Abstract: A method for operating an electrical energy storage system is described. Electrical energy is supplied to electrolyze first water to produce hydrogen and oxygen. A turbine is operated from the hydrogen and the oxygen to combine the hydrogen and the oxygen to deliver energy to the turbine by forming second water in a vapor phase in order for the turbine to operate an electric generator to generate electrical energy. The second water is condensed from the vapor phase into a liquid phase as liquid second water. The liquid second water is delivered to be electrolyzed into new hydrogen and new oxygen in order to recirculate the second water for electrolysis into new hydrogen and new oxygen. The electrical energy generated by the electric generator is distributed to customers by means of grid transmission lines.