Johannesburg residents are among the only South Africans who experience four-and-a-half hours of load-shedding under stage 2, with most other South Africans only being subject to two-hour blackout periods.
Eskom recently rectified this for the areas of Johannesburg that it supplies, but City Power, which supplies power to the majority of built-up areas in Johannesburg, said its load-shedding schedule will remain unchanged.
This is because the nature of the electricity grid in Johannesburg makes it impossible to reduce load-shedding periods to two hours.
“We chose four hours because of many reasons – including our capacity to manage it, the interconnectivity of our network, and the ability of our infrastructure to handle the load-shedding demand,” City Power spokesperson Isaac Mangena told MyBroadband.
He said that unlike other power utilities in South Africa, City Power is not able to adequately separate areas into blocks for load-shedding on a more refined scale.
“For example, Tshwane is able to switch off Mamelodi and Attridgeville, without impacting parts of central Pretoria or Centurion. Ekurhuleni also can switch off Springs, or Vosloorus without impacting Katlehong, or Germiston,” Mangena said.
“With City Power, you have for example Orlando substation that feeds almost 20 substations, which may translate to 20 suburbs or townships such as Lenasia, Eldorado, Mulbaryon, Nirvana, Mondeor etc., most of which are in different geographic areas.”
“If we switch off Orlando, all those suburbs are going to be affected. So unlike other municipalities, we don’t have the luxury to separate our network blocks for now,” he said.
“There is nothing we can do”
Mangena noted the adverse effect that more than four hours of load-shedding has on South Africans who are working from home due to the COVID-19 pandemic, but said there is nothing City Power can do to resolve this.
“Load-shedding is done by Eskom, and as City Power, while we sympathize with our customers, there is nothing we can do,” he said.
“Even ourselves as the power utility we feel the pinch, more so in terms of the knock-on effect our network, infrastructure, and manpower in terms of tiredness and overtime.”
He said that switching off the power for four hours means that customers will lose power less frequently, and it has a reduced impact on the health of the municipal power grid.
“Currently, with four hours of load-shedding we switch customers off once a day, and maybe come back and switch them off after 24 hours,” Mangena said.
“We opted for that because with two hours it will force us to switch off customers frequently, at least two to three times a day.”
Substations exploding due to load-shedding
The municipal electrical infrastructure is also severely impacted by being switched off and on regularly, making four-hour load-shedding blocks preferable.
“By its nature, electricity infrastructure is not meant to be switched on and off,” Mangena said.
“Our ageing infrastructure won’t stand two-hour frequent switching. Already, we have a challenge of substations blowing up due to on and off of load shedding.”
“[On Monday] at Nursery substation in Roodepoort, a transformer blew up after restoration. The same thing happened in Ennerdale, Randburg substations, etc.,” he said.
City Power, therefore, has no current plans to adapt its load-shedding schedule, although it noted that it had received a number of suggestions from “different stakeholders”.
“If anything changes, we will involve our customers and communicate accordingly,” Mangena said.