Wednesday, May 23, 2012

Technology and Society--The Artificial Leaf

I was struck by an article in a recent New Yorker about a scientist who has invented what might be a solution to the energy needs of the second and third world (he calls them “the non-legacy world; the “first world” is the “legacy world). While his “artificial leaf” won’t recharge your Tesla roadster, it has the potential to make a huge difference to billions of people all over the world.  The following is an abstract from The New Yorker website, with a link to the full article.

The New Yorker: Dept. of Invention

The Artificial Leaf

Daniel Nocera’s vision for sustainable energy.

by David Owen May 14, 2012 

Daniel Nocera was a science-minded high-school junior in New Jersey at the beginning of the Arab oil embargo, in 1973. At the end of the decade, the Iranian revolution, followed closely by the outbreak of war between Iran and Iraq, precipitated a second oil crisis. By then, Nocera was a graduate student in chemistry at the California Institute of Technology. Within a short time, he had decided to devote his science career to energy.

Most of the energy we use comes from photosynthesis. Green plants store energy from the sun in certain chemical bonds, and we exploit that energy when we eat plants, or when we eat animals that have eaten plants, or when we burn either plants or substances ultimately derived from plants: firewood, peat, coal, oil, natural gas, ethanol.

Nocera decided in the early eighties that the chemistry of green plants was the likeliest place to seek an answer to civilization’s long-term energy difficulties. When the price of oil dropped in the mid-eighties, alternative-fuel research declined in popularity as an academic pursuit. But he persisted in his research, seeking a way to inexpensively replicate solar-energy conversion as performed by vegetation.

 At the 2011 national meeting of the American Chemical Society, Nocera announced a tangible breakthrough: a cheap, playing-card-size coated-silicon sheet that, when placed in a glass of tap water and exposed to sunlight, split the water into hydrogen and oxygen. The process that Nocera calls “artificial photosynthesis” could be described more precisely as solar-powered electrolysis of water: using energy from the sun to electrochemically split water into hydrogen and oxygen.

 Nocera isn’t the only scientist working on artificial photosynthesis. The field is at least four decades old, and interest in it has grown in recent years.  The article mentions the work of John Turner, a scientist at the National Renewable Energy Laboratory, which is funded by the Department of Energy. 

Owen visited Nocera’s lab at M.I.T. and discussed the challenges of adapting the artificial leaf for household use. Since the early eighties, Nocera has focused on providing energy for the world’s poorest people. “If there’s one thing that’s unique to the technology development I’ve done, it’s been doing science with the super-poor in mind.” His emphasis is largely humanitarian; it also arises from his belief, as a scientist, that the only way to meet the world’s projected energy needs without causing intolerable environmental harm will be to work, in effect, from the bottom up—an approach that’s very different from the ones that dominate energy research.

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