Brace for a cold, dark winter, warns Eskom

HIGH electricity demand in winter means South Africans can expect a dark cold season, with Eskom confirming that load shedding can be expected.

The winter profile has a low morning peak at 6am and a high evening peak at 6pm. “These morning and evening peaks increase as it gets colder. The last week of May we have the highest demand for the year,” Eskom said.

Load shedding, however, could not only occur during peak periods, it said.

This emerged during a virtual press conference yesterday at which Eskom updated the media after announcing stage 2 load shedding until Monday due to generation capacity constraints.

The latest round of rolling blackouts has been attributed to a shortage of generation capacity owing to delays in returning generators to service, as well as breakdowns of nine generators.

Eskom’s chief operations officer, Jan Oberholzer, said: “Over the long weekend, when the demand for electricity is lower than normal, we took the opportunity to take large generators out of service to do minor repairs as well as address some running defects.”

However, several units tripped on Saturday and Sunday when they returned to service and the situation got worse on Monday.

“On Monday, during the day, we had eight units tripping. What is extremely disappointing, we had four units that have been delayed in returning to service, creating a further shortfall.”

Eskom chief executive André de Ruyter added that the power utility had total losses of 14758MW.

“This gives an indication of the significant capacity constraint we face, that’s about three Medupi-sized power stations that are not available. We have a deficit between our demand and available generation capacity. We do not wish to deplete all of our reserves in continuously meeting excess demand because then we know we will run out of diesel to fire our open-cycle gas turbines and we will run out of capacity in our pump storage systems. We have to protect our reserves. We are working very hard to return units to service.”

These systems, he said, were important to prevent a total blackout.

Eskom system operator general manager Isabel Fick added: “It depends on what happens on the system at the time. The system is extremely dynamic and therefore we have to do what happens at any stage. You would have noticed we often only implement load shedding in the night. However, this time it is not possible because of the high number of units that are not available to us.

“We are struggling to meet demand in the daytime as well.”