Eskom’s Winter Woes Easing: The Unexpected Respite from Load-Shedding

There’s a flicker of hope in the otherwise dark tale of Eskom’s load-shedding this winter, as the severity of the power cuts seem to be on a surprising decline.

The Unexpected Contributors: Rooftop Solar and Cooler Operating Temperatures

Hein Vosloo, former senior manager of Eskom transmission, recently shed light on a few factors leading to the reduced intensity of load-shedding in the early mornings and daytime. Speaking to radio station RSG, Vosloo pointed out that self-generated rooftop solar power and decreased power station operating temperatures have been influential.

“The rooftop PV solar capacity is currently outperforming solar farms in power contribution,” Vosloo said.

• Eskom’s grid is powered by about 2,787MW of solar capacity from farms.
• Peak power supplied in April 2023 was 2,395MW.
• To beat this peak generation, between 375,981 and 438,645 rooftop solar systems would be needed.

There’s a good chance that a significant portion of the rooftop solar contribution mentioned by Vosloo comes from businesses who have adopted much larger rooftop solar systems.

Blowing Away Load-Shedding: The Impact of Wind Farms

Wind farms have also been punching above their weight in terms of energy generation. Eskom data indicates a peak contribution of 4,378MW in April 2023 from these farms. Vosloo suggests that recent daily peak generation ranges between 1,000MW to 1,500MW. This uptick in wind power has effectively reduced load-shedding stages.

Revived Coal Units and Better Efficiency: A Silver Lining for Eskom

Vosloo added that some coal power station units, previously under maintenance, have now been restored and are back online. These revived units have brought a substantial increase of around 3,000MW in capacity.

Additionally, power stations’ Energy Availability Factors (EAFs) have shown improvement due to natural cooling during winter, leading to better operational efficiency.

Energy expert Chris Yelland highlighted in a recent tweet that the EAF saw a week-on-week increase of three percentage points between Week 21 and Week 22 of 2023. However, this is still lower compared to the same week last year.

A Looming Threat: Wage Disputes Could Disrupt the Positive Trend

Despite the positives, Eskom is teetering on the brink of trouble as wage negotiations with its three biggest unions head into the final round. With unions rejecting Eskom’s highest offer of a 5.25% wage increase and demanding substantial hikes, Eskom’s recent respite from load-shedding could be short-lived.

High Peak Demand: A Persistent Challenge for Eskom

While daytime load-shedding has seen a reprieve, the power situation remains precarious during peak periods. Eskom’s recent consumption patterns show extensive reliance on diesel for running its open-cycle gas turbines (OCGTs) over peak demand periods.

The Prognosis: Cautious Optimism for Eskom

Despite the existing challenges, Eskom’s latest 52-week system outlook shows a slight improvement from a month ago. Winter weeks previously expected to have a deficit of 2,001MW or more, now show a deficit between 1,001 and 2,000MW. It’s not a perfect picture, but certainly a shade brighter than before.