Carbon neutral electricity production by Synechocystis sp. PCC6803 in a microbial fuel cell

► Carbon neutral conversion of light directly to electricity using cyanobacteria in an MFC. ► Operation costs reduced since carbon source and mediator are no longer required. ► Maximum power output of 7.5 mW/m3 achieved under high intensity lighting. ► Maximum CO2 removal of 625 mmol/m3 over 20 h of MFC operation. ► Sustained output of 11.7 mW/m3 for 24 h with three MFCs connected in series.