Chevrolet Volt
The Chevrolet Volt E-Flex concept vehicle is a range-extended electric car with 40 miles battery range and 640 total range.

Chevy Shocker: Meet the Volt

GM gives EV World a sneak peek at its newest electric car

By Bill Moore

You're looking at the Chevy Volt "E-Flex" concept car. It is being unveiled today at the 2007 North American International Auto show in Detroit. And it's electric!

That's right, in concept at least, it's a battery electric car with 40 miles of EV-only driving range. Now that doesn't sound like much, but here's the secret, it has a one liter, 3-cylinder onboard, flex-fuel engine that together with the car's lithium ion batteries is projected to give the car a driving range of 640 miles. That's enough to drive from Detroit to DC on single tank of fuel.

And it can be plugged in to recharge the battery from the power grid or the owner's residential solar panels.

Of course, like any concept car, the Volt is intended to be a look into the future of what GM thinks its next generation range-extended electric car may look like. For the near-term, sources a GM tell EV World that the immediate target platform for its first range-extended electric car -- which the company insists it is applying serious research efforts towards -- will be its current global car platform on which the Opel Astra and Chevy Cobalt are based.

Clearly, GM has learned lessons from its abortive EV1 program, starting with the fact that the Volt and the Astra/Cobalt platforms are 4+ passenger vehicles instead of the two-seats of the original EV1, which plays a starring role in last summer's hit documentary, "Who Killed the Electric Car?"

Like the EV1, however, the lithium ion battery will sit in a tunnel between the passenger seats. The turbocharged, one liter 3-cylinder IC engine, which serves to power the on-board generator only, is mounted up front under the hood/bonnet.

GM envisions several different variants of the IC engine including one that will run on pure ethanol or E100. A diesel engine capable of using biodiesel might also be a future option, as could be a hydrogen fuel cell. Larry Burns, GM's VP for R&D, noted that the Volt would require only half the hydrogen storage capacity as found in the Sequel to get the same 300 miles range.

The company decided to give the car its 40 miles of electric driving range based on research that shows 78% of Americans dive less than 40 miles a day round trip to and from work. Recharged overnight from a common 110 volt outlet, the owner could end up never having the IC engine turn on during a normal week.

The car's computer controls monitor the state of charge (SOC) of the battery pack making sure it never drops below 30% SOC and never exceeds 80% SOC. This is to protect the battery and ensure a long cycle life. When the battery drops to 30 %, the IC engine turns on and through the onboard electric generator provides sufficient electric current to both drive the vehicle and recharge the battery pack. Once the pack is back to 80% SOC, the engine turns off and the vehicle runs off the power stored in the battery.

GM's Bob Lutz estimates that burning E85 in the Chevy Volt would result in the equivalent of 150 mpg and 525 miles per gallon of gasoline. He notes that even if the owner forgets to plug the car in at night to recharge the 400 lbs (181kg) battery pack, the car will still get an estimated 50 mpg while the generator recharges the battery.

Of course, the biggest obstacle to making the range extended electric car a reality is the battery and towards this end, GM recently contracted with Johnson Controls and Cobasys to separately work on developing lithium ion batteries that might someday power an electric, plug-in version of its Saturn VUE/Aura vehicles, which are slated to be equipped with the GM/DaimlerChrysler/BMW-developed "Two-Mode" hybrid drive system by 2009.

Given the pace of progress being made by companies like A123, which recently partnered with Cobasys to jointly work on the GM lithium ion battery program, and Altairnano, GM thinks it'll be possible to have the batteries it needs for the Saturn plug-in program and, by extension, the Volt project sometime in the 2010 to 2012 timeframe.

That isn't that far away, folks.

But what is perhaps the most exciting aspect of the Chevy Volt program isn't its muscular styling that says electric cars can be both powerful and green, but how it is an expression of an evolution in thinking at General Motors and their apparent willingness to listen to the chorus for change and learn from the handwriting on the wall.

To quote Larry Burns from GM's press release, "Whether your concern is energy security, global climate change, natural disasters, the high price of gas, the volatile pricing of a barrel of oil and the effect that unpredictability has on Wall Street - all of these issues point to a need for energy diversity.

"Today, there are more than 800 million cars and trucks in the world. In 15 years, that will grow to 1.1 billion vehicles. We can't continue to be 98-percent dependent on oil to meet our transportation needs. Something has to give. We think the Chevrolet Volt helps bring about the diversity that is needed. If electricity met only 10 percent of the world’s transportation needs, the impact would be huge."

Times Article Viewed: 69672
Published: 06-Jan-2007


blog comments powered by Disqus