Transportation's Role in Reducing U.S. Greenhouse Gas Emissions ...

Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions: Volume 2
vehicles can be designed to use ethanol blends at up to 85 percent at only modest additional
cost. Introducing such vehicles today would allow for faster adoption of the fuel in the
future, if production constraints can be overcome.
A general GHG performance standard for vehicles is another potential option as an
alternative (or in addition to) a low-carbon or renewable fuel standard. This approach
directly measures GHG emissions per mile from vehicles rather than measuring GHG
emissions by a fuel efficiency or fuel carbon content proxy. A GHG emissions standard
would allow fuel producers and vehicle manufacturers to develop the most cost-effective
combinations of vehicle and fuel technology to reduce GHG emissions. GHG performance
standards for vehicles have been proposed in California, along with a low-carbon fuel
standard. To be effective, a GHG performance standard must reflect the life-cycle emissions
associated with the fuel, not just the emissions produced by the vehicle in operation.
Ultimately, significant additional research and development is needed to make many of
these low-carbon fuels commercially viable. Additional funding could be provided to
advance research to make new feedstocks commercially viable, such as cellulosic ethanol-
and algae-based biodiesel. Major advances are needed for hydrogen fuel cell technology as
well as for battery technology in order to make these fuel sources practical for consumers as
well as cost-competitive with current fuels and vehicles. The U.S. government already is
funding research on renewable fuel sources, for example, through the Department of
Energy’s FreedomCAR and Vehicle Technologies Program (U.S. DOE, 2006).
It is clearly desirable to avoid contradictory or overlapping policies. However, multiple
policy levers may still be needed to assist vehicle and fuel producers in focusing research,
development, and production resources on complementary technologies and to provide
consistent incentives to consumers. Whenever possible the government should strive to set
“technology-neutral” policies that allow markets to select the most cost/effective GHG
reduction technologies, while recognizing that in practice this may be difficult, especially
with respect to fuel technologies. In particular, the level of coordination required between
vehicle manufacturers, fuel and feedstock producers, and providers of distribution
infrastructure suggest that multiple policy levers may be necessary, sometimes focusing on
particular technologies.
Summary Evaluation
Table 2.2 summarizes the strategies discussed in this section and presents an assessment of
each strategy’s effectiveness, cost-effectiveness, and cobenefits, as well as a summary of
key Federal policy initiatives that would be needed to implement the strategy beyond
current levels. A similar summary is provided in Section 3 for other vehicle technologies,
including advanced internal combustion engines, hybrids, and plug-in hybrids.
The factors presented in the table are rated according to the following metrics:
2-16