The power station comprises six 300 MW GEC generator/motors coupled to Francis-type reversible turbines. The generators are vertical-shaft, salient-pole, air-cooled units each having 12 electromagnetic poles weighing 10 tonnes each, producing a terminal voltage of 18 kV; synchronous speed is 500 rpm. From standstill, a single 450-tonne generator can synchronise and achieve full load in approximately 75 seconds. With all six units synchronised and spinning-in-air (water is dispelled by compressed air and the unit draws a small amount of power to spin the shaft at full speed), 0 MW to 1800 MW load can be achieved in approximately 16 seconds. Once running, at full flow, the station can provide power for up to six hours before running out of water.