Unit 3 of the Ingula Pumped Storage Scheme which is located near the KwaZulu-Natal town of Van Reenen was synchronised to the national grid on Saturday‚ making it the final unit to be synchronised‚ Eskom said.

Synchronisation is the process whereby the generator in the unit is electrically connected to the national power grid‚ in such a way that its power is perfectly aligned with all the other generators to generate and deliver electricity into the national power grid.

Ingula unit 3 was synchronised to the national grid on March 6 this year and supported the grid until April 6 when an electrical incident occurred. After almost 500‚000 man-hours of work without any safety incidents the team completed the repair and has synchronised the unit back onto the national grid‚ Eskom said.

Ingula’s Unit 4 went into commercial operation on June 10 while Units 2 and 1 were put into commercial operation on August 22 and August 30 respectively.

“Ingula’s four units are located 350m underground in the world’s largest machine hall in mud-rock. To turn the more than 500 ton rotating mass of the Generator Rotor and Turbine‚ water is released from Ingula’s upper dam‚ Bedford Dam‚ situated 460m higher and two kilometres away. Water rushes down to the turbines at around 60km per hour with enough water passing through each turbine to fill an Olympic-sized swimming pool in six seconds. Rotating at 428 revolutions per minute‚ each unit will produce 333 MW‚ a total for the station of 1 332MW‚” Eskom said.

It added that Ingula‚ which is situated along the Little Drakensberg escarpment and straddles the borders of Kwazulu-Natal and the Free State‚ is part of Eskom’s peaking fleet of power stations. It can respond to demand increases on the national grid within two and half minutes.

Upon completion Ingula will be Africa’s newest and largest pumped storage scheme and the 14th largest in the world.