Former Eskom COO Jan Oberholzer said improved power station reliability, lower demand, less maintenance, more rooftop solar, and burning more diesel helped to reduce load-shedding.
Oberholzer will leave Eskom on 31 July 2023 after he has agreed to part ways with the power utility by mutual agreement.
Oberholzer was on a fixed-term contract to support the Koeberg Nuclear Power Station’s long-term operation and Kusile Power Station projects.
He shared his views on the lower-than-expected load-shedding this winter, saying there is nothing sinister behind it.
The former Eskom COO said five factors have helped limit power cuts to stage 6 so far this winter.
- Improved power station reliability – When Andre de Ruyter took office in January 2020, Eskom launched a comprehensive maintenance plan to improve power station reliability. The results are starting to filter through.
- Lower demand – Winter electricity demand this year is between 850 MW and 1,000 MW lower than last year. This accounts for one load-shedding stage.
- Less planned maintenance – Eskom has significantly reduced its planned maintenance in recent weeks, increasing the energy availability factor and limiting the need for higher stages of load-shedding.
- More rooftop solar installation – South Africa’s installed solar rooftop PV increased from 983 MW in March 2023 to 4,412 MW in June 2023. This helped Eskom to have less demand during the day,
- Burning more diesel – Eskom is spending far more on diesel to run its Open-Cycle Gas Turbines (OCGTs). In 2023, it has already spent R12.4 billion on diesel.
Oberholzer said the impact of increased rooftop solar PV was particularly striking as it significantly decreased daytime electricity demand.
Previously, Eskom saw two demand peaks in the morning and evening, with relatively high daytime demand between these two peaks.
In 2023, the situation changed. Daytime demand is significantly lower, which helped Eskom to limit the use of emergency reserves like pumped storage during the day.
A much higher diesel budget further means that Eskom had more freedom to use OCGTs to limit load-shedding.