Johannesburg - Power utility Eskom will implement Stage 4 load shedding from 5pm to 10pm on Monday night.
The power provider said it was implementing load shedding due to a further loss of generating capacity.
Eskom spokesperson Sikhonathi Matshantsha said: “Unit 2 of the Kusile Power Station tripped earlier this afternoon, taking 720MW of generating capacity with it. While this unit has since returned to service, it will slowly load up to full capacity during the night.
“This added loss of capacity regretfully requires Eskom to increase load shedding to Stage 4 from 5pm until 10pm tonight.”
Eskom said it would continue to closely monitor the system.
The power utility said there were other challenges causing constraints to the grid, but it also reported that several generating units had returned to service at the Hendrina, Tutuka and Kriel power stations.
However, a unit at the Arnot Power Station was taken off-line for repairs.
Matshantsha said: “We currently have 1 904MW on planned maintenance, while another 17 255MW of capacity is unavailable due to breakdowns.
“Eskom would like to remind the public that load shedding is implemented only as a last resort to protect the national grid.
“We therefore urge all South Africans to continue using electricity sparingly, especially between 5am and 9am in the mornings and 4pm to 10pm in the evenings.”
On Monday afternoon, Eskom appealed to all South Africans to reduce their usage of electricity in order to limit the impact of load shedding.
Last week, Eskom implemented Stage 2 load shedding between 5pm and 10pm in the evenings as the grid continues to be constrained.