Are hydrogen, ethanol or electricity on track to replace fossil fuels? Major challenges remain. By Jim Motavalli
Hydrogen
Fuel-cell vehicles run on hydrogen gas, the most abundant element in the universe. The fuel cell, which chemically converts hydrogen to electricity (with water as a byproduct), has the potential to eventually replace the internal-combustion engine, because it's far more than just the best environmental choice. The reason the auto industry is spending billions of dollars on fuel cells is because it sees the potential for a much better car than internal combustion can deliver, with improved performance, fuel economy, range and emissions, too.
The most optimistic predictions see us driving fuel-cell cars by 2015 or 2020, though skeptics such as Joseph Romm, author of The Hype About Hydrogen (Island Press), think it might take longer. General Motors has said it will have a production-ready fuel-cell vehicle in place by 2010. Honda is a significant contender in the fuel-cell race, and has made the most progress with cold starting and general drivability. Honda has lent its FCX fuel-cell vehicles to journalists and to average drivers as part of a testing program. The next generation of the FCX will reportedly have a 340-mile range.
Environmentalists such as Amory Lovins, head of the Rocky Mountain Institute, have long predicted that the world will eventually have a hydrogen energy economy, but in recent years the chorus has grown to include many people at high levels of government and industry. A hydrogen economy will abandon internal-combustion engines completely, and it will also eventually replace the electric grid to your house, and even your flashlight and computer batteries.
Ethanol
The supply of corn-derived ethanol, also known as ethyl alcohol or grain alcohol, is increasing rapidly, from 2.1 billion gallons in 2002 to 3.4 billion gallons in 2004. In early 2005, there were 81 ethanol plants in 20 states, with an additional 16 under construction. Ethanol is used both as an alternative fuel and as an octane-boosting, pollution-reducing additive to gasoline.
Traditional ethanol production from corn has not had a stellar track record. Congress routinely awards large subsidies and tax breaks for ethanol production, but its interest seems more to appease farm state voters and agribusiness than to provide an alternative to imported oil. Most "bi-fuel" vehicles equipped to run on ethanol (and receiving tax credits to do so) usually run on gasoline because ethanol infrastructure is lacking. Senator Charles Schumer (D-NY) describes the energy bill provision requiring ethanol content in gasoline “nothing less than an ethanol tax levied on every driver” and a “boondoggle.”
The U.S. is a major corn producer, so could corn-based ethanol take over from gasoline as the mainline fuel for transportation? Hardly. Cornell economist David Pimentel says we’d have to devote nearly all our farmland to the cause if we wanted to produce enough grain-based ethanol to power the economy. And corn ethanol is notoriously energy-intensive to produce, though the American Coalition for Ethanol denounces as “outrageous” the accusation that it actually has a negative energy balance.
Some environmentalists champion so-called cellulosic ethanol, which could be made from agricultural, municipal and forestry waste, including corn stalks, sawdust or waste paper. “Not quite lead into gold, but maybe more valuable for the U.S. economy, for cutting air pollution, and for reducing dependence on foreign oil,” says the Department of Energy.
Technical breakthroughs have made large-scale cellulosic ethanol production feasible at a reported 60 to 80 cents per gallon. According to Washington Monthly, “An estimate by the consulting firm Burrill Company [predicts that] if the waste products of all American farms were converted into cellulosic ethanol (a long-term, best-case scenario to be sure) it would provide 25% of all the energy needed to run our transportation system -- about the same percentage which we import today from Venezuela and the Persian Gulf combined.”
Focusing on the “feedstock,” or raw material, may be missing the point, says Sarah Hessenflow Harper, a national security and climate security analyst at Environmental Defense. Harper says what we need are energy-efficiency and low-carbon standards that any bio-fuel would have to meet to win certification (like the organic standards for agriculture). “The current market assigns no value to reducing carbon,” she says, “so there’s no incentive to develop an energy-efficient version of ethanol. If we send the right market signal, then technological development will evolve to meet the new standard.”
Electric Vehicles
There are currently no generally available battery-powered cars on the U.S. market, and any electric vehicle (EV) enthusiast will eventually be forced to admit that 90-mile cruising ranges have failed to convince most Americans to sign up to plug in. It’s the batteries, stupid. Today, some EV supporters have turned to the so-called plug-in hybrid (a Toyota Prius with an extra battery pack) as a workable compromise.
According to Dontcrush.com, which led a successful campaign to stop Toyota from, yes, crushing its fleet of 1,000 battery-powered RAV4 EVs, “The cost of plugging in to the grid and charging up at home is the equivalent of pennies per gallon on the average electric bill as compared to $3-plus a gallon at the pump today….With a plug-in hybrid, which uses a battery-powered electric motor for the first 30 to 50 miles, most American commuters would rarely if ever need to fill up or even top off with gasoline unless making a long trip. Since 50% of Americans do not drive more than 20 miles per day, the electric range of a plug-in hybrid would power nearly all of our daily driving.”
But pure battery cars face challenges. On the ground, nickel-metal-hydride (NiMH) batteries of the type seen in hybrid vehicles are still expensive and in short supply. Many EV models still rely on heavy and inefficient lead-acid batteries. Lithium-ion (Li-Ion) batteries show great promise and, combined with a lightweight composite body shell, could presumably give EVs a 300-mile-plus range. But very few have been seen in vehicles yet.
The EVs that are on the market are low-volume and highly specialized. One example of the latter is the Tango, an odd-looking (very narrow) electric hot rod capable of reaching 60 mph in four seconds (but with a range of only 80 miles). Actor George Clooney has a Tango, but they seem a long way from cost-effective commuter transportation.
MIT battery researcher Donald Sadoway thinks that the performance of Li-ion batteries can be greatly improved using solid-state technology (no liquid). His concept uses multilayered thin-film laminates. “You’re looking at something that’s similar to a potato chip bag: a polymer web coated with a different layer of chemistry,” he says. “We can make that by the square mile -- it’s not difficult to do. We’re talking about a doubling or tripling of the capacity of today’s batteries.”
A battery breakthrough would make all the difference. Until then, EVs are likely to remain in limbo.
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This article has been reprinted courtesy of E/The Environmental Magazine. It first appeared in the January-February 2006 issue of that publication.
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