Will Hydrogen Clear the Air? Maybe Not, Say Some
November 12, 2003 By MATTHEW L. WALD
WASHINGTON, Nov. 11 - Widespread hydrogen use has been
enthusiastically embraced by major corporations and
environmentalists alike as a panacea for global warming and
the depletion of fossil fuels, and is a particular favorite
of the Bush administration. But skeptics, and even some
hydrogen advocates, say that use of hydrogen could instead
make the air dirtier and the globe warmer.
Next week, the Bush administration is convening a meeting
of the energy ministers of 15 countries to Washington for a
four-day meeting with the theme of an "International
Partnership for the Hydrogen Economy." President Bush
himself pledged in the State of the Union address in
January that "the first car driven by a child born today
could be powered by hydrogen, and pollution-free."
Use of hydrogen fuel cells could certainly help eliminate
tailpipe pollution and dependence on foreign oil. But
hydrogen is only a way to store energy. Where the energy
comes from in the first place is where the problems start.
The most ambitious use of hydrogen is in a car powered by
a fuel cell - a batterylike device that turns hydrogen into
electricity while emitting only heat and water vapor.
Hydrogen can also be burned directly in engines much like
those that run on gasoline, but the Energy Department goal
is fuel cells because they get twice as much work out of a
pound of hydrogen.
Intense research is now going on at major companies and
universities in North America on the development of a
practical fuel cell. Success could have a profound effect
on the 200 million motor vehicles in use in the United
States, making the streets cleaner and quieter, with
hydrogen-powered electric motors. The transition to
hydrogen could also wean the country away from gasoline and
The main source for hydrogen today is natural gas, which is
in short supply, is cumbersome to convert, and may have
better uses. Waiting in the wings is coal, burned in old
power plants around the country that are already the focus
of a national dispute over their emissions. Coal is cheap
and abundant, and produced by major companies that are
eager to continue mining and using it. But it is a leading
source of carbon dioxide, an important global warming gas,
and pollutants that cause more immediate problems, like
smog and acid rain.
"Even though fuel cells are great devices, you can still do
unwise things with them," Patrick B. Davis, a team leader
in the Energy Department's fuel cell program, told a recent
meeting of experts at the University of South Carolina
examining the engineering challenges.
The long-term hope is to make hydrogen from emission-free
"renewable" technologies, like windmills or solar cells. In
fact, hydrogen may be an essential step to translate the
energy of wind or sunlight into power to turn a car's
wheels, experts say. But electricity from renewable
technologies is so costly that even companies based on
these technologies see problems.
At Sharp Solar, which says it is the world's largest
manufacturer of solar cells, Ronald Kenedi, the general
manager, said that it was entirely possible that the energy
source to produce hydrogen for vehicles would initially
turn out to be coal, rather than the sun or wind. "That is
the danger," he said in a telephone interview. "It seems
like hydrogen is the buzz word right now, with the
president talking about it, and maybe putting some money
towards it," he said. "But the first stop on the hydrogen
trail will be coal."
For now the government is mostly glossing over the problem.
A strategy document published by the Energy Department in
November, 2002, the "National Hydrogen Energy Roadmap,"
suggests marketing the idea of hydrogen to the public as
the "freedom fuel." Another suggested theme was "Hydrogen
is everywhere - it's right in our backyard."
"Hydrogen," the department said, "is the 'man on the moon'
equivalent for this generation." In fact, the latter
analogy might prove apt, with hydrogen fuel cells
resembling the Apollo rockets, as an impressive technology
that was made workable and repeatedly demonstrated, but not
capable of making major inroads into general use.
For now, fuel cells are about 100 times as expensive, per
unit of power, as internal combustion engines.
A likely source of hydrogen is from a machine called an
electrolyzer, which is like a fuel cell in reverse. The
difference is that a fuel cell combines oxygen from the air
with hydrogen to produce an electric current, and water as
a byproduct; an electrolyzer runs an electric current
through water, to split the water molecule into its
constituent hydrogen and oxygen atoms.
The problem is that if the electricity came off the power
grid to run an electrolyzer for the production of hydrogen,
about half of it, on average, would be generated by burning
From an entrepreneur's point of view, coal has a tremendous
advantage. At Proton Energy, a Connecticut company that
builds the electrolyzing machines that use current to
produce hydrogen, Walter Schroeder, president and chief
executive, laid out the problem in terms of dollars per
million B.T.U.'s, a standard quantity of heat in the fuel
At $20 a ton, he pointed out, a million B.T.U.'s of heat
from coal costs roughly 82 cents. At $1.75 a gallon for
unleaded regular gasoline, the price per million B.T.U.'s
is $15.40. To use coal to run cars, the coal has to be
converted into electricity, then into hydrogen, then back
into electricity in the car, all of which costs money. But
Mr. Schroeder is betting that his system can do that for a
lot less than the difference between $15.40 and 82 cents.
The president's proposal contained an implicit recognition
that a big part of the fuel cell question is the fuel, not
the conversion device. He called for spending $1.7 billion
over five years, with $1.2 billion of that on hydrogen,
including production, delivery and storage.
Another problem is carbon dioxide, a greenhouse gas.
According to the Energy Department, an ordinary
gasoline-powered car emits 374 grams of carbon dioxide per
mile it is driven, counting the energy used to make the
gasoline and deliver it to the service station, and the
emissions of the vehicle itself. The same car powered by a
fuel cell would emit nothing, but if the energy required to
make the hydrogen came from the electric grid, the
emissions would be 436 grams per mile, 17 percent worse
than the figure for gasoline.
The car would emit no nitrogen oxides, a precursor of smog,
but the power plant would; exactly how much is now the
subject of a national debate.
Hydrogen is commonly manufactured today at refineries and
chemical plants, by mixing natural gas and steam. Natural
gas is made of hydrogen and carbon atoms; steam is made of
hydrogen and oxygen atoms. The reaction, called steam
reforming, produces hydrogen and carbon dioxide.
According to the energy department, if fuel cells in cars
used hydrogen from steam reforming of natural gas, cars
would emit 145 grams of global warming gases per mile. That
is a drastic improvement over the 436 grams emitted by the
production of hydrogen using grid electricity, and a major
improvement over gasoline's 374 grams, but experts say it
may not be a particularly good use of natural gas.
One reason is that if the engineers had simply replaced the
gasoline with the natural gas, skipping the hydrogen fuel
cell step in between, the total carbon dioxide emissions
per mile would fall to 310 grams, according to the Energy
Department. No new technology is required for that step;
buses burning natural gas in internal combustion engines
are common today.
And there is a second option that involves hardly any new
technology, hybridization. In a hybrid, a fossil-fueled
internal combustion engine can turn the wheels or a
generator that is used to charge batteries, and the
batteries run an electric motor to drive the wheels. The
Toyota Prius and the Honda Insight use that system.
Hybridization improves the fuel economy of the Honda Civic
by 43 percent, according to the company. So replacing a
gasoline car with a hybrid electric fueled by natural gas
would cut the grams of global warming gases to about 177 a
That still leaves the fuel cell that runs on hydrogen from
natural gas with an advantage over the typical hybrid of
about a fifth, or a further reduction of about 32 grams of
global warming gases per mile. But the fuel cell bus is
many times more expensive than an ordinary or hybrid bus,
and the fuel costs several times as much as diesel. And the
natural gas hybrid solution is available almost
immediately; it would be many years before fuel cell buses
made a substantial debut.
Reuel Shinnar, a professor of chemical engineering at City
College of New York, reviewing the options for power
production and fuel production, concluded in a recent
paper, "A hydrogen economy is at least twice as expensive
as any other solution."
Supporters of fuel cell cars say that hydrogen can be made
from almost anything, including hydropower, new nuclear
reactors, and technologies barely dreamed of, like microbes
that will produce hydrogen from waste materials, and that
this justifies the research even if early batches of
hydrogen come from coal.
"The mantra is, we don't choose now," said William Craven,
manager, regulatory and technical affairs at the
DaimlerChrysler Corporation. When it comes to hydrogen
production he said, the trick at this stage is to "keep the
But some parts of the portfolio are more environmentally
beneficial than others. Dan W. Reicher, a former assistant
secretary of energy for conservation and renewables, who
now manages a fund that invests in companies that produce
energy from renewable sources, put it this way: "Not all
hydrogen is created equal."