In the system envisioned by Alistair Miller and Romney Duffey of Atomic Energy of Canada, nuclear power plants would be paired with wind turbines to power electrolysis cells, which make hydrogen by passing an electric current through water.
Wind on its own is too variable, Miller says, leaving electrolysis equipment frequently idle and driving up costs. "The economics just don't work," he says. "It produces very expensive hydrogen."
Pairing it with nuclear would keep the equipment operating closer to full capacity and bring the cost down, he says. A bonus is that when the wind is strong and electricity demand is high, excess power can be sold at a profit to the grid. This means that, unlike traditional electricity-based hydrogen production, Miller's system actually makes hydrogen cheaper as the cost of electricity goes up.
Using time-varying electricity price data from Ontario and Alberta, Miller and Duffey calculate that their system can produce hydrogen at $2 per kilogram, easily meeting the U.S. Department of Energy's goal of $2 to $3 per kilogram by 2015. One kilogram of hydrogen is considered equivalent to one gallon of gasoline.
Miller and Duffey recently presented their system, which they call NuWind, at the 2005 Canadian Chemical Engineering Conference in Toronto.
Other hydrogen advocates aren't thrilled about the idea of building nuclear power plants to produce hydrogen, however.
"The nuclear guys are always trying to come up with arguments to make their industry more green," says Daniel Sperling, co-director of the Hydrogen Pathways Program at the University of California at Davis. "Nuclear's got all kinds of challenges." Concerns raised frequently include nuclear waste disposal, potential terrorist attacks on reactors and nuclear weapons proliferation.
Miller argues that radiation from nuclear power plants is tiny compared to what people get from natural sources and that there are cheaper paths to nuclear proliferation than building a nuclear power plant. He also maintains that the risks of terrorist attacks are overblown. "You can fly a 747 into a nuclear reactor and it's very bad for the 747 but it won't actually do anything to the meter-thick concrete around the reactor core," he says.
And given growing concerns about climate change, he says, society can't afford to dismiss any options for reducing carbon emissions. "We need all the carbon-free sources we can possibly lay our hands on."
Despite his doubts, Sperling says nuclear shouldn’t be dismissed out of hand for hydrogen production. "I wouldn't see spending money on nuclear to hydrogen at this point, but we should keep it open as an option."
Aside from the environmental and security issues, hydrogen from the nuclear-wind system would have other hurdles to overcome, including the added costs of distributing the fuel.
"I think it's certainly possible that you can produce hydrogen that's competitive in price with gasoline and that's produced from a relatively clean source, if you're including nuclear in that," says energy market analyst Roberta Gamble of Frost & Sullivan. "The problem is the transportation of the fuel, the integration into the fuelling system, and then whether or not it would ever be used."
Gamble is doubtful that fuel-cell cars will catch on among consumers, especially within the next 10 or 15 years, when the nuclear-wind system would be most useful. After that, other hydrogen-production technologies being researched could be ready and might make the nuclear-wind system obsolete.
Nearly all hydrogen today is obtained from natural gas in a process called steam methane reforming. But unlike electrolysis, this method produces carbon dioxide, and is growing more expensive as natural gas prices rise.