Photosynthesis Drives Solar Fuel Cell

Combine carbon, marine sediment, seawater         and light and you’ve got a simple way to generate electricity from         sunlight.

The proof-of-concept solar fuel cell is powered by graphite         electrodes that are covered by microbe films and embedded in marine         sediment. One type of microbe uses sunlight to turn carbon dioxide         and water into glucose and oxygen. Another type of microbe converts         the glucose and oxygen back into carbon dioxide and water, producing         electricity in the process.

The fuel-cell waste—carbon dioxide and water—is recycled         as input for the photosynthesis step.

Artificial photosynthesic devices produce small amounts of         energy but are inexpensive. Microbial photosynthesic devices promise         be long-lasting and durable because the biofilms can assemble and         repair themselves.

Research paper:
A         Self-Assembling Self-Repairing Microbial Photoelectrochemical Solar         Cell
Energy & Environmental Science, published online January 6,          2009

Researchers’ homepage:
Energy         Harvesting Program, Center for Bio/Molecular Science and Engineering,          Naval Research Laboratory

Eric Smalley is editor of Energy Research News. He has written about technology since 1987 and has freelanced for many publications including Discover, Scientific American, Wired News and The Boston Globe on topics ranging from quantum cryptography to global warming.