An energy harvester includes an elongated tubular casing extending around a longitudinal axis between opposed first and second ends. A body is arranged in the casing. A helical electrical winding is wound around the longitudinal axis. The body is arranged to move along the longitudinal axis with alternate motion away from the first end towards the second end and away from the second end towards the first end. As a result of this alternate motion, an electromotive force is produced in the at least one helical electrical winding. Furthermore, at least one of the first and second ends includes a piezoelectric transducer that is configured to co-operate in a kinetic energy transfer relationship with the at least one body to generate an electric voltage as a result of the at least one body reaching, in the alternate motion, an end-of-travel position towards the piezoelectric transducer.