Researchers at Caltech and Berkeley Lab have, in only two years, nearly doubled the number of materials known to have potential for use in solar fuels - putting solar fuels on the fast track to commercial viability. They did so by developing a process that promises to speed the discovery of commercially viable solar fuels that could replace coal, oil, and other fossil fuels. Solar fuels are created using only sunlight, water, and carbon dioxide. Researchers are exploring a range of target fuels, from hydrogen gas to liquid hydrocarbons, but producing any of these fuels involves splitting water. To create practical solar fuels, scientists have been trying to develop low-cost and efficient materials, known as photoanodes, that are capable of splitting water using visible light as an energy source. Over the past four decades, researchers identified only 16 of these photoanode materials. Now, using a new high-throughput method of identifying new materials, the researchers from Caltech and Berkeley Lab have found 12 promising new photoanodes.