Callide C3 within 8 hours of return to service early Sunday morning 25th July 2021 … but rebid and pushed back further!

On Friday evening (as  noted here) there was no sign of the return to service of Callide C3 and the data published for 18:00 on Friday showed that the unit was expected to be back on Sunday.

Readers might remember that:

1)   Unit C3 tripped offline on 25th May 2021 in conjunction with the Callide C4 Catastrophe (so that will be 9 weeks ago on Tuesday); and

2)  That the return to service date has been adjusted a number of times already

3)  … Which would be due, at least in part, to the complexities involved in the ‘never seen this situation before’ factor as they try to simultaneously:

(a)  get Callide C3 back into service

(b)  whilst also readying Callide C4 for a very long repair process.


(A)  Unit C3 has not returned (yet?) on Sunday 25th July 2021

The sun is setting on Sunday 25th July 2021, so here’s a quick report (and another snapshot from ez2view, this time at 17:05 and it shows both:

1)  That the unit has not yet made its appearance, in output data; but

2)  With the most recent ‘MT PASA DUID Availability’ data set being published for 18:00 yesterday (Sat 24th July) we see the expectation was, then, that the unit would be available for today:



(B)  Looking forward the coming week

Utilising this pre-configured 14-day trend in the web-based ‘Trends Engine’ contained within ez2view, we look forward over the coming week (and back a week as well):



A couple quick observations:

1)  Tomorrow morning when the next ‘MT PASA DUID Availability’ data set is published, we’ll lose visibility up until Sunday 1st August.   In the trend above of region-wide available generation, there is no obvious step up in Available Generation in predispatch or ST PASA (assuming the unit is still unavailable now) that would clearly show the timing of expected return to service.

2)  We do see see that the current expectation is for elevated prices on Monday evening – and also (even more rubbery) Tuesday evening and Thursday evening:

3)  Also worth noting the low and negative prices seen through daylight hours today and yesterday meant that the weekend would not have delivered a great return for a unit returning to service at this time.


(C)  Comparing most recent (publicly available) bids

Readers should remember that (apart from the Registered Generator themselves) there is no visibility in the current day of how any other generator is bidding. 

1)  Hence we don’t really know what has changed since 04:00 this morning – with Callide C3, or any other unit

2)  Tomorrow after 04:00 we’ll be able to look back at bids and rebids placed for today (but that will be for another article sometime).


Utilising the ‘Bids & Offers’ widget in ez2view and looking back 7 days we see that the generator has been adjusting its return to service (RTS) expectations on Monday 12th July (discussed on Tuesday 13th), Thursday 15th July (discussed on Sunday 18th), Monday 19th July, Wednesday 21st July (hence no output on Friday 25th July) and most recently a rebid yesterday (24th July) at 19:46:


Using the ‘Bid Comparison’ function (the widget shown underneath) we compare the rebid placed 19:46 yesterday with the expectation (for yesterday’s market day) placed on Wednesday 21st July at 16:14.

1)  Wednesday’s advanced ‘Daily’ bid for Saturday shows the unit being available for the trading periods (i.e. half hours) ending 03:30 and 04:00 on Sunday morning … i.e. this morning; but

2)  At 19:46 Saturday the AEMO received a rebid from the Generator:

(a)  with rebid reason ‘1945P Unit RTS Revised’;

(b)  Which shifted the volume out of those two half hour periods … and pushed the RTS timing back to some point in the future that’s not visible to us at this point.

(c)  Hence it seems clear that Callide C3 was within 8 hours of operations until it was pushed back to some point in the future (currently unknown).

3)  So it seems like we’re getting quite close to seeing output?!

About the Author

Paul McArdle
One of three founders of Global-Roam back in 2000, Paul has been CEO of the company since that time. As an author on WattClarity, Paul's focus has been to help make the electricity market more understandable.

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