State-owned electricity utility Eskom reported on Monday that an improvement in plant performance had enabled it to avoid load-shedding for 36 consecutive days since the declaration of an extended period of rotational power cuts in March.

However, COO Jan Oberholzer reiterated that the risk of load-shedding would remain for the coming six to 12 months, during which Eskom would implement a nine-point recovery plan to improve the energy availability factor of its underperforming coal fleet.

As part of a winter plan outlined jointly with the Department of Public Enterprises on April 3, Eskom said it intended to avoid load-shedding during the high-demand winter months, and that should cuts be required, they would be limited to Stage 1, or between 1 000 MW and 2 000 MW.

From March 14 to 23, a total of 595 GWh of load was shed by the utility over a period of ten consecutive days, with the supply deficit arising primarily as a result of a high level of unplanned breakdowns across its coal fleet.

The shortfall was exacerbated, however, when the deadly Cyclone Idai destroyed transmission infrastructure carrying power from Mozambique to South Africa, and after Eskom ran short of diesel and water reserves to power its open-cycle gas turbines (OCGTs) and its pumped-hydro schemes respectively.

During the height of load-shedding in March, unplanned breakdowns climbed to over 12 000 MW and, at points, Eskom instituted Stage 4 load-shedding, resulting in nation-wide cuts of between 4 000 MW and 5 000 MW.

Oberholzer attributed the recent improvement in plant performance partly to daily planned maintenance of more that 7 000 MW over the Easter weekend, during which unplanned plant failures fell to as low as 5 260 MW.

In a statement, Eskom reported that adequate diesel-tank levels at the OCGTs had also been restored, along with dam levels at the pumped-storage schemes.

One of the two power lines from Mozambique had been recovered, which meant Cahora Bassa was currently contributing up to 900 MW to the South African grid.

On April 14, Kusile Unit 3 was synchronised to the grid and the unit at the coal power station project had already achieved 400 MW during capability and acceptance testing, which would continue for the next few months.

“As we continue to perform essential plant maintenance, while carefully balancing the country’s energy requirements with the available capacity, the risk that we may implement load-shedding over the next six to 12 months remains. However, this will only be done as a last resort,” Oberholzer said.