Abstract: The invention relates to a system for converting rotational energy from a slow moving rotary input shaft, like the shaft of a wind turbine, into electrical energy to be supplied to a grid. The system comprises a support structure for supporting a main bearing for the input shaft, a generator coupled to the input shaft and arranged on the support structure, and a power converter that is electrically coupled between the generator and the grid. This converter is arranged on the support structure, and may further be structurally integrated with the generator. The generator may be an induction generator comprising a removable cage type rotor. The generator may comprise a stator which includes heat pipes connected to a lubricating and/or cooling system for a transmission, and the stator may be removably mounted on free ends of the heat pipes.