| 
 Electric
vehicles (EVs) are propelled by an electric motor (or motors)
powered by rechargeable battery packs. Electric motors have several
advantages over internal combustion engines (ICEs):
- Energy efficient.
Electric motors convert 75% of the chemical energy from the batteries
to power the wheels—internal combustion engines (ICEs) only
convert 20% of the energy stored in gasoline.
- Environmentally
friendly. EVs emit no tailpipe pollutants, although the
power plant producing the electricity may emit them. Electricity
from nuclear-, hydro-, solar-, or wind-powered plants causes no
air pollutants.
- Reduce energy
dependence. Electricity is a domestic energy source.
- Performance
benefits. Electric motors provide quiet, smooth operation
and stronger acceleration and require less maintenance than ICEs.
The Down Side: Batteries
EVs face significant battery-related challenges:
-
 Driving
range. Most EVs can
only go 150 miles (or less) before recharging—gasoline
vehicles can go over 300 miles before refueling.
- Recharge time. Fully recharging
the battery pack can take 4 to 8 hours.
- Battery cost: The large
battery packs are expensive and usually must be replaced one or
more times.
- Bulk & weight: Battery
packs are heavy and take up considerable vehicle space.
Researchers are working on improved battery technologies to increase
driving range and decrease recharging time, replacement frequency,
weight, and cost. These factors will ultimately determine the future
of EVs.
Additional
Information
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