On 13 March 2025 the AER released its draft determination for the Default market offer prices for 2025–26 (DMO 7).

ACIL Allen supported us in the design of a forecasting approach for wholesale and environmental costs. We also instructed ACIL Allen to produce a long run marginal cost (LRMC) estimate for South Australia to provide a comparative data point against our current forecasting approach for wholesale costs. 

The report Wholesale energy and environment cost estimates for DMO 7 draft determination by ACIL Allen was published alongside the draft determination on 13 March 2025.

The report LRMC estimates for South Australia by ACIL Allen was also published alongside the draft determination on 13 March 2025.

On 13 March 2025 the AER released its model for calculating DMO prices for 2025–26.

As set out in the DMO 7 draft determination, the AER’s approach is to use a cost build-up approach to calculate the DMO price, taking into account forecast costs for wholesale electricity, network, environment and retail costs. The model calculates the expected changes in these costs for 2025–26 for each area and customer type.

The information contained in the model is set out in the DMO 7 draft determination, and we have published the model to provide stakeholders with additional transparency on how we propose to calculate the DMO prices for 2025–26.

We requested AEMO provide the interval meter data used to simulate the load profiles and have published this data for the first time as supporting information alongside the DMO 7 draft determination. The data provided is at 30-minute intervals with both customer types aggregated (residential and small business), by DMO region. This provides transparency regarding a key input to our wholesale energy cost modelling, allowing stakeholders to consider inputs in more detail.

We have also published the DMO 7 assumed patterns of supply in Excel format.

Following the publication of the DMO 7 draft determination on 13 March 2025, stakeholder engagement activities were undertaken as part of the consultation process. These activities provided stakeholders with opportunities to clarify aspects of the draft determination and inform their written submissions.

13 March 2025 - 3 April 2025

We invited interested parties to make written submissions on the DMO 7 draft determination. Submissions closed on 3 April 2025. Seventeen (17) written submissions were received and 16 are published below, with the remaining submission provided to the AER confidentially.