‘A very, very tight winter’ ahead with Eskom short of 3 000 megawatts

As South Africans brace for what is set to be a bitter winter, interim Eskom chief executive Calib Cassim has confirmed that the utility will have 3 080 fewer megawatts of capacity than it did last year.

This is as three of Kusile power station’s units go offline. It will also be the first winter without the 960 megawatts from Koeberg nuclear power station’s unit one, which is only expected to come back online in September.

If the interventions planned to carry Eskom through the winter do not achieve the desired results — and unplanned outages exceed expectations — then the likelihood of stage eight load-shedding during demand peaks “is extremely high”, Cassim said. The utility’s winter plan has factored in 15 000 megawatts of unplanned loss factor.

As Cassim and his colleagues briefed the public on Eskom’s winter plan on Thursday morning, South Africans were in the grips of stage four load-shedding and facing the prospect of stage six in the evening. The rolling blackouts have been deleterious to the country’s economy, shaving as much as two percentage points from GDP growth in 2023.

According to Cassim, Eskom’s energy availability factor — the ratio of the energy that the available capacity could have produced during a period — has deteriorated to 52%, against the 60% previously expected for March 2023.

Segomoco Scheppers, Eskom’s chief executive for transmission, said: “As has been indicated, and I think is now common cause, this is going to be a very, very tight winter in terms of supply and demand balance.”

He said Eskom has 26 500 megawatts of available capacity daily. But the utility estimates that demand is projected to peak at 33 000 megawatts. “So we have a shortfall and that is for the period into which we are operating and we are moving into with time.”

The unpredictability of Eskom’s performance could also worsen the winter outlook, Scheepers said. “In terms of capacity that is available, we are starting on the backfoot,” he noted.

According to Scheppers, depending on demand and plant performance, the country may endure up to stage eight load-shedding. But, in Eskom’s base case (in which there are 15 000 megawatts of unplanned loss factor) load-shedding will reach between stage three and stage five from now to the end of August.

“So this is going to be a very difficult winter … We are in a difficult space and we really need all of us to make efforts to contribute,” Scheepers said, later adding that the effect of possible strike action at Eskom has not been factored into the utility’s winter outlook.

Cassim and Scheppers underlined that load-shedding is needed to ensure the country’s energy grid is balanced. On Wednesday, Eskom released a statement refuting speculation that the country could soon experience a total blackout.

“The risk of a national blackout, while inherent to the operation of a large power system, has an extremely low likelihood of materialising given the implementation of a number of control measures, including load-shedding,” Eskom said.

“The grid is by no means at a higher or imminent risk of a collapse and it would take an unforeseen and sudden sequence of events that results in a cascading collapse of the transmission or generation system, leading to a complete loss of supply across the country.”