July 23, 2014
Science Finds New Routes to Energy
Posted on Apr 17, 2014
By Tim Radford, Climate News Network
This piece first appeared at Climate News Network.
LONDON—While politicians posture, and climate scientists sigh sadly, researchers in laboratories continue to devise ingenious new ways to save energy, increase efficiency, and make the most of solar power.
Darren Drewry of the Jet Propulsion Laboratory in California and two colleagues from the University of Illinois have a computer model that could design soybean crops able to produce 8.5% more nourishment, use 13% less water and reflect 34% more sunlight back into space.
They report in the journal Global Change Biology that they can achieve all three goals by breeding for slightly different leaf distribution on the stalk, and for the angle at which the leaf grows, using a technique called numerical optimisation to try a very large number of structural traits to get the best results. “And surprisingly, there are combinations of these traits that can improve each of these goals at the same time,” says Dr Drewry.
In the great evolutionary challenge match, plants fight for the light and try to put each other in the shade. “Our crop plants reflect many millions of years in the wild under these competitive conditions,” said Stephen Long, a plant biologist. “In a crop field we want plants to share resources and conserve water and nutrients, so we have been looking at what leaf arrangements would best do this.”
Square, Site wide
They could reduce the canopy to let light through to lower levels to increase yield, or they could heighten the canopy to reflect light back into space and offset climate change.
“We can also model what these plant canopies can do in a future climate, so that it will be valid 40 or 50 years down the line,” says Praveen Kumar, an environmental engineer.
At Stanford University in California, other scientists have thought of a way to make biofuel without benefit of fields, plants or sunlight. They report in Nature that they have devised an oxide-derived copper catalyst that can turn carbon monoxide – the lethal gas in car exhausts and coal-burning power stations – directly into liquid ethanol of the sort now made from corn and other crops.
What’s more, they say, they can do this at room temperature and normal atmospheric pressures. The technique rests on the ability to turn copper oxide into a network of nanocrystals of metallic copper that would serve as a cathode in an electrolysis reaction and reduce carbon monoxide to ethanol.
Biofuel is expensive: it takes time, fields, fertiliser and water. It takes 800 gallons of water to grow a bushel of corn, which in turn yields three gallons of ethanol. The new technique could eliminate the crop, the time, and a lot of the water.
Ten-fold efficiency gain
And it opens another way to exploit captured CO2 as a power source. Carbon dioxide can be turned efficiently and easily into carbon monoxide. The new oxide-derived copper catalyst could then turn carbon monoxide into ethanol with ten times the efficiency of any normal copper catalysts.
The team would like to scale up their catalytic cell and see it powered by solar or wind energy. “But we have a lot more work to do to make a device that is practical,” said Matthew Kanan of Stanford.
Meanwhile, scientists in Oregon report in the Royal Society of Chemistry journal RSC Advances that they have tested a new way to tap the sun’s rays, and to use that power to make solar energy materials at the same time.
Once again, the match of nanoscience and copper has provided unexpected consequences. By focusing light continuously on a continuous flow micro-reactor, the researchers have synthesized copper indium nanoparticle inks that could make thin-film solar cells in minutes. Other processes might take hours to deliver the same materials.
“It could produce solar energy materials anywhere there’s an adequate solar resource and in this chemical manufacturing process, there would be zero energy impact,” said Chih-Hung Chang of Oregon State University.
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