This is an excerpt from EERE Network News, a weekly electronic newsletter.
Microbes Found to Convert Organic Matter Into Electricity
Researchers at the University of Massachusetts (UMass) have found that a class of energy-harvesting microbes known as "Geobacters" can convert organic matter into electrical energy. In a January issue of Science magazine, the researchers reported on how they built a simple battery using mud from Boston Harbor and two graphite electrodes. They then determined that Geobacters were responsible for generating the electricity. After other microorganisms broke down the large organic molecules in the mud into acetate, the Geobacters were able to transfer electrons from the acetate molecules to the graphite electrode, generating a current. The Geobacters were also able to generate electricity from toluene. One possible application, according to the researchers, would be to harvest sediment on the ocean floor to generate electricity for deep-sea submarines. See the UMass press release.
More traditional technologies for harvesting ocean energy draw on the mechanical energy of waves or tides and on the thermal energy of the ocean. To learn more about these technologies, see the EREN Ocean Energy page.