COST-BENEFIT ANALYSES OF ALTERNATIVE LIGHT DUTY TRANSPORTATION OPTIONS FOR THE 21ST CENTURY

摘要

New fuels and alternative vehicles will be required to substantially cut our dependence on foreign oil and reduce our transportation sector carbon footprint. Biofuels such as biodiesel and ethanol, especially if made from cellulosic feedstocks, are promising. Natural gas might reduce oil consumption and make modest reductions in greenhouse gas emissions, but only as a temporary transition fuel. Hydrogen and electricity could eventually become key zero-carbon transportation fuels.In terms of alternative vehicles, gasoline-powered hybrid electric vehicles (HEVs) are already making an impact in the light duty vehicle fleet, and plug-in hybrid electric vehicles (PHEVs) that derive some of their energy from the electrical grid may soon enter the marketplace. The combination of biofuels and PHEVs will reduce oil consumption, and-depending on the types of fuels used to generate electricity in any region of the country-may help to appreciably reduce greenhouse gas emissions. Ultimately all-electric vehicles powered either by fuel cells or by batteries could make a major contribution to achieving our long-term societal goals.