Johannesburg - South Africa's electricity system remains severely constrained and unpredictable and this will necessitate rolling power cuts until Friday morning, state utility Eskom said on Thursday.
In a statement Eskom, which has struggled with breakdowns in its generating units in recent months, said it had lost additional generation capacity overnight with breakdowns of over 14 000 MW.
"Our emergency reserves are also insufficient to meet the demand for electricity during the day. As a result we have to load shed throughout the day until tomorrow," it said.
"Owing to inadequate maintenance over a number of years, the system remains vulnerable to unplanned outages. We remind customers that load shedding is an essential and controlled measure to ensure that the integrity of the grid is not compromised."
The company will effect Stage 2 load shedding, which entails suppressing up to 2 000 MW of demand to avoid tripping the national grid.