We’re approaching the end of May 2026, which means we’re almost 10 months since the 31st July 2025 go-live date for unit-level data (and other changes) in ST PASA.

… our ez2view software was upgraded to v9.12 in June 2025 in anticipation of those changes, and there’s been a number of articles since 31st July utilising this extension to visibility:
(a)  including with respect to Semi-Scheduled assets
(b) Thought unfortunately Semi-Scheduled assets are still invisible in MT PASA DUID Availability!

A number of our clients have asked us what we’re doing in our software with respect to the way ST PASA will be changing as a result of the AEMO’s current ST PASA Replacement project … which is still ongoing:

1)  and described on the AEMO ‘ST PASA Replacement Project’ sub-site here.

2)  with additional details on the AEMO’s ‘Consultation on ST PASA Replacement Project Procedures’ subsite here as well.

The process is ongoing, which was why it was of interest to us to listen into ‘Workshop 3’ that was held on 11th May 2026 – where the AEMO walked the audience through a 59-page slide deck:

PS on Tue 9th June 2026, we added this link to where the presentation lives on the AEMO website, after someone pointed us to it (many thanks).

With 59 pages of detail there’s no way I’m cover to cover everything – I just wanted to highlight a couple things in particular (at least in part for easier reference for our internal team in the coming weeks and months):

Project status

There were a couple slides (and some discussion) that dealt with project status – including slide 7:

The ST PASA Forecasting Infrastructure

Slide 8 outlined the workshop objectives … with the term ‘Uncertainty Margin’ really jumping out to me, given the investment we’d already made (such as via GenInsights21 and the GenInsights Quarterly Updates analysis):

The ‘Uncertainty Margin’ for different units (and different types of units)

There was plenty of content in the workshop (and we’ve followed up to clarify our understanding later) with respect to ‘Uncertainty Margin’ for different units … and different types of units.  The way AEMO will apply these in ST PASA will be:

• to subtract off the Uncertainty Margin from the expected resource to produce an ‘Adjusted Production/Capability Forecast’
• with a slight difference for type:
  • With Semi-Scheduled units using the lower of UIGF or MaxAvail in the bid (post the August 2023 change)
  • And Scheduled units just using MaxAvail in the bid.

To whet your appetite, here’s Slide 24 (for Semi-Scheduled units):

… and Slide 25 (for some Scheduled units)

But what really focused my attention was slide 26:

The reason why it focused my attention was because it showed some similarities to analysis we’d completed (and updated several times) for GenInsights21 and the GenInsights Quarterly Updates reports:

1)  And which we occasionally posted about, such as in the article ‘Is VRE forecastable? (Part 1 in what might be a series)’ on 27th February 2025.

2)  Though analytically-minded readers should note that our method varied a little in several ways, including:

(a)  Completing a ‘forecast convergence’ style analysis 24 hours ahead of dispatch; and

(b)  Concentrating on the 90% range between the 5% and 95% POE exceedances, to highlight the spread of the uncertainty.

Stimulating further analysis…

The confluence of three factors here has prompted us to do a bit more number crunching…

Factor #1)  As noted above, we’re now ~10 months since unit-level ST PASA data went live;

Factor #2)  The details provided in this AEMO workshop (one of the few I actually had a chance to attend) prompted more thinking …

Factor #3)  and it just so happens that a couple of us will be at the CEC Wind Industry Forum on Tuesday this week (26th May 2026).

Note that I have not found, yet, where the full slide deck lives on the AEMO website?