Electric Vehicles
Car Prototype Generates Electricity, And Cash

December 9, 2007

The price of oil nearly reached $100 a barrel
recently, but a new University of Delaware prototype vehicle demonstrates how
the cost of the black stuff could become a concern of the past.

A team of UD faculty has created a system that enables vehicles to not only run
on electricity alone, but also to generate revenue by storing and providing
electricity for utilities. The technology--known as V2G, for
vehicle-to-grid--lets electricity flow from the car’s battery to power lines and back.

“When I get home, I’ll charge up and then switch into V2G mode,” said Willett
Kempton, UD associate professor of marine policy and a V2G pioneer who began
developing the technology more than a decade ago and who is now testing the new
prototype vehicle. The UD V2G team includes Kempton as well as Ajay Prasad,
professor of mechanical engineering; Suresh Advani, George W. Laird Professor of
Mechanical Engineering; and Meryl Gardner, associate professor of business
administration, along with several students.

When the car is in the V2G setting, the battery’s charge goes up or down
depending on the needs of the grid operator, which sometimes must store surplus
power and other times requires extra power to respond to surges in usage. The
ability of the V2G car’s battery to act like a sponge provides a solution for
utilities, which pay millions to generating stations that help balance the grid.
Kempton estimates the value for utilities could be up to $4,000 a year for the
service, part of which could be paid to drivers.

The technology will work on a large scale, he said, because on average 95
percent of all cars are parked at any given time. One hour a day of car usage is
the average in America.

“A car sitting there with a tank of gasoline in it, that’s useless,” he said.
“If it’s a battery storing a lot of electricity and a big plug that allows
moving power back and forth quickly, then it’s valuable.”

Kempton already has one of those large plugs at his home. He has a 240-volt plug
that gives the battery a full charge--or a range up to 150 highway miles--in
just two hours. A smaller, standard 110-volt plug works but provides a full
charge in about 12 hours. The smaller plug also moves less power for the grid
operator when the car is in V2G mode, Kempton explained.

“The bigger the plug, the more power you can move, the more revenue,” he said,
explaining that it cost about $600 to have the larger plug installed.

But even though Kempton is supplying power to the grid with the prototype car,
he’s not getting paid for it--yet.

PJM, the grid operator for 14 states, including Delaware, is keen on the
technology and hosted a demonstration of the V2G car. But PJM requires at least
300 megawatts to purchase power. That means the UD team and its collaborators
must get 300 cars up and running.

The prototype car is a stepping-stone to that goal. Kempton is working with UD
mechanical engineers Prasad and Advani, who plan to add V2G to the University’s
hydrogen fuel cell bus. Next, the team, including the company that created the
car, California-based AC Propulsion, will test the prototypes and fix any
potential problems they bring to light. Then they’ll begin creating a user
interface that will let drivers, for example, tell the car to never go below 50
percent charge while in V2G mode.

Helping him to learn what types of features potential buyers would want on the
car and to identify potential buyers are business administration faculty member
Gardner and her students. They’ve done a pilot survey of nearly 100 drivers
that’s shown there’s a lot of interest in the technology, she said.

“We also want to provide information on how to market the car,” she said, so her
team is asking people questions like how much they would be willing to pay for
it and how they feel about driving a car that’s better for the environment than
a gasoline-powered vehicle.

That last question gets Kempton, who also is involved in College of Marine and
Earth Studies research on offshore wind farms, the most excited. He explained
that even if the electricity used to charge the car is produced by a coal-fired
power plant, the car itself produces no carbon dioxide emissions. If a wind farm
fuels the electricity from the power plant, he explained, the car and its power
source would be emissions free.

And even though the green aspect of the car is key for Kempton, he knows
consumers might have some other, more practical, questions about the vehicle,
such as, “What’s it like to drive?”

Zippy yet quiet, being behind its wheel is a thrill, he said. “I hate getting
back in my gas car. It feels sluggish.”

V2G prototype specifications

The Car: Manufactured by vehicle technology company AC Propulsion; formerly a
Toyota Scion, which was chosen because it is light yet provides plenty of
passenger room

Emissions: The car itself produces no carbon dioxide emissions

Acceleration: 0 to 60 miles per hour in 7 seconds

Top Speed: 95 miles per hour

Range: 120 highway, 150 city

Battery Life: 5 years or about 50,000 miles (being tested and verified)

Recharge: 2 hours using 240-volt plug or overnight using 110-volt plug

Maintenance: No oil changes; brakes last three times longer because the car has
regenerative braking, a mechanism that slows the car and returns power to the battery


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