LOS ANGELES — Remember the hydrogen car?
A decade ago, President George W. Bush espoused the environmental promise of cars running on hydrogen, the universe's most abundant element. "The first car driven by a child born today," he said in his 2003 State of the Union speech, "could be powered by hydrogen, and pollution-free."
That changed under Steven Chu, the Nobel Prize-winning physicist who was President Obama's first Secretary of Energy. "We asked ourselves, 'Is it likely in the next 10 or 15, 20 years that we will convert to a hydrogen-car economy?'" Dr. Chu said then. "The answer, we felt, was 'no.' " The administration slashed funding for hydrogen fuel cell research.
Attention shifted to battery electric vehicles, particularly those made by the headline-grabbing Tesla Motors.
Graphic | Hydrogen Powered
The hydrogen car, it appeared, had died. And many did not mourn its passing, particularly those who regarded the auto companies' interest in hydrogen technology as a stunt to signal that they cared about the environment while selling millions of highly profitable gas guzzlers.
Except the companies, including General Motors, Honda, Toyota, Daimler and Hyundai, persisted.
After many years and billions of dollars of research and development, hydrogen cars are headed to the showrooms.
Hyundai has been leasing the hydrogen-powered Tucson sport utility, which it describes as the world's first mass-produced fuel cell car, since June, for a $2,999 down payment, and $499 a month. (That includes the hydrogen. A lease on a gas-powered Tucson is about half as much.) This week, Toyota is introducing a sedan called Mirai, which means "future" in Japanese.
"It's a no-brainer that I think the next evolution is to go to fuel-cell based technologies," said Nihar Patel, the vice president for North American business strategy at Toyota, at a conference here last week.
The Mirai will go on sale in California this year for $57,500 — cheaper than the Tesla Model S.
California is spending millions of dollars to build hydrogen fueling stations, aiming to increase the network from nine today to 50 by the end of next year, mostly around Los Angeles and the San Francisco Bay Area. Japan and Germany, two other early markets for hydrogen cars, are building a similar number of stations.
"We really believe that we're at a turning point here," Mr. Patel said.
The combustion of one gallon of gasoline releases almost 20 pounds of carbon dioxide. In 2012, some 1.8 billion tons of carbon dioxide were discharged by cars and trucks in the United States, or more than a quarter of the nation's greenhouse gas emissions. Concerns about climate change are intensifying discussions about alternatives to gasoline and diesel engines.
Battery electric cars and fuel cell cars are, at their cores, both electric cars with the inherent advantages of electric motors — jack rabbit acceleration, near silence and zero tailpipe emissions of greenhouse gases.
The difference is where the electricity comes from.
Instead of storing their charge in batteries, the fuel cells in hydrogen cars are miniature power plants, generating a flow of electricity in the chemical reaction of combining hydrogen and oxygen into water. The oxygen comes from the air; the hydrogen, compressed at 10,000 pounds per square inch, is stored in tanks.
The exhaust from the tailpipe? Water that is clean enough to drink.
Toyota officials talk of selling a "portfolio" of vehicles that includes hybrids and battery electric cars. But hydrogen fuel cells are front and center.
Not surprisingly, the strategy has its critics, particularly from competing Tesla. Elon Musk, the billionaire chief executive of Tesla, mocks fuel cells as "fool cells" that will lose in the marketplace to battery electric cars like his. Battery electrics are more efficient than fuel cells and are cheaper to operate. And there are currently many more places to plug in than places to top off a tank of hydrogen.
But battery electric cars have major technological shortcomings, too. They take time to recharge, they do not go as far as hydrogen cars between refueling, and the batteries required for larger vehicles make building them impractical, because the current lithium-ion batteries simply cannot hold enough energy to take larger vehicles over longer distances.
In California, Toyota sells an electric Rav4 sport utility vehicle that is powered by Tesla batteries and has a range of only 103 miles. That collaboration was limited to 2,600 vehicles and ends this year.
After a point, adding more batteries has diminishing returns; the additional power just goes to lugging the additional weight.
That is why most battery electric cars have been small, like the Nissan Leaf, aimed at commuters. For batteries to be practical in minivans, pickup trucks and larger S.U.V.s, "the next chemistry has to be better," said Craig Scott, the manager of advanced technologies at Toyota USA. "No one even knows what that chemistry is."
Hydrogen fuel cells readily scale up, even to trucks and buses.
A kilogram of hydrogen contains as much chemical energy as a gallon of gasoline, but fuel cells are more efficient than internal combustion engines, so fuel-cell cars like the Mirai have a 300-mile range, comparable to present-day gasoline cars. Filling up at a hydrogen pump takes about the same few minutes as filling a tank of gas, instead of hours plugged in to an outlet. Even Tesla's high-powered superchargers need 20 minutes to give a Model S half a charge.
"It's the technology that lets people act the way they normally drive without making any compromises," Mr. Scott said.
The questions surrounding hydrogen fuel cells have always been "How expensive?" and "Where does the hydrogen come from?"
Building a fuel cell small enough to fit in a car, operate for years and not cost a million dollars posed challenges that the carmakers say they have conquered.
A fleet of 119 fuel cell-powered Chevrolet Equinoxes that General Motors introduced as a demonstration project in 2007 has covered more than three million miles, with the odometers on some of the vehicles passing 120,000 miles.
"Since 2010, we've gotten to where we've checked off most of the technological challenges," said Charles E. Freese, the head of G.M.'s fuel cell efforts.
The cost has come down, too, in large part from reducing the amount of expensive platinum required. The platinum is used as a catalyst to bring the oxygen and hydrogen together.
Mr. Patel said the fuel cell in the Toyota Mirai was smaller than the previous generation and 95 percent cheaper.
Nonetheless, Toyota likely will lose money on each Mirai it sells, but it also initially lost money on the Prius, its now-successful electric-gasoline hybrid.
The fuel-cell market will start small. Toyota said it could build 700 Mirais next year. Hyundai said its production line has the capacity to build a few hundred fuel-cell Tucsons a year. About 60 Tucsons will be leased in Southern California by the end of the year.
As economies of scale grow and the technologies improve, the hope is that fuel cell cars will follow the trajectory of the Prius, which evolved from a money-losing oddball to a profitable mainstream offering. "If that's an example of a test, we want to repeat that test going forward," Mr. Patel said.
Some of the most vociferous objections to hydrogen cars have been made over environmental concerns.
In an interview with MIT Technology Review in 2009, Dr. Chu said fuel cell cars needed "four miracles," including an economical, renewable source of hydrogen. Most hydrogen today comes from stripping hydrogen atoms off natural gas molecules. That produces carbon dioxide as a byproduct and undercuts the goal of reducing greenhouse gases. Solar-powered electrolyzers to split water into hydrogen and oxygen would eliminate greenhouse gases but would be more expensive.
Hydrogen advocates say that in California, where a large percentage of electricity already comes from solar and wind, hydrogen cars would help reduce greenhouse gas emissions. But electric-battery supporters dispute that analysis and say bigger gains would come from putting the electricity directly into batteries.
Skeptics also doubt that billions of dollars would be spent building a nationwide hydrogen infrastructure.
Dr. Chu, now a professor at Stanford University, is still among the skeptics — he, like Mr. Musk, sees electric batteries as the more promising path. But he said advances in solar and wind technologies made producing hydrogen by splitting water more economical. "I began to see more possibilities of clean hydrogen production," he said in an interview last month.
Other technologies could emerge, too. A hydrogen station in Fountain Valley, about 45 minutes from downtown Los Angeles, is in front of a wastewater treatment plant, because the hydrogen comes from human waste.
After bacteria digest what has been flushed down toilets to produce a mix of carbon dioxide and methane, the gases are cleaned up and fed to a different type of fuel cell that produces electricity, heat and hydrogen, and the hydrogen is piped to the pump.
That demonstration project, producing about 200 pounds of hydrogen a day, helps fulfill California's mandate that a third of the hydrogen for cars come from renewable sources.
Scott Samuelsen, the director of the National Fuel Cell Research Center at the University of California, Irvine, said some drivers reported, given the cycle of human waste to energy, "There is something comforting about fueling here, that they are actually contributing to the fuel."
Source : http://www.nytimes.com/2014/11/18/science/earth/hydrogen-cars-join-electric-models-in-showrooms.html
