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Ultracapacitors: the future of electric cars or the 'cold fusion' of autovation?

ZENN Motors says its electric car will cruise for 250 miles on a single five-minute charge. Skeptics cry shenanigans.

By Staff writer of The Christian Science Monitor / April 16, 2008

Buzz: The Canadian automaker will use ultracapacitors instead of fossil-fuel engines.

Courtesy of Zenn Motors


Ian Clifford wants to start a global revolution by building a practical, everyday car with no gasoline engine, no batteries, and no emissions.

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While big Detroit automakers ponder a future plug-in car that goes 40 miles on a battery charge before its gas engine kicks in, Mr. Clifford's tiny ZENN Motor, a Toronto maker of low-speed electric cars, announced in March that it will build a new highway-speed (80 m.p.h.) model that goes 250 miles on a charge – and can recharge in just five minutes.

Having no batteries, the new "cityZENN" model will use a breakthrough version of a common electrical storage device called an ultracapacitor to store power from a wall socket, the company says. Fuel costs to operate it would be about one-tenth of today's gas-powered vehicle.

If that astounding claim is real (and there are many skeptics), it could revolutionize automotive travel by making all-electric cars competitive with gas-powered vehicles and easing the world's dependence on oil.

"The big problem has always been the battery and its limits," says Clifford, ZENN's founder and CEO in a phone interview. "This new technology is a 180-degree shift that represents the end of fossil fuel as a transportation fuel."

That's because the same ultracapacitor technology could be used across the grid to provide cheap electric storage for wind and solar power, he says. In turn, this process could power millions of ultracapacitor vehicles with no emissions at all. With the cars' fast-charge capability, recharging stations could pop up to help make even longer trips routine.

Ultracapacitors – also called supercapacitors – are more powerful cousins of the basic capacitor. With activated carbon at their core to act as a sponge for electrons, ultracapacitors can absorb power – or send a charge – far faster than batteries. They are also far more durable.

First used in the 1960s, ultracapacitors today are widely found in electronic devices such as computers. In cameras, they retract and expand zoom lens. Yet the power stored by today's ultracapacitors is still only about 5 percent as much as a modern lithium-ion battery, far too little to power a car by themselves.

The reported breakthrough was made by ZENN's business partner EEStor, a Cedar Park, Texas, firm headed by respected computer industry veteran Richard Weir, who's named on the company's patent. The company is now nearing commercial production of its new "electrical energy storage unit" or EESU, Clifford says.

But privately held EEStor has had little to say publicly or to the press – and that secretiveness has inspired incredulity among many debating the topic on Internet forums.

But in a break with that tradition, Tom Weir, the company's vice president and general manager, responded to e-mailed questions.

"EEStor's technology has the opportunity to touch every aspect of daily life from very big to very small devices," Mr. Weir writes. "We also see a whole new generation of products ... based around our technology."

Added credibility arrived with the January announcement by Lockheed Martin, the big defense company, of an agreement to use EEStor technology for military and homeland security applications. It refers to the EEStor "ceramic battery" providing "10 times the energy density of lead-acid batteries at 1/10th the weight and volume."