1661894185361 Resizedimage154116penn State

Bioelectricity: Discovery shows bacteria can be used for power

Jan. 7, 2005

Scientists at Pennsylvania State University, University Park, Pa., have developed a technology that can turn raw sewage into raw power. The device, called a microbial fuel cell, provides a clean energy source with the potential for enormous financial savings due to reduced electricity use, researchers say.

So far, experiments have produced between 10 mW and 50 mW of power per square meter of electrode surface, or about 5% of the amount needed to run one small Christmas tree light. At the same time, the process removes up to 78% of organic matter as measured by biochemical oxygen demand (BOD). As a result, the microbial fuel cell itself acts as a small wastewater treatment plant.

This flat-plate microbial fuel cell, which operates in continuous-flow mode, has a proton-exchange membrane sandwiched between two carbon paper electrodes. Channels force flow into a serpentine path in the system.


Such a unit would be especially attractive in developing countries. It also could be used to treat waste from animal farms, food-processing plants and even manned space missions.

Similar in design to a hydrogen fuel cell, the microbial fuel cell captures electrons that are naturally released by bacteria as they digest organic matter, and then it converts the electrons into electrical current. Dr. Bruce Logan, an environmental engineer at Penn State, doesn’t envision using his microbial fuel cell for the same type of applications as hydrogen fuel cells, such as in automobiles or houses. “We see using this any place where there’s a high concentration of organic matter,” he says.

Logan plans to build a larger version of his microbial fuel cell for demonstrations; he hopes to have the design completed in about six months. “Our goal is a system, around a cubic yard in volume, producing around 30 kWh of electricity,” he says.

Sponsored Recommendations

Keys to Improving Safety in Chemical Processes (PDF)

Many facilities handle dangerous processes and products on a daily basis. Keeping everything under control demands well-trained people working with the best equipment.

Get Hands-On Training in Emerson's Interactive Plant Environment

Enhance the training experience and increase retention by training hands-on in Emerson's Interactive Plant Environment. Build skills here so you have them where and when it matters...

Rosemount™ 625IR Fixed Gas Detector (Video)

See how Rosemount™ 625IR Fixed Gas Detector helps keep workers safe with ultra-fast response times to detect hydrocarbon gases before they can create dangerous situations.

Micro Motion 4700 Coriolis Configurable Inputs and Outputs Transmitter

The Micro Motion 4700 Coriolis Transmitter offers a compact C1D1 (Zone 1) housing. Bluetooth and Smart Meter Verification are available.