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

Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions: Volume 2
containers within a contained area. These trucks can easily be brought back to their
charging station as the battery becomes depleted. Also, time spent idling waiting to load
and unload would not require energy consumption (Port of Los Angeles, 2008).
Electrification of other HDVs such as school buses also is feasible. Because school buses
move along a preplanned route and return to their storage yards and park twice per day,
concerns over range could be managed. Buses could be charged both during the day and
overnight for their morning and afternoon trips. These vehicles are likely to use lead-acid
batteries for the near future. This battery technology is much older than NiMH and Li-ion
systems and is fully demonstrated. Batteries of this type are much less expensive than
those that would be found in light-duty BEVs and their increased weight is less of a
concern for the heavy-duty market. However, BEV use is not considered feasible for most
heavy-duty applications, given range requirements (for long-haul trucks), and the limited
ability for many applications to charge overnight (Muster, 2000).
Electricity-powered transport also is used for various urban transit options, including
trolleys, subways, and light rail. It also is used for intercity rail, although currently only
the Northeast Corridor in the United States (between Boston and Washington, D.C.) is
electrified. Intercity rail electrification could be used for both passenger and freight trains.
Magnetic levitation (maglev) trains utilize electrically powered magnet systems to float the
train above the track without the use of wheels. The first commercial maglev trains ran in
the 1980s in Birmingham, U.K., providing a low-speed shuttle service between the airport
and the railway station. The experimental Japanese maglev train JR-Maglev MLX01 broke
the world speed record for ground transportation in 2003, reaching a speed of 361 mph.
An 18-mile Maglev system opened in 2004 connecting the Shanghai city center with the
city’s airport. Currently, a maglev system is being considered to link Los Angeles and Las
Vegas and to replace drayage trucks that operate at the ports of Los Angeles and Long
Beach. However, maglev trains require the construction of special purpose tracks which
are incompatible with existing rail infrastructure.
Magnitude and Timing of Reductions
Life-Cycle Emissions
Because electric vehicles do not burn fuel at the point of service, they do not emit
pollutants at the tailpipe. However, the life-cycle emissions for producing and delivering
electricity can be significant, particularly GHGs for electricity generated from combustion
of fossil fuels such as coal. In 2008, about 48 percent of U.S. electricity was generated from
coal, followed by 21 percent from natural gas. Methods of generating electricity with little
to no GHG emissions include nuclear power (19 percent of 2008 generation), and
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