Photosynthesis is a seemingly simple process whereby plants use the sun's energy to convert carbon dioxide (CO2) into fuelin their case, food in the form of sugars. "The equation looks deceptively simple from a chemistry point of view, but it involves hundreds of steps and many, many different components," explains Brudvig, the Eugene Higgins Professor of Chemistry and professor of molecular biophysics and biochemistry. The Yale Solar Group ultimately hopes to develop the technology for commercial photoelectrochemical cells that would use sunlight to churn out oxygen on one end and transportation fuel on the other. Hydrogen, as the other component in H2O, is an obvious "green" fuel choice, but it's volatile, so the group is also looking at ways to potentially produce a liquid fuel such as methanol down the road. Whatever fuel is generated would be carbon-neutral, because the CO2 it would produce when burned would simply replace the CO2 that was taken out of the environment and used to create it in the first place. Harnessing the power of photosynthesis to make green fuel | R&D Mag Ain't science grand?