A couple of us in the team noted several related things over this weekend – including this LinkedIn update from Geoff Eldridge at GPE speaking to recent operations at some of the Bayswater units.
Geoff highlights that included two-shifting at BW02 over this weekend (both Saturday 4th October 2025 and Sunday 5th October 2025):
In his update:
1) Geoff points back to ‘AGL’s successful completion of the first two-shifting trial for Bayswater unit 4 (on 7th September 2024)’.
2) He highlights a few other occasions when this has happened – such as:
(a) In autumn 2025, including:
i. Monday 17th March 2025;
ii. Saturday 22nd March 2025;
iii. Saturday 26th April 2025.
(b) and now spring 2025:
i. Such as last Saturday 27th September 2025,
ii. and this weekend as well (Saturday 4th October 2025 and Sunday 5th October 2025).
3) Importantly, he writes:
‘This is not a conventional outage — the boiler remains fired to minimise thermal movement of plant components. It is a strategy that can be overall cheaper than running through periods of very low or negative prices, while also creating headroom for renewables in the middle of the day.’
A quick (initial) look at the BW02 two-shifting over this weekend
Because there’s some relation to some of the subject matter I’m considering speaking about at this week’s inaugural NEMdev conference in Brisbane, I opened up the ‘Bids & Offers’ widget in ez2view at the 13:55 dispatch interval on Sunday 5th October 2025:
I’ve done this (at least in part) to record that:
1) On Saturday 4th October 2025 the BW02 unit was offline by 08:06 (NEM time) and back online by 15:06 (NEM time), as captured in this ‘Notifications’ widget alert in ez2view at the time:
2) This morning (Sunday 5th October 2025) the BW02 unit was offline by 08:11 (NEM time, noting no daylight savings), as captured in this ‘Notifications’ widget alert in ez2view at the time:
We’ll come back to those times later…
A coincidence of events, on Sunday 5th October 2025
Having noted earlier today how ‘AEMO issues (short-notice, short-lived) direction for System Strength in NSW on Sunday 5th October 2025’, readers following closely will note the overlap of events on Sunday 5th October 2025:
- At 07:25 the Direction for System Strength is issued … for a unit at MURRAY to ‘Synchronise and operate as a synchronous condenser at 0730 hrs 05/10/2025’
- At 08:11 BW02 is offline
- From 08:30 the Direction for System Strength is cancelled
I’ve not had time to look at what (else) happened (e.g. another unit starting up) to give AEMO reason to see that the boost to System Strength was not required.
Some caution for (other) NEM observers – seeing two-shifting where it isn’t there
Following the initial buzz about AGL’s two-shifting trial (not to dismiss those units that have been capable of it for longer), some of our clients contacted us to point out that some other analysts were also highlighting other cases since that time which (those other analysts) were supposing:
- were related to ‘two shifting trials’ for their own units.
- and involved the approach of ensuring the boiler also remained fired up, with the turbine ‘just’ bypassed.
With a bit of investigation offline it turned out that these supposed two-shifting trials were not, in fact, as those other analysts had claimed – but related to other drivers.
So just a note of caution:
1) Geoff’s a good operator:
(a) In his images, we can see he did look at rebid reasons (whereas other examples from other Observers/Analysts I had shown to me did not appear to have done that, because the rebid reasons pointed to other circumstances entirely).
(b) But even in this case (and I’m sure Geoff confirmed this independently), readers should note that there’s insufficient information in the rebid reasons recorded above to confirm such things as whether the boiler remained fired on these occasions.
2) I add this as a general note of caution to NEM observers and commentators more generally.
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