Thirsty? Imagine bending down to your car tailpipe and taking a big slurp.
Hydrogen-powered vehicles could make that possible (though you'd probably prefer to get your drinking water elsewhere). Unlike gasoline-driven combustion engines, the hydrogen fuel cell generates power not by burning, but through a chemical reaction in which hydrogen and oxygen are converted into energy with water as the only byproduct. It's not just clean, as a fuel source, hydrogen offers nearly three times the energy of gasoline since it burns hotter and faster.
The concept of such a clean car is appealing, but a growing number of critics are saying it's time to wake up and embrace technologies, such as gas-electric hybrid vehicles, that they say are more feasible.
"The things that matter here are energy security, climate change and air pollution," said David Keith of the Department of Engineering and Public Policy at Carnegie Mellon University in Pittsburgh. "Focusing on fuel-cell cars makes no economic sense for any of these goals."
President Bush declared in his 2003 State of the Union address that he aimed to have hydrogen-powered cars on the road in significant numbers by 2020 and pledged $1.2 billion in federal money for the effort. The energy department followed up this year by including $318 million for both fuel cells and hydrogen production in its 2005 budget.
Thinkers like Jeremy Rifkin of the Foundation on Economic Trends argue that adopting a hydrogen-fueled economy could not only lead to cleaner skies, but also liberate the country from its dependence on foreign oil and make energy more accessible to the masses. This is because each hydrogen fuel-cell vehicle contains the parts to essentially be a portable power plant. This means that when not in motion, cars could be hooked up to help power outside units.
"In the new hydrogen fuel-cell era, even the automobile itself is a 'power station on wheels' with a generating capacity of 20 kilowatts," he wrote in his book, "The Hydrogen Economy: The Creation of the Worldwide Energy Web and the Redistribution of Power on Earth."
But in the past year, two reports, one from the National Academy of Sciences and another in the journal "Science," plus a recently published book have all argued that placing such focus on hydrogen fuel-cell vehicles may be counterproductive. A better, more viable solution could lie in a technology that is already catching on -- the hybrid vehicle.
"We already have a technology that can reduce emissions by 30 (percent) to 50 percent," said Joseph Romm, chief official for alternative fuels for the Department of Energy under President Clinton and author of the book "The Hype About Hydrogen: Fact and Fiction in the Race to Save the Climate." "So I think hybrids, not fuel cells, should be the focus of government policy for the next two decades."
Burning Natural Gas to Get Hydrogen
Romm and others point out that hydrogen is a fuel carrier, not a fuel source, which means it must be produced from other sources. While the hope is renewable resources, such as windpower, might someday be used to produce hydrogen, right now the most cost-efficient way of making it is from natural gas in a process that releases carbon dioxide into the atmosphere. And that, critics say, defeats the purpose of switching to hydrogen in the first place.
"I have a light bulb in my room and it's not emitting carbon dioxide -- it's perfectly clean," said Keith, who co-authored the July 2003 "Science" paper that argued against a rush toward hydrogen fuel cells. "But that's not the point. The point is producing the electricity to power it is polluting."
Then there is the major hurdle of developing a network of hydrogen-fueling stations and supply systems to service the fleet of hydrogen powered cars. In mid-November, Shell opened its first hydrogen service station outside Washington, D.C. The station is one of some 22 new stations for fuel-cell and hydrogen-powered vehicles built in the past year.
But many more will be needed if the nation is to be equipped with "hydrogen highways," as California Gov. Arnold Schwarzenegger has described his state's hopeful future network of more than 200 hydrogen fuel stations. So far the state has only two.
"The challenges in developing a fuel-cell car and the needed infrastructure are enormous," said Romm. "You might say, 'It's the infrastructure, stupid.'"
Romm and Keith even suggest that some car company executives have embraced the hydrogen fuel-cell concept to stave off demands to improve fuel efficiency of their gas-powered vehicles.
"By telling the public they're working on this ultimate solution, they can then say don't push us on emissions standards," said Keith.
Car company representatives dismiss such claims as "ridiculous" and contend there's no reason why the automotive industry can't pursue hybrid vehicle and hydrogen fuel-cell technology at the same time.
"Hydrogen fuel cells are only the long-term part of our strategy to reducing fuel consumption," said Kyle Johnson, an engineer with General Motors. "In the short term, we're continuing to improve our fuel combustion engines. Then in the mid-term, we will bring out hybrids … in the long term, we continue to contribute resources to fuel cells."
Tom Watson, chief engineer for Ford's fuel-cell program, maintains the company is hopeful the hydrogen vehicle concept does have a future. He adds that much of what they learn in designing hydrogen fuel-cell vehicles can and has been applied in their gas hybrid models.
"We believe that fuel-cell vehicles have a future in the marketplace," he said. "The only question is in the timing."
While it may take a while to develop lines of fuel cells, several car companies, including Ford, General Motors and BMW are adjusting combustion engines so they burn on hydrogen.
"Then we'll have the mechanism to stimulate the creation of a hydrogen infrastructure," said Watson.
California Law Could Help Hybrids
Regardless of how far long it may take to develop a hydrogen infrastructure, could there be any harm in working toward one? Keith argues that federal money would be better spent in advancing the design and sales of hybrid vehicles. Right now, federal support of the part gasoline-powered, part electric-powered vehicles is a $2,000 tax deduction, which will sunset to $500 in 2006 and expire by 2007.
That's not enough, says Keith. Federal money could be invested in hybrids to improve their customer appeal and help make them more efficient, perhaps by combining a diesel engine with an electric one.
"What we do now will affect the policy landscape," he said. "We don't want to waste money now."
On the other hand, hybrid vehicles appear to be growing quite popular on their own. About 47,500 hybrid vehicles were sold in the United States in 2003, according to data released last week by J.D. Power. In 2005, the company predicts 206,000 hybrids will be sold.
The cars could become even more popular if a new law in California is enacted.
The state law sets limits on carbon dioxide emissions from vehicles starting in the year 2009, with toughening standards each following year. Automakers say the requirements would demand extreme improvements in emissions standards and could raise the price of cars by as much as $1,000 per vehicle. Companies are expected to sue to stop the law's enactment.
If it is enacted, however, state officials expect other states to follow their lead and this could prompt a surge in hybrid vehicle sales.
As it is, spiraling gas prices have already given hybrids a boost. Nonetheless, Romm argues, a little extra boost never hurts.
"I don't think anything the government is doing will hurt hybrids," he said. "I just think they could do more."