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.
Ian Clifford wants to start a global revolution by building a practical, everyday car with no gasoline engine, no batteries, and no emissions.Skip to next paragraph
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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."
In 2005, Kleiner Perkins Caufield & Byers sunk $3 million into EEStor. ZENN also invested $3 million and will get exclusive rights to retrofit vehicles with the system – and produce new mid-size cars using EESUs.
According to EEStor's patent application, the breakthrough is based on a technically arduous process of purifying and fabricating units with barium titanate, a material known to retain vast amounts of power.
"The main feature of the EESU is the charge and dis-charge at electric speed," Weir writes. "This is a key enabling factor for the advancement of the next generation of vehicles. Another feature is the amount of power the EESU can store. Lastly, the EESU is expected to be considered fully 'green.' "
Competitors rev their engines
At the North American International Auto Show in January, AFS Trinity created a stir by strutting its "extreme hybrid" plug-in concept vehicle that uses ultracapacitors to boost battery life and get 150 miles per gallon. The Bellevue, Wash.-based company sees ultracapacitors as a natural fit with new generation lithium-ion batteries that are vital to plug-in hybrids. Company chairman Edward Furia compares batteries to a long-distance runner (providing the stamina a car needs over the long haul) while ultracapacitors are akin to a weight lifter – giving cars that 0-to-60 oomph while minimizing impact on the delicate battery.
As oil prices rise, new ultracapacitor research has emerged. Companies like Maxwell Technologies, Panasonic, Nippon Chemi-Con, and others are working on advanced devices with attributes of both an ultracapacitor and a battery, according to a November report from the Institute of Electrical and Electronics Engineers (IEEE). But the recent focus is only a continuation of a long-term fascination with ultracapacitors in automobiles.
A small fleet of ultracapacitor-powered buses began running in Moscow in 1995, and some garbage trucks in the US now use ultracapacitors to efficiently absorb energy from braking – and discharge it for acceleration, the IEEE article notes. Honda's Dualnote concept car in 2002 also showed off ultracapacitors' ability to instantly absorb braking energy and then return it in acceleration. German automaker BMW is also said to be evaluating ultracapacitors in their hybrid vehicles.