A few days after I got my new 2004 Toyota Priushybrid car, I was stopped at a light in San Francisco, when a couple in the next car started waving wildly at me. I lowered the passenger window, and the man and the woman yelled in unison: “How do you like your new car?”
While I sputtered something about how it's great, the woman gushed: “Thanks for driving it!”
When's the last time a stranger thanked you for driving? Never mind the fact that when I didn't own a car, no one ever thanked me for walking; the curiosity and excitement about cleaner car technology is palpable to anyone who's been behind the wheel of a hybrid, even for an afternoon.
Hybrid gas-electric cars make drivers feel they can do something to reduce their contribution to air-pollution and global warming and even over-dependence on foreign oil without giving up the perks of four wheels. “The bottom line is we can't change America's love affair with the automobile, but we can change the automobile,” says Dan Becker, the Washington, DC, director of Sierra Club's Global Warming program, which is currently promoting hybrid cars with a cross-country road trip tour called: “I will evolve” (www.iwillevolve.org).
But it's hydrogen fuel-cell cars, not hybrids, that American auto manufacturers, the federal government, and the governor of California are betting on as the cars of the future. They promise this new technology will take drivers beyond the internal-combustion engine altogether, emitting nothing but water from the tailpipe.
President Bush predicted in his January 2003 State of the Union address that the first car of a child born today would be a hydrogen fuel cell car, and he pledged federal funds for hydrogen fuel research and development. And in April 2004, California's Governor Arnold Schwarzenegger—a Hummer driver himself—pledged to create the nation's first “hydrogen highway” by developing a network of some 200 hydrogen fueling stations on the state's major roads by 2010.
The most ardent advocates of hydrogen fuel cells, such as Jeremy Rifkin, author of The Hydrogen Economy: the Creation of the World-wide Energy Web and the Re-distribution of Power on Earth, foresee the cars revolutionizing not just the way that we get around, but how power is created and distributed for homes and businesses. The fuel cell uses hydrogen to generate electricity on board the car to power the vehicle. What else could that electricity be used for? When parked, cars could be plugged into outlets to become mobile mini-power plants, thwarting both terrorist threats to centralized plants and monopolistic power-companies' greed.
But the transition from the internal-combustion engine to a fuel-cell future is littered with obstacles that cast doubt on just how green a fuel-cell car will ever be.
How green are fuel cells?
While hydrogen is the most abundant element in the universe, it takes energy to separate it from other molecules. Hydrogen is therefore not an energy source, like oil, natural gas, and the sun, but an energy carrier like electricity. Most hydrogen sold today is extracted from natural gas. It can also be generated by separating hydrogen from water through electrolysis, but that takes a lot of electricity. In much of the country that electricity comes from highly polluting coal—50 percent of power plants are coal-fired. So much for freedom from fossil fuels. But there's promise that renewable sources of energy like wind, solar, and biomass could be used to generate hydrogen, which could fulfill the green-dream of a truly pollution-free car.
Even so, some experts doubt that's an efficient—forget cost-effective—use of renewable energy. If our concern is greenhouse gases, wouldn't we be much better off directly supplanting coal-fired electric power plants with wind, say, rather than using the wind to produce hydrogen to power a fuel cell for driving? In a hydrogen fuel-cell car, hydrogen is used to generate electricity.
And all these steps waste energy, since every time energy changes form—from wind to electricity to hydrogen to electricity again—a percentage of the energy is lost. In addition, to be transported to or within a vehicle, hydrogen must be compressed, which uses energy, too.
These inefficiencies are why Roel Hammerschlag of the Institute for Lifecycle Environmental Assessment and Patrick Mazza of Climate Solutions, in their joint paper “Questioning Hydrogen” (forthcoming in Energy Policy), conclude: “Renewable generation technologies are brought most efficiently to affect greenhouse gas emissions via electricity, not hydrogen.”
Some environmentalists see all the public sector excitement about hydrogen in more sinister terms—a kind of green smokescreen to give the Bush Administration and American automakers cover, while they refuse to raise fuel-economy standards on existing cars and continue to market highly profitable and gas-guzzling SUVs. The tantalizing promise of hydrogen may fool the public into thinking it's okay to do nothing about greenhouse gases, air pollution, and our over-dependence on foreign oil now.
But physicist Amory Lovins of the Rocky Mountain Institute, one of the hydrogen fuel cell car's strongest advocates, dismisses this view in his paper “Twenty Hydrogen Myths,” although he concedes it would help the government's credibility if it would both promote hydrogen and create more incentives for consumers to buy hybrids today. He argues that the tremendous efficiency gains by hydrogen-powered fuel cells over the traditional combustion engine outweigh all the energy losses incurred in turning energy into hydrogen and compressing hydrogen for transport or storage. Hammerschlag and Mazza counter that these efficiency gains can be had with electric batteries, like those in electric cars or hybrids, without the losses associated with making hydrogen.
Some skeptics think that over-promising about the hydrogen future now could backfire later. Californians need only look as far as the now almost entirely unused electric-vehicle charging stations that dot their freeways. “Electric vehicles were overhyped and prematurely introduced into the marketplace,” says Joseph Romm, author of The Hype About Hydrogen, who under Clinton was the chief energy department official in charge of alternative energy. “And as you see, General Motors has withdrawn every single one of the electric vehicles from the marketplace and squished them. They've recycled them all.”
Even though the auto industry backed away from electric cars as soon as the state allowed them to, the technological legacy of those now-crushed electric vehicles is seen in the gas-electric hybrid car that I drive today, which cuts tailpipe emissions 90 percent, and greenhouse-gas emission in half. Maybe a cautiously optimistic hope for the hydrogen fuel cell future is that all the energy and investment and even the gauzy hype about it now will yield unexpected efficiencies and innovations for transportation tomorrow that haven't even been conceived of yet.
Katharine Mieszkowski (firstname.lastname@example.org) is a senior writer for Salon.com, based in San Francisco. The Hammerschlag/Mazza paper on hydrogen is available at www.ilea.org/downloads/MazzaHammerschlag.pdf.