Zero Emission Vehicles: - Electric and Hydrogen Cars
The vehicles most capable of dealing with pollution, climate
change, and oil security are electric-drive vehicles (EVs) powered by batteries,
flywheels, or hydrogen fuel cells. Powered by electric motors they have no
combustion engine on board. As a result, they are Zero Emission Vehicles (ZEVs),
at least as far as the vehicle itself is concerned. Of course, somewhere there
is an energy plant making electricity or hydrogen, and the emissions of these
plants must be evaluated to determine the total impact of the EVs.
How much battery-powered electric vehicles can cut CO2
emissions depends mostly on two factors: the electrical efficiency of the
vehicles, and the emissions from the power plants that produce the electricity
used to charge them. If EVs are charged by electricity from natural gas
power plants (steam), carbon dioxide emissions would fall by about 50 percent
compared with comparable gasoline vehicles.59 In contrast, charging
EVs with electricity generated from coal would cut greenhouse gas emissions by
only about 20 percent. Charging from oil-fired plants would reduce emissions by
about 30 percent. In the longer term, CO2 and pollution emissions
could be entirely eliminated by using renewable energy technologies to charge
the batteries. Regardless of which fuel is used to generate the electricity, EVs
could be powered strictly from domestic sources, improving both national
security and the nation's balance of trade. Switching to battery-powered EVs
would significantly reduce emissions in urban areas - EVs emit no street-level
pollutants. If the batteries were charged at night avoiding peak power demands
during the day, no new power plants would have to be built. Ozone, which cannot
form without sunlight, would be reduced. No matter how they are recharged, the
use of EVs would lead to reduced oil consumption. The greatest reduction would
come from recharging them without burning
oil.