Johannesburg - Eskom says it will embark on major capital investment projects and major repairs that carry significant risk and will serve to further increase load shedding.
Over the last few months Eskom has been rolling out different stages of load shedding and on Monday stage 3 load shedding returned.
Eskom said the return of the higher stage was due to the high level of breakdowns as well as the depleted emergency generation reserves.
Eskom said these risk factors would remove more than 2 300MW of generating capacity from the system.
Eskom cautioned the public to anticipate the increased risk of load shedding until these problems were resolved over the next six to 12 months.
On Tuesday Eskom held a state of the system media briefing, the power utility said it is concerned about the high levels of unplanned outages, which contributed to the 155 days of load shedding experienced since January.
To limit the stages of load shedding, Eskom said it 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 load shedding remains quite high,” said Jan Oberholzer, Eskom Group chief operating officer.
Oberholzer said that December 8, 2022, Unit 1 of the Koeberg Nuclear Power Station that’s had 384 days of uninterrupted supply today, would be shut down for normal maintenance and refuelling, and the replacement of the three Steam Generator Replacements (SGR) as part of the long-term operation to extend the operating life of Africa’s only nuclear power station.
He said the most reliable of Eskom’s generation machines, the unit was anticipated to return to service during June 2023. This would 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,” said Oberholzer.
He said on October 23, duct (chimney) structural collapse 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, had inflicted another serious blow to Eskom’s efforts to improve the availability of electricity generation capacity and to reduce the implementation of load shedding.
Oberholzer said this loss of the Kusile units added additional strain to an already constrained generation system.
“Unit 4 is the only one currently on load at Kusile,” he said.
Oberholzer said the extent of the damage to the Kusile duct system would be established over the next few weeks as investigations into the structural failure picked up speed.
The investigations into the duct failure would also establish whether there was any risk to Unit 3 of Kusile, whose chimney is also housed in the same stack as the other two units.
This would determine whether it could 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.
“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,” he said.
Oberholzer said while Eskom worked on returning these large units to service, they would have to continue limping along to meet demand for electricity, particularly over the next six to 12 months.
He said when it came to coal stock and rain readiness, Eskom continued 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%.
Oberholzer said the high levels of planned maintenance, impacted by a high rate of breakdowns, contributed to the low EAF.
He saId 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.
Eskom say 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.
Eskom said some of the existing generation capacity must be taken offline as the older power stations reach retirement age and the end of their licensed 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 licensed operating lives.
Within its own scope of influence, Eskom said it has led initiatives that would 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.
Eskom says this would produce at least 2 000MW in new generation capacity on approximately 6 200 hectares of land over the next few years.
The Star