Reader Question: Why Hasn’t Detroit Embraced Ultracapacitors?

This post is in response to a comment on David’s Blog post  “The Chevy Volt Needs an Ultracapacitor”

COMMENT: Wistful? I’m curious why you, the CEO, are failing at getting these car companies to adopt your product? If it’s so much better than batteries then why aren’t they flocking to your company? I know they all know about your product. Heck, I’ve known about your product for over 10 years. But there has to be some reason over why it isn’t being used.

Off the top of my head some possibilities are:- a) expense, the manufacturers are looking at $$’s per kilowatt-hour of stored energy.. b) are control circuits complicated.. c) reliability.. d) kilowatt-hours per liter of volume.. All of those are important considerations a vehicle maker has before adopting a product, right?

–David Herron

Hello David,

First, just for background, I spent more than 25 years of my career with divisions of General Motors, most of them with Packard Electric, designing and manufacturing automotive wiring and electronics, so I have some insight into the very deliberate decision-making processes that have put the “Detroit 3” where they are today.  Maxwell ultracapacitors have been adopted by European car companies and we have been involved with the European design cycle for several years. So, car companies have adopted the technology, just not the ones in Detroit…. yet.

Second, we don’t claim that ultracapacitors are “better” than batteries. Batteries and ultracapacitors are complementary.  A battery, with its high-energy density, is like a marathon runner; the ultracap, whose forte is power density (rapid charge and discharge), is like a sprinter.

For decades every car on the road has had a lead-acid battery, so battery technology is well understood, and mass production has allowed battery makers to deliver them at a very low cost.  However, lead acid batteries aren’t capable of absorbing much regenerative braking energy and can’t tolerate deep charge/discharge cycling, so they aren’t practical for hybrid or electric cars. That’s why the industry has turned to much more expensive advanced battery chemistries such as nickel metal hydride for current hybrids and lithium-ion for EVs and HEVs now in development.   For those batteries to meet the cycling and power requirement of such vehicles they have to be oversized, driving their cost higher yet. A “hybrid” energy system employing ultracapacitors to handle power requirements such as braking energy recuperation and acceleration and using batteries to meet energy requirements would be less expensive and last longer. And the technology to do that is real and readily available today.

Toyota already has incorporated ultracapacitors into the braking system of its hybrid Prius. Continental AG is incorporating them into a fuel-saving “stop-start” automotive system a major European automaker will begin producing this year. Here in the U.S., side-by-side testing by the National Renewable Energy Laboratory (NREL), co-sponsored by GM, demonstrated that an ultracapacitor pack weighing significantly less than comparable batteries can meet the energy storage requirements of a mild hybrid auto.  Additional studies have shown that an ultracapacitor pack would offer the added benefits of better cold weather performance and longer operational lifetime. Just last week at the Washington Auto show, U.S. Energy Secretary Dr. Steven Chu stated that a combination of ultracaps and batteries can “improve the gas mileage in all vehicles” by more efficiently absorbing regenerative braking energy.

Ultracapacitors have proven their value, safety, efficiency and durability in more than 1,000 public transit buses now in daily revenue service in the U.S., Europe and Asia, so we aren’t suggesting that U.S. automakers take a “leap of faith.” Rather, we are suggesting that Detroit could reinvent itself and create U.S. jobs by taking advantage of cost-effective, readily available, American technology to produce the energy-efficient, environmentally-friendly cars consumers want.