South Africa has been experiencing lower load-shedding in winter this year, contrary to warnings of a dark winter in 2023. However, this may soon change as temperatures drop and Eskom’s energy availability factor (EAF) declines.
Eskom told Daily Investor that there are several factors that have led to lower stages of load-shedding being needed to balance the supply and demand of the national power system:
- Reduced electricity demand experienced as of 1 June 2023.
- The generation capacity available has improved significantly over the past 3 weeks enabling more of the country’s demand to be met.
- The winter electricity demand profile is characterised by high morning peaks and extremely high evening peaks but relatively low demand during the day. This has been exacerbated by the rapid increase in rooftop PV that has been installed across the country.
- The combined effect has allowed Eskom to limit the dispatch of open cycle gas turbines (OCGTs) over the morning and evening peak periods, resulting in a more manageable situation regarding diesel delivery to the OCGT power stations. The high evening peak, unfortunately, still requires load-shedding to be implemented as there is insufficient installed capacity of OCGTs to make up the entire shortfall.
- Both Eskom and the independently owned OCGT power stations have increased diesel deliveries. This has taken enormous effort throughout the supply chain, particularly from suppliers and transporters.
- The warmer-than-usual weather so far this winter has resulted in lower-than-anticipated demand for electricity.
The combination of these factors has seen South Africa go without load-shedding during the day on weekdays since 6 June.
However, on 28 June, Eskom announced a slight escalation of load-shedding. The utility said a delayed return to service of some generation units forced the utility to implement stage 2 load-shedding during the day from 7:00 to 16:00, while Stage 3 will remain in the evenings.
In a statement on 25 June, Eskom reported an EAF of 56% of installed capacity due to breakdowns amounting to 16,524MW, while a further 4,376MW was offline due to planned maintenance.
Eskom told Daily Investor, “A high demand for electricity for the remainder of winter will be determined largely by how cold weather sets in across the country in the coming weeks and what the generation capacity available will be when that occurs”.
“During the warmer period, stage 3 or 4 load-shedding is to be expected, while colder periods may increase this. Should a cold spell coincide with multiple generator breakdowns, high stages of load-shedding may be necessary for a short duration.”
Therefore, should Eskom’s EAF continue to worsen and demand increase, South Africa will soon face higher stages of load-shedding again.
Chair of the National Rationalised Specifications Association of South Africa, Vally Padayachee, recently said the significant test for Eskom will come at the end of July and early August.
He said Eskom’s generation fleet would come under pressure during this period, as demand tends to increase throughout winter and peak at the beginning of August.