The power utility says electricity should be used sparingly between 5pm and 9pm.
Steve Lennon and Erica Johnson have resigned from the power utility.
The resignations come as the embattled parastatal battles financial problems.
The agreement will see Russia’s atomic energy agency providing up to eight nuclear reactors to South Africa.
The deal paves the way for the building of up to 9.6 gigawatts of nuclear power plants by 2030.
South Africa has up to five years to go before its electricity supply crisis is over.