The invention relates to a method for operating a regenerative bipolar membrane fuel cell and regenerative bipolar cell for storing and generating energy. The method according to the invention comprises: —providing a regenerative bipolar membrane fuel cell comprising: —a reactor with an anode compartment having an anode and a cathode compartment having a cathode; and —a number of cell units separating the anode and cathode compartments, wherein the cell unit comprises an anion exchange membrane, a cation exchange membrane, and a bipolar, with the membranes defining compartments; —providing a fluid on both sides of the bipolar membrane with ion concentrations such that water activity difference between the fluids on both sides of the bipolar membrane is minimized; —storing energy in an energy storage state by providing an external current to the reactor such that a p H difference between fluids in contact with the bipolar membrane is achieved; —switching between the energy storage state and an energy generation state; and —regenerating energy in the energy generating state from the p H difference between fluids in contact with the bipolar membrane.