The Australian Energy Regulator (AER) today published a report into prices exceeding $5,000 per megawatt hour (MWh) in the National Electricity Market (NEM) during July, August and September 2025.
The wholesale 30-minute energy prices exceeded $5,000 per MWh 7 times in the quarter - all on 2 July in South Australia. This compares to 66 high prices in the previous quarter and 54 high prices in the same quarter last year.
The high energy prices were intermittently forecast from the day prior and occurred due to a combination of contributing factors including low wind output, planned network outages and participant rebidding.
Prices for the Frequency Control Ancillary Services (FCAS) exceeded $5,000 per MW in two consecutive 30-minutes 53 times in the quarter. These prices resulted in administered pricing which is a price safety net that caps further high prices from occurring.
The planned network outage of one Tailem Bend to Tungkillo line in South Australia contributed to all FCAS high prices this quarter.
Two participants own 74% of registered capacity and demonstrate structural dominance of the South Australia lower 1 second FCAS market. Further analysis of the structure of this market will be conducted as part of the Wholesale Electricity Market Performance Report.
The high FCAS prices occurred across 9 separate days in July and August 2025. High prices were forecast for most of these days:
- 24 July for seven 30-minute trading intervals
- 27 July for six 30-minute trading intervals
- 3 August for nine 30-minute trading intervals
- 4 August for four 30-minute trading intervals
- 7 August for two 30-minute trading intervals
- 8 August for three 30-minute trading intervals
- 9 August for two 30-minute trading intervals
- 16 August for ten 30-minute trading intervals
- 17 August for ten 30-minute trading intervals
Background
Significant price outcomes reporting
The AER is required to report into significant price outcomes in the NEM.
30-minute wholesale electricity prices do not often reach $5,000 per MWh, but with a market price cap of $20,300 per MWh prices can occasionally exceed this reporting threshold. This reporting framework is intended to pick up these outlier events.
A high price may occur due to a variety of factors, including outages that adversely affect supply-demand conditions in the wholesale market.
The AER’s role in monitoring wholesale energy markets and reporting on high price events helps to enhance market transparency and compliance.
Our analysis provides a foundation to detect non-compliance, market irregularities, inefficiencies, and consumer harm. We draw on this work to advise stakeholders and market bodies on wholesale market issues.
The AER has published a Guideline for how we report into significant price outcomes.
Review of Significant price reporting guidelines for wholesale electricity
The AER has conducted a review of the Guideline which concluded the current significant price outcome criteria of $5,000/MWh is no longer fit for purpose.
We are inviting feedback on our proposed changes to the Guideline which primarily related to the methodology used to determine which price outcomes in the electricity wholesale market should be reported on.
We currently expect to publish our final updated Guideline on 20 January 2026.