South African power utility Eskom resumed rolling power cuts on Wednesday, plunging millions in Africa's most advanced but ailing economy into darkness for a fourth day in a row.
South Africa is in the middle of its worst electricity crisis since 2008 and South Africans are subjected to frequent controlled blackouts, which Eskom implements to prevent the grid from collapsing.
(READ MORE: Eskom switches to stage 3 load shedding)
Eskom, which provides 95 percent of the country's power, said it would cut 2,000 megawatts from 0400 GMT until 2000 GMT.
"The electricity supply system remains very constrained and vulnerable due to a shortage of generation capacity as several units are currently out of service due to planned and unplanned outages," it said in a statement.
(READ MORE: Government knows Eskom solution but lacks resolve)
Eskom is scrambling to build new power stations to ease razor-thin supply margins, but has been beset by delays at its massive Medupi plant where construction was hobbled by labour relations squabbles this week.
An extended series of rolling power outages in 2008 caused misery for millions and cost the country billions of dollars in lost output.