Eskom planning for stage 8 load shedding

 ·20 Feb 2023

Eskom says that it is in the process of reviewing its documentation and schedules that govern stages of load shedding, forming contingencies for if the country hits stage 8.

The power utility said that the review process is underway and is currently sitting with regulators and industry, and it will look at different stages of load shedding and contingencies for stage 8 – however, it stressed that this is not anticipated at this stage.

Eskom chief executive Andre de Ruyter said that the power utility is working hard to restore generating capacity, and hopes to de-escalate stage 6 load shedding by the weekend.

In state of the system update on Monday (20 February), the CEO said that Eskom currently has 23,877 MW of generation offline, which is roughly half the total installed capacity.

The is due to 3,766 MW being offline for planned maintenance, full load losses of 12,018 MW, partial losses of 5,993 MW, and outside losses – related to coal supply issues – of another 2,100 MW.

He said that the current evening peak is forecast at 27,782 MW, which presents a shortfall of around 5,834 MW, necessitating continued stage 6 load shedding.

De Ruyter said that the risk of stage 8 load shedding is always present, given the high levels of unreliability inherent to the grid and only having 2,000 MW to manouever around system failures.

He said the reason load shedding is implemented to protect the system from a total blackout and collapse, and the national operator has assured that there is a very low probability of a total blackout. This is largely thanks to load curtailment during time of high demand.

Stage 8 load shedding is part of the contingency in place, however. De Ruyter assured that the country is unlikely to go beyond that.

When will stage 6 end?

De Ruyter said that the power utility anticipates returning 3,000 MW to the grid on Monday, and 2,000 MW each on Tuesday, Wednesday and Thursday, which should bring stability to the grid.

This means that stage 6 load shedding is expected to continue until the Wednesday peak at the very least, after which stages will be downgraded to stage 4 and hopefully stage 3 by the weekend.

The chief executive said that the Open Cycle Gast Turbines are currently being run hard, which is why stage 6 load shedding is required.

He added the there were some diesel constraints over the weekend which caused issues – but these have been resolved. He said the funding issues around diesel have also been resolved with the backing of National Treasury.

The current shortfall is derived from a host of issues at play.

There are currently three units out at the Kusile Power Station. These have been rendered inoperable due to the fact there was a build up of slurry in unit 1’s flue, which collapsed.

When it collapsed, units 2 and 3 also collpased and were damaged to the extent they were no longer operable, de Ruyter said. This has led to 2,160 MW being offline.

In addition to this, Unit 1 of the Koeberg Nuclear Power Station is on an outage to extend its life by 20 years. The project is on track to be completed by the end of June. Following this, Unit 2 will be coming offline in August. However, the peak winter months in July and August will have full supply from the station. 928 MW is offline from the maintenance.

The balance of outages are due to critical failures of equipment. Kusile Unit 5 suffered an air gas heater fire – while some energy has been clawed back , it will only be synchronised in July. 700MW is offline from this unit.

Medupi Unit 4 – which suffered a hydrogen explosion – is only scheduled to return to service in September 2024.

De Ruyter also added that load loss due to high ambient temperatures (ie, weather), which affects the cooling system, also amount to 600MW. These losses are often not discussed.

In total, there is over 5,000 MW that is simply not structurally available, the CEO said.

Read: Stage 8 load shedding alarms are ringing

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