An electrical power generator includes a first part having an elongated shape, a first end and a second end. The first part is arranged for attachment to a base in correspondence with the first end and configured to be located in a fluid and configured such that, when said fluid moves, the first part generates vortices in said fluid so that a lift force is generated on the first part, which produces an oscillating movement of the first part. In addition, the generator includes a subsystem configured for converting the oscillating movement of the first part into electrical energy. The subsystem is at least partially housed within the first part.