Web address:
http://www.sciencedaily.com/releases/2008/07/080731143345.htm
'Major
Discovery' Primed To Unleash Solar Revolution: Scientists Mimic Essence Of
Plants' Energy Storage System
ScienceDaily (Aug. 1, 2008) —
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 shine.
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 importance 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.
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.
Adapted from
materials provided by Massachusetts Institute of Technology,
via EurekAlert!,
a service of AAAS.
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Massachusetts
Institute of Technology (2008, August 1). 'Major Discovery' Primed To Unleash
Solar Revolution: Scientists Mimic Essence Of Plants' Energy Storage System. ScienceDaily.
Retrieved August 2, 2008, from
http://www.sciencedaily.com/releases/2008/07/080731143345.htm