'A handful of power generating units, including two at Matla, one at Koeberg and Arnot, are currently offline.' Eskom's spokesperson said.
For the first time since late June, power utility Eskom has warned of a constrained power supply.
In the past, Eskom put out similar warnings ahead of rotational load shedding.
South Africa experienced several days of load shedding in mid-June.
At the time, Eskom blamed the power outages on acts of intimidation and sabotage by workers who were locked in wage negotiations. Unions denied they were involved.
The wage negotiations are still on-going.
“The national grid is expected to be constrained this evening due to instability at several power stations due to acts of intimidation. Several power stations [are] now running at skeletal staff, a move that could compromise our ability to ensure security of power supply,” wrote Eskom spokesperson Khulu Phasiwe in a tweet on Monday afternoon.
The power utility was also investigating why certain units had gone offline, Phasiwe said.
“A handful of power generating units, including two at Matla, one at Koeberg and Arnot, are currently offline. Investigations are continuing to determine the cause of these outages. A conveyor belt was cut at Matla power station in what management believes is an act of sabotage.”
Phasiwe added that coal trucking at Majuba and Duvha power stations had stopped due to “acts of intimidation”.
“This poses a threat to security of power supply,” he said. — Fin 24
* This is a developing story