Eskom confirmed that load shedding will be downgraded to Stage 1 on Friday.

Eskom chair and acting CEO Jabu Mabuza told a media briefing on Thursday evening that stage 1 load shedding will take place from 09:00 to 23:00 on Friday.

Find your load shedding schedule

Mabuza apologised to the nation, especially matriculants who are writing exams and businesses, for the negative impact caused by the unexpected outages.

Eskom has blamed the current wave of power cuts which began on Wednesday on boiler leaks at six power-generating units. Some of these units are now online. Eskom's plants are on average 37 years old, which is contributing to the problems, Mabuza stressed .

Eskom COO Jan Oberholzer said the company would be using the services of its subsidiary company Rotek to conduct maintenance of boiler leaks in future. Eskom previously planned to put the maintenance contract out to tender.

Also contributing to the supply constraints was the failure of a conveyor belt feeding coal from Exxaro's Grootegeluk mine to the Medupi power station in Lephalale, Limpopo. It broke down on Saturday.

The 7km-long conveyor coal belt transported 4,000 tons per hour to Medupi. The tail-end of the belt suddenly snapped and twisted, with the weight of the coal damaging the belt. "All the human expertise" possible has been gathered to fix it, and it should be back working by next week Wednesday, Mabuza said.

A spokesperson earlier told Fin24 that coal was now transported with bulldozers between the mine and Medupi.

Since Saturday, Eskom has been relying on open cycle gas turbines "extensively" to make up for the electricity shortfall. But the expensive diesel stocks that fuel these turbines ran low, which contributed to the load shedding.

Divided in three?

These turbines are only for emergencies and Eskom can't afford the diesel bills of running them for an extended time.

But Mabuza said that Eskom is using much less diesel that it has in the past. In the past financial year, Eskom burnt diesel worth R6bn to keep the lights on in South Africa - in the year to date, it only used R500m.

The last load shedding was on March 23rd - South Africa had 206 days without outages, says Oberholzer.

Mabuza expects that government will announce its plans for Eskom's future structure within days. Eskom is expected to be split into three units: generation, transmission and distribution. Mabuza acknowledged that this would reduce the "concentration risk" at Eskom.