Deferred generator maintenance has caused an overload of unplanned repairs, resulting in a week of darkness for South Africa.

On Tuesday, unplanned outages resulted in 9 500 MW being cut off the grid, while planned outages accounted for 5 000 MW, according to Eskom spokesperson Khulu Phasiwe.

After implementing a third day of stage 2 (2 000 MW cut) load-shedding at 06:00 on Tuesday, Eskom escalated the outages to stage 3 (4 000 MW cut) at 18:00.

Phasiwe said that in addition to the technical problems experienced earlier on Tuesday, Eskom encountered more outages.

“There were further partial load losses, which means that a generator’s valve probably needed replacing,” he said.

“To replace a valve, engineers need to shut down a generator feeding about 600 MW into the grid,” he said. “Once the generator has cooled and they replace the valve, it will take another four to six hours to synch it back into the system.”

Phasiwe said partial load losses were increasing in terms of number because of the deferred maintenance, a strategy that has been criticised by the current Eskom leadership. “The delayed maintenance is coming back to haunt us,” he said.

“The power stations are running for a much longer duration and are being run harder,” he said “It is happening at a critical moment when we see an increase in demand.”

“We won’t finish the backlog before winter,” he said. “That is a reality. We have more unplanned outages than planned outages.”

“Technicians told Eskom that they will try reducing unplanned maintenance in winter to 6 000 MW and they are comfortable they will manage it,” he said.  “We will have difficult position going forward.”

Majuba power station’s silo, which collapsed in November 2014, would take over 24 months to repair, but contingency measures were being implemented to increase coal going into burners, said Phasiwe.

Majuba is only producing between 2 000 MW and 2 600 MW of its 4 110 MW capacity due to the silo collapse, he said.

“The investigation into that incident will be concluded in June,” he said.

News24.com