Eskom has confirmed that stage two load-shedding will commence from 9pm on Thursday evening due to “system constraints” and “depleting emergency resources”.

“We have been using pumped storage schemes and open cycle gas turbines excessively over the past few days in order to supplement capacity,” the power utility said in a system update on Thursday.

These reserves had to be replenished overnight.

“Unplanned outages are slightly reduced at 12,683MW as at 1.30 this afternoon.”

The rolling blackouts would last from 9pm Thursday to 6am Friday.

“We unreservedly apologise to South Africans for the negative impact this may have on them,” said Eskom.

Eskom said unplanned outages were at 13,063MW at 6am on Thursday, slightly up from 12,620MW on Wednesday.