Winter load-shedding warning for South Africa

Although Eskom has made progress in its energy supply, the country is still only one outage away from shedding its return.

Recently, Eskom announced that its power system has been further improved and is more reliable than it was in recent years. The group said load-shedding is not expected in Winter 2025 if unplanned outages remain below 13GW.

If outages increase to 15GW, load-shedding will be limited to a maximum of 21 days out of 153 days at Stage 2—an improvement over the prior winter’s worst-case prediction of Stage 5 load-shedding.

Eskom added that this improved winter outlook is due to a 3.1 GW decrease in unplanned outages compared to the previous year. As a result, the forecast range has been lowered to 13 – 15GW, down from 14 -17GW in Winter 2024.

Last winter, there was no load-shedding, with average unplanned outages at 12.3 GW—significantly below the Winter 2024 base-case projection of 14 GW.

“This year’s Winter Outlook prediction is built on an improvement in operational performance and overall efficiency,” said Dan Marokane, Eskom Group Chief Executive.

“Loadshedding was the lowest in Eskom’s last Financial Year (FY) 2025 than in the previous 2 years. In FY 2025, we delivered power 96% of the time. In the previous year, the figure was just 9.9%.”

Marokane explained that Eskom’s diesel open cycle gas turbines were utilised approximately 50% less in FY2025 compared to the two previous financial years, saving around R16 billion.

“Against this progress, we have seen some setbacks in operational excellence, as evidenced by the recent load-shedding requirements between January and April 2025.”

“A targeted plan has been implemented to reinforce operational discipline and accelerate recovery initiatives to address the root causes related to the recent load-shedding events.”

However, while these improvements are positive, South Africa isn’t out of the woods where load-shedding is concerned.

Load-shedding still on the table

De Wet Taljaard, Technical Advisor at Investec Sustainable Solutions, explained on the Everything Counts podcast that the electricity supply industry’s vertically integrated structure is changing.

The first significant change was separating the transmission business from Eskom into the newly formed National Transmission Company of South Africa. This marks a shift in how electricity is supplied in the country.

Unfortunately, 75% to 80% of all electricity is still supplied by Eskom, and most of their generation comes from coal-fired power stations. Many of these are reaching the end of their design and operational life.

As these structures age, they become increasingly difficult and expensive to maintain. Naturally, they also pose a greater risk of failing.

One indicator is the Energy Availability Factor (EAF), a measure of the online capacity for operating and generating electricity.

The EAF needs to be between 65% and 70% for the power system to be stable and the risk of load shedding reduced. This is also the target outlined in the Energy Action Plan, the government’s recovery plan for the sector.

From 1 to 17 April 2025, Eskom confirmed that the year-to-date EAF stood at 56.63%, slightly lower than during the same period in 2024, when it was 57.67%.

In 2023, the worst year of load shedding on record, with over 6,800 hours across 284 days, the EAF was 54.7%. That means the country is only about 2% better now than during the worst year on record, Taljaard said.

This shows that the power system remains delicately balanced. If anything unexpected occurs, as happened earlier this year, South Africa could slip back into load-shedding.

In other words, South Africa is only one power outage away from load-shedding returning. While Eskom may be improving, it is only one part of the problem.

Municipalities are also facing infrastructure and maintenance challenges. Other issues, like cable theft and faulty transformers, are also contributing to an unstable electricity supply.