'Major discovery' from MIT primed to unleash solar revolution
Scientists mimic essence of plants' energy storage system
Anne Trafton, News Office
July 31, 2008
http://web.mit.edu/newsoffice/2008/oxygen-0731.html
In a revolutionary leap that could transform solar power from a
marginal, boutique alternative into a mainstream energy source, MIT
researchers have overcome a major barrier to large-scale solar power:
storing energy for use when the sun doesn't ****ne.
Until now, solar power has been a daytime-only energy source, because
storing extra solar energy for later use is prohibitively expensive
and grossly inefficient. With today's announcement, MIT researchers
have hit upon a simple, inexpensive, highly efficient process for
storing solar energy.
Requiring nothing but abundant, non-toxic natural materials, this
discovery could unlock the most potent, carbon-free energy source of
all: the sun. "This is the nirvana of what we've been talking about
for years," said MIT's Daniel Nocera, the Henry Dreyfus Professor of
Energy at MIT and senior author of a paper describing the work in the
July 31 issue of Science. "Solar power has always been a limited,
far-off solution. Now we can seriously think about solar power as
unlimited and soon."
Inspired by the photosynthesis performed by plants, Nocera and Matthew
Kanan, a postdoctoral fellow in Nocera's lab, have developed an
unprecedented process that will allow the sun's energy to be used to
split water into hydrogen and oxygen gases. Later, the oxygen and
hydrogen may be recombined inside a fuel cell, creating carbon-free
electricity to power your house or your electric car, day or night.
The key component in Nocera and Kanan's new process is a new catalyst
that produces oxygen gas from water; another catalyst produces
valuable hydrogen gas. The new catalyst consists of cobalt metal,
phosphate and an electrode, placed in water. When electricity --
whether from a photovoltaic cell, a wind turbine or any other source
-- runs through the electrode, the cobalt and phosphate form a thin
film on the electrode, and oxygen gas is produced.
Combined with another catalyst, such as platinum, that can produce
hydrogen gas from water, the system can duplicate the water splitting
reaction that occurs during photosynthesis.
The new catalyst works at room temperature, in neutral pH water, and
it's easy to set up, Nocera said. "That's why I know this is going to
work. It's so easy to implement," he said. 'Giant leap' for clean
energy Sunlight has the greatest potential of any power source to
solve the world's energy problems, said Nocera. In one hour, enough
sunlight strikes the Earth to provide the entire planet's energy needs
for one year.
James Barber, a leader in the study of photosynthesis who was not
involved in this research, called the discovery by Nocera and Kanan a
"giant leap" toward generating clean, carbon-free energy on a massive
scale.
"This is a major discovery with enormous implications for the future
prosperity of humankind," said Barber, the Ernst Chain Professor of
Biochemistry at Imperial College London. "The im****tance of their
discovery cannot be overstated since it opens up the door for
developing new technologies for energy production thus reducing our
dependence for fossil fuels and addressing the global climate change
problem." 'Just the beginning' Currently available electrolyzers,
which split water with electricity and are often used industrially,
are not suited for artificial photosynthesis because they are very
expensive and require a highly basic (non-benign) environment that has
little to do with the conditions under which photosynthesis operates.
More engineering work needs to be done to integrate the new scientific
discovery into existing photovoltaic systems, but Nocera said he is
confident that such systems will become a reality.
"This is just the beginning," said Nocera, principal investigator for
the Solar Revolution Project funded by the Chesonis Family Foundation
and co-director of the Eni-MIT Solar Frontiers Center. "The scientific
community is really going to run with this."
Nocera hopes that within 10 years, homeowners will be able to power
their homes in daylight through photovoltaic cells, while using excess
solar energy to produce hydrogen and oxygen to power their own
household fuel cell. Electricity-by-wire from a central source could
be a thing of the past.
The project is part of the MIT Energy Initiative, a program designed
to help transform the global energy system to meet the needs of the
future and to help build a bridge to that future by improving today's
energy systems. MITEI Director Ernest Moniz, Cecil and Ida Green
Professor of Physics and Engineering Systems, noted that "this
discovery in the Nocera lab demonstrates that moving up the
transformation of our energy supply system to one based on renewables
will depend heavily on frontier basic science."
The success of the Nocera lab shows the impact of a mixture of funding
sources - governments, philanthropy, and industry. This project was
funded by the National Science Foundation and by the Chesonis Family
Foundation, which gave MIT $10 million this spring to launch the Solar
Revolution Project, with a goal to make the large scale deployment of
solar energy within 10 years.
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