A method, comprising: providing electric power to a utility grid, which includes driving an adjustable alternator coupled to the grid with a spark-ignited internal combustion engine; detecting a low voltage condition of the utility grid; and, in response to the low voltage condition: changing spark ignition of the engine, wherein the changing of the spark ignition includes retarding spark ignition timing; and adjusting an electromagnetic field produced by the alternator; characterised in that: a low voltage condition of the grid is determined as a function of loss of voltage zero cross and low absolute voltage peak magnitude between two zero crosses; the changing of the spark ignition comprises directing a maximum level of retarded spark ignition timing when the engine speed exceeds a designated upper threshold and returning to nominal spark ignition timing when the engine speed drops below a designated lower threshold, thereby modulating the timing between a maximum retarded spark ignition timing and a nominal spark ignition timing based on the speed of the engine during the low voltage condition; and the method comprises operating with modified spark timing and an increased alternator field to slow the engine and maintain synchronization with the grid. providing electric power to a utility grid, which includes driving an adjustable alternator coupled to the grid with a spark-ignited internal combustion engine; detecting a low voltage condition of the utility grid; and, in response to the low voltage condition: changing spark ignition of the engine, wherein the changing of the spark ignition includes retarding spark ignition timing; and adjusting an electromagnetic field produced by the alternator; characterised in that: a low voltage condition of the grid is determined as a function of loss of voltage zero cross and low absolute voltage peak magnitude between two zero crosses; the changing of the spark ignition comprises directing a maximum level of retarded spark ignition timing when the engine speed exceeds a designated upper threshold and returning to nominal spark ignition timing when the engine speed drops below a designated lower threshold, thereby modulating the timing between a maximum retarded spark ignition timing and a nominal spark ignition timing based on the speed of the engine during the low voltage condition; and the method comprises operating with modified spark timing and an increased alternator field to slow the engine and maintain synchronization with the grid. changing spark ignition of the engine, wherein the changing of the spark ignition includes retarding spark ignition timing; and adjusting an electromagnetic field produced by the alternator; characterised in that: a low voltage condition of the grid is determined as a function of loss of voltage zero cross and low absolute voltage peak magnitude between two zero crosses; the changing of the spark ignition comprises directing a maximum level of retarded spark ignition timing when the engine speed exceeds a designated upper threshold and returning to nominal spark ignition timing when the engine speed drops below a designated lower threshold, thereby modulating the timing between a maximum retarded spark ignition timing and a nominal spark ignition timing based on the speed of the engine during the low voltage condition; and the method comprises operating with modified spark timing and an increased alternator field to slow the engine and maintain synchronization with the grid. a low voltage condition of the grid is determined as a function of loss of voltage zero cross and low absolute voltage peak magnitude between two zero crosses; the changing of the spark ignition comprises directing a maximum level of retarded spark ignition timing when the engine speed exceeds a designated upper threshold and returning to nominal spark ignition timing when the engine speed drops below a designated lower threshold, thereby modulating the timing between a maximum retarded spark ignition timing and a nominal spark ignition timing based on the speed of the engine during the low voltage condition; and the method comprises operating with modified spark timing and an increased alternator field to slow the engine and maintain synchronization with the grid.