Operating self-refueling power-generating systems

A self-refueling power-generating system comprising:

• a reversible anion-exchange membrane (AEM) device that comprises a single stack having a plurality of electrochemical cells with respective anion-exchange membrane assemblies, wherein the single stack is operable both, and alternately, as a fuel cell in a fuel cell mode, using hydrogen from at least one hydrogen tank, to generate power and as an electrolyzer in an electrolyzer mode to generate hydrogen and fill the at least one hydrogen tank for self-refueling the power-generating system,
• wherein hydrogen and oxygen are supplied and received from the reversible AEM device in respective hydrogen and oxygen closed circuits, wherein the oxygen received from the reversible AEM device is separated from the water or dilute alkaline electrolyte in a gas/liquid separation module, and
• a controller configured to operate the self-refueling power-generating system by:
• operating the reversible AEM device in the fuel cell mode when energy is required therefrom,
• when not operating in the fuel cell mode:
• calculating an amount of hydrogen needed to fill the at least one hydrogen tank mode and with respect to based on consumption of hydrogen during the operation in the fuel cell mode,
• determining, with respect to the calculated amount of hydrogen and an availability of external power, a required tank filling time,
• determining a target electrolysis efficiency,
• determining if sufficient filling time is available based on the required tank filling time and the availability of external power, and;
• if sufficient filling time is available operating the reversible AEM device in the electrolyzer mode at an optimized electrolysis profile that corresponds to the determined target electrolysis efficiency, or
• if sufficient filling time is not available providing an alert and operating the reversible AEM device in the electrolyzer mode at a maximal electrolysis current.