Chemist Tries to Solve
World's Energy Woes
August 08, 2005 — By Brian Bergstein, Associated Press
CAMBRIDGE, Mass. — A U.S. chemist is
trying to determine how the world will produce enough energy to supply 9
billion people by mid-century -- and whether that can be done without
pumping off-the-charts amounts of carbon dioxide into the air.
Daniel Nocera, 48, is working to achieve an old, elusive dream: using
the bountiful energy in sunlight to split water into its basic
components, hydrogen and oxygen. The elements could then be used to
supply clean-running fuel cells or new kinds of machinery. Or the energy
created from the reaction itself, as atomic bonds are severed and
re-formed, might be harnessed and stored.
There is a beautiful model for this: photosynthesis. Sunlight kickstarts
a reaction in which leaves break down water and carbon dioxide and turn
them into oxygen and sugar, which plants use for fuel.
But plants developed this process over billions of years, and even so,
it's technically not that efficient. Nocera and other scientists are
trying to replicate that -- and perhaps improve on it -- in decades.
Hydrogen is the most abundant element in the universe, but it's
generally locked up in compounds with other elements. Currently, it is
chiefly harvested from fossil fuels, whose use is the main cause of
carbon dioxide emissions blamed for global warming.
And so while hydrogen fuel cells -- in which hydrogen and oxygen combine
to produce electricity and water -- have a green reputation, their
long-term promise could be limited unless the hydrogen they consume
comes from clean sources.
That's where Nocera's method comes in. If it works, it would be free of
carbon and the epitome of renewable, since it would be powered by the
sun. Enough energy from sunlight hits the earth every hour to supply the
world for months. The challenge is harnessing it and storing it
efficiently, which existing solar technologies do not do.
"This is nirvana in energy. This will make the problem go away," Nocera
said one morning in his office at the Massachusetts Institute of
Technology, where the Grateful Dead devotee has a "Mean People Suck"
sticker on his window. "If it doesn't, we will cease to exist as
humanity."
Lots of people have explored this challenge, but Nocera had a big
breakthrough when he used light to coax multiple hydrogen atoms out of
liquid. The key was figuring out the right chemical catalyst.
Nocera's 2001 paper on the process in the journal Science, written with
graduate student Alan Heyduk, turned heads. Venture capitalists rang his
phone off the hook offering to fund him in an alternative-energy
company.
The achievement, and its revolutionary prospects, won Nocera this year's
Italgas Prize, a $100,000 award given annually by an Italian utility to
a top energy researcher.
"Dan is even-money (odds) to solve this problem," says Harry Gray, a
renowned California Institute of Technology chemist who was Nocera's
graduate adviser.
But there's a catch. In fact, there's a few, and they illustrate how
hard it can be to move alternative energy beyond the proof-of-concept
phase.
Nocera has performed the reaction with acidic solutions, but not water
yet.
The catalyst he used was a compound that included the expensive metal
rhodium. To be a practical energy solution, it will have to be made from
inexpensive elements like iron, nickel or cobalt.
Nocera's reaction got the photons in light to free up hydrogen atoms,
but that's only half the equation. The harder part will be to also
capture the oxygen that emerges when water molecules are split. That
way, both elements can be fed into a fuel cell, making the process as
efficient as possible.
Nocera and scientists not affiliated with his work say those steps are
achievable. But first, major advances in basic chemistry will be
necessary for the reactions to be well understood.
As a result, Nocera believes it might be 20 years before engineers might
design systems based on his work. And he frets that too few scientists
are exploring the problem, with many top minds instead focused on
biomedical research.
"This is a massive construction project," he says. "You can go back to
building New York City in the '20s and '30s. You can't do it with just a
few construction workers. So I need more construction workers, more hard
hats, with me as a hard hat."
There's another big hurdle. While Nocera plugs away at trying to save
the world, some people don't believe it needs saving.
Most scientists concur that continuing to burn fossil fuels will send
the amount of carbon dioxide in the atmosphere -- it's now 35 percent
higher than in preindustrial times -- to dangerous levels, causing
global temperatures to rise with potentially devastating effects.
"We are literally poisoning ourselves," Nocera says. "People don't get
it because they can't see it."
But this is a famously politicized topic in the United States, where
some powerful political leaders question the science behind global
warming. And that, many scientists say, diverts attention and funds from
trying to solve the problem.
And even among people who believe global warming's risks are too great
to ignore, there is no consensus on what kind of green energy should
come to the rescue.
Nocera cites a calculation by Caltech chemist Nathan Lewis that power
demands in 2050 will be so great that just to keep carbon dioxide
emissions at twice preindustrial levels, a nuclear plant would have to
be built every two days. There's not enough room on the planet's surface
for other widely touted solutions such as wind and biomass to have much
impact.
Only the sun is the answer, Lewis argues.
Critics of that vision say many energy technologies being explored --
including improved ways of storing electricity and different kinds of
fuel cells -- will come online in the next few decades and throw off
today's extrapolations about the future.
Arno Penzias, who won the Nobel Prize for confirming the Big Bang and
now invests in alternative energy startups for New Enterprise
Associates, contends there are dozens of ideas more promising than ones
involving hydrogen.
When told about Nocera's project, Penzias gets heated, saying it is
unlikely to be practical.
"It is so far from being revolutionary that it's not even worth
mentioning," Penzias says. "It will be a big yawn."
Nocera seems to thrive on such opposition, because he expects to prove
naysayers wrong.
It's part of his blunt enthusiasm, which manifests itself when he
discusses the joys of teaching chemistry to freshmen ("They love me") or
when he meets with his grad students to discuss the status of their
research.
Those sessions often devolve into arguments over the meaning of some
data or the direction that projects ought to take. Provoked by Nocera's
intensity -- he'll exclaim, "I'm dying here!" in a tone resembling
neurotic comic Larry David -- tempers often rise.
One student recently threw an eraser at Nocera, leaving a pink welt on
his back that Nocera later showed off with a laugh.
"There were times I absolutely hated working for him, because he knew
how to press all of my buttons and drive me absolutely insane," says
Heyduk, now assistant professor of chemistry at the University of
California, Irvine. "He knew I was the kind of person that needed to be
challenged all the time."
Nocera believes this constant prodding at what's possible is the essence
of science. As evidence, he reels off several ancillary developments
from his research, including microscopic sensors that detect biological
hazards, which attracted funding from the Defense Advanced Research
Projects Agency.
Pointing to a whiteboard sketch of his vision for using sunlight to
split water, Nocera acknowledges that it ultimately might not be an
energy panacea.
"Is it right? Maybe not. But it will be something. And it might be
something I can't see right now," he says. "That's OK. But you don't
stop doing something because you can't see it. It's antiscientific. It's
anti-intellectual."
Source: Associated Press |