Electric utility Eskom says a total collapse of the national grid would be an unforeseen event and the system operator would not be able to provide advance warning if it happened.
In the event that the grid collapses, it would result in a total power outage – leaving the entire country without power for “a few weeks” while it recovers.
The group published a guide to the load shedding process this week, informing the public about how it manages energy supplies and how load shedding fits into the overall picture.
South Africa was plunged into phase 6 load shedding over the weekend, with warnings from industry experts that it could get much worse during the week.
Although the load shedding was reduced to phase 5 on Tuesday, the network remains incredibly volatile and vulnerable to further outages.
In a media briefing on Sunday (Sept. 18), Eskom noted that load shedding schedules are moving up to phase 8, where 8,000 MW will be taken off the grid. If capacity problems go beyond this level, it is up to the grid operator to determine how much extra capacity must be drawn per province.
Eskom said load shedding is the last resort to avoid a nationwide power outage.
When the system is under pressure, it first goes into voluntary or contractual emergency reduction where large energy consumers – mostly industrial – are asked to reduce their load on the grid.
If this does not balance demand, load shedding is implemented.
“If preventive measures, including shutdown, are insufficient, the national electricity grid will collapse. A blackout is unforeseen and therefore the system administrator will not be able to make an announcement in advance,” it said.
“A national blackout will have huge consequences and every effort is being made to prevent it. Depending on the nature of the emergency, it may take a few weeks to just recover of a blackout.”
Andre de Ruyter, CEO of Eskom, said there was no imminent threat of a blackout, and the fact that Eskom was able to manage supply and demand through load shedding – even in phase 6 – was an sign that the system is working, since -shedding is precisely designed to avoid a total blackout.
Despite this, the utility said it is adequately prepared for a catastrophe and regularly conducts “black start” tests.
“A black start test is basically when you test several pieces [power] factories to look at their suitability should we end up in an unfortunate situation when we blacken the whole system,” it said.
“[Black start tests] are done on a three-yearly basis for different parts of the plant. There have also been a number of different tests performed at different intervals.”
The energy company conducted one of its major black-start tests on August 23, 2022.
Read: 3 new programs to increase Eskom’s power capacity in South Africa – but there’s a catch