Electric generator
![U.S. NRC image of a modern steam turbine generator (STG).](/Images/godic/202502/14/Modern_Steam_Turbine_Generator4650.jpg")
![Early Ganz Generator in Zwevegem, West Flanders, Belgium](/Images/godic/202502/14/Generator-200711174650.jpg")
![The Faraday disk was the first electric generator. The horseshoe-shaped magnet (A) created a magnetic field through the disk (D). When the disk was turned, this induced an electric current radially outward from the center toward the rim. The current flowed out through the sliding spring contact m, through the external circuit, and back into the center of the disk through the axle.](/Images/godic/202502/14/Faraday_disk_generator4650.jpg")
![This large belt-driven high-current dynamo produced 310 amperes at 7 volts. Dynamos are no longer used due to the size and complexity of the commutator needed for high power applications.](/Images/godic/202502/14/High-Current_Copper-Brush_Commutated_Dynamo4650.jpg")
In electricity generation, a generator is a device that converts mechanical energy to electrical energy for use in an external circuit. The source of mechanical energy may vary widely from a hand crank to an internal combustion engine. Generators provide nearly all of the power for electric power grids.