Chevy Volt Fuel Cell Drive - Close Up View
Close up view of early engineering illustration of the hydrogen fuel cell version of Chevy Volt E-Flex electric car. Powered by a Fifth Generation GM fuel cell stack the same size as a four-cylinder gasoline engine, the 70kW (94hp) electric power plant produces the same output as the Fourth Generation version found in the fuel cell Chevy Equinox but is half its size.

Chevy's Future Fuel Cell Volt

MP3 Audio from second press briefing on General Motor's Volt electric car program, March 29, 2007.

By Bill Moore

Publisher's note: although this conference call was held on March 29, 2007, GM embargoed the media from publishing any reports on it until April 19, 2007.

Dr. Larry Burns began the second press briefing [GM battery briefing] by enumerating all the reasons why General Motors is focusing billions of precious research dollars on electric-drive vehicles, both hybrid, plug-in and hydrogen fuel cell.

He pointed to the on-going 'war on terror', the 2003 power blackout in the American northeast, the hurricanes of 2005, the leaks in the Alaska oil pipeline, the ongoing tensions with Venezuela, the growing public acceptance of the reality of global warming, the roaring economies of China and India, and oil price volatility: all equating to a serious energy security problem, one that will have a detrimental impact on an auto industry whose products are 98 percent dependent on petroleum.

He reminded the journalists present in Detroit and those listening in on the conference call, that 60 percent of America's fuel is now imported and China is now importing 45 percent of the petroleum it uses. Between now and 2030, half of the growth in energy demand will come from China and India.

"It's a matter of business", he said that GM find ways to displace oil and energy diversity is how it plans to do this, including building vehicles that use ethanol, electricity and hydrogen. He stressed that "purely electric" vehicles "will be a big part" of this strategy: vehicles that are electrically-driven where the source of their electricity may come from batteries, onboard internal combustion generators and hydrogen fuel cells.

Burns explained that the Chevy Volt concept car, which GM debuted in January at the Detroit Auto Show, is the model for what he called a "plug & play" approach that enables GM engineers to make use of a common electric-drive system on which they can mix and match energy sources: liquid fuel, battery, hydrogen. He pointed out the commonalities between the IC engine-generator version of the Volt and the fuel cell variant, as well as their differences.

The fuel cell stack and balance of plant (BOP) controls sit in the same location as the IC engine-generator version. The lithium ion battery (16kW in IC, 8kW in fuel cell variant) occupies the same tunnel between the passenger seats. The 4 liter, 10,000 psi hydrogen storage tank replaces the liquid fuel tank. However, unlike the IC model, the fuel cell model will make use of 3rd generation electric wheel motors instead of a central e-motor like that depicted in the illustration above.

Where the IC-variant will have a projected 40-miles of electric-only range before the engine-generator spins up, the fuel cell Volt instead will be able to operate 20 miles in battery-only mode after having been recharged overnight like the IC model using less-expensive grid power. Burns observed that the hydrogen Volt is currently designed to be a fuel cell-based plug-in hybrid, essentially making it an all-electric car with some of its energy stored in batteries and some in its hydrogen tank, while its sibling is a range-extended EV; an admittedly subtle distinction. It's smaller lithium battery pack is mainly intended to provide transient power assist for the fuel cell, as well as capturing regenerative braking energy.

Dr. Burns emphasized that GM sees this as the logical pathway to a hydrogen and electric future, where electricity and hydrogen are interchangeable energy carriers for power created from a diversity of fuel: coal, nuclear, hydroelectric and renewables. Interestingly, an engineering executive with GM's biggest competitor made this same observation privately to EV World just two days earlier.

GM's Vice President for Research and Development pointed out that at present, the world produces 50 millions tons of hydrogen annually, much of it used to make fertilizer and to upgrade heavier crude oil to gasoline. That 50 million tons is sufficient to fuel 25 percent of the world's current fleet of motor vehicles. In addition, the hydrogen used to refine gasoline alone would be sufficient to fuel 60 million hydrogen vehicles.

Burns thinks it is ironic that the same oil companies who are being forced to build ever-larger hydrogen production facilities in order to refine increasingly heavy, poorer quality crude oil [surely a sign o fpeak oil] may, in fact, be building the hydrogen infrastructure for tomorrow's fuel cell electric vehicles.

While the hydrogen variant of the Volt hasn't yet been built, GM has embarked on production engineering of the vehicle. It also will begin field trials of its fuel cell Equinox late this year, a program that will eventually include 100 vehicles in market tests between 2008 and 2009. While these vehicles use what could now be considered "obsolete" fuel cell technology, Burns is confident that by 2009 GM will have enough data and experience to demonstrate that its fuel cell package will be economically competitive with today's internal combustion engines. In fact, Burns sees it as being a "tipping point" of sorts when he will know with a level of confidence that GM's fuel cells can reach the target's he's set in terms of cost, performance and durability.

Based on the progress GM has already made between its Generation Four and Generation Five stacks, it would appear that the technology race between PEM fuel cells and lithium ion batteries is only intensifying.

Pointing to the two variants of the Volt, he said that the IC-generator version can be recharged in 4-5 hours, the fuel cell version in 4-5 minutes. Which approach will dominate in the future will depend on which technology matures first. GM's strategy of a common electric-drive architecture will allow it to balance the ratio of electricity coming from each energy storage medium: the liquid-fueled, IC engine-generator, the batteries and/or the fuel cell.

Burns concluded by musing about the possibility of future car owners being able to walk into a dealership, with the real world performance data from their previous car in hand and order the exact vehicle that matches their driving habits. And because the cars of the future will be increasingly software driven, those vehicles will be able to be tweaked to adapt to changes in personal driving patterns.

It's certainly a bold vision and engineering challenge -- Bob Lutz called it the toughest challenge GM has taken on -- and there are likely to be many hurdles -- not the least of which is the availability of natural gas from which all that hydrogen will be reformed -- but it clearly points in the direction of an increasingly EV World and that's a very good thing for us all.

You can listen to Dr. Burn's 30-minute press briefing using either of the two MP3 players above, or you can download it to your computer for playback or transfer to your favorite MP3 device. The download URL is: http://www.evworld.com/evworld_audio/gm_eflex_brief.mp3.

Also be sure to also check out GM Battery Brief Breakfast and GM Battery Brief, as well as Meet the Volt: Chevy's Shocker

Times Article Viewed: 34254
Published: 19-Apr-2007


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