A sorting machine comprising propulsion devices installed on ground and at least a train of interconnected carriages provided with supporting wheels including electrical alternators to supply electrical power onboard. The alternators are housed within the wheels which comprise a fixed inner ring bearing stator windings made integral with a fork supporting the wheel and a rotative outer ring hosting permanent magnets and spinning around a shaft in front of the windings. The generator wheels, when driven by the sorting machine motion, supply small contributions of electrical power which are added up into the electrical distribution bus, a cable that is common to all the interconnected carriages of the sorting machine. Small contributions add up to several kw of power amount available and the carriage servos are able to take advantage of the available power to activate the belt units in order to load parcels and sort to destinations.