A system is disclosed for providing inerting gas to a protected space, and also providing electrical power. The system includes an electrochemical cell comprising a cathode and an anode separated by a separator comprising a proton transfer medium. Inerting gas is produced at the cathode. A fuel source comprising methanol or formaldehyde or ethanol and a water source are each in controllable operative fluid communication with the anode. A controller is configured to alternatively operate the system in a first mode of operation where water is directed to the anode fluid flow path inlet and electric power is directed from a power source to the electrochemical cell, and in a second mode of operation in which the fuel is directed from the fuel source to the anode fluid flow path inlet and electric power is directed from the electrochemical cell to the power sink.