In presidential campaign of 2004, Bush and Kerry managed to find one piece of common ground: Both spoke glowingly of a future powered by fuel cells. Hydrogen would free us from our dependence on fossil fuels and would dramatically curb emissions of air pollutants, including carbon dioxide, the gas chiefly blamed for global warming. The entire worldwide energy market would evolve into a "hydrogen economy" based on clean, abundant power. Auto manufacturers and environmentalists alike happily rode the bandwagon, pointing to hydrogen as the next big thing in U.S. energy policy. Yet the truth is that we aren't much closer to a commercially viable hydrogen-powered car than we are to cold fusion or a cure for cancer. This hardly surprises engineers, fuel cell manufacturers and policymakers, who have known all along that the technology has been hyped, perhaps to its detriment, and that the public has been misled about what Howard Coffman, editor of fuelcell-info.com, describes as the "undeniable realities of the hydrogen economy." These experts are confident that the hydrogen economy will arrive-someday. But first, they say, we have to overcome daunting technological, financial and political roadblocks. Herewith, our checklist of misconceptions and doubts
about hydrogen and the exalted fuel cell.
1. HYDROGEN IS AN ABUNDANT FUEL
True, hydrogen is the most common element in the universe; it's so plentiful that the sun consumes 600 million tons of it every second. But unlike oil, vast reservoirs of hydrogen don't exist here on Earth. Instead, hydrogen atoms are bound up in molecules with other elements, and we must expend energy to extract the hydrogen so it can be used in fuel cells. We'll never get more energy out of hydrogen than we put into it.
"Hydrogen is a currency, not a primary energy source," explains Geoffrey Ballard, the father of the modern-day fuel cell and co-founder of Ballard Power Systems, the world's leading fuel-cell developer. "It's a means of getting energy from where you created it to where you need it."
2. HYDROGEN FUEL CELLS WILL END GLOBAL WARMING
Unlike internal combustion engines, hydrogen fuel cells do not emit carbon dioxide. But extracting hydrogen from natural gas, today's primary source, does. And wresting hydrogen from water through electrolysis takes tremendous amounts of energy. If that energy comes from power plants burning fossil fuels, the end product may be clean hydrogen, but the process used to obtain it is still dirty.
Once hydrogen is extracted, it must be compressed and transported, presumably by machinery and vehicles that in the early stages of a hydrogen economy will be running on fossil fuels. The result: even more C02. In fact, driving a fuel cell car with hydrogen extracted from natural gas or water could produce a net increase of CO2 in the atmosphere. "People say that hydrogen cars would be pollution-free," observes University of Calgary engineering professor David Keith. "Lightbulbs are pollution-free, but power plants are not."
In the short term, nuclear power may be the easiest way to produce hydrogen without pumping more carbon dioxide into the atmosphere. Electricity from a nuclear plant would electrolyze water-splitting H2O into hydrogen and oxygen. Ballard champions the idea, calling nuclear power "extremely important, unless we see some other major breakthrough that none of us has envisioned."
Critics counter that nuclear power creates long-term waste problems and isn't economically competitive. An exhaustive industry analysis entitled "The Future of Nuclear Power," written last year by 10 professors from the Massachusetts Institute of Technology and Harvard University, concludes that "hydrogen produced by electrolysis of water depends on low-cost nuclear power." As long as electricity from nuclear power costs more than electricity from other sources, using that energy to make hydrogen doesn't add up.
3. THE HYDROGEN ECONOMY CAN RUN ON RENEWABLE ENERGY
Perform electrolysis with renewable energy, such as solar or wind power, and you eliminate the pollution issues associated with fossil fuels and nuclear power. Trouble is, renewable sources can provide only a small fraction of the energy that will be required for a full-fledged hydrogen economy.
From 1998 to 2003, the generating capacity of wind power increased 28 percent in the U.S. to 6,374 megawatts, enough for roughly 1.6 million homes. The wind industry expects to meet 6 percent of the country's electricity needs by 2020. But economist Andrew Oswald of the University of Warwick in England calculates that converting every vehicle in the U.S. to hydrogen power would require the electricity output of a million wind turbines-enough to cover half of California. Solar panels would likewise require huge swaths of land.
Water is another limiting factor for hydrogen production, especially in the sunny regions most suitable for solar power. According to a study done by the World Resources Institute, a Washington, D.C."based nonprofit organization, fueling a hydrogen economy with electrolysis would require 4.2 trillion gallons of water annually-roughly the amount that flows over Niagara Falls every three months. Overall, U.S. water consumption would increase by about 10 percent.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.