Take a hydrogen atom, comprised of one proton and one electron. Strip the electron and run a car. That's the basic premise behind the energy efficiency crowd's latest craze, the fuel cella unit that facilitates the chemical reaction described above using compressed hydrogen gas and oxygen, and creates electricity for a car's motor. Because fuel cells generate power chemically rather than through combustion, they produce zero emissionsa fact that's caused some experts in the field to tout the fuel cell as a potentially sustainable alternative to fossil fuels.
Vehicle Emissions Breakdown
Click here to find out more about the major chemical contributors to air pollution, brought to you by Georgetown University's Advanced Vehicle Development Department.
Honda's FCX, Courtesy Honda
When Chicago introduced three hydrogen-fueled city buses in September 1995, Mayor Richard Daley drank a glass of lukewarm water collected from their tailpipes as a testament to the fuel cell's environmental cleanliness. The fuel cell itself emits no particulate matter and just trace amounts of hydrocarbons and nitrogen oxideboth major contributors to ozone-depleting smog found in higher amounts in gasoline vehicle emissions. In terms of efficiency, most passenger vehicles utilize only 15 percent of the energy available in a gallon of gasoline, while the fuel cell takes advantage of at least 40 percent of hydrogen's energy potential.
The fuel cell's most oft-hyped virtue is its potential to be an entirely renewable energy source. And the average fuel-cell vehicle can travel about 170 miles at 55 mph before needing more hydrogen. But its introduction to the mass market is a still long way off. First, the question of how to establish a renewable source of hydrogenideally from wind, solar, or geothermal generatorshas yet to be answered. (Hydrogen is currently manufactured from fossil fuel, which undermines the zero-emissions goal in the cradle-to-grave fuel cycle.) Second, the technology to produce fuel cells is very expensive. The price tag for each Chicago fuel-cell bus was nine times the usual $200,000 cost of purchasing a city bus, and many hydrogen-powered passenger cars cost more than a million dollars.
But the most significant hurdle to mass-production of fuel cell vehicles may be the chicken-egg quandary of establishing fuel-station infrastructure. In order for dealers to begin selling fuel-cell cars, hydrogen filling stations would need to start rooting themselves across the nation. Otherwise, the auto industry will be forced to bank on customers willing to take a leap of faithbuying a car under the assumption that fuel stations will pop up along the highway like weeds. This is risky business in a less-than-buoyant economy.
Despite obstacles related to cost and infrastructure, however, many major car companies are currently experimenting with the fuel cell. Jim Kliesch, a research associate at the American Council for an Energy-Efficient Economy (a non-profit that works with businesses and public interest groups to promote both economic prosperity and environmental protection) estimates that 20 or 30 years will pass before the fuel cell passenger vehicle will be common in suburban driveways. Even after leasing five fuel-cell powered FCX hatchbacks to the city of Los Angeles this year, Honda PR manager Andy Boyd agrees with Kliesch. "It's a fuzzy crystal ball," Boyd says. "Tomorrow, someone could hit a major technological advance."
Want to find out more? Check out our green fuel guide: