreted as capturing the time dimension of the physical investments themselves. And the committee does not examine any of the redistributional consequences of a shift to hydrogen. In particular, such a massive transition will lead to economic opportunities for some established companies, many new companies, and many individuals, while reducing the economic opportunities for some established companies and individuals. The committee does not examine these potentially important consequences.
The energy security implications examined are related to the imports of energy, in particular, petroleum and natural gas. The committee examined the impacts on the use of gasoline, impacts that can be expected to translate directly to impacts on the imports of crude oil or petroleum products. Impacts on the use of natural gas were examined. An increase in demand would cause an increase in price, which in turn could increase domestic supply. Thus, it is not clear what fraction of this increase in natural gas use would translate into increases in natural gas imports. However, it is assumed that most of this increase in natural gas use would translate directly into increases in natural gas imports, consistent with projections in Annual Energy Outlook 2003 (EIA, 2003). The committee did not try to quantify other impacts on energy security associated with changes in the vulnerability of the energy infrastructures to human error, mechanical breakdown, or terrorism. However, the committee does recognize that choices of distributed production versus central station production, choices of particular hydrogen transportation options, and choices of precise locations of new plants can have significant impacts on energy security.
The committee analyzed several implications relative to domestic resource use. For biomass production, it examined the amount of land that would be required to grow the crops used as feedstocks. For coal-based hydrogen production, it examined the amount of coal that would be used over time. For technologies involving sequestration, it examined the amount of CO2 that would be sequestered on a year-by-year basis and the cumulative quantity sequestered. The committee did not try to quantify several other resource use impacts: it did not examine the amount of land that would be required for wind farms, production facilities, or distribution infrastructure; it did not examine the impacts on water use for steam reforming processes or for biomass production; it did not attempt to examine any labor force issues; nor did it examine the needs for metals or other materials for fuel cells, electrolyzers, or production facilities, or the number of pipelines, or other infrastructure.
Starting with the assumption that the many problems related to the use of hydrogen in vehicles are solved, a plausible but optimistic vision of the penetration of hydrogen technologies into the fleet of vehicles was created. In this vision, as described in Chapter 3, the committee assumes that GHEVs initially begin capturing market share from conventional vehicles, reaching 1 percent in 2005 and growing by 1 percentage point per year until hybrids reach 10 percent market share in 2014. With the introduction of hydrogen vehicles in 2015, initially the market share of GHEVs grows by 5 percentage points per year, while that of hydrogen vehicles grows by 1 percentage point annually. During this period, the market share of conventional vehicles declines by 6 percentage points annually. As hydrogen vehicles continue to grow in popularity, with their market share increasing, the market share of GHEVs peaks in 2024 at 60 percent and then begins declining by 2 percentage points annually. After reaching a 10 percent market share in 2024, hydrogen vehicles begin increasing their market share by 5 percentage points per year until capturing a 60 percent market share in 2034. In that year, hybrids capture 40 percent of the market, and conventional vehicles are no longer purchased. From that point on, hydrogen vehicles increase their market share by 10 percentage points per year, until hydrogen vehicles ultimately capture 100 percent of the market for new vehicles in 2038. The committee considers this vision to repre-
Criteria pollutants are air pollutants emitted from numerous or diverse stationary or mobile sources for which National Ambient Air Quality Standards have been set to protect human health and public welfare. The original list of criteria pollutants, adopted in 1971, consisted of carbon monoxide, total suspended particulate matter, sulfur dioxide, photochemical oxidants, hydrocarbons, and nitrogen oxides. Lead was added to the list in 1976, ozone replaced photochemical oxidants in 1979, and hydrocarbons were dropped in 1983. Total suspended particulate matter was revised in 1987 to include only particles with an equivalent aerodynamic particle diameter of less than or equal to 10 micrometers (PM10). A separate standard for particles with an equivalent aerodynamic particle diameter of less than or equal to 2.5 micrometers (PM2.5) was adopted in 1997.