October - December 1999
Fuels and Vehicles for 2020:
How the New Technologies Measure Up
Regulating Hazardous Air Pollutants
in Urban Areas: Recommendations from
Energy Laboratory Symposium
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n Energy Laboratory assessment of likely new technologies for passenger cars in 2020 has come up with no overall winners in the race for cars with lower greenhouse-gas and other emissions. Initial results from the assessment show that the gains from continued work on conventional fuels and vehicles are so great that emerging technologies like the fuel cell will have trouble competing. By 2020, conventional vehicles will be twice as efficient, half as polluting, and cost little more. New technologies will provide somewhat greater efficiency and emissions gains but at a much higher cost. With little or no private benefit to purchasers, the new technologies are unlikely to succeed in the marketplace unless government action or public pressure calls for major reductions in greenhouse-gas emissions. The MIT researchers compared the technologies using data from various sources, adjusted so that key assumptions were consistent. Calculations included energy use and emissions not only from driving the vehicle but also from making and delivering the fuel--a change that dramatically reduced the attractiveness of some technologies. The assessment examined how vehicle purchasers, fuel manufacturers, vehicle distributors, and all other major "stakeholders" would trade off dozens of characteristics of different technologies, from cost and safety to convenience and familiarity. The analysis confirmed that what is unimportant to one stakeholder group can be a real "show-stopper" for another. Identifying critical showstoppers and developing strategies to overcome them is the researchers' ultimate goal. They are now completing their initial assessments and are beginning to examine other technologies, including biomass fuels and battery vehicles, and other types of vehicles, including light and heavy trucks.
n July 1999, an Energy Laboratory symposium of scientists, regulators, and industry and public interest representatives examined the scientific challenges posed by the US Environmental Protection Agency's new Integrated Urban Air Toxics Strategy. This strategy describes EPA's plans for substantially reducing public health risks in urban areas from air toxics, or "hazardous air pollutants" (HAPs), a wide-ranging group of emissions that cause cancer or other health problems and are emitted by cars, smokestacks, dry cleaners, auto body shops, and many other sources. ("Criteria" pollutants such as ozone and sulfur dioxide are regulated separately.) Symposium participants recommended continuing research on sources of HAP emissions; on processes whereby HAPs change in the atmosphere; on routes by which HAPs enter the human body; and on health effects, including the effects of exposure to multiple HAPs and of variations among individuals. Other recommendations included revising EPA's plan to monitor many HAPs in many locations. Monitoring should instead focus on critical HAPs in selected areas and on sources that are controllable. More attention should be given to indoor air pollution, the primary health risk for many people. Work to identify the dangerous constituents in diesel exhaust should continue, but tighter restrictions on overall diesel emissions are probably warranted now. High priority should be placed on controlling mercury emissions, especially from electric power plants. Finally, EPA should communicate better, both with the general public and with state officials, who have the most experience with data and programs particular to their regions.
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