The power utility switched to Stage 2 blackouts from 14:00 on Friday afternoon.
Eskom said in his latest System Status Bulletin released on Thursday that the electricity system remains significantly constrained, but the situation is expected to improve slightly going into the weekend, when electricity demand eases slightly.
However, it will return to being constrained next week
Eskom implemented stage 1 load shedding, moving to stage 2 later in the day for most of the week due to a shortage of generating capacity. Several units are currently out of service due to maintenance, it said.
According to Eskom although certain areas will be without electricity for a certain period, about 96% of South Africans will still continue to receive power supply at the same time.
The power utility called on all South Africans to pull together over the next few months and use electricity sparingly.
Homeowners and businesses can do so with just four steps: first, switching off geysers and pool pumps; second, switching off non-essential lights; third, efficient use of air-conditioners by keeping the room temperature at 23°C; and finally, responding to the alerts on TV each evening, it said.