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| Macro of Wet Leaf (Photo credit: Wikipedia) |
General Electric is promoting a feel-good collection of videos these days.
Each film chronicles an innovative idea, like Daniel Nocera’s. This Harvard chemist has pioneered the artificial leaf, an invention that generates energy the way a tree does. Light strikes a container of water and out bubbles hydrogen, an energy source.
The short film about his idea has Mr. Nocera saying that his device will one day be in people’s homes, pumping out energy.
“Close your eyes,” he says, and “think about your house being its own power station.”
Such artificial-leaf optimism could also be found a year ago in a Los Angeles Times article that held the artificial leaf “could create enough clean fuel to power a home for a day in developing countries.” And the year before that, in The New Yorker. Or go back one more year, to The New York Times, where Mr. Nocera said, “Our goal is to make each home its own power station.”
So, where are the power stations?
Prowl the edges of contemporary invention, and you experience a lot of this frustration. A scientist announces a breakthrough in battery technology or algae biofuel, and the talk ramps up quickly.
But there always seems to be an obstacle between the big idea and self-sufficiency. Sometimes, it’s the idea itself – a technological bug that seems fixable turns out to be weird and inscrutable. But in this case, the technology is sound, say researchers including David Tiede of the Argonne National Laboratory in Chicago.
Mr. Nocera’s idea is based on Photosynthesis. When light bombards a leaf, it splits water in the leaf into oxygen, and then binds the hydrogen with carbon dioxide to make carbohydrates, its food.
Mr. Nocera’s leaf mimics this process. A vessel of water is exposed to light. A silicon strip coated in catalysts breaks down the water molecule such that on one side oxygen bubbles up, and on the other, hydrogen, which can be used as a fuel.
The issue isn’t the invention – it’s how to use it.
“If I give you a canister of hydrogen that we got from the artificial leaf, you can’t use it right away,”
Mr. Nocera said.
You need a fuel cell, which can turn hydrogen into electricity.
There are efforts to begin incorporating such energy technology into daily life, such as the development of hydrogen-powered cars.
“If we had fuel cells in your house and your car, then everybody would be trying to implement the artificial leaf right now,” Mr. Nocera said.
The other obstacle is the market place.
A few years ago, he was asked to produce the energy equivalent of a gallon (3.78 liters) of gasoline and keep costs around $3. As he neared that number, the fossil-fuel industry upset his plans with a surge in cheap natural-gas extraction, driven by hydraulic fracturing or fracking.
But therein lies a glimmer of hope. Hydrogen can be produced by fracking, but it comes at a cost of carbon pollution. Still, widespread fracking might lead to widespread hydrogen use.
“Fracking could drive the establishment of an infrastructure for using hydrogen at the home,” Mr. Nocera said. “And then the next thing everybody might say is, yeah, but that hydrogen is making CO2. Then the artificial leaf would show up.”
Unable to resist, he said, “Your house will be its own gas station.”
Taken from TODAY Saturday Edition, April 12, 2014
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