Resilience of roof-top Plant-Microbial Fuel Cells during Dutch winter

The Plant-Microbial Fuel Cell (P-MFC) is in theory a technology that could produce sustainable electricity continuously. We operated two designs of the P-MFC under natural roof-top conditions in the Netherlands for 221 days, including winter, to test its resilience. Current and power densities are not stable under outdoor conditions. Highest obtained power density was 88 mW m−2, which is lower than was achieved under lab-conditions (440 mW m−2). Cathode potential was in our case dependent on solar radiation, due to algae growth, making the power output dependent on a diurnal cycle. The anode potential of the P-MFC is influenced by temperature, leading to a decrease in electricity production during low temperature periods and no electricity production during frost periods. Due to freezing of the roots, plants did not survive winter and therefore did not regrow in spring. In order to make a sustainable, stable and weather independent electricity production system of the P-MFC attention should be paid to improving cathode stability and cold insulation of anode and cathode. Only when power output of the Plant-Microbial Fuel Cell can be increased under outdoor conditions and plant-vitality can be sustained over winter, it can be a promising sustainable electricity technology for the future.

► Plant-Microbial Fuel Cells (P-MFCs) produce sustainable electricity under outdoor conditions.
► During frost periods no electricity is produced in P-MFCs.
► Cathodes limit performance of P-MFCs under outdoor conditions.
► Spartina anglica in P-MFCs does not survive on a roof-top during Dutch winter.
► The P-MFC needs optimization of power output to be a promising sustainable electricity technology.