‘Running on Empty’ … a reminder of the implications of Shallow Storage

No, I’m not speaking here of the precarious liquid fuel scarcity situation Australia finds it in, because a succession of Federal Governments have adopted a ‘she’ll be right mate!’ approach to Energy Security.

1)  with the current War in the Middle East revealing yet again that our Emperors have no clothes.

2)  though note we did write about those challenges here on 23rd March, and  also on 29th March.

Not sure how many others have noticed this, but the past few days in South Australia have revealed some of the underlying implications of the current ‘shallow storage only’ approach to new energy storage asset development in this Energy Transition?

Opening up the ‘Trends Engine’ in ez2view this morning (Thursday 9th April 2026), I’ve quickly put together this trend view of aggregate Battery State of Charge for the SA Large Battery fleet:

Those with a licence to the software can open their own copy of this query here.

As noted in the trend:

1)  Early Monday evening (6th April 2026 at ~18:00 NEM time) we see:

(a)  The aggregate battery State of Charge for the BESS fleet in South Australia at roughly 1,600MWh

i.  Which (scanning a longer history offline) appears to represent roughly ‘100% full’ for the current fleet;

ii.  A reminder to readers that a MWh represents a unit of volume, whilst a MW represents a rate.

(b)  That comes after a textbook period of charging strongly with negative prices

2)  However only two days later (Wednesday 8th April 2026 at ~18:00 NEM time) we see that the State of Charge barely scrapes past ~1,000MWh

(a)  and that’s after the battery fleet as a whole had to charge with prices very healthy indeed … at +$50/MWh or above for hours through yesterday afternoon.

(b)  because we see that the aggregate state of charge was very low indeed (<200MWh or perhaps only 5% capacity … only vapours left in the metaphorical tank).

(c)  That’s gotta hurt:

i.  Not just in terms of individual battery near term cash position

ii.  But also in terms of real world reminder to the business case for shallow storage (and the need for deeper storage, from a system perspective).

What triggered this situation?  A quick look at this trended Fuel Mix chart highlights that (whilst there may also have been other factors at work), a ~24 hour spell of poor VRE yield:

1)  Firstly with a period of low wind overnight, which led to higher prices that the batteries discharged into;

2)  Then with a day providing lower solar yield, which kept prices high … at which prices the batteries still needed to purchase to charge.

Those with a licence to the software can open their own copy of this query here

Nothing else, at this point.