Electricity producer Eskom has confirmed that Unit 3 at the 1 332 MW Ingula pumped-storage scheme, in the Drakensberg, was synchronised to the national grid on October 29, making it the fourth and final 333 MW unit to be synchronised at Ingula.

Unit 3 was previously synchronised on March 6, 2016, but was damaged in an “electrical incident”, on April 6. Subsequent repairs involved almost 500 000 person-hours of work.

Ingula’s Unit 4 entered into commercial operation on June 10, 2016, with units 2 and 1 entering commercial operation on August 22, 2016, and August 30, 2016, respectively.

As with the State-owned utility’s other major projects, Medupi and Kusile, the construction phase has been associated with both cost overruns and delays. In addition, Ingula was the site of a serious safety incident, which resulted in the death of six construction workers on October 31, 2013. The incident and subsequent investigation resulted in the closure of the site for a number of months.

The project was initially expected cost R8.9-billion, but the budget has been revised on several occasions and the plant is now expected to cost closer to R30-billion.

Ingula’s four units are located 350 m underground in the world’s largest machine hall in mud-rock. To turn the more than 500 t rotating mass of the generator rotor and turbine, water is released from Ingula’s upper dam, Bedford dam, situated 460 m higher and two kilometers away. Water rushes down to the turbines at around 60 km/h with enough water passing through each turbine to fill an Olympic-sized swimming pool in six seconds.

Upon completion Ingula will be Africa’s largest pumped-storage scheme and the fourteenth largest in the world.

KOEBERG RETURNS TO SERVICE
Meanwhile, Eskom also reports that Unit 1 at its Koeberg nuclear power station, in the Western Cape, has been returned to service, following a refuelling outage, initiated on September 19.

The State-owned utility said in a statement that the 42-day maintenance and refuelling shutdown was also the shortest Koeberg outage since 1998. The power station’s two units are shut for refuelling, inspection and maintenance on a 15- to 18-month rotation, when one-third of the used nuclear fuel is replaced with new fuel.

The unit will ramp up to its full load of 960 MW over the coming few days and is currently operating at 30% while final start-up tests and commissioning are performed.