Electric Vehicles
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The push to design electric cars arose from the serious air
pollution problems experienced in Southern California and around
most major cities in the country. California’s problem
was so bad that the legislature enacted legislation back in
the mid 1990s stating that “2% of new vehicles sold after
1998 must be zero-emission vehicles…meaning battery or
fuel cell driven vehicles.” The 2% per year level has
not yet been reached but as technology advances, the number
is growing.
Battery operated vehicles will reduce air pollution. Tests
were run at the Argonne National Laboratory comparing gasoline
and battery driven vehicles. These are the results:
- Electric vehicles cut carbon monoxide and hydrocarbon emission
by 98%. Carbon Monoxide is a poisonous gas that can cause
both heart and lung problems. Hydrocarbons are responsible
for ground level ozone.
- Reduce the emission of nitrous oxide and sulfur oxide which
are key components of acid rain.
- Reduce the amount of particulates (soot) which are suspected
of being a primary cause of asthma.
- Produce less carbon dioxide at slower speeds than gasoline
engines.
If Electric Cars Are So Great, Why Doesn’t Everyone
Drive One?
The biggest reason is that the batteries used to power them
are both heavy and expensive plus the cars can’t travel
far enough between recharges to make them practical. Even very
attractive tax incentives failed to move new electric cars out
of the showroom.
Enter the Hybrid Electric Vehicle.
These vehicles come equipped with two different methods of
powering the vehicle: A small gasoline engine and an electric
motor. The gasoline engine powers the vehicle directly at higher
speeds and recharges the battery. The electric motor powers
the vehicle at slower speeds and in start and stop traffic.
No more range limitation and no need to plug the vehicle in
to recharge the batteries.
Both Toyota and Honda started selling hybrids in 2000. The
five passenger Toyota Prius got 52 mpg in town and 45 mpg highway.
The smaller Honda Insight got 70 mpg combined. Unless needed
to move the vehicle, the gasoline motor is shut off which explains
the better gas mileage in town.
Most of the hybrids also use the energy from braking to help
recharge the battery as well. Several New York City busses use
a hybrid diesel combination to power them. Hybrids combine the
best features of both electric and gasoline vehicles and also
cut the air pollution approximately in half.
Fuel Cell Vehicles
Fuel cells can make electricity without burning anything. There
aren’t any moving parts.
Fuel cells create electricity through a chemical process in
much the same way as our body does. The fuel cell “eats”
hydrogen and oxygen. Its waste products are heat and water.
A fuel cell vehicle is truly a zero-emission vehicle. At least,
zero harmful emissions. A typical fuel cell is shown below.
Anode – an anode is a piece of negatively
charged material
Catalyst – catalysts are substancesl
that can cause the hydrogen atom to be separated into free electrons
and protons
Electrolyte – an electrolyte is a substance that
allows electrons to flow as a current so they can be used to
run an electric motor.
Cathode – a cathode is positively charged
material used to mix the protons with oxygen.
In 1999 Mercedes introduced a concept car powered by a fuel
cell that could travel 90 miles on a large thermos of hydrogen.
The biggest drawback to using fuel cell vehicles is being able
to produce enough hydrogen to power them. Hydrogen can be extracted
from any hydrocarbon fuel like gasoline but large amounts of
carbon dioxide are produced as a result. The future of electric
vehicles is already here.
The only decisions left are how to provide a large enough fuel
supply to power them. The internal combustion engine’s
remaining days are numbered.
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