On 4th January 2024 we’d written ‘An initial review of Cohuna Solar Farm through 2023 – including bushfire effects (related to electrical equipment onsite?)’ … and article that had included several postscript based on new details that we became aware of (or were alerted about).
Now it’s Wednesday 29th January 2024, and we’re approaching 13 months later after that article – and this is coinciding with us* being in the home straight for the looming release of the GSD2024.
* in this case the ‘us’ is the combined team across Global-Roam Pty Ltd (i.e. the providers of this WattClarity service, amongst other products) and the team at Greenview Strategic Consulting.
In checking through a ‘draft at 27th Jan 2025’ version of the GSD2024 , some of the team has asked some questions about the following trend at Cohuna Solar Farm … and particularly the fact that there’s been absolutely no output from the farm since early April 2024 (or even into January 2025, noting the slivers below):
Click on the image to open a higher-resolution view in another window.
I can’t say I’d been particularly watching this plant, so seeing the long off-line period was a particular surprise. I’ve lifted out the whole page (which is a ‘B’ Page) and omitted some of the data that’s not really material to the questions the team has been asking. By sharing this excerpt above (whilst stressing that it is from a draft!) we are wondering if some of our more informed readers might be able to either:
Request #1) Help us understand more, directly in answers; and/or
Request #2) Point us at other resources on the internet (articles and so on) that might have already answered these questions.
Internal questions, and data checking
When this internal conversation started, I could recall writing the article above, but was a bit hazy on the details, so the first two things I did were:
Step #1) Re-read the article linked above in order to stimulate memory
Step #2) Open up the ‘Bids & Offers’ widget in ez2view, time-travelled back to the end of the 2024 calendar year, looking back 365 days and focused on COHUNSF1. From this process, the following image was produced:
Because the ez2view data set is largely independent in our process than that the process that produces the GSD2024, it gives us some confidence that the data* we see is factually correct … even if it does raise questions about what it means.
* ‘the data’ … especially including the 9-month gap in output!
Step #3) So we take a step further and add the ‘Bid Table’ onto the display in order that we can scroll through (offline – way too many to be captured in a single screenshot) the various bids and rebids seen at this unit through 2024:
(a) As noted in the image, we have right-click the column and ‘Grouped by Rebid Explanation’ in order to provide some highlighting of the rebid (and bid) explanations used through the year.
(b) This reveals some specific text of rebid reasons I can’t recall seeing for any other units … so I do wonder (as an aside) about the bidding application used by the generator (i.e. Potentia Energy … the rebranded Enel Green Power).
i. There was a single rebid submitted on 13th Feb 2024 (a day that was infamous in 2024 for a whole range of broader reasons) with the reason being ‘inverters stopped in compliance with energy safe victoria’s requirements’, which looks manually submitted. Interestingly a rebid category of E (notionally for Error in the AER’s Guidelines) was used for that one.
ii. But there are also a whole (large!) series of rebids that surely must have been automatically submitted through January, February or March that used either of these rebid reasons:
‘Not economically viable to generate due to Forecast Regional Price and/or regional FCAS costs’ OR
‘Economically viable to generate due to Forecast Regional Price and/or regional FCAS costs’.
… now I’ve not looked at any bid specifically, but assume this was cycling the plant on, or off, based on price expectations.
iii. and there are obviously more
Step #4) Curious to see the fuller picture we moved the the ‘Bids & Offers’ widget in ez2view to real time and shortened the look-back to just look at January 2025 (though you will need to wait a year to see summary results in the GSD2025!)
With a big of squinting, we can (just barely) see some type of small activity over some days in January 2025 that we might also look to explore.
Surfing for more information…
So with questions spurred on from the above, we went off to internet land to see what someone else might have written that might help to explain why the unit had been offline for so long (including whether it was related to earlier Energy Safe Victoria requirements, or whether it was completely independent) … and also what the recent glimmer of activity might mean. I’ve collated what I found in the following table.
| Date, or Date Range (chronological order) |
Details |
|---|---|
|
Happenings in 2020 |
|
|
4th March 2020 |
This page from the Essential Services Commission of Victoria notes: ‘Cohuna Solar Pty Ltd as trustee for the Cohuna Solar Trust (formerly Cohuna Solar Farm Pty Ltd as trustee for the Cohuna Solar Farm Trust) was granted an electricity generation licence on 4 March 2020. ’ … added for completeness (but also note the variation on 7th January 2025 noted below). |
|
27th May 2020 |
Approaching 5 years ago now, Giles Parkinson had written ‘Victoria’s Cohuna solar farm complete, joins queue for commissioning’ … added here for completeness, because it appeared in my search. |
|
Happenings in 2023 |
|
|
8th December 2023 to 17th December 2023 |
Our earlier article noted the period offline relevant to an Energy Safe Victoria notice.
|
|
22nd December 2023 |
Our earlier article referenced an article on 22nd December 2023 in PV Magazine about the Cohuna Solar Farm. |
|
28th December 2023 |
In our search now we’ve also found another PV Magazine article by David Carroll titled ‘Cohuna solar plant resumes operations after Energy Safe shutdown’. |
|
Happenings in 2024 |
|
|
4th January 2024 |
It was on 4th January 2023 we’d written ‘An initial review of Cohuna Solar Farm through 2023 – including bushfire effects (related to electrical equipment onsite?)’ … and article that had included several postscript based on new details that we became aware of (or were alerted about). |
|
13th February 2024 |
As noted above, there was a single rebid submitted on 13th Feb 2024 (a day that was infamous in 2024 for a whole range of broader reasons) with the reason being ‘inverters stopped in compliance with energy safe victoria’s requirements’, which looks manually submitted. But there’s some things I don’t understand here: 1) There’s nothing I can find on the Energy Safe Victoria website about any requirement issued in February. 2) This snapshot from the ‘Unit Dashboard’ widget in ez2view looking back over both the 12th and 13th February shows the effect of the rebid (and inverters being set to 0) in that the unit had no output on the day:
Small-size image here, click on image to open a larger view.
|
|
29th March 2024 |
Date of last output at the COHUNSF1 (in 2024). Via the ‘Unit Dashboard’ widget in ez2view looking back at the day (image below) we see that the following dispatch intervals jump out.
We see: 1) At the 11:10 dispatch interval: (a) volume bid at –$1,000/MWh so a Target of 16MW and FinalMW of 8MW (b) Because of a negative LHS factor on the ‘V^^V_MLNK_KGTS’ constraint equation, the constraint would like output to increase as much as possible. 2) At the 11:15 dispatch interval, rebid with reason ‘Not economically viable to generate due to Forecast Regional Price and/or regional FCAS costs’ takes effect (lodged at 11:08) to move volume to the Market Price Cap bid band: (a) Target set at 0MW, (b) but FinalMW is 11MW (i.e. ramps up, not down) so we derive the Conformance Status as ‘Off-Target’. 3) At 11:20 the unit ramps down to 3MW (target = 0MW) 4) At 11:25 the Availability drops to 0MW: (a) because UIGF drops to 0MW (b) noting that MaxAvail in the bid is still 20MW. From this point we did not see any further Availability, Target or Output through 2024 from the Solar Farm!
|
|
31st March 2024 |
On 31st March 2024 there was a rebid submitted at 07:48 (NEM time) with a rebid reason of ‘CHANGE IN PLANT AVAILABILITY’ (i.e. in capitals, suggesting perhaps manually entered) that set the availability of the plant to 0MW from the 08:05 dispatch interval onwards (i.e. both MaxAvail and PASA Avail). There’s not been any significant change in Target or Output since (i.e. now 10 months later). There was a second rebid on that day, this one submitted at 14:13 (NEM time) with a rebid reason of ‘CHANGE IN PLANT AVAILABILITY’. 1) This had the effect of reinstating the MaxAvail and the PASA Avail to be 20MW. 2) But we see that the UIGF was still set to 0MW 3) Note that: (a) We presume this was because of some SCADA data (such as ELAV or LOCL, perhaps) passed through to ASEFS, (b) but are unable to check (because that data was not made accessible to the market until mid August 2024).
|
|
6th April 2024 |
On 6th April 2024, there was another bid submitted that reset the MaxAvail and the PASA Avail back to 0MW. |
|
7th April 2024 |
At 07:51 on 6th April 2024 as a ‘Daily Bid’ to take effect at 04:05 on 7th April 2024 was lodged that moved Availability and PASA Avail down to 0MW: 1) Noting that Availability into NEMDE had been 0MW anyway for several days beforehand due to ASEFS. 2) Because it was a Daily Bid, no rebid reason was required (nor was any given). So there’s no clue there in terms of what the longer-term prognosis might be….
|
|
April to December 2024 |
We could find nothing in this time-range. Certainly no output. |
|
9th December 2024 |
Unrelated to the issues confronting Cohuna Solar Farm itself, on 9th December 2024 there was the announcement of company re-branding in ‘Potentia Energy Revealed As New Brand For Leading Australian Renewable Energy Company’. |
|
Happenings in 2025 |
|
|
6th January 2025 |
The 11:05 dispatch interval on this way was the first time the FinalMW for the COHUNASF1 had been non-zero since 29th March 2024. As captured in this snapshot from the ‘Unit Dashboard’ widget in ez2view, the number rounds down to 0MW but is ever-so-slightly non-zero:
Small-size image here, click on image to open a larger view. We wonder if this is the start of a return-to-service process following a very lengthy outage?
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7th January 2025 |
At the top of this table, we noted that this page from the Essential Services Commission of Victoria notes: ‘Cohuna Solar Pty Ltd as trustee for the Cohuna Solar Trust (formerly Cohuna Solar Farm Pty Ltd as trustee for the Cohuna Solar Farm Trust) was granted an electricity generation licence on 4 March 2020. ’ … but note also that it says: ‘Licence varied This licence was last varied on 7 January 2025.’ … with the ‘Record of Decision’ downloadable here (but this was just related to a change in Licensee name).
|
|
Today (Wednesday 29th January 2025) |
Which brings us to this article today. |
|
In the coming days… |
Hopefully soon we will be able to release the GSD2024, with the completed statistical data for COHUNASF1 along with all the other DUIDs across the NEM that operated in any of the 11 x markets at any point in 2024. |
Looking forward to learning more?!
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