The Australian Energy Regulator (AER) today published a report into energy prices exceeding $5,000 per megawatt hour (MWh) in the National Electricity Market (NEM) during October, November, and December 2025.
The wholesale 30-minute price of electricity exceeded $5,000 per MWh 3 times in the quarter. This compares to 7 high prices in the previous quarter and 23 high prices in the same quarter in 2024.
The high price events all occurred in NSW across 3 separate days in November and December 2025:
- 25 November for one 30-minute period
- 26 November for one 30-minute period
- 19 December for one 30-minute period.
The high prices were not forecast. Common contributing factors across high prices this quarter were:
- a sudden increase in demand due to a significant reduction in rooftop solar generation,
- generating units unable to start or ramp up quickly enough, and
- network limitations that prevented cheaper generation from getting to load centres.
Rebidding only contributed to the high prices on 25 November.
Background
Significant price outcomes reporting
The AER is required to report into significant price outcomes in the NEM.
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.
Revised Significant price reporting guidelines
In 2025, we conducted a review of the Significant price reporting guideline (Guideline) published in 2022 which describes our approach for monitoring and reporting significant price outcomes. The review concluded the significant price outcome criteria of $5,000 per MWh was no longer fit for purpose. A revised guideline setting out a new significant price outcome criteria and approach was published in January 2026.
This report is the last report that falls under the guideline published in 2022 using the significant price outcome criteria of $5,000 per MWh. We will apply the revised significant price outcome criteria outlined in the 2026 guideline for reporting events from Q1 2026 onwards.