This rule change request from ERM Power sought a number of amendments to the Medium Term Projected Assessment of System Adequacy (MT PASA) to improve transparency and accuracy, and extend the projected outlook of MT PASA from two to three years.

The MT PASA is a key part of the reliability framework in the NEM. It is one component of the information that AEMO must publish to inform the market of prevailing and forecast conditions, and when reserves may be running low, to elicit a market response. Providing information to the market helps market participants make operational and investment decisions with respect to reliability and also helps AEMO manage the power system. 

Final determination

On 20 February 2020 the Australian Energy Market Commission (AEMC), or Commission made a more preferable final rule to amend the MT PASA. 

The final rule:

• improves transparency of the MT PASA process
• makes market information available when it is most needed 
• extends the period generation availability is published from two to three years. 

These changes will give the market more granular detail on projected assessments of power system reliability and generation availability. They will likely result in participants making more effective and efficient decisions on how they interact with the market.

The key features of the more preferable final rule are that it will provide the market with:

• information on the generation availability of individual scheduled generating units
• an extended outlook of generation availability from two to three years
• a maximum and minimum aggregated scheduled generating availability adjusted for forced outage assumptions
• transparency of intending generation included as an MT PASA input
• greater transparency of the maximum and minimum values of daily forecast peak demand, from both the adjusted 50% and 10% probability of exceedance (POE) load traces used in the reliability assessment
• actual demand and forecast demand published in the same format (operational ‘as generated’)
• a requirement on participants to provide MT PASA inputs that represent their current intentions and best estimates.

The key differences between the final rule and the proposed rule are that the Commission has: 

• extended the outlook of published generation availability from two to three years, instead of extending the full MT PASA from two to three years
• made a change to require AEMO to publish the maximum and minimum values of daily peak demand forecasts, from both the adjusted 50% and 10% probability of exceedance (POE) profiles of load traces used in the reliability assessment. This is instead of publishing an additional daily peak demand forecast of 90POE
• made the Australian Energy Regulator's proposed change requiring participants to provide MT PASA inputs that represent their current intentions and best estimates
• not made the proposed draft rule for requiring more frequent updates to AEMO's demand forecast, a key input into the MT PASA.

Background and consolidation of related rule changes

On 31 March 2019 ERM Power submitted two rule change requests:

• Improving MT PASA transparency and accuracy
• Extension of MT PASA duration.

These rule change requests sought to make amendments to the MT PASA. As a result, they have been consolidated into one rule change request.

The sections below provide a chronology of key stages leading up to the Commission final determination.

Early submission to the draft determination

ERM Power made an interim submission to the draft determination. They submitted:

• alternative approaches to two proposals in its rule change request (that the AEMC did not make in the draft determination). 
• a new change that would require generators to submit an explanation when a generating unit is unavailable.

ERM Power’s interim submission to the draft determination is published below. Stakeholders were encouraged to consider these issues when making a submission to the draft determination. Submissions were due by 9 January 2020. 
 

Draft determination   

On 24 October 2019 the Commission made a more preferable draft rule to amend the MT PASA. Submissions to this draft determination were due by 9 January 2020.

Consultation paper

On 18 July 2019 the AEMC published a consultation paper on the proposed changes to the MT PASA. Submissions were due 15 August 2019 and are published below.