Johannesburg – The construction of Eskom silos is under scrutiny following the devastating collapse of a coal silo at one of South Africa’s biggest power stations.
While reports early on Monday morning said that load shedding has been suspended, Eskom warned on Sunday that electricity supply will be tight for weeks – possibly months – until the damaged Majuba infrastructure is rebuilt and other silos checked for flaws.
Majuba’s output dropped from 3 600MW on Saturday morning to just 600MW on Sunday night, and Eskom expects a difficult week ahead as it aims to stabilise the system and build up generating reserves.
Despite the weekend’s relatively low industrial and commercial demand, Eskom on Sunday had to load-shed 1 500MW.
Eskom group executive (sustainability) Steve Lennon said there were risks of load shedding this week, particularly on Monday night from 6pm to 8pm, Wednesday from 6pm to 10pm and through the whole of Thursday.
Eskom said load shedding would be avoided if possible, but urged consumers to check load-shedding schedules.
The investigation into the silo collapse has already started.
“We aim to identify the causes so that we can fix that gap. But much more than that, provide assurance to business that we are not running similar risks on other similar designs not only at Majuba, but at other stations as well,” Eskom’s acting group executive (technical and commercial) Matshela Koko said.
He added that they would check three key areas:
* The silo designs – to assure themselves there were no design flaws and that the designs are still appropriate.
* The construction itself.
* Whether the silos were used appropriately.
Concerns are also focusing on construction flaws.
“These type of silos don’t have a history of failure,” Koko said. “Globally, the failure at Majuba is the second of its kind.” The other was in Germany.
Koko said the silo collapse had been captured on camera, which would help to discover what happened, and there were “adequate clues in the rubble”.
He said the concrete reinforcement rebar may not have been adequate, and there were indications of corrosion.
Sabotage is not regarded as likely. “I don’t see anything now that points to sabotage. We don’t suspect it,” Koko said.
Majuba is one of the youngest power plants, coming fully on stream in 2001. The coal silos should last for at least 50 years.
“We are concerned about the type of defects we see,” Koko said. “We won’t load the other silos until we have inspected them.”
Koko confirmed reports that the silo in the Majuba stockyard was defective and had not been used for a decade, but said this had nothing to do with the current problem.
Eskom’s first priority was to ensure Majuba was safe and could operate in the short term.
Eskom group executive (generation) Thava Govender said it could take about two weeks to clear the rubble of the collapsed silo.
With the collapsed silo blocking the central conveyor belts, Eskom is trucking coal to manually load the silos further down the conveyor belts to get coal to some units.
Keeping those boilers running means running about 15 trucks an hour, plus front-end loaders to load trucks and other equipment.
The Majuba problem means the utility will now also have to rewrite its summer maintenance programme to juggle available power. Some maintenance can’t be rescheduled as it is required by law or for safety standards, Eskom said.
Eskom isn’t putting time frames on fixes or investigations yet.
“We need to allow the next few days to explore solutions,” Eskom acting group executive for capital, Dan Marokane, said.
So that means it’s back to the deeply unpopular load shedding.
Social networks are already full of complaints, with people posting about power blackouts – from Joburg and Pretoria to Port Elizabeth and Cape Town.
Eskom repeatedly apologised for the problems on Sunday.
Lennon said that while load shedding would be kept to a minimum, consumers should expect “very tight months” into next year.
It’s going to cost as well, not just to rebuild Majuba, but also to run the expensive open cycle gas turbines. Lennon said it was worth using these as the cost to the economy of not using those power stations was far greater.
“This is my baptism of fire,” said Eskom chief executive Tshediso Matona, who took office at the beginning of last month.
Check the schedules online:
For Eskom direct customers, look on Eskom’s website at www.eskom.co.za.
City of Joburg customers should look on www.citypower.co.za or call City Power’s hotline 086 056 2874.
Ekurhuleni metro customers should look on www.ekurhuleni .gov.za
The load-shedding schedules do not mean that power will definitely be off during those times, but that if the municipality or utility has to drop power usage at that time, then those specific areas will be cut.
The load shedding does not rule out other cuts for planned maintenance (which should have advance notice) or for unplanned cuts due to equipment failures or theft.
The Ekurhuleni metro said it had been load shedding since 8.30am on Sunday, in line with Eskom’s request.
The City of Cape Town said the load shedding schedule for Cape Town was at a stage 3 on Sunday (a 4 000MW savings).
Neil Ballantyne, head of revenue protection and electricity services, said it was important to note the city was wholly reliant on Eskom for the electricity supply to the entire city.
“The city regrets the inconvenience caused, but would like to assure residents that all areas are treated fairly, whether they are supplied by the city or by Eskom.”
He urged consumers to do their part by switching off non-essential appliances and monitoring their usage.
“If a customer’s electricity supply remains off for longer than the period specified in the schedules, they should please send an SMS to the city’s technical operations centre on 31220. “Residents are requested to minimise water usage because in some instances water supply is reliant on electrical pumps.”
Load shedding schedules are available on the city’s website. http://www.capetown.gov.za/en/electricity/Pages/LoadShedding.aspx
Eskom customers can contact its customer call centre on 0860 037 566.
On Sunday night the eThekwini Municipality urged consumers to use electricity sparingly.
Deena Govender, the city’s senior manager for electricity pricing and marketing, said the power cuts started at about 8am. Two “blocks” or areas were taken down at a time for about two hours.
“This will be until Eskom sorts out the problem. The load shedding will happen between 8am and 10pm,” he said.
Govender urged consumers to ensure they switched off all appliances and only switched them on again, as needed, when power returned.
He urged residents to follow the schedule at http://www.durban.gov.za/Documents/CityServices/Electricity/loadshedding_schedule.pdf.
Eskom said load shedding had been done to ensure the power grid did not suffer a blackout.
Parts of Tshwane were without power as the loadshedding schedule kicked in, much to the disappointment of residents who complained that Sunday was a bad day to be without electricity.
Some said the blackout went on for longer than the two hours scheduled under the programme published by the city, while others said they were not on the schedule but had no power.
The blackouts would be on a two-hour rotational basis. Residents are advised to visit www.tshwane.gov.za to view the blackout times. – Additional reporting from Pretoria News, Cape Argus and The Mercury.