South Africans could be suffering escalating power outages by the weekend following the collapse of a coal silo at power plant.
The country's power utility, Eskom, said that the blackouts that started on Sunday were likely to continue.
The news came as the government announced that Eskom needs $6.5bn (£4.7bn) to avoid a power crisis.
The power cuts are being blamed on poor maintenance practices stretching back many years.
Already tight capacity became further squeezed after the collapse of a coal silo at the Majuba power station in the east of the country on Sunday.
It is the second time this year that Eskom has imposed rolling blackouts.
The company generates almost all of South Africa's electricity and analysts say that the power outages could severely affect the economy.
The country's mining sector in particular is very vulnerable to any reduction in electricity available.
Last month, the national Treasury announced it would inject R20bn ($1.8bn) into Eskom, but some analysts say that is nowhere near enough to reverse years of underinvestment and lack of maintenance of the power infrastructure.
The blackouts and the potential for them to become worse has worried foreign investors for some time.
The rand fell slightly against the dollar in morning trade on Wednesday.