EDF Climate 411 Blog - August 14, 2007
Hydrogen Fuel Cell Vehicles

This is Part 2 of a three-part series on Vehicle Fuels and Technology.

1. Plug-in Cars: The Lowdown
2. Hydrogen Fuel Cell Vehicles
3. Fossil Fuels and Biofuels

Hydrogen fuel cell vehicles got a big boost when President Bush made them part of his 2003 State of the Union address:

Tonight I'm proposing $1.2 billion in research funding so that America can lead the world in developing clean, hydrogen-powered automobiles… With a new national commitment, our scientists and engineers will overcome obstacles to taking these cars from laboratory to showroom, so that the first car driven by a child born today could be powered by hydrogen, and pollution-free.

That generated a lot of interest in hydrogen cars! So what are they, and can they become mainstream in the next 20 years?

Honda FCX fuel-cell car.
Honda FCX fuel-cell car.

Hydrogen fuel cells take in hydrogen and oxygen, and put out water, heat, and electricity - no pollution at all. Sounds good, but there's a catch - producing the hydrogen fuel can itself generate significant greenhouse gas emissions and other pollutants. And that's not the only serious problem.

Honda is the first company to put a fuel cell demonstration car into the hands of ordinary consumers. Yet as Steve Ellis, Honda's Manager of Fuel Cell Vehicles, told me hydrogen-powered cars are not likely to be mainstream for another 10 to 20 years. Many industry analysts put the number at well over 20 years, and some think it will never fly. All agree it's not a near-term solution.

Chevrolet Sequel fuel-cell car.
Chevrolet Sequel fuel-cell car.

Joseph Romm, in "The Hype about Hydrogen", notes five main problems with hydrogen cars as they currently stand:

  1. They are extremely expensive, currently costing around $1 million (for example, the GM Sequel and Honda's FCX). Most of this cost is in the fuel cells. If history is any guide, it will take decades for the cost to come down sufficiently.
  1. On-board fuel storage is a huge problem - literally - since at room temperature and pressure, hydrogen takes up 3000 times more space than an energy-equivalent amount of gasoline. There are several ways to store hydrogen, but all known approaches are complex and costly.

Storing hydrogen as a liquid isn't practical because it takes so much energy to liquefy and then convert back to gas. Storing it as compressed gas requires 300 to 600 times atmospheric pressure, and even then the tanks take up more than five times the space of a gasoline tank.

A National Academies study [PDF] noted, "In even the best case of improved compression efficiency and high pressure on-board tanks, the energy, space, cost, and weight penalties are formidable." It goes on to recommend that the U.S. "halt efforts on high-pressure tanks and cryogenic liquid storage" since "neither approach can reach DOE targets for energy density". A Department of Energy review reached a similar conclusion.

  1. There are serious safety issues with hydrogen fuel since it's among the most flammable substances known. It is vastly easier to ignite than gasoline, and leaks are much harder to detect and control. A cell phone or flashlight could ignite it, as could static electricity or an electric storm a few miles away.

Russell Moy, former Project Manager for hydrogen storage at Ford Motor Company, wrote about this in an article for the Energy Law Journal [PDF]: "Industrial experience has shown that 22 percent of hydrogen accidents are caused by undetected leaks, despite the standard operating procedures… of specially trained hydrogen workers. With this track record, it is difficult to imagine how the general public can manage hydrogen risks acceptably." Chemical Engineer Reuel Sinnar put it even more strongly [PDF]: "A hydrogen car as presently envisioned is a potential suicide bomb that cannot be detected by any of the standard methods that detect explosives."

  1. Producing hydrogen is expensive and energy-intensive [PDF]. The same energy currently used to create electricity would be used to create hydrogen, and today this mostly involves the use of fossil fuels (see House testimony of Dr. John Heywood of MIT). Current methods using natural gas produce significant CO2 emissions, and there is a serious question of whether a renewable fuel used to create hydrogen wouldn't be better used to replace electricity now generated from coal, since generating electricity is much more efficient than producing hydrogen power for vehicles.
  1. There's no fueling station infrastructure for hydrogen.

Building a hydrogen fuel infrastructure will be very expensive. A National Renewable Energy Laboratory report estimates the cost at $837 million [PDF]. Others say it could be tens of billions of dollars.

Companies hesitate to build something so expensive when there are no cars to use it. Similarly, automakers are reluctant to manufacture hydrogen cars when there's no infrastructure, because consumers won't buy them if they can't fuel them. This is generally referred to as the "chicken-and-egg" problem.

There's another obstacle to infrastructure. Ideally, hydrogen would be produced in a central location so carbon emissions from its manufacture could be efficiently sequestered. But that isn't set up yet, so initially the hydrogen would be created locally. No one wants to invest large amounts of money in an infrastructure that will be abandoned.

All these problems may be solvable, but it will take time. And you can't necessarily trust the automakers' predictions. In 2001, our automobile expert, John DeCicco, Ph.D., wrote an in-depth review of fuel cell vehicles [PDF] for the Society of Automotive Engineers. In it he noted that "Several automakers have pledged the introduction of fuel cell vehicles, including buses, by 2003-2005." It's 2007, and beyond a few demos I don't see them yet! Dr. DeCicco considers the hydrogen car an "utterly speculative proposition."

Maybe we'll have hydrogen fuel cell vehicles by 2030, but in 20 years, who knows? Perhaps some new and better technology will come along, and research into hydrogen power will be abandoned. None of us can know which technology will be the future, but we do know this: the world can't wait 20 years to reduce CO2 emissions from vehicles. So while the hydrogen car is worth researching for the long term, the heavy emphasis placed on it by the Bush Administration is ill-considered.

GM has said that the government shouldn't require it to focus on near-term fuel economy improvement because it would detract from its fuel cell work. Given the urgency of the global warming problem, it would be a serious mistake not to explore the many more accessible ways to cut carbon emissions while waiting for a silver bullet.

The author of today's post, Sheryl Canter, is an online writer and editorial manager at Environmental Defense.

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