Earlier today (Friday 7th November 2025) we saw something strange in our display of the ‘Generator Outages’ widget from ez2view with respect to the Waratah BESS, as a result of which:
1) We posted the article ‘What’s up with Waratah BESS (unplanned outage till 3rd May 2026)?’;
2) Following from which we started conversations with a range of different people – including:
(a) Some people we know at Akaysha Energy, the owner/operator of the battery;
(b) But also with a range of other knowledgeable NEM (and battery) stakeholders we though might help us answer some of the questions that data posed for us.
From these conversations came more information (and some more questions as well), as a result of which we’re publishing a few more articles* separately to follow on. This is one of those articles.
* There are several reasons for there being separate articles, including:
1) Because the 4pm (NEM time) newsletter for today has already triggered, so we wanted to ensure that our readers are aware of these additional pieces of information … hence the discrete articles
2) But it’s also likely that it will be useful to link directly into some of them at different points in time.
Almost exactly 3 months ago we posted a ~12 month chronological record of the history of Waratah BESS in the article ‘Recapping operations at Waratah BESS (including enablement for SIPS) … to August 2025’. That article contained both:
- A trend over time; and also
- A tabulated record of key events in its timeline
… with both to the date of publication (Friday 8th August 2025).
Because some of the conversations (and questions) this afternoon related to operations over time (and in particular changes since August 2025), we thought it would be useful to update both of these, as follows:
A trend over time
Given that I’d prepared a trend analysis in the ‘Trends Engine’ within ez2view it was a pretty simple process to re-open the query and have the most recent 3 months of daily statistics stream into the record now stretching back for just over 14 months:
Again, remember that
- (post IESS) the charging side of any battery (now a BDU) is shown as negative numbers.
- to click on the image for a full screen view
There’s some pretty clear differences compared to the chart from three months earlier, which we will discuss in the table below.
More events in its lifetime (August to 7th November 2025)
Rather than copying in the table from three months earlier, we’ve just picked up where we left off in the earlier article, and have added in more recent events
| Date, or Date Range | Description of Event |
|---|---|
|
Friday, |
Obviously we need to make note of today’s change to the MT PASA DUID Availability data for the WTAHB1 unit, and the questions that arose for us when we saw these:
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from 19th October 2025 |
Since 19th october, the market-based delivery of the unit has been more muted: 1) Availability: (a) on discharge has peaked at 150MW; 2) Output has been more muted, as well: (a) A quick scan says peak discharge of ~60MW Covering this time-range, we posted ‘A quick look at (plant-related) rebids for Waratah BESS from 19th October to 8th November 2025 (with PASA Avail 350MW)’. In that article: (a) We note that the PASA Availability has been consistently 350MW: (b) We wonder about how: i. following the testing at Hold Point 5, other steps are to be taken to enable the unit to operate at higher capacity than 350MW ii. and we wonder what these steps might be, and how long they might take. |
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mid-October 2025 |
As noted with respect to the trend chart above: 1) peak (or close to peak) discharge was achieved on blocks of days: (a) 10th october 2025, 2) peak (or close to peak) charge was achieved on blocks of days: (a) 10th october 2025, These operations at full capacity were noted in media articles at the time – including: 1) Belatedly now, we have added ‘A quick look at (plant-related) rebids for Waratah BESS to 19th October 2025 (during Hold Point 5 testing for full discharge)’ in order to see in more detail. In particular, we can see: (a) The unit PASA Availability was set at 779MW (both charge and discharge) for the duration of Hold Point 5 testing (when peak charge and discharge was achieved) (b) But this was reverted to 350MW (each way) from Saturday afternoon 18th October 2025. 2) On 11th October, Giles Parkinson published ‘Australia’s most powerful battery injects full capacity into grid for first time as it nears commissioning’, in which he wrote; ‘Australia’s most powerful battery has injected its full 850 megawatt (MW) capacity into the grid for the first time as it nears full commissioning and another step change in the way the electricity grid is managed.’ 3) On 13th October, George Heynes wrote ‘Akaysha Energy’s Waratah Super Battery discharges its first full output to Australia’s NEM’ and said: ‘Owned by its developer, Akaysha Energy, the Waratah Super Battery, sized at 850MW/1,680MWh, achieved its first full output to the NEM on Friday (10 October) at 08:30. This is the first full discharge for the BESS since it was initially energised at 350MW/700MWh in August.’ … and … ‘Specifically, the SIPS Control System can monitor 36 transmission lines in real time and respond instantaneously to system events. This dynamic balancing act prevents disruptions and allows existing transmission infrastructure to operate at higher capacities, effectively “running harder” without compromising reliability. Through the SIPS, the Waratah Super Battery will also serve as a stopgap measure until the Hunter Transmission Project – a major infrastructure initiative to connect inland Renewable Energy Zones (REZ) to the rest of New South Wales – comes online.’ 4) The article ‘Waratah Super Battery in Australia Injects Full Capacity’ noted: ‘At 8:30 am on October 10 morning, Waratah went on to inject its full capacity of 850 MW as it conducted the last hold point testing, and then thereafter charged at a rate of 844 MW in the early afternoon.’ … and … ‘To add to the intricate scenario, the shock absorber contract for Waratah happens to be linked with three other facilities – the Sapphire wind farm, the Metz solar farm, and the Tumut pumped hydro generator, which is also going to respond should Waratah have to step in. The fact is that the contract is also sculpted, which means that at times Waratah will be required to make available 700 MW and 1,400 MWh of capacity and may have less capacity at other times. It is going to trade the rest of the capacity of the battery on the open market.’ |
|
13th October 2025 |
Not directly related to my current questions about Waratah BESS, but for ease of our future references I am adding in here a note about Giles Parkinson’s article ‘“Hard to defend:” Snowy says its bidding strategy hit by line upgrades for super battery’, as it speaks about the impact of network activities to connect the Waratah BESS. For context of readers here, the article notes: ‘Snowy Hydro says its underlying performance was affected by a lower return from its generation activities, partly due to the absence of “one-off” market events (such as huge price spikes), and the impact of the new Waratah Super Battery being built on the Central Coast.’ … and … ‘“FY25 was also characterised by a number of transmission constraints in New South Wales, caused by line upgrades to support the Waratah Super Battery.’ . |
|
7th October 2025 |
Not directly related to my current questions about Waratah BESS, but for ease of our future references I am adding in here a note about Paul Garvey’s article ‘Secret NSW power reports kept from public’, as it speaks a lot about modelling of Waratah BESS operations. For context of readers here, the article notes: ‘At least 10 reports, studies and presentations focused on the electricity market impact of the Minns government’s emissions reduction policies and renewable energy targets between June 2024 and July 2025 have been conducted, although public access to all 10 documents under Freedom of Information laws have been refused.’ … and … ‘The tenth document, which modelled different scenarios in the electricity market stemming from the $1bn Waratah Super Battery, was also denied public release, despite the department identifying multiple reasons why its disclosure would be in the public interest.’ … and the article continues for several paragraphs about this. |
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4th October 2025 |
On 4th October 2025 we wrote ‘AEMO updated MT PASA guidance, on 3rd October 2025’ , and this pertains to WTAHB1 because of the text in Market Notice 129413 as follows: ‘Increases to transmission ratings for lines between Yass and Sydney West associated with the Waratah Super Battery Project are expected to be incorporated in coming weeks, which will likely decrease projected risks in New South Wales.’ … though I have not looked now to see if such transmission rates have been incorporated. |
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d2 September 2025 |
Might add more in here later… |
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4th September 2025 |
Not directly related to Waratah BESS, but in the interests of fullness of record, the company noted ‘Akaysha Energy secures A$300 million corporate debt facility to accelerate growth’. That release included the following statement: ‘The new facility follows a series of significant milestones for Akaysha Energy, including the recent achievement of COD on Stage 1 of the Waratah Super Battery, the most powerful BESS in the world.’ This was then noted in a range of media outlets. However none of the reports I read contained anything useful noting about Waratah BESS. |
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31st August 2025 |
On 31st August 2025, we’d published the article ‘Looking more at (commissioning) operations at Waratah BESS through August 2025’. |
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29th August 2025 |
Because it’s quite relevant to the startling change in forward-looking availability for WTAHB1 that happened today, worth flagging in this table that it was back on Friday 29th August 2025 that the AER published its PASA Compliance Bulletin and Checklist, as we have belatedly now noted. |
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25th August 2025 |
On 25th August 2025, Giles Parkinson noted ‘Super “shock absorber” battery smashes records again as it charges and discharges at unseen levels’. That article notes: ‘On Monday morning, as part of its ongoing testing, it injected up to 708 MW into the grid, and just minutes later turned around and charged at the same rate.’ (which we can see in the chart above) … and … ‘Waratah, for the most part, will be paid to act as a giant “shock absorber”, which means ensuring it has enough capacity – up to 700 MW and 1,400 MWh, depending on the time of day – that can respond in case a lightning strike or other issue affects the transmission lines transporting power into the state’s major load centres. The “shock absorber” contract allows the transmission lines to operate at greater capacity – and it also involves the Sapphire wind farm, the Metz solar farm and the Tumut pumped hydro facilities to also respond should the battery be called into action.’ |
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16th August 2025 |
On 16th August, Giles Parkinson published ‘Waratah, Australia’s most powerful battery, smashes output record again’, in which he noted: That article notes: ‘It is now more than half way through the commissioning process – which began in September last year – and on Friday afternoon injected a record 530 MW into the grid as it prepared to graduate to a new “hold point” that is part of the lengthy and detailed commissioning process.’ (which we can see in the chart above) … and … ‘Waratah has already started to deliver its shock-absorber function, officially known as a System Integrity Protection Scheme (SIPS), although only at half capacity for the moment as it works through the commissioning process. The SIPS contract will require it to deliver up to 700 MW and 1400 MWh of capacity at peak times, and as little as 300 MW and 600 MWh at others, in line with the “sculptured” nature of the deal. When it intervenes, possibly to address a generation or network outage, three paired generators – the Metz solar farm, the Sapphire wind farm and the Tumut pumped hydro project – may be required to dial down their output to keep the grid in equilibrium. Financial details of these contracts have not been released.’ |
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The last entry in the earlier table, published on: |
In that earlier article, we’d noted: Worth readers noting two (other) things with respect to the month of August (in addition to the below): Additional Observation #1) We see in the chart above that: (a) the peak ENERGY discharge from the battery, to date, has been at the rate of 369MW: i. on 17th June 2025 … and then on some days subsequently ii. but note that this does not include any enablement for Raise FCAS services. (b) but note that this is under half of the registered Maximum Capacity of the unit (850MW) Additional Observation #2) It’s worth noting (with respect to the note below about May 2024) that 19th August 2025 was the date at which Eraring Power Station had earlier been slated to close. |
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Worth also explicitly noting: |
On 1st August 2025,the AEMO communicated by MN128419 that: ‘——————————————————————- From : AEMO ——————————————————————- Notice ID : 128419 ——————————————————————- Reason : AEMO ELECTRICITY MARKET NOTICE. The Waratah Super Battery System Integrity Protection Scheme (SIPS) has been enabled by TransGrid at 1758 hrs 01/08/2025. Manager NEM Real Time Operations ——————————————————————- … which was subsequently flagged in various official locations, including: 1) On 5th August Akaysha Energy wrote ‘The Waratah Super Battery is online’; … which noted that: ‘Akaysha Energy is proud to announce that the first 350 megawatts (700 megawatt hours) of the Waratah Super Battery is online and performing its role as a ‘shock absorber’ for the NSW electricity grid in case of events like heatwaves, lightning strikes and bush fires.’ 2) On 5th August EnergyCo wrote ‘Waratah Super Battery Project begins partial operation as shock absorber for NSW grid’. 3) On 5th August TransGrid wrote ‘Transgrid specialists deliver Australian-first control system to support Waratah Super Battery Project’. It was also picked up in the media, including the following: 1) On 4th August on RenewEconomy, Giles Parkinson wrote ‘Australia’s most powerful battery is now officially operating as the grid’s biggest shock absorber’., which noted a number of things, including: ‘The SIPS scheme requires the Waratah battery to make available up to 700 MW and 1,400 MWh at various times, and less capacity at others, depending on the season and the time of day. Initially, it will deliver half of that contract size until it completes its commissioning process, expected before the end of the year. The original timeline for the project was for it to be delivered in full by May, although that timeline was allowed to slip after the decision by the NSW to underwrite a two-year extension to the Eraring coal generator, that is now expected to close in 2027, although it may stay open longer.’ 2) On 5th August via the ABC, Sarah Forster wrote ‘Waratah Super Battery connected to NSW power grid and switched on’. 3) Of course, I noted it here in August. … and elsewhere |
Once again … if readers see I have missed (or misunderstood) significant event(s), please feel free to add comments … and note that I might return later, to add in more details (as a useful future source of linkages about the Waratah BESS).
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