Solar Power Energy Breakthrough

Solar Power Energy Breakthrough



August, 2008 - Within 10 years,

homeowners could power their homes in daylight with solar photovoltaic

cells, while using excess solar energy to produce hydrogen and oxygen from

water to power a household fuel cell. If the new process developed at the

Massachusetts Institute of Technology finds acceptance in the marketplace,

electricity-by-wire from a central source could be a thing of the past.

"This is the nirvana of what we've been talking about for years," said

MIT's Daniel Nocera, senior author of a paper describing the simple,

inexpive, and efficient process for storing solar energy in the July 31

issue of the journal "Science."

"Solar power has always been a limited, far-off solution. Now we can

seriously think about solar power as unlimited and soon," Nocera said.

Until now, solar power has been a daytime-only energy source, because

storing extra solar energy for later use is expive and inefficient. But

Nocera and his team of researchers have hit upon an elegant solution.



Inspired by the photosynthesis performed by plants, Nocera and Matthew

Kanan, a postdoctoral fellow in Nocera's lab, have developed a new process

that will allow the Sun's energy to be used to split water into hydrogen

and oxygen gases.

Later, the oxygen and hydrogen can be recombined inside a fuel cell,

creating carbon-free electricity to power buildings, homes or electric

cars - day or night.

The key component in the 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 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 in plants during photosynthesis.

The new catalyst works at room temperature, in neutral pH water, and is

easy to set up, Nocera said. "That's why I know this is going to work.

It's so easy to implement," he said.

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 op up the door for developing

new technologies for energy production thus reducing our dependence for

fossil fuels and addressing the global climate change problem."

Currently available electrolyzers, which split water with electricity and

are often used industrially, are not suited for artificial photosynthesis

because they are very expive and require an 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."

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 said, "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."


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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