Future Tech

We put the pedal to the hydrogen

By Brad Lemley, Michael Kelley|Tuesday, October 01, 2002
RELATED TAGS: GLOBAL WARMING


Toyota's fuel-cell-powered FCHV-4 accelerates quickly, thanks to a boost from a conventional battery.

Like robotic butlers and good-tasting soy milk, fuel-cell-powered cars seem always to be just over the horizon. These days, an environmentally conscious motorist can walk into a Toyota or Honda dealer and snap up an efficient gasoline-electric hybrid, but the omega point of green driving—the pollution-free hydrogen fuel cell vehicle—is so elusive that one wonders if it will ever become tangible. Why should we believe these things are the future if we can't take them out for a spin now?

The question is particularly tantalizing if, like me, you are both an environmentalist and a gearhead. So my heart leaped on a muggy afternoon last June when I got to drive not one but three hydrogen fuel cell vehicles on a test track outside Washington, D.C. They exist. They go. Some even have air-conditioning.

First, a little background. A fuel cell combines hydrogen from a tank and oxygen from the air to make electricity, with water and hot air the only by-products. Automakers, governments, and environmentalists like the technology because it emits no pollution at the point of use and because hydrogen won't run out and can't be monopolized by any country. Hydrogen is the most abundant element in the universe; it makes up two-thirds of the ocean.

Every major automaker in the world is feverishly researching fuel cells. The first production-run vehicles for fleet use are expected to roll out late this year, with consumer versions arriving sometime around 2008. There are no public hydrogen filling stations in the United States yet, but the consensus among automakers is that good cars, coupled with government incentives, will soon lead to a modest fueling infrastructure. That infrastructure will in turn breed more cars, which will breed more filling stations, until hydrogen nudges gasoline aside.

But none of this will happen if fuel cell cars are inferior to their conventional counterparts and that's why I was first in line at the Turner-Fairbank Highway Research Center in McLean, Virginia, for an afternoon "Ride & Drive." The event, part of the 2002 Future Car Congress sponsored by the Department of Energy and the U.S. Council for Automotive Research, attracted about 50 reporters, engineers, and government officials. A wild array of futuristic cars paraded before us, including advanced gas-electric hybrids, high-pressure-injection diesels, and battery-powered sport utility vehicles.

While the others drew polite comments, the buzz was clearly around the three hydrogen fuel cell vehicles, two Japanese and one American. When this trio first pulled into view on the track, they looked conventional except for one telling detail: the tailpipe. I bent down to inspect the Ford Focus FCV. Instead of a hot exhaust pipe pumping out noxious fumes, I saw a small grille cut into the rear bumper, from which a trickle of pure water dripped onto the asphalt. Now that's a revolution.

During my test-drives, I found the Japanese fuel cell vehicles responsive, virtually silent, and just plain fun. Surprisingly, both were hybrids. In addition to the fuel cell, they incorporated a secondary power source to help with acceleration and hill climbing. "Hybridizing between a fuel cell and a battery just makes sense," said Toyota engineer Justin Ward as we zoomed along in his company's roomy FCHV-4, a modified version of the Highlander SUV. "A fuel cell likes to run at a steady load, so when you stomp on the pedal, it really helps to have the battery to give you a boost," Ward said. Drawing on its experience with the gas-electric Prius sedan, Toyota put the exact same nickel-metal hydride battery pack into this vehicle. The car's regenerative braking also recouped energy that would otherwise be lost as heat. Acceleration was brisk, and the soft whirr from the 80-kilowatt, 107-horsepower electric motor made for a civilized driving experience. With a reported top speed of 93 miles per hour, the car seemed ready for the American highway.

Above: A look in the trunk shows that fuel cell technology is still at an infant stage. The awkward hydrogen storage tank in Ford's P2000 would never be acceptable in a production car. Below: The greatest appeal of the technology is its cleanliness: The only "exhaust" is water that forms when the hydrogen combines with oxygen from the air.

"Japan takes fuel cells very seriously," said Ward. "There are already two hydrogen filling stations in Tokyo; there will be five more soon. The government is strongly behind the technology." So is Toyota. The company makes its fuel cells in-house, unlike virtually every other automaker. The advantage is clear: Toyota engineers managed to cram the entire fuel cell assembly under the hood, while some other manufacturers resort to odd tricks such as elevating the car's floor several inches. "We really fought putting the cells in the floor," said Ward. "It raises the passenger's feet and makes sitting less comfortable."

Honda's hybrid fuel cell entry, the FCX-V4, was equally refined: Its ride was nearly indistinguishable from that of a conventional Honda Civic. "One unique thing about our technology is we use an ultra-capacitor rather than a battery to assist the fuel cell," said Honda engineer Steve Mathison. A capacitor stores electricity in a physical form—on a pair of metal plates that accumulate positive and negative charges—rather than in a chemical form, as batteries do. Capacitors can acquire and discharge voltage more quickly than batteries can, but they store less energy per cubic foot. Theoretically, the Honda should have accelerated the same as or even more briskly than the Toyota, but the actual difference, if any, was difficult to detect.

My final fuel cell foray of the day was in Ford's Focus, and it was the least satisfying journey. Mashing the throttle conjured memories of a 1966 Volkswagen Microbus I owned in college. "Acceleration isn't really snappy," conceded Anthony Eggert, the manager of Ford's Fuel Cell Partnership office in West Sacramento, California. In Ford's defense, Eggert pointed out that this car was an early prototype powered solely by a fuel cell and that the next incarnation from Ford will be yet another hybrid. "The whole industry is going the hybrid route," he said.

Aside from the lack of filling stations, the biggest hurdle facing hydrogen fuel cell cars is range. Most of today's fuel cell vehicles have one or more carbon-fiber-wrapped aluminum tanks filled with gaseous hydrogen at 3,600 to 5,000 pounds per square inch. Even at those pressures, the tanks hold only enough hydrogen to go about 180 miles. Research suggests that is not sufficient to satisfy many American drivers, which is why, said Mathison, "there's been a lot of discussion about going to 10,000 psi."

But that raises a question: Will a soccer parent embrace shuttling the kids around in a vehicle crammed with super-high-pressure tanks full of inflammable hydrogen? Ward insisted that the tanks are extremely tough: "We've dropped them from cranes 100 feet to the ground and nothing happens. In a wreck, they don't puncture, they just shift around." If an accident is bad enough to snap supply lines, multiple shutoffs should kick in—inertial sensors, power-loss sensors, and ambient gas sensors are designed to clamp off any leaking gas to prevent a fire.

Even so, there remains a problem of perception. "The average person's understanding of fuel cells is not great," said Joe Irvin, communications manager for the California Fuel Cell Partnership. "When you give people the specifics, they like the concept, but invariably they worry about safety, and the Hindenburg comes up." Such fears might be eased by recent studies that suggest the Hindenburg's inflammable skin—not the explosive tendencies of its hydrogen fuel—caused the dirigible to burst into flames in 1937 (see "The Hindenburg Revisited" in Discover, November 2001, page 55). And as fuel cell cars roll closer to dealerships, expect to hear plenty about the relative dangers of carrying gasoline around in a tank.

I am still not sure the public will buy it. But I left my day at the track convinced that hydrogen fuel cell cars are real and—unlike soy milk—tantalizingly close to palatable.





For more, check out the California Fuel Cell Partnership Web site (www.fuelcellpartnership.org) and "The Hydrogen and Fuel Cell Letter" (www.hfcletter.com).


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