Electric vehicles are the least
polluting mode of transportation
available today. They
also can operate very economically
while using little or
no petroleum fuel.
Do Battery-operated
Electric Vehicles Pollute?
There are two kinds of electric vehicles
currently in use: battery-operated
electrics and hybrid electric vehicles,
or HEVs. Battery-operated electrics
run on electricity stored in batteries,
electricity that ultimately comes from
generating plants that also provide
our homes with electrical power.
With HEVs, most electricity is
produced by small onboard generating
plants driven by internal combustion
engines. HEVs can be designed to run
on gasoline, diesel, or alternative fuels.
Battery-operated electric vehicles are
sometimes referred to as “zero emission
vehicles” because they do not
directly pollute through tailpipe
emissions, fuel evaporation, fuel
refining, or fuel transport to service
stations. A certain amount of
pollution, however, is associated
with the use of these vehicles. This
comes from power plant emissions.
Pollution levels from battery-operated
electric vehicles remain extremely low
even when these emissions are taken
into account.
One reason this is true is that the
generators and motors used in electric
vehicles are much more efficient than
the powertrains of internal combustion
engines. The difference is such
as to make it more efficient to burn
an amount of fuel in a power plant
to generate electricity for an electric
vehicle than to burn it directly in a
vehicle’s internal combustion engine.
Adding to the efficiency of electric
vehicles is the technique of regenerative
braking. This involves slowing
and stopping a vehicle by absorbing
its energy and converting it to
electricity that may be returned to
the vehicle’s onboard battery. In a
conventional vehicle, this energy
is simply wasted as heat.
Of course, burning less fuel in going
a certain distance does not necessarily
make for less pollution. That depends
on the efficiency of and emissions
from the power plant providing
the electricity. Over 95% of the fuel
used to generate electrical power
comes from within the U.S. in the
form of coal, natural gas, nuclear
power, hydropower, and renewable
energy sources.