An energy-harvesting system, adapted to supply an electrical load, comprising: - a transducer, configured for converting energy coming from an energy source external to said system into an electrical signal (V TRANSD); and - a first storage element coupled to the transducer for receiving at input said electrical signal and configured for storing electrical energy, said system being characterized in that it further comprises: - a second storage element coupled to the electrical load; and - a switch, connected to the first and the second electrical-energy storage elements (12, 16), operable for electrically coupling and, alternatively, uncoupling, the first and second storage elements (12, 16) to/from one another, the second storage element being configured to store electrical energy and supply the electrical load, the energy-harvesting system further comprising a control logic, which is coupled to said switch, characterized in that the control logic comprises: a comparator with hysteresis, configured for receiving on a first input a first comparison signal (V P) indicative of the electrical energy stored in the second storage element, receiving on a second input a predefined second comparison signal (V R) which defines a reference value (V R), generating around the reference value an hysteresis interval delimited by a first threshold value (V L ') lower than the reference value and by a second threshold value (V H ') higher than the reference value, and to supply at output a third comparison signal (V COMP) indicating a result of a comparison of the first comparison signal (V P) with the first and the second threshold values; and a control and driving circuit (38, 40), configured for receiving at input the third comparison signal (V COMP) and, on the basis of the third comparison signal (V COMP), closing the switch when the first comparison signal (V P) is lower than the first threshold value, and opening the switch when the first comparison signal (V P) is higher than the second threshold value. - a transducer, configured for converting energy coming from an energy source external to said system into an electrical signal (V TRANSD); and - a first storage element coupled to the transducer for receiving at input said electrical signal and configured for storing electrical energy, said system being characterized in that it further comprises: - a second storage element coupled to the electrical load; and - a switch, connected to the first and the second electrical-energy storage elements (12, 16), operable for electrically coupling and, alternatively, uncoupling, the first and second storage elements (12, 16) to/from one another, the second storage element being configured to store electrical energy and supply the electrical load, the energy-harvesting system further comprising a control logic, which is coupled to said switch, characterized in that the control logic comprises: a comparator with hysteresis, configured for receiving on a first input a first comparison signal (V P) indicative of the electrical energy stored in the second storage element, receiving on a second input a predefined second comparison signal (V R) which defines a reference value (V R), generating around the reference value an hysteresis interval delimited by a first threshold value (V L ') lower than the reference value and by a second threshold value (V H ') higher than the reference value, and to supply at output a third comparison signal (V COMP) indicating a result of a comparison of the first comparison signal (V P) with the first and the second threshold values; and a control and driving circuit (38, 40), configured for receiving at input the third comparison signal (V COMP) and, on the basis of the third comparison signal (V COMP), closing the switch when the first comparison signal (V P) is lower than the first threshold value, and opening the switch when the first comparison signal (V P) is higher than the second threshold value. a comparator with hysteresis, configured for receiving on a first input a first comparison signal (V P) indicative of the electrical energy stored in the second storage element, receiving on a second input a predefined second comparison signal (V R) which defines a reference value (V R), generating around the reference value an hysteresis interval delimited by a first threshold value (V L ') lower than the reference value and by a second threshold value (V H ') higher than the reference value, and to supply at output a third comparison signal (V COMP) indicating a result of a comparison of the first comparison signal (V P) with the first and the second threshold values; and a control and driving circuit (38, 40), configured for receiving at input the third comparison signal (V COMP) and, on the basis of the third comparison signal (V COMP), closing the switch when the first comparison signal (V P) is lower than the first threshold value, and opening the switch when the first comparison signal (V P) is higher than the second threshold value.