When I visited Lawrence Berkeley National Laboratory in March, Frances Houle, the deputy director of the Joint Center for Artificial Photosynthesis, showed off one of the center’s latest advances. It is a device that breaks down water into hydrogen and oxygen in sunlight. The lab’s researchers had previously used artificial light to drive the process; this was the first time they were doing it with natural light. Fixed to a thin metal stand on the roof of the center’s building above Berkeley, with a spectacular view west across San Francisco Bay, the small device has a solar cell that supplies the energy needed for a chemical catalyst to split the water. At the top of the device, pure hydrogen bubbled up.
Created in 2010 under Secretary of Energy Steven Chu, the center, commonly called JCAP, has an audacious goal: to create fuels using only sunlight, carbon dioxide, and water (see “Artificial Photosynthesis Effort Takes Root”). Done economically, that would be a Promethean achievement, representing a huge step toward solving the two outstanding challenges in shifting from fossil fuels to renewable energy: storing large amounts of energy for later use, and powering forms of transportation that cannot easily run on batteries.
“All of the studies of a clean energy system I’ve ever seen identify the same two technology gaps,” says Nate Lewis, the center’s founding director. “Massive grid-scale energy storage to compensate for the intermittency of wind and solar power, and an energy-dense, carbon-neutral liquid transportation fuel.” Turning sunlight into fuel would enable solar energy captured during the day to be stored, transported, and used when the sun’s not shining. The same fuel could replace fossil fuels that power today’s aircraft and ships. “There are no such things as a plug-in electric airplane or ship,” adds Lewis.To read more, click here.