One of our keen readers and ez2view users has pointed this out to us, so we’re sharing this with you now via this snapshot of ‘Bids & Offers’ widget in ez2view as at 12:55 NEM time on Saturday 10th January 2026 looking back at Thursday 8th January 2026 and Friday 9th January 2026:
A few quick pointers…
Thursday 8th January 2026
Operations on Thursday 8th January 2026 appear fairly typical for the battery (i.e. with some of its capacity withheld by virtue of being contracted to supply SIPS services)
Friday 9th January 2026
However on Friday 9th January 2026 we see the period boxed in yellow that’s definitely not ‘normal’:
1) as seen in the Bid Table at the bottom, this commenced from the 16:05 dispatch interval NEM time with the rebid reason being ‘SIPS Activated’.
2) The table in the image is not long enough (one needs to scroll):
(a) but the yellow box lasts until the 21:30 dispatch interval NEM time
(b) there are some other rebids not shown in the image relevant to SIPS operations as well.
3) Keen readers will have noted that, in the time range 16:00 to 21:30 we had:
(a) ‘At 16:03 there was an unplanned outage of Dederang – Murray No 67 330kV line’
(b) ‘At 17:00 there was an unplanned outage of Dederang – South Morang No2 330kV line’
(c) With respect to the later spike in discharge (at 20:05):
i. I could not immediately map to a Market Notice speaking of network disruption,
ii. but do remind readers that at 20:03 the first in the next lot of rebids noting ‘SIPS activated’ was received at the AEMO
iii. and I did see MN132651 as follows, which speaks to some inability to actually reach its dispatch target:
‘——————————————————————-
MARKET NOTICE
——————————————————————-
From : AEMO
To : NEMITWEB1
Creation Date : 09/01/2026 21:05:22
——————————————————————-
Notice ID : 132651
Notice Type ID : NON-CONFORMANCE
Notice Type Description : Details of Non-conformance/Conformance
Issue Date : 09/01/2026
External Reference : NON-CONFORMANCE Region VIC1 Friday, 9 January 2026
——————————————————————-
Reason :
AEMO ELECTRICITY MARKET NOTICE
NON-CONFORMANCE VIC1 Region Friday, 9 January 2026
AEMO has declared the following unit as non-conforming under clause 3.8.23 of the National Electricity Rules:
Unit: VBB1
Duration: 09/01/2026 20:30 to 09/01/2026 21:05
Amount: -250 MW
Constraint: NC-V_VBB1
Auto-generated on behalf of Manager NEM Real Time Operations
——————————————————————-
END OF REPORT
——————————————————————-’
iv. so I’ve attached this ‘Unit Dashboard’ view of a zoomed-in time range to provide more context:
v.
Saturday 10th January 2026
Also notable is the period highlighted in the second yellow box on Saturday 10th January 2026 that also features strong charging of the batteries.
1) This occurs between 11:10 and 11:30 today
2) We’d need to wait till tomorrow to see (via ‘next day public data’) what the bidding was
3) At this point there is not a market notice that speaks to any network event in that time-range (and there also was not a strong discharge).
While not a direct explanation for batteries on the 10th, I note there were minimum load concerns from 11am (NEM Time). Demand was not as low as forecast, possibly due to shading of solar in Melbourne by bushfire smoke.
“132659
MINIMUM SYSTEM LOAD
10/01/2026 04:17:29 AM
Forecast Minimum System Load (MSL1) condition in the VIC region on 10/01/2026
AEMO ELECTRICITY MARKET NOTICE
AEMO has detected that there is an elevated risk of insufficient demand to maintain a secure operating state in the VIC region on 10/01/2026.
Minimum System Load (MSL) conditions are forecast when demand is less than the relevant MSL threshold. The advisory MSL thresholds are:
– MSL1: 2116 MW
– MSL2: 1616 MW
– MSL3: 735 MW
The demand is forecast to be below the MSL1 threshold for the following period:
From 1100 hrs to 1430 hrs 10/01/2026. Minimum demand is forecast to be 1783 MW at 1230 hrs.”
A little background on the VBB System Integrity Protection Scheme (SIPS):
The scheme reserves 250 MW of the VBB’s 300 MW capacity between ?November & ?March each year to provide AEMO the ability to run transmission between Snowy/NSW and Melbourne (the Murray-Dederang and Dederang-South Morang 330kV lines) at higher capacity levels. These are parallel circuit pairs and normally have to be run below a level that would not rapidly overload the remaining circuit if one line in a pair trips. The SIPS scheme allows AEMO to run the lines to higher ratings by triggering the VBB to rapidly discharge at 250 MW if there is a line trip: this extra supply near Melbourne reduces flow on the remaining line to a level that allows sufficient time for market redispatch if the tripped line remains out of service.
The VBB discharge events discussed in Paul’s article show the scheme operating when different lines on the Murray-Dederang-South Morang corridor tripped, presumably due to bushfire smoke or lightning.
Note that the market bids are “housekeeping” to reflect what the battery has physically done in response to a line trip: the SIPS scheme operates outside the market and doesn’t rely on the 5 minute bidding and dispatch cycle.