REVERSIBLE SOLID OXIDE CELL SYSTEM

Disclosed is a reversible solid oxide cell system that selectively operates in a fuel cell mode that produces electricity from methane as fuel if electricity production is needed, and an electrolyzer mode that produces methane by reacting carbon dioxide with hydrogen obtained by electrolyzing water using produced electricity, wherein the modes share a hybrid tank storing methane and carbon dioxide to provide efficient production and storage of energy. The reversible solid oxide cell system includes a hybrid tank to store methane and carbon dioxide isolated by an adjustable partition, and a reversible solid oxide cell (rSOC) operating in an electrolyzer mode and in a fuel cell mode.