Monday 4 August 2008

Discovery uses solar power 24/7

Original Article

In what is being hailed as a major breakthrough in solar energy, researchers at the Massachusetts Institute of Technology have found a way to use the sun’s abundant, non-polluting rays as a power source even when the sun isn’t shining.

“What we’re doing allows you to use (solar panels) 24/7, because you can use the fuel that they generate any time you want,” said Daniel Nocera, MIT’s Henry Dreyfus Professor of Energy and one of two men behind the discovery.

As the world’s demand for energy has grown, scientists have long looked toward the sun as a source of free, clean power.

Yesterday, Nocera and MIT postdoctoral fellow Matthew Kanan unveiled a low-cost, highly efficient way to use the sun’s energy to split water into hydrogen and oxygen.

The technology then recombines the oxygen and hydrogen inside a fuel cell to create carbon-free electricity, which may be used, even after dark, to heat or power a home.

“This is a major discovery with enormous implications,” said energy expert James Barber of Imperial College London.

The key component in Nocera and Kanan’s discovery is a new catalyst that produces oxygen from water; another catalyst produces hydrogen.

The new catalyst consists of cobalt metal, phosphate and an electrode, placed in water.

When electricity 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 from water, the system can duplicate the water-splitting reaction that occurs during photosynthesis.

“It’s simple, easy to implement and cheap,” Nocera said.

He predicted that it could be household technology in 10 years.

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