It’s called load rotation and this week it plunged large swathes of Joburg into darkness.
The new term is being used by City Power to explain a series of imposed rolling blackouts across the city that the utility apparently had to implement to ease the pressure on an ageing infrastructure.
Load rotation, said officials, would be around for the foreseeable future as poor maintenance and under-performance was expected to trigger more outages across the city.
But for many Joburgers, the new blackout buzzword was confusing, with many over the last couple of days, believing the darkness was caused by load shedding Eskom had introduced.
But as Nico de Jager, MMC for Environment and Infrastructure Services, explained, load rotation was implemented by City Power and was localised to suburbs that were directly affected by a lack of capacity from a substation. Power, he said, was rotated to the different suburbs that were affected. Load shedding was done by Eskom to reduce high demand.
Load rotation was done for longer with some suburbs going without power for five hours at a stretch.
On Thursday evening, residents across the eastern suburbs of Joburg had their own experience of load rotation when a newly commissioned transformer at the Sebenza substation blew a gasket.
According to De Jager, it would take between three and four days to fix the gasket, but in the meantime the plan was that Kelvin Power station would increase supply to cover the electrical shortfall. The increased supply, he said, was likely to be available from last night.
City Power, however, issued a warning to residents. “We urge all our customers to use electricity sparingly and switch off geysers and other appliances that are not in use,” City Power said.
“But it is going to get worse before it gets better,” said De Jager.
The planned blackouts that were supposed to ease the city’s electrical grid was also causing harm to infrastructure.
Energy expert Ted Blom said that during a power outage transformers, that had not been maintained properly, tripped when the electricity was switched on again.
“The problem is that transformers need to have their oil changed every seven years and this is not being done,” he said.
He believed it could take years to sort out the problem.
There have been complaints by residents that there have been no advanced warnings to these load rotations and schedules posted on the City Power website were not being adhered to.
De Jager conceded that City Power’s communication on the cause of the recent spate of blackouts was poor.
Ronald Chauke, Outa’s portfolio manager for energy, said there was a lot of confusion over who was causing the blackout. “Eskom and City Power keep blaming each other for load shedding,” he said.
Eskom spokesperson Khulu Phasiwe, however, said this was not the case and that it and City Power worked closely. Eskom had not carried out load shedding since June 16.
However, as more outages were likely, there was a growing concern about what affect this would have on the economy.
While it was difficult to estimate the cost of power outages, Chauke believed that a day of load shedding could bleed as much as R5billion from the economy.
“What we need is for the energy sector to be reformed for there to be more competition so that you and I can choose who we want to use as a power supplier,” said Chauke.
Joburg was expected to be hit with another cold front next week. By Tuesday, Gauteng could face temperatures in the mid-teens, with cold nights.
The chill was expected to put extra pressure on the grid, and could subject Joburg to more blackouts - this time under that new name, load rotation.