[tt] 'Major discovery' from MIT primed to unleash solar revolution - MIT News Office

[Brian Atkins]

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 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.

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.

-- 
Brian Atkins
Singularity Institute for Artificial Intelligence
http://www.singinst.org/