Eskom managed to keep the lights on for nearly 10 consecutive days, offering a welcome break from the persistent specter of load shedding. However, on Sunday, the unwelcome announcement of “Stage 2 and Stage 3” load shedding made a return at 4 pm, with Stage 3 implemented overnight and Stage 2 in place on Monday.
This marked the end of the longest load shedding hiatus since September of the previous year.
Contributing Factors to Load Shedding Suspension
Eskom’s ability to stave off load shedding for this duration was attributed to several key factors.
First, the return of two units at the Kusile Power Station, which exceeded expectations on the temporary recovery plan following a flue duct collapse last year, contributed around 1,000MW to electricity generation.
While it is uncertain if these units have reached their full production capacity, their return provided a much-needed boost to Eskom.
Coal Fleet Performance
In addition to Kusile’s contribution, the coal fleet’s efficiency, albeit temporary, showed significant improvement.
The coal fleet consistently produced over 20,000MW, representing a remarkable performance given that it struggled to reach 18,000MW during the coldest winter months.
Kusile alone accounted for half of this improvement, and for several hours, the coal fleet even surpassed 22,000MW of generation.
Energy Availability Factor
These factors have had a substantial impact on Eskom’s energy availability factor, which measures the available generation capacity. It reached a yearly high of 60.46%, a notable achievement. The previous highest recorded was 59% in week 23.
The Role of Other Contributors
Apart from the coal fleet, other elements have played a role in the absence of load shedding. Two weeks ago, Eskom used its open cycle gas turbines (OCGTs) sparingly, relying on them for fewer than 10 hours.
However, over the past week, there was a shift in this trend, with a significant reliance on burning diesel, particularly from Tuesday onward.
Wind energy also played a part, generating up to 2,500MW two weeks ago and maintaining a similar level of contribution last week.
However, wind generation decreased from Tuesday, increasing the reliance on diesel. The recent cold front has boosted wind capacity.
During daylight hours, solar photovoltaic systems produce between 1,500MW and 1,900MW. While Eskom doesn’t account for the nearly 4,000MW of installed solar capacity from businesses and residential customers, it undoubtedly helps reduce daytime demand.
Challenges and Upcoming Demands
Eskom currently faces breakdowns in generating capacity totaling 16,150MW, along with 5,950MW out of service for planned maintenance.
Monday night is expected to have a peak demand of 27,557MW, which is lower than the winter peak demand profile by approximately 5,000MW.
In summary, a combination of factors, including the return of units at Kusile, improved coal fleet performance, contributions from wind and solar energy, and reduced demand during daytime, contributed to Eskom’s temporary reprieve from load shedding.
However, the utility continues to face challenges, especially as it anticipates increasing demand during the colder months.