It's been just over a year since President Bush announced his support for the alternative power supply known as hydrogen fuel cells. And while White House backing does provide needed funding and initiative for researchers, the road to a hydrogen-powered economy is still very bumpy. At 2004 annual meeting of the American Association for the Advancement of Science in February, researchers examined the problems and promise of hydrogen fuel cells that could soon power everything from automobiles to kitchen appliances.
In his State of the Union address last year, President Bush pledged to promote energy independence for the nation, while dramatically improving the environment. "In this century, the greatest environmental progress will come about, not through endless lawsuits or command and control regulations, but through technology and innovation," he said. "Tonight I am proposing $1.2 billion in research funding so that America can lead the world in developing clean, hydrogen-powered automobiles."
Many in the United States and around the world saw Mr. Bush's proposal as a major step forward in the search for an efficient and affordable alternative to fossil fuels, especially in automobiles. According to Energy Department scientist David King, hydrogen power researchers are hoping to match the efficiency of today's cars, whether measured in miles per gallon or kilometers per liter.
"The target is to be equivalent on an energy basis with gasoline," he said. "Really what's driving the hydrogen economy is replacing petroleum requirements in automobiles and trucks. So the goal is to power a fuel cell vehicle using hydrogen and get essentially the same equivalent miles per gallon."
Hydrogen can be stored in fuel cells, a concept similar to storing power in batteries. Through a chemical reaction, the hydrogen produces electricity and the only byproducts are water and heat. So, by re-charging hydrogen fuel cells, a car or even a local power plant could constantly produce power with no harmful emissions, such as the carbon dioxide released by burning fossil fuels like coal or gasoline.
But there are clouds on the horizon of this alternative vision. Several issues complicate the potential use of hydrogen as a power source in the immediate future. At the top of the list, according to fuel cell researcher Subnash Singhal, is 'the bottom line.'
"The biggest hurdle today is clearly the cost, cost of the fuel cells. And the cost of producing hydrogen and storing them and distributing them," he said.
Mr. Singhal says most of the research being done by both industry and the government is addressing this cost issue. While research continues, fuel cell vehicles are cruising down the highways of several countries, including the United States, Canada, Iceland and Japan. But these cars and busses are experimental, for demonstration purposes only, and are several times more expensive to operate than traditional gas or diesel-powered vehicles. And even if that cost comes down, there's another roadblock to their wider use: there is no infrastructure in place for re-fueling the fuel cells. Canadian hydrogen fuel developers hope to have several re-fueling stations in place in time for the 2010 Vancouver Winter Olympics. But there will only be enough stations to supply the limited number of vehicles in use during the Games. One of the challenges in designing and operating these stations is safety, according to Russell Moy. The engineer and attorney, who's worked in many aspects of the hydrogen fuel industry, told AAAS members hydrogen is much more volatile than gasoline or diesel and therefore could be much more dangerous.
"What this means is that a spark or static, the amount of energy that would ignite hydrogen is one tenth what would be need to ignite some of these other more traditional fuels. In addition the hydrogen has an invisible flame and it has no odor," he said.
Chemicals can't be added to hydrogen to create an odor as is done with natural gas. And while it is difficult to reach the necessary concentrations of hydrogen for it to ignite, Mr. Moy says there are circumstances where it is possible. Because of these dangers, he says higher insurance premiums could be a hidden cost for sellers and distributors or even homeowners with a hydrogen powered car in the garage.
But even if safety issues can be addressed and the costs of operating hydrogen-powered vehicles can be reduced, there is still a fundamental problem: where do you get the hydrogen?
"You've got to use a primary fuel to get the hydrogen, and you've got to have a source in order to get the hydrogen," he said.
As chemical engineering professor E.G. Meyer explains, although hydrogen is the most common element in the universe, on earth it's usually chemically bound to other elements, so it's not in a form that can be easily transferred into fuel cells.
"Nuclear energy, solar energy, fossil energy are all primary energy sources. Hydrogen is not, it doesn't exist, it has to be produced. Electricity is not, it has to be produced," he said. "So in each case, with hydrogen or with electricity you have to produce them with a primary energy source. And in this country we produce almost all of our electricity with the primary source of coal."
The University of Wyoming professor says that means hydrogen is not the clean and easy power supply many people believe it is. Using coal or even natural gas to make the hydrogen produces harmful emissions, even if the fuel cells themselves burn cleanly. Professor Meyer says the only way to produce hydrogen without such emissions is by using nuclear energy, which creates usable hydrogen directly from water rather than petroleum products. Most researchers do agree with President Bush's assessment that hydrogen fuel cells have great potential, but they warn that the significant challenges in costs, safety and resources mean this power source won't be commonplace anytime soon. Many of these problems will take years, even decades to solve according to a report released this month by the National Academy of Sciences. The authors cite the advantages of hydrogen fuel technologies, but also urge further study of other alternatives to fossil fuels.