Eskom has warned of prolonged loadshedding over the next few months as major capital projects and repairs will reduce available generation capacity.

Starting over the next few weeks, these projects and repairs will remove an additional 2300MW of generating capacity from the system.

The power utility anticipates a high risk of loadshedding for the next 6 to 12 months.

Of serious concern is the high levels of unplanned outages, which contributed to the 155 days of loadshedding experienced since January.

To limit the stages of loadshedding, Eskom had to heavily rely on the extensive use of open-cycle gas turbines (OCGTs), burning millions of litres of diesel.

“Due to the vulnerability and unpredictability of the power system, coupled with the major capital projects, maintenance and major repairs to be executed starting during the next few months, the risk of continued loadshedding remains quite high,” said Jan Oberholzer, Eskom Group Chief Operating Officer.

On 08 December 2022, Unit 1 of the Koeberg Nuclear Power Station, which has enjoyed 384 days of uninterrupted supply today, will be shut down for normal maintenance and refuelling, and the replacement of the three Steam Generators (SGR) as part of the long-term operation to extend the operating life of Africa’s only nuclear power station.

The most reliable of Eskom’s generation machines, the unit is anticipated to return to service during June 2023. This will remove 920MW of generation capacity from the national grid during this time.

Koeberg Unit 2 was returned to service after a forced shutdown to remedy the control rod slippage issue and has been operating for 51 days today.

The 23 October 2022 duct (chimney) structural collapse that has shut down Unit 1 of the Kusile Power Station; and the decision to delay the return to service of Units 2 and 3 as a precautionary measure, has inflicted another serious blow to Eskom’s efforts to improve the availability of electricity generation capacity and to reduce the implementation of loadshedding.

This loss of the Kusile units has added additional strain to an already constrained generation system. Unit 4 is the only one currently on load at Kusile.

The extent of the damage to the Kusile duct system will be established over the next few weeks as investigations into the structural failure pick up speed. The investigations into the duct failure will also establish whether there is any risk to Unit 3 of Kusile, whose chimney is also housed in the same stack as the other two units. This will determine whether it can be returned to service. Unit 3 was online at the time of the duct failure and continued generating at a steady pace for a week.

Eskom says what can be said with certainty at this point is that returning the Kusile units to service is still at least a few months away.

Major repairs and maintenance projects

“This is the reality of operating a shrunken generation system bereft of any reserve margin – every single breakdown pushes the whole system to the edge,” said Oberholzer. “This loss of capacity, temporary as it is, will make for a very challenging summer season, particularly as this is our peak planned maintenance period where a number of units at various power stations have to be shut down to conduct much needed maintenance.”

While Eskom works on returning these large units to service, we will have to continue limping along to meet demand for electricity, particularly over the next six to 12 months, said Oberholzer.

Coal stock and rain readiness

This means Eskom continues to experience a tough period in terms of its generation operations, especially on the coal generation side of the business, with the year-to-date energy availability factor (EAF) falling to the current 58.53%. The high levels of planned maintenance, impacted by a high rate of breakdowns, contributed to the low EAF.

There has, however, been some notable progress and sustained good performance on several aspects of the business. Coal stock levels are healthy at an average of 35 days, excluding Medupi. Including Medupi, this doubles the coal stock-days to just under 70.

Rain Readiness plans have proven to be resilient and have ably withstood the unusually high summer rainfall season last year, which included heavy storms that caused considerable damage in some parts of the country with critical generation infrastructure. The plans are in place for the current rainy season.

“All coal-fired power stations plans have been stress-tested to ensure they are again able to withstand the high rainfall period,” said Thomas Conradie, the Acting Managing Director for Generation.

The Transmission and Distribution divisions are performing to expectation. However, increased equipment failure, theft and vandalism on the transmission and distribution networks negatively impact operations, safety, and reliability. Electricity theft and non-payment continues to manifest as both operational and financial risk.

New Build Programme

Kusile Unit 4 achieved commercial operation on 01 June 2022, ahead of the expected target date of January 2023, and is currently producing the maximum 720MW. This brings the capacity brought to the national grid through the New Build Programme since 2005 to a total of 15 533MW.

A fire during commissioning in the Gas Air Heater of Kusile Unit 5 on 17 September 2022 has delayed the commercial operation of this unit by an estimated 12 months. The unit was scheduled to be synchronised to the grid early 2023 and contribute to the grid during capability tests prior to commercial operation, which was planned for the middle of 2023.

Retiring power stations and the Just Energy Transition

Some of the existing generation capacity must be taken offline as the older power stations reach retirement age and the end of their licenced operating lives. The last unit of Komati Power Station was taken offline in October. Generating units at Grootvlei, Hendrina and Camden power stations must also be taken offline over the next five years as they will reach the end of their licenced operating lives.

Within its own scope of influence, Eskom has led initiatives that will result in four independent power producers to invest at least R40 billion in new renewable plants on land leased at four of its power stations. This will produce at least 2 000MW in new generation capacity on approximately 6 200hectares of land over the next few years years.

This is the first phase of the land lease programe, which will raise hundreds of billions in renewable energy investment without any underwriting recourse to Eskom and the taxpayer.

To contribute to closing the supply gap, Eskom will repurpose these power stations and take advantage of the existing Transmission infrastructure in these facilities and convert these coal-fired power stations to renewable sources. This not only allows Eskom to continue generating much-needed electricity in these and other areas, but also to continue extending economic opportunities to the host communities under its Just Energy Transition programme.

The process to convert the retired Komati Power Station to renewable energy sources commenced in earnest during September, when Eskom and the Cape Peninsular University of Technology opened the first accredited renewable energy training centre in South Africa at the power station. The South African Renewable Energy Technology Centre (SARETEC) is dedicated to training existing Eskom employees and members of the community as technicians and artisans to manufacture, install and maintain renewable energy components.