One of the most interesting methods of generating solar power is artificial photosynthesis: copying plants to convert water and sunlight into energy. Artificial photosynthesis has the potential to produce storable fuel in a more ecologically-friendly way than traditional solar power generation, and generators can be built in self-contained units that make them useful in remote areas. Most solutions so far, however, have relied on rare and expensive metals and difficult manufacturing processes. A recent paper in Accounts of Chemical Research details how researchers led by Daniel Nocera of MIT created a version that may actually see widespread deployment.

Nocera's artificial leaf essentially places a light-absorbing material between two layers of film. When placed in water and exposed to sunlight, the film splits the water into hydrogen and oxygen, allowing the hydrogen to be captured and stored for future use. Unlike the previous versions, though, it relies on common metals like cobalt, nickel, and zinc, which — unlike the platinum that's often used — are all cheap and easily obtainable, and it can be manufactured at a relatively low cost. If the leaf is more widely produced and used, Nocera says, it could "provide global society its most direct path to a sustainable energy future."