Move over trees. Here comes the sun

UNC-CHAPEL HILL (US) — It’s time to take the middle men—the plants—out of the solar energy equation. A new area of energy research called artificial photosynthesis aims to do just that by overcoming one of the biggest obstacles in solar power: energy storage.

Artificial photosynthesis uses sunlight to create potential fuel sources, such as oxygen and hydrogen from wastewater or even hydrocarbons like methane from water and carbon dioxide.

Tom Meyer, the Arey Distinguished Professor of Chemistry at the University of North Carolina at Chapel Hill, says if the approach is successful we won’t need to rely on trees for what’s known in scientific circles as “solar fuel production from biomass”—the age-old method humans have used for their energy supply since pre-historic times: burning wood.

“Sunlight helps grow trees. People burn wood, a form of fuel, to generate energy. For eons, firewood has been the only option we’ve had for being able to ‘store’ solar energy until we need to use it.” Meyers says.

“The main problem with current solar power technology is that if the sun’s not shining, you’re out of luck,” Meyer adds. “Solar fuels give us the ability to collect and stockpile that energy.”

Meyers is leading UNC’s new Energy Frontier Research Center, one of 46 such centers recently established by the U.S. Department of Energy with funding that includes American Recovery and Reinvestment Act support.

The goal is to advance the nuts-and-bolts research that will take solar power to the next level and beyond, says John Papanikolas, associate professor of chemistry and coprincipal investigator of the new center.

“Basic science is the key,” says Papanikolas. “In terms of the technology currently available, many people think that if we all put solar panels on our roofs, we’ll be fine. But that’s so far from the truth it’s not funny. We really need technology that we haven’t even thought of yet.”

That’s where solar fuels come in, as well as another focus of the center’s work—developing next-generation photovoltaics, a technology and research field related to converting sunlight directly into electricity, using devices such as solar panels and solar cells.

Current materials are still bulky, inefficient, and expensive. Papanikolas estimates that generating enough solar power to meet the equivalent of the U.S.’s electricity needs would require a solar panel 10,000 square miles in size (i.e., slightly larger than Vermont) and costing $10 trillion.

The UNC team and their colleagues are exploring avenues that could result in the creation of inexpensive “solar shingles” on roofs and other such applications.

“The energy future will be driven by a shift to new energy sources that minimize environmental impacts. Hydrocarbons such as coal and oil currently provide about 85 percent of the country’s energy, but they’re a finite source.”

Along with UNC, Duke University, North Carolina State University, N.C. Central University, and the University of Florida are also partners in the Energy Frontier Research Center.

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