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

Transportation's Role in Reducing U.S. Greenhouse Gas Emissions: Volume 1
gasoline on a per mile basis. While vehicles using electricity generated from the
current U.S. average generation mix can reduce GHG emissions by about 33
percent, compared to today’s gasoline-powered vehicles, the GHG benefits of
electricity will depend strongly upon the source of electricity generation. 66 Coalfired
electric plants may provide only modest benefits, or even increase net GHG
emissions, unless successful carbon sequestration technologies are developed.
Assuming increasingly lower GHG-intensity electricity generation, per-vehicle
benefits could be as high as 78 to 87 percent in 2050, providing a total reduction
in transportation emissions of 26 to 30 percent. Again, this assumes a 56 percent
LDV market penetration by this time, which is the high end discussed in the
literature. Considerable research and development on battery technology,
notably to reduce costs and weight, is still required to bring electric vehicles to
the point of being cost-effective and accepted by consumers. 67
Cost-effectiveness is highly uncertain for most fuel options, and will depend
upon advances in technology for the particular fuel and vehicle combination, as
well as fuel prices. The costs for different fuels will fluctuate significantly
depending upon supply and demand factors in other sectors, as well as the
transportation sector, making it especially difficult to predict the market
competitiveness of alternative fuels.
From a Federal policy perspective, several categories of policy options could be
pursued in order to encourage adoption of low carbon fuels. Options include:
fuel standards; market incentives, such as pricing and tax policies; and additional
funding for research and development.
Other policy interventions may be helpful as well. For example, incentives for the
production of flexible fuel vehicles can help overcome the dilemmas of fuel
suppliers not introducing new low-carbon fuels until a sufficient number of
vehicles can use them, and vehicle manufacturers not introducing alternative fuelready
vehicles until a fuel supply is available.
For fuels entailing completely new production, distribution and vehicle
platforms (e.g., hydrogen fuel cells), optimal modes or restricted markets can be
identified to test comprehensive deployment on a small scale. Federal
coordination and regulation may help ensure that both the fuel and vehicle
sectors are focused on mutually supportive objectives.
66 The 33 percent reduction may not be typical for in-use electric vehicles. It will depend
upon the timing of when charging occurs, e.g., for peak vs. off-peak electricity demand
periods, and furthermore vary by region of the country (depending upon the local
generation mix).
67 Vol. 2 Sec. 3.9.
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