Fuel from the Sun

The U.S. Department of Energy has awarded $122 million to establish a research center in California to develop ways of generating fuel made from sunlight. The project will be led by researchers at Caltech and the Lawrence Berkeley National Laboratory, and will include researchers at various other California institutions, including Stanford University, the University of California, Irvine, and the University of California, Berkeley.

The goal, says Nate Lewis, director of the center and a chemistry professor at Caltech, is to commercialize fuels made using only sunlight, water, and carbon dioxide. For years, researchers have been exploring ways to mimic photosynthesis: the way a plant can capture solar energy and store it in chemical bonds by splitting water and carbon dioxide. But the pace has been slow. The new research center will employ rapid, automated experimentation methods to accelerate the process of discovering new catalytic and photovoltaic materials. “So instead of the few dozen choices for catalysts that we have, we want to be in a position to choose from millions of different candidates,” says Harry Atwater, a professor at Caltech, and a team leader on the project.

One of the biggest breakthroughs in this area came from Dan Nocera’s lab at MIT two years ago. Nocera, a professor of chemistry, developed a cheap catalyst that would split water and release oxygen. Researchers at other institutions have been working on other isolated parts of the photosynthetic process–for instance, designing materials that would trap light more efficiently, synthesizing catalysts for water-splitting that will be cheap and easy to make, and creating membranes to separate the resulting fuels from the starting compounds. Progress has been incremental, but has yet to produce a practical method for making fuels.

The new center will align isolated research into a single, focused collaboration, says Lewis. “There are various individual groups making progress on different fronts, but there is no one benchmarking these catalysts to determine which one is better than the other ones,” says Lewis. To see solar energy become a scalable, economically viable reality, Lewis says, collaboration is “essential.”

The first step is to set up two facilities–one on the Berkeley Laboratory campus and one on the Caltech campus. The two research stations will house the 150 researchers and 30 principal investigators who will work full-time on the project over the next five years. They will work to develop better catalysts, light absorbers, and energy-storage materials, and research how to assemble the various parts into a small prototype solar fuel generator.