In his 2003 State of the Union address, President Bush announced a $1.2 billion research initiative, “so that the first car driven by a child born today could be powered by hydrogen, and pollution-free.” The April 2003 issue of Wired magazine proclaimed, “How Hydrogen can save America.” General Motors has said the promise of hydrogen cars justifies delaying fuel-efficiency regulations.

Yet, for all the hype, a number of recent independent studies raise serious doubts about the prospects for hydrogen cars. In February, a prestigious National Academy of Sciences panel concluded, “In the best-case scenario, the transition to a hydrogen economy would take many decades, and any reductions in oil imports and carbon dioxide emissions are likely to be minor during the next 25 years.” And that’s the best case. Realistically, as I explain in my new book, "The Hype about Hydrogen: Fact and Fiction in the Race to Save the Climate,” a premature push towards hydrogen cars would undermine efforts to reduce global warming.

For hydrogen cars to become practical for consumers and desirable for the environment, several major technology breakthroughs will be required and the nation will have to shift its energy policy towards clean energy sources. As someone who helped oversee the Department of Energy’s clean energy program in the mid-1990s—and a ten-fold funding increase for hydrogen—I believe continued research remains important because of hydrogen’s potential to provide a pollution-free substitute for oil post-2030.

But going beyond research and development (R&D) at this point to actually building the hydrogen infrastructure—as many advocate—is both unjustified and unwise. Here’s why.

MULTIPLE BREAKTHROUGHS NEEDED
A hydrogen economy rests on two pillars: a pollution-free source for hydrogen, and a fuel cell for converting it into useful energy without generating pollution. Fuel cells are small, modular, electrochemical devices, similar to batteries, but which can be continuously fueled. For most purposes, you can think of a fuel cell as a “black box” that takes in hydrogen and oxygen and puts out only water plus electricity and heat.

Hydrogen is not a readily accessible energy source like coal or wind. It is bound up tightly in molecules like water and natural gas, so it is expensive and energy-intensive to extract and purify. More than 95% of U.S. hydrogen is produced from natural gas because that is the cheapest method, although such hydrogen is still far more expensive than gasoline. A hydrogen infrastructure built around current technologies would cost more than $600 billion, according to an Argonne National Laboratory study.

Last September, a panel of scientists convened by the U.S. Department of Energy (DOE) reported that transportation fuel cells “can now deliver power at about $3000/peak-kilowatt (kW) compared with $35/peak-kW for internal combustion engines.” The most mature hydrogen storage systems—using ultrahigh pressure—contain seven to ten times less energy per unit volume than gasoline, and require a significant amount of compression energy. The National Academy study concluded such storage has “little promise of long-term practicality.”

The DOE panel noted, “to be economically competitive with the present fossil fuel economy,” the cost of producing hydrogen would have to be reduced “by a factor of 4.” They concluded that bridging these gaps requires "revolutionary conceptual breakthroughs” and a “long-range program of innovative, high risk/high payoff basic research.”

If this sounds like it will be a long time before we see a commercially viable car, that should be no surprise. Technology breakthroughs that revolutionize the energy sector are rare. Wind power and solar power have each taken two decades to achieve a tenfold decline in prices, and they still comprise well under 1% of U.S. electricity generation.

Alternative fuel vehicles are an even greater challenge because they must overcome the trillion-dollar investment in the gasoline fueling infrastructure. Based on discussions with dozens of experts, it is unlikely that hydrogen cars will achieve even a 5% market share by 2030. But we needn’t be in a hurry to deploy hydrogen cars.

THE ENVIRONMENTAL CHALLENGE
Any premature push toward hydrogen cars would mean the hydrogen would come from the cheapest source today, natural gas. Yet, North American gas supply constraints mean we would just be trading imported gas for imported oil.

More important, a fuel cell car running on hydrogen from natural gas will not reduce greenhouse gases compared to hybrids like the Toyota Prius running on gasoline. In fact, given the hydrogen fueling stations Royal Dutch/Shell proposes to build, fuel cell vehicles would generate about twice the greenhouse gas emissions of the best hybrids. Hydrogen cars would also have more total emissions of particulates, oxides of nitrogen, and mercury than the best new hybrids.

Equally important, such a strategy would divert natural gas from a far better use—replacing the power generated from coal plants. A megawatt-hour of electricity from combined cycle natural gas plants releases about 800 pounds of carbon dioxide, whereas a megawatt-hour of even new coal plants can release more than 2200 pounds. If the nation had an unlimited supply of cheap natural gas, we could use it for all purposes, but we do not. We need it for clean power.

Similarly, electricity from renewables can directly displace four times as much carbon dioxide from coal power compared with using that renewable power to make hydrogen for fuel cell vehicles. And these savings can all be achieved without spending hundreds of billions of dollars on a new hydrogen infrastructure and fuel cell vehicles. A July 2003 analysis in Science magazine concluded: “Until CO2 emissions from electricity generation are virtually eliminated, it will be far more cost-effective to use new CO2-neutral electricity (e.g., wind or nuclear) to reduce emissions by substituting for fossil-generated electricity.”

The U.S. Congress, however, won’t even pass legislation requiring 10% of electricity in 2020 to be new renewables. So hydrogen cars are a post-2030 global warming strategy.

Right now, delivering renewable hydrogen to a car in usable form is prohibitively expensive—equal to gasoline at $6 to $10 a gallon. Hydrogen cars will remain inferior to the best hybrids in cost, range, annual fueling bill, convenience, safety, and greenhouse gas emissions until we achieve major breakthroughs in CO2-neutral hydrogen production, fuel cells, and hydrogen storage.

While hydrogen cars might have limited value as fleet vehicles in very polluted cities before 2030, they are unlikely to achieve mass-market commercialization by then. Neither government policy nor business investment should be based on the belief that hydrogen cars will have meaningful commercial success in the near- or medium-term.

This article is based on material from the book, “The Hype about Hydrogen: Fact and Fiction in the Race to Save the Climate,” by Joseph J. Romm published by Island Press.