A method of supplying an electrically controllable system having variable optical/energy properties in transmission or in reflection, including at least one carrier substrate with a multilayer that allows migration of active species, including at least two active layers separated by an electrolyte, the multilayer being placed between two electrodes connected respectively to upper and lower current leads respectively. In addition to a constant first energy potential, a time-varying second energy potential is applied between the current leads, the first and second energy potentials being designed to ensure switching between two states having different optical/energy properties in transmission or reflection.