Being driven by hydrogen

The fuel cells are promoted as a way to reduce pollution and dependence on foreign oil. They won the endorsement of President George W. Bush in January 2003 when he pledged $1.2 billion for hydrogen research, and American automakers are testing fleets of experimental vehicles. Fuel cells power components on the space shuttle and more than 50 experimental cars and buses now use them on American and European roads.

But stumbling blocks include coming up with ways to store hydrogen, developing a nationwide system of fuelling stations and finding inexpensive ways to extract hydrogen — from water, gasoline or other sources.

The United States’ Department of Energy is offering $200 million in contracts to universities, research laboratories and automakers for developing ways to produce, deliver and store hydrogen for use in fuel cells. The first contracts are likely to be awarded in December, said Patrick Davis, a DOE spokesman.

Experts do not expect mass production of hydrogen-powered cars until at least 2010. But federal funding commitments have rekindled debates. Scientists at the California Institute of Technology warn that a sudden shift to hydrogen fuel cells could send more hydrogen into the upper atmosphere, cooling the skies and damaging the protective ozone layer.

Because hydrogen travels skyward, the researchers say the increase could triple the number of hydrogen molecules in the stratosphere, where it would oxidise and form water. ‘‘This would result in cooling of the lower stratosphere and the disturbance of the ozone chemistry,’’ according to the study published in Science.

The researchers acknowledge technologies could be developed to control hydrogen releases. But they recommend that growth of the fuel cell industry be regulated.

In a second study, scientists at Carnegie Mellon University and the University of California, Berkeley, say clean air benefits from fuel cells are years away and that developing infrastructure for refuelling could cost as much as $5000 a vehicle. It would be much cheaper to put emission controls on smokestacks, they say.

‘‘Solutions should be problem-driven, and there are more cost-effective solutions for many of these serious environmental and energy security problems,’’ wrote David Keith, a co-author and an associate professor of engineering at Carnegie Mellon. The report was published in Science in July.

But other scientists believe hydrogen fuel cells are a viable alternative. Romesh Kumar, chemical engineer and head of the fuel cell group at the Argonne National Laboratory in Illinois, said fuel cells may one day be like electricity and power a range of devices. ‘‘It’s clean, it can be controlled and there are no harmful emissions from it,’’ he said. LAT-WP