Johannesburg - Eskom CEO Brian Dames on Thursday guaranteed that the parastatal will keep the lights on, despite heavy rains across the country affecting coal supply to power stations.
"Early heavy rainfalls have required us to activate contingency plans to minimise disruptions to coal production and logistics," he said.
"Challenges remain due to coal handling and coal quality issues," Dames said at a media briefing in Johannesburg.
Coal stockpiles are reported at an average of 41 days across the system.
Dames says Eskom has enough capacity between now and the end of summer, but warned about tight supply.
"The bottom line is the system is tight; we don't have adequate reserves. The pressure going forward is about having enough reserves," he said.
In addition to unexpected heavy rains, Dames said other risks included the unplanned shutdown of a unit at one of its biggest stations, Koeberg.
As a result, maintenance at other power stations has been rescheduled until the Koeberg unit returns to service, which is expected by this month.
Eskom said energy demand is currently about 29 000 megawatts (MW), but this is expected to rise to between 31 000 MW and 32 000 MW over the next two weeks.
Demand is set to increase by winter to about 38 000 MW.
"In the next two years, there is an energy gap and therefore an immediate focus is needed on energy efficiency," said Dames.
He said the utility wanted to take a different route to balance the gap between electricity demand and supply.
"We have started work and we are monitoring the system. We will start doing things differently," he said.
Dames appealed to electricity users, including big companies, to do their part in saving electricity.
"If you are not using it, switch it off."