Eskom chief executive Brian Dames warned on Thursday that the utility faced a long summer of maintenance of its power plants, increasing the risk of load-shedding.
Dames was speaking at a press conference in Cape Town, part of Eskom’s quarterly briefings on the state of the country’s electricity system.
The capacity of municipalities to handle the demand on their local distribution systems was also a key issue because it was from them most residential users received their power he said.
Although the system was tight, Eskom was confident that South Africa would not return to the dark days of power blackouts.
“We have made it clear that we can’t guarantee that [load-shedding] will not be the case. But I am confident that we can deal with this,” Dames said.
Eskom’s reserve margin had increased to just under 17%, said Dames, although this was forecast to fall to about 14% once the impact of maintenance was felt.
He said Eskom had a maintenance backlog of about 30 planned outages — the majority of which involved the shutdown of plants for inspection.
Most residential customers, however, “sit behind municipalities” and much investment was needed by municipalities to upgrade their networks, many of which were decades old, Dames told the Mail & Guardian.
“They [municipalities] are critically looking at upgrading their networks,” he said.
“Where we are required to assist, we certainly will. The company will be investing R10-billion in upgrading its networks this year.”
Dames said that this year’s winter, when peak demand rose dramatically in the mornings and evenings as South Africans heated their homes, had not been as difficult a period as had been anticipated.
This was thanks in part to the reduction in demand by large industries that were paying higher tariffs over the winter months and were therefore saving power.
Strikes also meant that the use of power in large industries such as mines had dropped off during some of the coldest weeks of winter.
Weaker than expected economic activity, though a negative sign for the country as a whole, had been another factor in making power usage lower than expected, he said.
But tough weeks are forecast for the summer months, particularly in October and November, when Eskom forecasts shortages of between 1 000 and 2 000MW during peak times.
Eskom is still pushing to have a mandatory power conservation scheme introduced for its largest customers, if savings from its 500 top power users cannot be secured voluntarily.
About 134 large users are already participating in a voluntary energy conservation programme.
Dames stressed that Eskom wanted to introduce this as a further safety net. “It is something we want to have, but ideally never use,” he said.