Self-refueling power-generating systems

A method of configuring a power-generating system to be self-refueling and self-sustaining, wherein the power-generating system comprises:

• a reversible device comprising a single stack comprising a plurality of electrochemical cells with respective membrane assemblies, the single stack of the reversible device configured to be operated alternately as a fuel cell in a fuel cell mode and as an electrolyzer in an electrolyzer mode of the stack,
• wherein each of the membrane assemblies in the single stack has a hydrogen-side catalyst layer configured to catalyze hydrogen oxidation in the fuel cell mode and to catalyze hydrogen formation in the electrolyzer mode and an oxidant-side catalyst layer configured to catalyze oxygen reduction in the fuel cell mode and to catalyze oxygen formation in the electrolyzer mode, the catalyst layers being separated by a separation layer,
• a hydrogen unit configured to supply hydrogen to the reversible device when operated in the fuel cell mode, and receive and optionally compress hydrogen from the reversible device when operated in the electrolyzer mode, and
• a power connection configured to receive power from the reversible device when operated in the fuel cell mode, and deliver power to the reversible device when operated in the electrolyzer mode, wherein the power connection is configured to deliver the received power to an external load when required, and to receive power for delivery from an external source when available;
• the method comprising:
• determining operation of the reversible device in the fuel cell mode or in the electrolyzer mode according to power requirements and power availability,
• supplying oxygen to the reversible device in a closed circuit, by supplying oxygen to the reversible device when operated in the fuel cell mode, and receiving and compressing oxygen from the reversible device when operated in the electrolyzer mode, and
• supplying water or dilute alkaline electrolyte to the reversible device in a closed circuit, by supplying and receiving water or dilute alkaline electrolyte in conjunction with the closed oxygen supply circuit by separating oxygen produced by the reversible device in the electrolyzer mode from the water or dilute alkaline electrolyte received from the reversible device,
• wherein the water is supplied to and removed from the oxygen-side catalyst layer, together with the oxygen.