The dispatch price in Queensland spiked to $1,500/MWh at 18:25 and again at 22:40 yesterday evening – as shown in the following snapshots captured at the time, and emailed to ourselves, by some automated NEM-Watch alerts.
These spikes triggered some jitters for some of our clients who’ve lived through the most volatile summer Queensland experienced in 15 years over summer 2012-13 (analysed in detail in our extensive review) – generating comments along the lines of “it can’t be happening again!”.
Here’s a quick look at what happened:
1) First spike – to $1,500/MWh at 18:25
The first snapshot from NEM-Watch shows that the market was experiencing very moderate demand at the time, with more than 10,000MW of spare capacity across the NEM – and, even taking account of constraints on QNI and Directlink, plenty of spare capacity in the Queensland “Economic Island”.
Refer to this animation of 20th December to see some of the behaviours evident over last summer. This snapshot from ez2viewAustralia five minutes prior to the spike will illustrate a couple of factors:
(a) The presence of the transmission constraint impacting on flows over QNI – and a second constraint affecting Gladstone.
(b) Several rebids (in various portfolios) effective from 18:20.
I don’t have time to write commentary about all of this, though it’s easy to see in the software (by mousing over the “$” symbols) just which rebids were most material in setting the $1,500/MWh price.
2) Second spike – to $1,500/MWh at 22:40
Here’s the snapshot from NEM-Watch of the identical price spike later that evening:
We can see that the demand has dropped significantly over the intervening four-hour period, and yet the price finds its way back to the identical price point.
No time to post more details with ez2view, but it’s illustrative that this spike occurs coincident with factors not identical to those of four hours prior.
Stay tuned to WattClarity for observations about what actually does unfold over summer (plus perhaps for your chance to win your own BBQ, as well).