The mobile waste comminuting device of the invention comprises: at least one comminuting shaft; an internal combustion engine; at least one generator that is coupled to the internal combustion engine to convert mechanical energy supplied by the internal combustion engine into electric energy; at least one electric motor which is powered by the electric energy so as to drive the at least one comminuting shaft and change the direction of rotation thereof; and an energy store for storing energy and at least partly powering the at least one electric motor with electric energy, in particular for storing energy during periods of low power demand and supplying energy during periods of high power demand in relation to the nominal power of the at least one generator.