Scientists redefine “clean” energy by generating electricity from sewage
It's now possible to generate electricity from raw sewage, Stanford University researchers report. About the size of a D-cell, their prototype "microbial battery" is attached to two electrodes. The simple circuit is completed -- and the battery powered -- when those electrodes are dipped into a bottle of plant and animal waste dissolved in water.
Science World Report explains that the research, published in the Proceedings of the National Academy of Scientists, relies on a type of bacteria found in organic waste:
Scientists have long known of the existence of exoelectrogenic microbes. These organisms evolved in airless environments and developed the ability to react with oxide minerals rather than breathe oxygen in order to convert organic nutrients into biological fuel. For years, researchers have tried to find ways to use these microbes as bio-generators, but making this an energy efficient method has proven to be difficult.
Here's what an exoelectrogenic microbe looks under an electron microscope: