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My ride? It’s a power plant

Electric cars could sell battery power back to the grid in an emerging plan called V2G – ‘vehicle to grid.’

By Staff Writer for The Christian Science Monitor / April 24, 2009

University of Delaware professor Willett Kempton looks under the hood of a V2G electric car.

Courtesy of Jon Cox/University of Delaware

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Newark, Del.

Dragging an inch-thick power cord from a curbside charging station to his all-electric-drive car, Willett Kempton plugs it into a socket just above the vehicle’s front bumper and flashes the tiny smile of a man who thinks he knows something others do not.

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Perhaps he does. The University of Delaware professor’s test car isn’t merely charging up – it’s potentially sending power the other way, too.

A computer inside the car communicates with the giant Eastern PJM power grid. Through the connection, PJM can ask for extra juice from the car’s battery to balance fluctuating demand on the grid. The car’s dashboard computer checks the vehicle’s battery level and – if there’s enough charge to drive home – can sell the excess energy back to the power company at a profit.

While a handful of such vehicle-to-grid (V2G) research projects have emerged from California to Texas to Colorado, Dr. Kempton’s project has driven the farthest.

For more than a decade, Kempton has researched, lobbied, and agitated for these “cash-back cars.” His and other in-depth studies describe a future where electric-car owners plug in at malls, hardware stores, or home garages and earn $1,000 to $2,500 annually for the power they pump back into the system.

Such “regulating power” to help balance grid fluctuations is valuable – recently about $42 an hour for one megawatt’s worth. One car can’t do that much, of course. But 60 cars might – and still remain charged up enough to easily get where they need to go.

Kempton’s dream took a small but critical step closer in January when Newark, Del., became the first US city to license a V2G recharging station.

The scheme’s potential for millions of cars to act as a communal backup for the grid has finally caught the attention of utility operators, Detroit automakers, and even Washington policymakers.

President Obama mentioned V2G on “The Jay Leno Show” last month, though he avoided the wonky acronym. Jon Wellinghoff, the new chairman of the Federal Energy Regulatory Commission, says the nation’s shift to renewable power will require a growing V2G fleet. Because wind and solar power fluctuate throughout the day, it could destabilize the grid without a battery backup. Also cheap wind energy captured at night could be stored in millions of V2G vehicles for use during the day.

“These vehicles are a vital part of US energy security and our ability ultimately to provide for the economic stability of the country,” says Mr. Wellinghoff, an unabashed V2G backer and the man many credit with coining the term “cash-back cars.”

By this summer, Kempton’s consortium expects to deploy its first five V2G cars. Up to 200 more vehicles – retrofitted by conversion companies – could be on the road by next year, he predicts.