Plant Microbial Fuel Cell

Green electricity production by living plants in a microbial fuel cell.

Working principle from Wageningen site

Plants transform solar radiation and carbon dioxide into organic compounds. Part of the organic compounds is excreted by the roots of the plant (=rhizodeposition). These excreted organic compounds are oxidized by electrochemically active bacteria. During the oxidation, the bacteria donate the electrons to an anode which flow via an energy user to the cathode; hence electricity is generated. - http://www.ete.wur.nl/UK/Research/Renewable+Energy/Green+electricity+production+by+living+plants+in+a+microbial+fuel+cell/