Eskom's derived Energy Availability Factor fell again in September, to 69.5%. Unlike August, when increased planned maintenance explained the decline, September brought a rise in unplanned outages. Planned losses barely changed.

There was better news from nuclear generation: output recovered from August's interruption and stayed close to 653 MW throughout September. Average residual demand fell below 20 GW, while stronger wind generation lifted renewable output despite weaker solar generation.

September 2026 saw:

• EAF fall 1.5 percentage points from August and 0.8 points from September 2025
• Unplanned losses rise by 1.21 GW, to 8.10 GW
• Nuclear generation average 653 MW, up 24.8% from August
• Residual demand average 19,991 MW, the lowest September in the bulk record
• Combined OCGT output average 164 MW, down from August but 79.3% above September 2025
• Wind generation rise 18.3% year on year, offsetting declines in PV and CSP

July's jump in availability did not last. Eskom's derived Energy Availability Factor fell to 71.0% in August, from 75.6% in July, as planned maintenance returned. But unplanned outages improved again: the headline decline came from more scheduled capacity offline, with a smaller contribution from other losses.

The sharper deterioration was in nuclear generation. After three months near 650 MW, average output fell to 523 MW, with a sustained run of negative reported readings at the end of August. Demand also fell, reaching the lowest August average in the bulk record.

August 2026 saw:

• EAF fall 4.6 percentage points, while remaining the strongest August since 2018
• Planned outages rise by 2.6 GW, offsetting another 0.5 GW improvement in unplanned outages
• Nuclear output average 523 MW, with 98 consecutive negative hourly readings late in the month
• Residual demand average 20,920 MW, down 6.6% year on year
• OCGT output peak at 2,647 MW, more than three times July's peak
• PV and CSP set August hourly records, although total renewable generation remained slightly below August 2025

July delivered the strongest fleet-availability numbers in eight years. The Energy Availability Factor jumped to 75.6%, unplanned outages fell by 3 GW in a month, and Eskom kept diesel generation unusually low through the middle of winter.

The improvement came with two large qualifications. Nuclear generation remained stuck near 650 MW for a third full month, and average demand fell to the lowest July in the data. Solar also set a pair of seasonal records, although weak wind meant renewables as a whole did not break a record.

July 2026 saw:

• EAF jump to 75.6%, its highest monthly average since July 2018
• Total outages fall by 4.2 GW from June, to 11.6 GW
• Nuclear remain near 652 MW, after the station's output first dropped on 10 April and fell again on 25 April
• Demand fall to 21,726 MW, the lowest July on record
• PV and CSP set new July records, while weak wind pulled total renewable generation below July 2025
• OCGT output peak at only 790 MW, down from 2,322 MW in June

June extends May's shallow recovery by another notch — but the same cracks are all still there. The fleet is a little more available, mostly because winter maintenance is winding down and demand keeps falling. Koeberg is now into its second full month running a unit at reduced capacity with no public word, and June demand was the lowest on record for the month.

June 2026 saw:

• EAF edge up to 66.8% (from 65.5% in May), and ~6.5 points better than June 2025
• Nuclear stuck at 645 MW — a second consecutive month with a Koeberg unit crippled, still unexplained
• Demand fall to 21,795 MW — the lowest June on record, below even Covid-2020
• Exports stuck at the floor (652 MW), still less than half of imports
• Demand-reduction tools stood down — ILS peaked at zero for the first time in months

After April's wobble, May 2026 looks like a partial recovery on paper — but it's a shallow one, propped up by a still-broken Koeberg and the lowest May demand on record.

May 2026 saw:

• EAF recover to 65.8% (from 60.1% in April), but still below January–March
• Nuclear output get worse — averaging just 645 MW, with Koeberg running a unit at reduced capacity for a whole month
• A one-day OCGT peak of 2.9 GW, the highest in months — though average use stayed minimal
• Demand fall to 21,249 MW — the lowest May on record, below even Covid-2020

There have been many media statements around the end of the financial year about how well things are going at Eskom. In reality, things have not been going this badly in a while.

April 2026 saw:

• Worst EAF since May 2025
• Highest unplanned outages since July 2025
• Highest total outages since June 2025

Eskom Data - February 2026

Small reversal in the headline metrics - unplanned losses up a bit, EAF down a bit to below 70% again, but nothing too concerning here

Eskom data - January 2026

We skipped December as Eskom stopped publishing data in November and didn't fix it for several weeks.

Starting with a highlight: best EAF in January since June 2020!

Eskom data - November 2025

End of Diesel? According to the data, we never generated more than 350MW with the OCGT backup generators, which is the lowest I have on record except for nov 2020 which might also be a glitch.

Eskom data - October 2025

Not anything too interesting this month - EAF down again due to an increase in unplanned outages, but still 'ok' overall.