The best way to cut pollution?

Two US scientists have suggested we take a critical look at the future role of hydrogen-powered cars and consider simpler, cheaper options.

Alex Farrell, an assistant professor of energy and resources at UC Berkeley, and David Keith, an associate professor of engineering and public policy at Carnegie Mellon University, believe that there are several short- and long-term strategies that 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 money and public effort in (this) one area,’ he added.

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.

Current methods of producing hydrogen from oil and coal produce substantial carbon dioxide. Unless and until this 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.

What’s 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 if air pollution, greenhouse gases and imported petroleum could not be reduced in other ways. But they can, said Farrell.

For several decades to come, the most cost-effective method to reduce oil imports and CO2 emissions from cars will be to increase the fuel efficiency of existing car designs, the two scientists found.

‘You could get a significant reduction in petrol consumption pretty inexpensively by raising the fuel economy standard or raising fuel prices, or both,’ Farrell said.

‘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.’

All that’s lacking are economic incentives to encourage auto makers to make and drivers to buy fuel-efficient cars.

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.

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 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 behaviour, providing, instead, a subsidy for research that will lead to better cars whether they are hydrogen-powered or gasoline-powered.