Rhizosphere anode model explains high oxygen levels during operation of a Glyceria maxima PMFC

► Results show no direct link between photosynthesis and current generation in a PMFC. ► Exudates do not directly contribute to current generation in the PMFC. ► The model explains oxic zones around roots during current generation in a PMFC. ► Low coulombic efficiency is due to poor biodegradability of insoluble organic carbon.