UNDERSTANDING
HYBRID ELECTRIC VEHICLES (HEVs)
Recently I discovered
that some subscribers to this newsletter don’t
seem to appreciate the vital role that HEVs and plug-in hybrids (or PHEVs)
can have on the future of this country. Therefore, I have devoted this page
to explanations that might be helpful.
First
of all, the notion that nickel metal hydride or lithium ion
batteries are so bad for the environment
that they
negate the benefits
of electric power for small vehicle transportation is WRONG,
as is the myth that a rescue worker would be electrocuted if
he or
she dared to use the ‘jaws of life’ on anyone pinned
in an HEV. Such silly stories have been tossed around on the
internet to give negativists an excuse for staying in their ruts.
The
electric car has been around for over 100 years. Even though
it was quieter, cleaner and
much easier to start,
it lost out to
the gasoline-powered car because of its limited range and speed.
Gasoline is the most efficient hydrocarbon for an engine, and
it was abundant 100 years ago. Although we haven’t run out of
it yet, we now know that its supply is limited, and worse, it’s
damaging our environment in many ways. T. Boone Pickens urges us
to switch to natural gas (methane), because it’s cheaper and
cleaner. Like octane, however, it’s in limited supply, and
it also pollutes our air, just not as rapidly. So Pickens is
right about using more wind power, but wrong about switching
cars to methane.
The HEV allows small batteries to assist a small gas engine (as in the 2010
Honda Insight above) or the reverse (in the case of the Toyota Prius). The batteries
are recharged by the kinetic energy of the car during coasting or braking. The
best hybrid cars are light in weight, and they use ‘auto-stop’,
which shuts off the engine at red lights to save even more fuel.
But
HEVs are really just a niche along the evolution of the modern
car to the PHEV. PHEVs are similar to HEVs except for two things.
First, they have a larger battery pack so they can operate in
all-electric mode for local trips of 10 to 20 miles. Second,
they can be plugged into a standard 110V home outlet for recharging
without the engine running. Many are now delivering 100 MPG.
At
today’s battery and gasoline costs, driving a PHEV costs
a quarter to half that of a conventional gasoline-powered car. As
for reducing carbon emissions, that depends upon where you live,
but for the USA as a nation, it comes out to 42% per mile driven
on electric power. Owners who plug in their cars at night will be
more motivated than ever to install solar panels at home and harness
the sun’s clean energy rather than depend on a coal-fired
power-plant. You might find this hard to imagine right now, but
some forward-thinking engineers are predicting that one day,
vast numbers of PHEV-owners will sell energy from their car batteries
to help support the electric grid after sunset or when the wind
dies.
