Unit 3 of the Ingula Pumped Storage Scheme, located near Van Reenen in KwaZulu-Natal, was synchronised to the national grid on Saturday. Eskom said that this was the final energy unit that needed to be synchronised.

The power utility explained the process of synchronisation 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 6 March this year. It supported the grid for one month 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 1 and 2 were put into commercial operation on 22 and 30 August respectively.

“Ingula’s four units are located 350m underground in the world’s largest machine hall in mud-rock,” Eskom said. “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 added.

Ingula 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,” the power utility said.

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