In a paper appearing in the July 18 issue of Science magazine, Alex Farrell, assistant professor of energy and resources at UC Berkeley, and David Keith, associate professor of engineering and public policy at Carnegie Mellon University, present various short- and long-term strategies that they say would achieve the same results as switching from gasoline-powered vehicles to hydrogen cars.

"Hydrogen cars are a poor short-term strategy, and it's not even clear that they are a good idea in the long term," said Farrell. "Because the prospects for hydrogen cars are so uncertain, we need to think carefully before we invest all this money and all this public effort in one area."

Farrell and Keith compared the costs of developing fuel cell vehicles to the costs of other strategies for achieving the same environmental and economic goals.

"There are three reasons you might think hydrogen would be a good thing to use as a transportation fuel -- it can reduce air pollution, slow global climate change and reduce dependence on oil imports -- but for each one there is something else you could do that would probably work better, work faster and be cheaper," Farrell said.

President George W. Bush has proposed a federally funded, five-year, $1.7 billion FreedomCAR and Fuel Initiative to develop hydrogen-powered fuel cells, a hydrogen infrastructure and advanced automotive technologies.

Several announced candidates for president have also proposed major research efforts to develop hydrogen-fueled vehicles and technologies to produce, transport and store the hydrogen, while many scientists have praised the initiative.

For many people, the attraction of hydrogen is that it produces no pollution or greenhouse gases at the tailpipe. For others, the attraction is that hydrogen is a research program, not a regulation, and that some hydrogen-related research will also help develop better gasoline-powered cars.

One problem, said Farrell, an expert on energy and environment issues, is that this glosses over the issue of where the hydrogen comes from. Current methods of producing hydrogen from oil and coal produce substantial carbon dioxide.

Unless and until this carbon can be captured and stored, renewable (wind or solar) and nuclear power, with their attendant problems of supply and waste, are the only means of producing hydrogen without also producing greenhouse gases.

In addition, Farrell points out that setting up a completely new infrastructure to distribute hydrogen would cost at least $5,000 per vehicle. Transporting, storing and distributing a gaseous fuel as opposed to a liquid raises many new problems.

More billions of dollars will be needed to develop hydrogen fuel cells that can match the performance of today's gasoline engines, he said.

The benefits might be worth the costs of fuel-cell development and creating a new infrastructure, however, if air pollution, greenhouse gases and imported petroleum could not be reduced in other ways. But they can, said Farrell.

Improvements to current cars and current environmental rules are more than 100 times cheaper than hydrogen cars at reducing air pollution. And for several decades, the most cost-effective method to reduce oil imports and CO2 emissions from cars will be to increase fuel efficiency, the two scientists found.

"You could get a significant reduction in petroleum consumption pretty inexpensively by raising the fuel economy standard or raising fuel prices, or both, which is probably the cheapest strategy," Farrell said.

"This would actually have no net cost or possibly even a negative cost -- buying less fuel would save more money than the price of the high-efficiency cars. The vehicles would still be large enough for Americans and they would still be safe."

Technologies are now on the shelf to achieve better fuel efficiency, he said. All that's lacking are economic incentives to encourage auto makers to make and drivers to buy fuel-efficient cars.

"Automobile manufacturers don't need to invest in anything fancy -- a wide number of technologies are already on the shelf," he said, quoting, among other studies, a 2002 report by the National Academy of Sciences. "The cost would be trivial compared to the changes needed to go to a hydrogen car."

Petroleum substitutes like ethanol that can be used in today's vehicles also are a possible way to reduce oil imports, the researchers say, but more research is needed to reduce the environmental impact and cost of these options.

If one goal is to reduce greenhouse gases, it would be cheaper, Farrell and Keith argue, to focus on reducing carbon dioxide emissions from electric power plants than to focus solely on hydrogen-powered vehicles. But if passenger cars are targeted, fuel economy is still the key.

If it becomes necessary to introduce hydrogen into the transportation sector, the scientists say, a better alternative is to develop hydrogen-powered fuel cells for vehicles such as ships, trains and large trucks instead of cars.

Because these heavy freight vehicles have higher emissions, this strategy could provide greater air quality benefits. On-board hydrogen storage would be less of a problem also, and it would require a smaller fuel distribution network.

Farrell and Keith provide figures that support their arguments and conclude that more research needs to be done before committing ourselves to a hydrogen economy, which might begin to make sense 25 years down the road.

"Hydrogen cars are an attractive vision that demands serious investigation, but it's not a sure thing," they wrote.

Farrell speculates that hydrogen has become attractive to people across the political spectrum in part because it doesn't challenge drivers to change their habits. It also doesn't challenge the auto industry to change its behavior, providing, instead, a subsidy for research that will lead to better cars whether they are hydrogen-powered or gasoline-powered.

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