Eskom’s generating capacity is threatened with further instability because 12 power units could cease abruptly, creating a shortage of 4 956 megawatts.
(Madelene Cronje)
The relief from load-shedding in the new year has been short lived.
Eskom chief executive André de Ruyter said after weeks of good performance at the state power utility’s units, the situation has rapidly deteriorated. He likened the developments to the system going into cardiac arrest before stage two load-shedding had to be implemented.
This comes just a week after Eskom held a briefing on improvements in the system’s performance.
A number of units have broken down; others are taking longer to come back on line than anticipated.
De Ruyter emphasised that a system collapse would mean it would take two to three weeks to get the power grid back online.
“There are two reasons mainly: the first one is if there is inadequate supply, the second one is to maintain an adequate amount of reserves. Because we’ve had some challenges with the system, we have depleted our emergency reserves to the point that we risk not having back-up supply in the event of further issues with the generation system,” he said.
Eskom is running on diesel to keep the lights on at a hefty cost to the utility.
“Because of the poor performance of our coal-fired generation, we’ve had to run diesel to replenish our pump storage, which is a very expensive exercise, and something that we are loath to do,” De Ruyter said.
“Diesel remains a major concern, which is exacerbated by the increase in the diesel price, which caused a run on diesel immediately prior to the price increase last night, so supplies have run low.”
Eskom’s emergency reserves refers to the amount of pump-storage hours and the levels of diesel it takes to power them.
The shortage of generation capacity is also exacerbated by the loss of 720 megawatts of generation capacity at Medupi’s unit four, which was rocked by a hydrogen explosion. It will take two years to repair, at a cost of R2.2-billion.
At Koeberg, the nuclear power station in the Western Cape, De Ruyter said the station was currently being refuelled. The National Energy Regulator of South Africa gave Eskom the green light on 18 January to replace Koeberg’s three steam generators and work on this has commenced.
“Koeberg is incredibly competitive from a cost perspective. It is largely depreciated, and the plant has been very well maintained. As such, we are confident in applying to the nuclear regulator for a 20-year extension for the life of that plant,” De Ruyter told reporters on Wednesday.
Eskom’s chief operating officer Jan Oberholzer said the Duvha and Tutuka power stations remained among the most challenging, running on only three of five units. There were also challenges at Kendall, where the units are much bigger, at 600MW each. The power station is running on only four units.
“A power station that we did not expect to give us challenges was Kusile. For the last five days we had no units running. Kusile [unit] one came up a few times just for it to trip again. Yesterday we had some specialised resources on site. We may have been able to resolve some of the challenges and that unit may come online today,” Oberholzer said.
He emphasised that Eskom needed to ensure it was not running on diesel overnight.
“When we started reliability maintenance about 18 months plus ago, we were not ready and it is very difficult if you do not have an outage readiness of 80% plus before you open the breaker, so we do have some challenges. However we will continue and we will not sacrifice the reliability maintenance for the future,” he said.
Oberholzer said Eskom’s coal fleet remained unreliable and extremely unpredictable.
Tunicia Phillips is a climate and economic justice reporting fellow, funded by the Open Society Foundation for South Africa.