Electronic Design

Breaking The Fossil-Fuel Addicton: GM Readies Fuel Cells For The Masses

President Bush has called us a nation "addicted to oil." I had a taste of freedom from our fossil-fuel fixation when I road-tested a car powered by hydrogen fuel cells at GM's Advanced Technology Center in Torrance, Calif., earlier this month.

I've written about fuel cells before. But harvesting their power for a spin around the block has made me a true believer in the technology's viability to break our oil dependency and to do so soon, particularly if President Bush and Congress are serious about supporting infrastructure development.

My spin in a HydroGen3 wasn't the sort of "pressed into your seat" high-torque blastoff my hosts at GM described when recounting the victories of their S-10 electric truck over gas-powered Camaros in GM's worldwide drag-race demos. Rather, the remarkable thing about the HydroGen3 is the everyday familiarity of the driving experience.

GM took on the challenge of engineering a fuel-cell stack in the Opal Zafira, Europe's bestselling minivan. Given GM's goal of transforming the mainstream transportation and energy infrastructure, it made sense to fit fuel-cell technology into a mass-market vehicle.

So I hit the road with visions of the Hindenburg dancing in my head. (In researching, I've learned that hydrogen is no more dangerous than gasoline. It ignites more easily, but as a light gas, it dissipates quickly if released.) I also pondered whether, with just eight HydroGen vehicles in the U.S. representing hundreds of millions in research dollars invested, my insurance would cover my tour in a multimillion-dollar economy car!

The HydroGen3 is a straight fuel-cell car, not a hybrid. Its 200 mini cells are joined inside a stack that, remarkably, fits easily in the Zafira engine compartment. Compressed hydrogen is stored in two tanks under the rear seat—that's 3.1 kg at 10,000 psi, or enough to drive the five-passenger car for 150 to 180 miles. The chemical reaction produces 200 V between 80°C and 100°C. The car's central electric motor achieves a top speed of 99 mph. The Torrance team's dc-dc booster boosts the fuel-cell stack output of 200 to 320 V.

The team now is working on integrating an electric motor into the wheel itself. The individual rear-wheel motors will debut in the next-generation Sequel fuel-cell vehicle, an SUV-like model. The three-phase inductor wheel motors use permanent magnet flux to generate high torque.

LOOKING AHEAD
The HydroGen3s' onboard computers gather data to learn about potential field failures and keep innovation moving ahead to meet the GM goal of commercially viable technology by 2010. Six HydroGen3s are plying the streets around Capitol Hill, gathering performance data while garnering support for the Department of Energy's role in funding fuel-cell development. The U.S. Postal Service also uses a HydroGen3 to deliver mail in the D.C. area, and a fuel-cell-powered Chevy Silverado serves the USMC at Camp Pendleton.

HydroGen3's fuel-cell stack offers twice the energy efficiency of internal combustion engines. Part of that advantage is lost, considering the overall energy equation of producing the hydrogen fuel versus gasoline production. But the net efficiency gain (well-to-wheel) is about 17% over a hybrid and 35% over a standard internal combustion engine vehicle. Add in the environmental benefits of cars that don't produce greenhouse gasses (water being the only byproduct other than heat and electricity), and it's easy to see why my "everyday" fuel-cell driving experience may truly be an everyday experience before long.

THE FUTURE OF H2 ECONOMY
California is leading the way in the U.S. with its Hydrogen Highway project, a public/private partnership with 15 fueling stations opened, 16 on the drawing board, and a goal of 100 hydrogen stations and 2000 hydrogen-powered vehicles by 2010. California will oversee the hydrogen-generation infrastructure to ensure renewable energy sources generate at least 20% of hydrogen and that H2Net provides an initial 30% overall reduction in greenhouse gasses. Kudos to the state government in California for driving these efforts—and to the engineers at the Advanced Tech Center and throughout GM who have worked on this truly world-changing technology.

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