Johannesburg - Electricity supply will be extremely tight from April to July, Public Enterprises Minister Malusi Gigaba said in Johannesburg on Tuesday.
"As we are heading to winter, I would like to urge that electricity be used carefully," he said at a briefing by Eskom on the state of its system.
He said improvement of Eskom's maintenance practices was moving in the right direction.
"This will eventually ensure long-term security of reliable electricity supply."
He urged the country to continue supporting Eskom's effort to "keep the lights on".
"No effort is insignificant in this regard."
Eskom CEO Brian Dames said on Tuesday that the first unit of power utility Eskom's Medupi power plant is still due to come on line in the second half of 2014.