In his comment here on my earlier article about the solid block of operations at Tamar Valley Combined Cycle plant, Tim points to a long-running planned outage at the Poatina hydro plant in Tasmania, which Hydro Tasmania communicated via the update ‘Water flows to Brumbys Creek’ on 13th April 2026:

That article spoke to two different periods of outage:

‘ Work will take 9 months and to reduce impacts on our waterways and water users as much as possible, we’re scheduling this work over two years:

>13 July 2026 to 30 September 2026 (potentially extending to 9 October)

>April to September 2027.’

Given I had been in the depths of the PASA data for the earlier article, I thought I would have a quick look at availability for the Poatina Station in the MT PASA DUID Availability data:

• via the ‘PASA DUID Availability’ widget
• … which was upgraded in the v9.12 upgrade in mid-2025 to also provide nearer-term visibility into PD and ST PASA time horizon (given the AEMO had begun to publish that data, as well – including for Semi-Scheduled units to increase their visibility!)

A six unit (2 x DUID) facility at two connection voltages

Before we do, worth reminding those who are not TAS focused that the Poatina station has 6 units:

• with units 1 & 2 connected at 110kV;
• and units 3, 4, 5 & 6 connected at 220kV

… which, to make it more confusing, is modelled by AEMO as only two DUIDs:

• units 1 & 2 in a single DUID named POAT110  (with station ID PTINA110)
• units 3,4,5 & 6 in a single DUID named POAT220 (with station ID PTINA220)

We can see this in the AEMO single line diagrams included (with their permission) inside of ez2view, with a snapshot here:

In MT PASA DUID Availability

Looking firstly at the PTINA110 unit, we see the following:

Noting that the April article noted possible extension of outage out till 9th October 2026 (i.e. I’m assuming this meant return to service 10th October 2026) we see that the current details in MT PASA are:

• That this DUID returns to service 1st October 2026 (same day as PEC Stage 2 starts… will be a big day in the market).
• But only at part-load (which I wonder means only 1 of those 2 physical units available?

Currently the outage for next year:

• Begins 8th April 2027 (i.e. first day with 0MW availability)
• Ends 18th September 2027 (i.e. last day with 0MW availability)

Here’s the corresponding view for PTINA220 station ID:

From this view:

• 1st October 2026 is also the day when this unit comes back online (current expectation)
• Next year’s outage is the same

  • Begins 8th April 2027 (i.e. first day with 0MW availability)
  • Ends 18th September 2027 (i.e. last day with 0MW availability)
• But then coming back online not at full load (one of the 4 units off for a while longer, perhaps?).

So, noting the 1st October 2026 end of phase 1 of outage, we wonder how much longer we might see Tamar Valley Combined Cycle plant running?