Electricity Minister Kgosientsho Ramokgopa.
Bringing units 2 and 5 at Kusile online in late December, against a backdrop of lower industrial demand, will provide Eskom with sufficient capacity to stave off high levels of load-shedding, Electricity Minister Kgosientsho Ramokgopa said on Sunday.
“It cannot be overemphasised: if we build an additional buffer it means that we are less prone to these major fluctuations in the intensity of load-shedding,” he told a media briefing.
“And that is why unit number 2 of Kusile [is] important, unit number 5 at Kusile [is] important. We are targeting those to come by the end of the month… by the third of December.
“Once you build that buffer, even if you were to have this extraordinary event, there is some form of buffer and therefore the rate at which we intensify load-shedding might not be as severe as what we experienced over the past 30 hours or so.”
He said during this time, when load-shedding was ramped up to level 6, unplanned outages and partial load-losses did not exceed a combined 15 500 megawatts but demand had surged.
“So the major issue was not on the unplanned capacity loss factor, really your issue was on the demand.”
The minister said stage 6 load-shedding was necessary to preserve emergency reserves which had dipped uncomfortably low in the last two weeks.
“The major problem really started the week preceding the last one, where we had a significant amount of losses and these losses meant that we had to engage our emergency reserves.”
He said when Eskom turned to its emergency reserves, it was expecting units that were out of service, including at Kusile, to come back online soon to provide relief on the reserves.
This did happen but a number of other units failed, prompting Eskom to implement stage 6 load-shedding from Friday.
“The return of these megawatts were taken out by those units that were failing, which meant that we had to continue to run our emergency reserves.”
He said that a fortnight ago, emergency reserves were lying at below 70 percent.
“Here I am talking about our pump storage and about our open-cycle gas turbines, and as we continued to deploy them there was significant reduction in those reserves.”
There was difficulty particularly in replenishing diesel supplies to the gas turbines at Ankerlig, because there is no pipeline and it has to be transported by road, he added.
“The pace at which we were burning far exceeded the pace at which we could reasonably replenish this storage, and as a result we were seeing a major dip in relation to the levels of emergency reserves.”
Reserves plummeted on Thursday, and Eskom at the same time lost a number of units due to unplanned outages, prompting the need to escalate load-shedding. He dismissed suggestions that the power grid came close to collapse.
“It reached critical levels, and once it reached critical levels, our primary preoccupation now is to ensure that we protect the grid, so we took them out, so essentially we are not engaging the emergency reserves at the rate at which we have been engaging them,” he said.
“So we pulled them back, and as we pulled them back, it means there are less megawatts available, then it means we need to intensify loadshedding.”
Reserve levels were recovering as a result, Ramakgopa said, though diesel reserves at Ankerlig and Acacia were still around 50 percent on Sunday.
Units at Arnot and Tutuka power stations have returned to serve, Ramokgopa said.
It was expected that unit 5 at Medupi would return to service on Sunday, and units at Majuba and Lethabo power plants on Monday, he added.
“This gives us extensive relief.”
The return to service of unit 4 at Kriel, scheduled for Wednesday, has been delayed, however.
Eskom on Sunday morning announced that load-shedding would immediately be lowered to level 4, and further to level 2 during the day this week. Level 4 would apply overnight.
Ramokgopa said it was likely that there would be days in December with no load-shedding.
“Major industries are closing, so you are going to have demand that is going to dip, but what we do as demand is dipping, is we use that opportunity to ramp up planned maintenance.
“We will take it close to 7 000 megawatts.”
He said he hoped that with two additional units online at Kusile, the power utility’s unplanned capacity loss factor would dip below 14 000 megawatt.
“Therefore we should be having significantly lower stages of load-shedding and at some point there will be days where you will not have load-shedding at all, and we are really confident about that projection.”
It was hoped that unit 2 would return to service by the end of November, rather than just before Christmas, as is now the expectation.