The invention relates to an energy generator powered by tidal currents and comprises a turbine (10) in a turbine housing (30) for rotation therein about a substantially vertical axis. The turbine (10) is connected to a supporting column (22) that is pivotally supported (24) in the lower portion of the turbine housing and, with the aid of a plurality of rotating elements (36), is in engagement with an upper portion of the interior wall of the turbine housing. The turbine can thus be selectively rotated in said turbine housing with aid of the rotating elements (36).