04 September 2007

Ultracapacitors May Have Batteries Beat


Millions of inventions pass quietly through the U.S. patent office each year. Patent No. 7,033,406 did, too, until energy insiders spotted six words in the filing that sounded like a death knell for the internal combustion engine.

An Austin-based startup called EEStor promised "technologies for replacement of electrochemical batteries," meaning a motorist could plug in a car for five minutes and drive 500 miles roundtrip between Dallas and Houston without gasoline.

The technology also could help invigorate the renewable-energy sector by providing efficient, lightning-fast storage for solar power, or, on a small scale, a flash-charge for cell phones and laptops.

Skeptics, though, fear the claims stretch the bounds of existing technology to the point of alchemy.

So? I took alchemy in school. Blacksmithing too. They both still come in handy.

The result is an ultracapacitor, a battery-like device that stores and releases energy quickly.

Batteries rely on chemical reactions to store energy but can take hours to charge and release energy. The simplest capacitors found in computers and radios hold less energy but can charge or discharge instantly. Ultracapacitors take the best of both, stacking capacitors to increase capacity while maintaining the speed of simple capacitors.

Until EEStor produces a final product, Perry said he joins energy professionals and enthusiasts alike in waiting to see if the company can own up to its six-word promise and banish the battery to recycling bins around the world.

"I am skeptical but I'd be very happy to be proved wrong," Perry said.

The problem with capacitors is size. Capacitors are rated in terms of capacitance in units of farads. Most capacitors are very small and measured in microfarads. When I was learning how to fix radios for Uncle Sam's Misguided Children, my instructors told me that a one-farad capacitor would be about the size of a football field. That's maybe a little dated, along with the vacuum tubes they taught me about, although those are still being used for design and prototype work because they are highly adjustable. But I digress...

There are capacitors in every piece of electronic gear. Period. I think their earliest use in automotive technology was as the condenser in contact-breaker-point ignition systems, where they were used to prevent counterflow voltage from causing arcing at the points and subsequent rapid point wear. CB ignition has gone the way of the buggy whip.

In motorcycles, electrolytic capacitors are sometimes used as battery eliminators, providing a load for the charging system, in effect fooling the charging system into thinking the system has a battery. I explained this to my buddy Sluggo one time in his garage, and his reply was, "Damn, how ya gonna fool it now? You said it right in front of it!", pointing at his motorcycle.

There's no reason you couldn't do this on cars as well, if your car has a kickstarter.

In this age of electronic miracle progress, nothing seems impossible. I hope they can do it.

Crossposted at the world's other Best Blog.

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