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for long trips, and electrical outlets in
garages would provide the power for
short commutes. (Eventually, charg-
ing stations could be installed for
city dwellers.) And plenty of elec-
tricity is available, particularly over-
night. According to a study from the
Paci c Northwest National Laboratory,
there s already enough excess generat-
ing capacity at night to charge 84 per-
cent of the cars, pickups, and SUVs on
the road today, if they were all sud-
denly converted into plug-in hybrids.
A couple of weeks after my ill-fated
attempt to test-drive the plug-in car
in Washington, I m outside the head-
quarters of battery maker A123 Sys-
tems in Watertown, MA. Out front
is the shiny, aggressively styled GM
Volt. The car is there because GM has
selected A123 as one of two companies
that could end up providing the battery
technology for the Volt.
A123 makes a new type of lithium-
ion battery. Lithium-ion batteries,
which are now used widely in laptops
and cell phones, pack a lot of energy
into a small space. They take up just
one-sixth the space of the lead-acid
batteries used in previous types of elec-
tric vehicles, and they weigh one-sixth
as much. They also take up less than
half the space of nickel--metal hydride
batteries, the kind used in today s con-
ventional hybrids, while weighing just
a third as much.
But the type of lithium-ion battery
that s used in laptops and cell phones
has problems, including the occasional
tendency to overheat and, in rare cases,
burst into flame. Troubling as this
instability is in personal electronics,
it could be even worse in a car, which
uses a module that consists of hun-
dreds of times the number of batter-
ies found in an electronic device. On
top of that, although prices have been
coming down gradually, lithium-ion
batteries are still expensive.
All that could change as a result of
A123 s batteries, in which electrodes
based on cobalt oxide have been
replaced with iron phosphate elec-
trodes. At relatively low temperatures,
oxides release oxygen, which can drive
reactions that might heat up a battery
and cause it to explode. But phosphates
continue clinging to oxygen at much
higher temperatures. What s more,
iron is far cheaper than cobalt.
Volt or Bolt?
There is a giant "if " in all this, though.
To become practical and economically
viable, plug-in vehicles will need to be
Will automakers follow through
on their highly publicized announce-
ments about plug-ins? GM, for one, has
a reputation for quitting on innovative
engineering; the company s executives
scrapped an earlier all-electric vehicle.
And even though GM had an early lead
in conventional hybrid technology, it
failed to bring hybrids to market until
after the success of Toyota s Prius.
What will happen to plug-in plans if
gas prices drop, or if interest in reduc-
ing greenhouse gases wanes?
No one can predict the results of the
carmakers ckle decision-making pro-
cess. But a few things are clear. Plug-
ins are the most practical and enticing
alternative to the internal-combustion
engine that has been developed in
years. And their fate will depend on
whether automakers lear n from the
success of conventional hybrids and
fully embrace the new technology.
I did at last drive a working plug-in.
The converted car glided noiselessly
along the streets of Boston as I eyed
a gauge that estimated my mileage at
more than 150 miles per gallon. But on
the day that I saw the Volt on display at
A123 s o ces, GM wasn t giving rides;
the car was just a mock-up, without the
new batteries. As I sat in the driver s
seat and grasped the steering wheel,
sunlight streaming through the clear
roof, it was easy to believe that plug-
ins are on the way. But the mock-up
was also a harsh reminder that when it
comes to green innovation, U.S. auto-
makers have long been more eager to
show o ashy concept cars than to
manufacture vehicles that work.
Kevin Bullis is the nanotechnology and materi-
als science editor at Technology Review.
David Vieau, CEO of A123 Systems, shows
President Bush a converted Toyota Prius.
A123 s batteries, which can be recharged
from a standard electrical outlet, allow the
car to travel farther on electricity alone.
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