Current stage 2 load shedding to last until 22:00

Cape Town – Eskom has implemented stage 2 load shedding from 08:00 on Sunday, which will likely continue until 22:00 in the evening, it said in a power alert.

This was due to a shortage of generation capacity as several units were currently on unplanned outages "due to technical faults".

Koeberg unit 1 offline until June

Eskom said that Koeberg power station’s unit 1 would be shut down from on Monday for a scheduled refuelling, inspection and maintenance outage and is expected to return back to service at the end of May.

The unit has been down since last Sunday, when it tripped due to an earth fault, which was triggered by a scaffold touching the neutral earthing bar above the restricted earth circuit, Eskom said. "At 20:20 on Thursday, 5 February 2015, while the unit was being synchronised to the national grid, a breaker trip occurred resulting in a turbine trip."

The scheduled shutdown of Koeberg Unit 1 is part of Eskom’s overall maintenance programme for its fleet of power stations. Every 16 to 18 months, each of the two units at Koeberg is shut down for refuelling, inspection and maintenance. The routine shutdowns are scheduled so as to avoid having both units out of service at the same time and to avoid the winter months in each year, Eskom explained.

"During these routine planned outages, one third of the used nuclear fuel is replaced with new fuel," it said. "Statutory inspections and maintenance is performed, and modifications, that will ensure that international safety standards continue to be met or that improve the plant performance, are implemented."

Weekend load shedding

In a power alert issued late on Saturday, Eskom said it had stopped stage 2 load shedding at 22:43 that evening, 43 minutes after it was supposed to end. "It is important to note that restoration of power takes longer in some areas," it said.

"There is a shortage of generation capacity due to units that are currently out of service due to planned and unplanned maintenance," it explained.

"The focus is on returning the units that are on unplanned maintenance back on line in order to increase available capacity.

"Eskom will also use the weekend to build up diesel stocks and dam water levels for the open cycle gas turbines and pumped storage schemes respectively in order to ensure that these reserves are available to meet the electricity demand in the new week.

"We would like to thank all the customers who responded to our call and reduced their energy consumption, which helps reduce the severity of load shedding. We sincerely apologise for the inconvenience to affected customers.

"Eskom implements load shedding as a measure of last resort to protect the power system from collapsing, and we only shed what is required to balance demand and supply.

"The system will continue to be under severe pressure over the weekend and next week."