AEMO’s integrated system plan: forecasting and modelling questions and implications

Chief Scientist Alan Finkel reached into Stalin’s drawer of economic planning tools many times when he made recommendations to the state about how to improve the power system. Like collectivism, in practice, Finkel’s recommendations do not seem to be going well.

One of Finkel’s signature recommendations was the development of an integrated grid plan “ facilitate the efficient development and connection of renewable energy zones across the National Electricity Market”. The Australian Energy Market Operator (AEMO) renamed Finkel’s integrated grid plan the Integrated System Plan (ISP). AEMO states that its “… first ISP delivers a strategic infrastructure development plan, based on sound engineering and economics”, the latter part of this quote being a favourite energy mantra of Prime Minister Malcolm Turnbull.

No doubt Finkel had in mind that such a plan could be useful for policy makers if it was undertaken professionally and free of politics. AEMO states that its ISP is “a cost-based engineering optimisation plan” and that the ISP modelling “applied technology-neutral analysis to identify the required level and likely fuel type of supply investments required to meet future needs.” (AEMO, Integrated System Plan, July 2018, page 3.)

However, the modelling undertaken for the ISP requires the exercise of judgement, and there are some areas in which this judgement appears to be made to support certain conclusions. This note highlights several modelling and forecasting assumptions, that are hard to justify on an objective basis, which have skewed the final results. This raises serious questions about the usefulness of the ISP for policy makers and about the independence of AEMO itself.

Fuel prices

Between AEMO’s original release of its ISP modelling assumptions (in March 2018) and its release of the modelling results in the ISP report (in July 2018), AEMO substantially increased its assumed long-term coal price forecast:

  • AEMO’s initial assumptions had a coal price for new generation in NSW and QLD that averaged $2.01/GJ during the 2020s and 2030s.
  • AEMO’s final modelling had a coal price for new generation that averaged $3.77/GJ during the 2020s and 2030s.
  • This reflects an increase of almost 90%.

No other fuel prices were updated during this time.

AEMO states that these updates were to reflect the coal price forecasts from the Department of Industry’s June 2018 release of its Resources and Energy Quarterly report. But the long-term coal price forecast from this report was only 5% higher than the equivalent forecast from the December 2017 release of the report. This doesn’t seem to justify a 90% increase in assumed coal prices.

Were these coal price assumptions updated to ensure that no new coal plant was part of the future generation mix in the ISP?

In the same Resources and Energy Quarterly reports from the Department of Industry, the long-term gas price forecast increased by 10-15% between the December 2017 report and the December 2018 report. Given that the Department of Industry made a larger upward revision to gas price forecasts than coal price forecasts, why did AEMO not update its assumed gas price forecast at the same time that it updated its assumed coal price?

Emissions trajectory

The emissions trajectory modelled in the ISP is the trajectory to meet a 28% reduction in carbon emissions on 2005 levels by 2030 (consistent with the Paris agreement). Beyond 2030, the ISP models an acceleration of the emissions reduction trajectory to achieve a 70% reduction in 2005 levels by 2050.

This accelerated target is not current policy. Was this emissions trajectory chosen to ensure that the future generation mix is in the ISP is made up almost solely of renewable and storage?


In a future in which coal prices are not as high as AEMO forecast, and the emissions reduction trajectory beyond 2030 does not accelerate as AEMO has assumed, is investment in coal part of the least cost mix of new generation? Did AEMO model its original, lower, coal prices while developing the ISP?

What are the implications of this for the views AEMO put forward in the ISP? Would there be less investment in renewables? Would there be less need for development of transmission investment to support renewable energy zones?

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