Eskom implemented stage four-load shedding on Monday. Picture: GALLO IMAGES
Eskom implemented stage four-load shedding on Monday. Picture: GALLO IMAGES

Eskom’s operational crisis deepened on Monday, forcing it to shed 4,000MW — the biggest load it has ever dropped — to keep the grid stable.

Load-shedding moved from stage two to stage four in a matter of hours after six additional units went down on Monday morning. It is the first time that Eskom has implemented stage four load-shedding. This means that about 40% of Eskom’s fleet was unavailable to generate electricity.

Load-shedding is implemented by Eskom when electricity demand exceeds supply, placing the system at risk of tripping. The utility, which supplies more than 95% of SA’s electricity, is seen as a major risk to the country’s finances.

The units that went down unexpectedly on Monday were: Medupi 5 and 6, Grootvlei 1 and 2; Majuba 4; and Kriel 5. In addition, two units, Duvha 3 and Lethabo 5, are on long-term outage after recent explosions put them out of service.

Eskom said it was also experiencing lower than usual diesel supplies after the weekend.

The Grootvlei units and one Medupi unit were brought back online on Monday, but spokesperson Khulu Phasiwe said that units newly brought back on line frequently tripped again.

Speculation is rife that trade unions, which threatened "war" on Eskom following last week’s announcement that the utility would be split into three, were behind the sudden outages.

Eskom, however, gave no indication that this was the case.

Union leaders strenuously denied the allegations.

National Union of Metalworkers of SA spokesperson Phakamile Hlubi-Majola said: "All we know is what everyone knows; we don’t even know where the units that are affected are located. Numsa rejects allegations of sabotage."

The National Union of Mineworkers also denied any involvement in sabotage.

Energy expert and engineer Chris Yelland said that Eskom was struck by "random breakdowns. There is a very thin line between load-shedding and no load-shedding because Eskom’s reserve capacity is so tight.

"It happens randomly that we have unplanned breakdowns and when these overlap with one another, we are pushed over the line towards load-shedding.

"Eskom’s energy availability factor is about 64% at the moment, when it should be 80%," Yelland said.

The energy availability factor is the amount of electricity that Eskom’s plants can dispatch at any one time. The number has been falling since 2017 when it stood at 79%.

Eskom COO Jan Oberholzer told parliament in 2018 that it would take two years to restore Eskom’s power plants to an acceptable level of performance.

The political injunction in 2010 to "keep the lights on" by postponing maintenance and financial stress, which has led to shrinking maintenance budgets, are now catching up with Eskom. In the past four years, Eskom has slashed maintenance spending 50%.

Public enterprises minister Pravin Gordhan was locked in meetings over the crisis with the Eskom board and management on Monday afternoon.