Retrospective report

September 2026

Quarterly Model - Dispatch Retrospective

Per-region forecast accuracy for the Quarterly Model - Dispatch Retrospective model group during September 2026.

Model revision 1

Generated 1 October 2026 at 10:20 am (Sydney time)

Predictions use the generator availability AEMO published on 24 August 2026 at 9:00 am (Sydney time).

Region	MAE¹	Bias²	Average predicted price	Average actual price	Price spike windows³
NSW1	24.57	8.57	$73.89	$65.32	0
QLD1	20.12	-2.70	$54.40	$57.10	0
SA1	27.35	13.50	$51.21	$37.71	1
VIC1	21.78	12.47	$49.30	$36.83	0

¹Mean Absolute Error (MAE) is the average absolute difference between forecast and actual prices.

²Bias is the average difference between forecast and actual prices.

³To maintain an informative scale, we charted price spikes separately to other prices. We plotted the 6 hours before and after the RRP exceeded $500 as separate, region-specific charts. These price spikes are capped at $500 in the full region prediction charts.

NSW1

Region	MAE	Bias	Average predicted price	Average actual price	Price spike windows
NSW1	24.57	8.57	$73.89	$65.32	0

Endgame demand forecast under 2015 weather conditions vs dispatch TOTALDEMAND for NSW1

QLD1

Region	MAE	Bias	Average predicted price	Average actual price	Price spike windows
QLD1	20.12	-2.70	$54.40	$57.10	0

Endgame demand forecast under 2015 weather conditions vs dispatch TOTALDEMAND for QLD1

SA1

Region	MAE	Bias	Average predicted price	Average actual price	Price spike windows
SA1	27.35	13.50	$51.21	$37.71	1

Predicted and actual price over the Price Spike in SA1 between 2026-09-17 13:00:00 and 2026-09-18 01:30:00

Endgame demand forecast under 2015 weather conditions vs dispatch TOTALDEMAND for SA1

VIC1

Region	MAE	Bias	Average predicted price	Average actual price	Price spike windows
VIC1	21.78	12.47	$49.30	$36.83	0

Endgame demand forecast under 2015 weather conditions vs dispatch TOTALDEMAND for VIC1