Eskom’s summer outlook presented to lawmakers recently is incredibly disturbing and shows that the near-term prognosis for security of supply is as bad as it’s ever been.

Even though the utility’s ‘base case’ is premised on more realistic, albeit far higher, unplanned breakdowns of 13 000 MW, recent events suggest that there will be periods when those breakdowns exceed Eskom’s stressed-tested worst-case scenario of 16 000 MW.

In other words, while the base scenario points to 22 days of mostly Stage 1 load-shedding for the period from September to the end of March next year, South Africans should be bracing for worse.

Having already experienced more than 100 days of cuts this year, South Africans have a right to feel angry and anxious.

These anxiety levels would have increased further, given the incredibly poor performance of Eskom’s coal fleet during the initial days of September, when 42 generation units tripped in a single week, precipitating a sustained period of rotational cuts, often at Stage 4.

During that period, unplanned outages breached the 16 000 MW threshold on several occasions. It also coincided with a worrying underperformance of Koeberg Unit 2, which has tripped twice following its eventual return to service on August 7, having been shut on January 18 for an extended maintenance programme that was meant to have included the replacement of the unit’s three steam generators.

In the event, Eskom was entirely unprepared for the replacement, despite it running several years late, and the new steam generators are now scheduled to be installed only in August 2023, less than a year before Koeberg’s operating licence is due to expire.

Any licence extension hinges on the replacement of all six steam generators across both reactors, with Eskom still intending to take down Unit 1 in December for its extended maintenance.

In other words, Koeberg will not deliver more than half of its output for most, if not all, of the coming year, resulting in at least one stage of additional load-shedding when Eskom resorts to such cuts. There is also a risk that, given the delays and the obvious problems at Koeberg, the National Nuclear Regulator will not be in a position to grant Koeberg the 20-year life extension, on which the extended maintenance programme is premised.

Given that no large-scale capacity can be realistically installed in the coming 18 to 24 months, Eskom will continue using the same costly levers to balance the system over the period: diesel and load-shedding.

The direct costs of running the diesel plants to Eskom are massive, with R7.7-billion having already been burnt in the first half of the utility’s financial year.

The indirect costs of not running Koeberg, meanwhile, dwarf the official R20-billion life-extension budget.

Ending this vicious cycle requires massive and rapid investment in solutions that will deliver least-cost and clean electricity. No such electricity will be delivered from a 3 000 MW combined- cycle gas plant in Richards Bay, leveraged to volatile, dollar-based fuel imports.