• Eskom needed to shed 7 358MW of demand in order to keep grid stability last evening, which means that the utility was effectively at Stage 7.
• Despite this, Eskom officially claims it was only at Stage 6.
• With the cold snap expected to continue, Eskom is precariously getting closer and closer to conditions that could force Stage 8 loadshedding.

Despite improved power generation of almost 70 percent in recent weeks, a sudden cold front that saw snow fall across South Africa, has plunged the country into longer blackouts. On Wednesday morning, South Africans woke up to an imposed Stage 6 by the utility as the mercury dropped.

However, according to the “evening peak” updates Eskom publishes to its official Twitter account, the balance of the demand and energy availability at peak time (18:26) on Wednesday required that 7 358MW to be shed in order to maintain the integrity the country’s energy grid.

Despite this, Eskom officially claims that only 6 432MW were shed at the time. Shedding 7 358MW means that instead of Stage 6, South Africa was actually at Stage 7 loadshedding, approaching Stage 8 which requires around 8 000MW to be shed.

Also of concern was the number of diesel generators that Eskom was using to keep the power availability against the high demand as citizens huddled around heaters to keep warm. Eskom was forced to use 15 open-cycle gas turbines (OCGTs) last evening.

In contrast, just last weekend Eskom was using zero OCGTs, pointing to how unstable the grid is currently. But then, demand was only at 27 725MW as of Sunday.

High demand was not unexpected in winter. Eskom issued a statement in May that South Africans would have to brace themselves for Stage 8 loadshedding if winter demand exceeded 33 000MW (which it has) and if breakdowns exceeded 18 000MW. As of its last official power alert, breakdowns had only removed 16 000MW from the grid.

But with just 2 000MW to play with, only a few more breakdowns would cause Stage 8 loadshedding, unless demand significantly drops or generation vastly improves.

Another factor hampering energy availability in the last few days is a decline in renewable energy generation. On the weekend Eskom hit its highest-ever amount of electricity generated by renewable sources, at 2 656MW, which can effectively eliminate two stages of loadshedding.

Just three days later, it only managed 596MW showing a sharp decline in wind generation. This points to instability in Eskom’s renewable sources, probably because many of these are still new and are in small quantities. This means that environmental factors, like how much wind is blowing and sun is shining on a given day, will still impact the grid.

Not until Eskom has vast amounts of renewable generation infrastructure available will a few days of no wind and cloudy weather not make much of a difference.

The cold temperatures are expected to continue into the next two weeks at the least. We hope you’re stocked up with alternative power supplies.

[Image – Photo by Sixteen Miles Out on Unsplash]