Harvard scientists believe in the power of the good earth — literally. A team at the Boston-based college have created microbial fuel cell (MFC) batteries that derive energy from naturally occurring bacteria in soil. If the product takes off, the eco-friendly batteries could provide power for some of the 500 million people in sub-Saharan Africa who lack access to electricity.
The MFC batteries, which were recently honored as one of Popular Mechanics‘ 10 Most Brilliant Innovations of 2009, were first tested in Tanzania in 2008. The MFC came in the form of a five-pound bucket, and was made up of a graphite- cloth anode, chicken-wire cathode, mud with manure, a layer of sand which acted as an ion barrier and salt water which acted as an electrolyte. All components were hooked up to an electronic power-management board. The charge coming out of the device is strong enough to charge a cell phone or power LED lights.