Eskom says it has experienced a dramatic reduction in demand for electricity ahead of a three-week lockdown period, with demand dropping by some 6 000 MW on Thursday.
It expects demand to drop further during the 21 days, scheduled to kick off at midnight on Thursday night.
However, it said in a statement, it has had to take some units of the grid ahead of lockdown, which remain on standby should the need arise.
Eskom has previously said it does not anticipate having to implement any stage of load shedding during the lockdown, implemented to curb the spread of coronavirus.
While the power utility is classified as an essential service - meaning it may continue operating during the lockdown period - it has discontinued ongoing maintenance of its ageing plants for the time being, it said in a statement issued on Thursday evening.
This is because the number of staff on site must be kept to a minimum.
However, the statement said, some personnel are exempt from the lockdown and will be able to ensure electricity is supplied.
* Compiled by Marelise van der Merwe