Hydrogen may first replace carbon in an unlikely venue: the North Atlantic island nation of Iceland. Explosively volcanic, this mountainous country is already blessed with vast renewable energy resources in the form of geothermal and hydro power. The hot showers never run out: 90 percent of buildings are heated geothermally. But hot water cant power a tractor or trawler; largely because of its fishing fleet and metals industry, Iceland is one of the top per capita CO2 producers in the world.
The solution, says University of Iceland chemistry professor Bragi Árnason, is to capture the islands bountiful renewable energy in the form of hydrogen. "In thirty years," he predicts, "Iceland could be the first country consuming only clean, renewable energy."
Separating hydrogen out of water or other substances is not a technical challenge, but it does take energy. This could be supplied by fossil fuels, of course, but to keep the process totally clean, it has to come from a renewable sourcea geothermal plant in Iceland, a wind farm in North Dakota, a solar array in North Africa. Such clean hydrogen is, essentially, transportable renewable energy.
The trick is storing it. Liquid hydrogen isnt very practical, because it has to be maintained at 252 degrees Fahrenheit. As a gas, it has to be kept in bulky pressurized tanks. (Prototype hydrogen cars, whether using fuel cells or internal combustion engines, can presently only store the equivalent of four gallons of gas, although more highly pressurized containers could boost it to ten.) One of hydrogens drawbacks as an automotive fuel is that it would require an expensive new infrastructure of hydrogen filling-stations.
The alternative is to produce hydrogen on the spot, from methanol or gasoline, through an onboard device called a reformer. The drawback is that you still get CO2 emissions, if only half as much as from a gasoline engine. But gasoline-electric hybrids do that already, and theyre on the market now. "If were going to go with hydrogen fuel cells," says Ann Mesnikoff of the Sierra Clubs Global Warming and Energy Campaign, "they should be truly clean." (Iceland hopes that it can dodge this objection by producing methanol by combining hydrogen with CO2 captured from the stacks of Icelands metals industry, essentially recycling the waste gas.)
Icelands conversion to a hydrogen-powered economy has already been endorsed by its government, the oldest democratic assembly on the planet. The first step is the conversion of the Reykjavík bus fleet to hydrogen; demonstration buses should hit the road next year. Following will be the introduction of private fuel-cell vehicles, and finally the conversion of the trawler fleet.
"Im sixty-seven," says Árnason. "People in my generation will see the first steps. My children will see the transformation completed. And my grandchildren will live in this new hydrogen economy." Paul Rauber