Home' Technology Review : July August 2007 Contents Q&A
TECHNOLOGY REVIEW /
George Whitesides is a chemist
with a knack for translating
lab discoveries into things the
world nds useful. He has cofounded
numerous companies, including the
biotech giant Genzyme. In the late
1980s and 1990s, Whitesides, a
professor of chemistry at Har vard
University, helped make possible
today s nanotechnology boom by
demonstrating the possibility of
engineering molecules that self-
assemble into ordered materials. Now
he is turning his attention to nding
solutions to today s energy crisis.
Gleaning new insights from funda-
mental chemistry, he says, will be
crucial to meeting energy needs and
cutting increases in greenhouse-gas
emissions. TR s nanotechnology and
materials science editor, Kevin Bullis,
visited Whitesides in his Har vard
o ce to ask how chemistry can help.
TR: Why is chemistry central to energy?
Whitesides: Wind power is just
wind powering a turbine. With
nuclear, the actual power genera-
tion of course comes from the dis-
integration of the nucleus, which is
a physics event instead of a chemis-
try event. But essentially, everything
else is chemistry. You take fuel and
you burn it, and that s chemistry.
When you run a battery, various ele-
ments change their oxidation state,
and that s chemistry. Even in the pro-
cess of making a solar cell, the cru-
cial steps are largely chemistry. From
a ame to a battery to a solar cell,
the cr ucial elements are chemical.
What are our options for cutting
down on carbon emissions while
meeting our vast energy needs?
If the only issue were supply, we
could burn a lot of coal and build lots
of nuclear plants, and at least in the
United States, for the foreseeable
future we could have a fair amount
of [energy] supply. Because of cli-
mate changes, it s not just a question
of producing energy. It s a question
of producing energy in a way that
we can live with in the long term.
If you look at the available pieces,
from conservation to nuclear, solar,
whatever, and you put them all
together, we can t do it. We have to
do something di erently, and we
have to come up with new ideas.
This is not just an engineering
problem of taking things that we
know and applying them better.
How can basic chemistry
There s a lot of enthusiasm right
now for photosynthesis as a method
of both xing carbon and harvest-
ing sunlight in the form of plant mat-
ter, whether it s plant oils that can be
converted into biodiesel or biomass
that s somehow converted into buta-
nol or ethanol. Those processes are
a long way from being as e cient as
they might be. If we could nd a way
to dramatically improve the e ciency
of photosynthesis, that could be inter-
esting. Can we look at the enzymes
that are involved---the catalysts---and
tinker with them, readjust them so
that they become more e cient?
We understand many of the
pieces of the overall process of going
from sunlight and carbon diox-
ide and water to carbohydrates, but
there s a lot that we don t under-
stand. To reëngineer photosynthe-
sis, we rst have to understand it.
But relying heavily on biofuels could
have unintended effects, such as rais-
ing food prices. Unless we under-
stand the overall system, the things
we try to do to make things better ...
... can make things worse.
Cellulosic ethanol has some
good features. But it has all sorts of
problems. We don t know what the
energy costs are of doing this. You
need some energy to collect the stu ,
and to do the processing and to dis-
till the uids. There s the question
of whether we really can make large
quantities of it. It s seasonal. You
can only do it in parts of the coun-
try. You have to then think about tak-
ing this relatively low-energy thing,
biomass, and collecting it to a central
processing station. You can t a ord
to ship this stu over large distances,
which means the processing plants
are small and intrinsically ine -
cient for large-scale production. And
should we think of topsoil in Iowa
as a renewable or a nonrenewable
resource? We think about the prob-
lem of depleting petroleum reser-
voirs, but what about the problem
of depleting Iowa topsoil? We don t
know how this set of energy tech-
nologies all ts together. How do
we do agricultural energy produc-
tion, and how do we think about
agricultural land overall---for exam-
ple, the competition of energy
with food production, and just the
mere fact that the soil can wear
out if it s not managed correctly?
So what is the solution?
We need long-term investment.
We need new ideas. We need a cadre
of young people to work on it. This is
not a Manhattan Project. It s not
something in which we have a single
engineering objective and if we can
solve that, the mission is accom-
plished. It s going to have a large
number of components: Understand-
ing photosynthesis. Understanding
how to most e ciently make solar
cells. Making hydrocarbon-fuel
combustion more e cient. Making
energy transmission more e cient.
Understanding how the pieces work
together so that if we do this, we
know we re not actually going to
make the situation worse.
The chemistry of energy
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