Abstract: A power generation system is disclosed for supplying power to an electrical grid. The system comprises an engine (1) and an electrical generator (3) coupled to the engine for generating an electrical output. Power electronics (6) are provided for converting the output of the electrical generator into an AC output at the operating frequency of the electrical grid. The engine is operated at a speed which is non-synchronous with the operating frequency of the electrical grid and at which the brake specific fuel consumption of the engine is minimised. The power electronics may also facilitate waste heat recovery and the connection of external energy sources.