Researchers from the University of Washington in St. Louis have been working on microbial fuel cell that generates electricity from wastewater. The science behind this technology is quite simple. Wastewater contains, among other things, organic matter. This organic matter can serve as a feedstock for many bacterial reactions. If an electrode is placed within the system where bacteria can develop and colonize, then a fuel cell can be made. As the bacteria feeds on the organic material in the wastewater, they release electrons. These electrons are collected in the anode, which then move to the cathode (transferred through copper wires). When electrons are released and made to move, then electricity is generated.
According to current research, the present level of technology on microbial energy generation is around 160 watts per cubic meter of wastewater. The goal is to increase this power output ten times. When that happens, microbial fuel cell systems would provide households with enough renewable energy without much investment. Money and certainly energy, would then be saved from going down the drain.