AEMO publishes final Marginal Loss Factors for 2019/20

AEMO has released the final marginal electricity loss factors (MLFs) that will apply from 1 July 2019 to 30 June 2020 for electricity generation and loads connected to the National Electricity Market (NEM). The final determination follows the publication of draft MLFs in March and April, and incorporates new information subsequently received by AEMO.

AEMO calculates MLFs for the NEM transmission grid every year. After publishing initial draft electricity loss factors for 2019–20 in March 2019, AEMO became aware that some information previously received by AEMO no longer reflected expected commissioning schedules for several new generation projects.

AEMO deferred finalisation of the 2019–20 MLFs to give proponents an opportunity to provide the most recent and accurate information for AEMO to use in the MLF calculations. Updates were requested for 46 projects, with 29 providing AEMO with updated generation profiles.  

AEMO has recalculated all MLFs based on this updated information from proponents. This has resulted in changes to the MLFs from the draft factors published on 1 April 2019, including material changes for areas of Northern Queensland, South West New South Wales and North Western Victoria.

June 2019 Update to Marginal Loss Factors for 2019/20

AEMO has recently discovered that some generators in the 2019-20 MLF calculations, as published on 10 May 2019, were modelled with incorrect generation profiles. AEMO has now completed a full review of how generation is modelled in the MLF calculation to ensure conformance with the Forward-Looking Transmission Loss Factors methodology.

The revised 2019-20 MLFS and the Regional Boundaries and Marginal Loss Factor report are now published below.

Participants who wish to meet with AEMO to discuss their results should contact MLF 2019-20 Feedback.

• Regional Boundaries and Marginal Loss Factors for the 2019-20 Financial Year - updated 21 June 2019 (1.8 MB, pdf)
• 2019-20 MLF Applicable from 01 July 2019 to 30 June 2020 - updated 21 June 2019 (93 KB, xlsx)
• 2019-20 MLF Applicable from 01 July 2019 to 30 June 2020 - updated 10 May 2019 (83 KB, xlsx)
• Regional Boundaries and Marginal Loss Factors for the 2018-19 Financial Year - updated 11 July 2018 18 July 2018 (3.2 MB, pdf)
• 2018-19 MLF Applicable from 01 July 2018 to 30 June 2019 - updated 11 July 2018 18 July 2018 (85 KB, xlsx)
• Regional Boundaries and Marginal Loss Factors for the 2018-19 Financial Year - 29 March 2018 (1.7 MB, pdf)
• 2018-19 MLF Applicable from 01 July 2018 to 30 June 2019 - 29 March 2018 (1.3 MB, pdf)
• Regional Boundaries and Marginal Loss Factors for the 2017-18 Financial Year - updated 06 November 2017 13 November 2017 (3.2 MB, pdf)
• 2017-18 MLF Applicable from 01 July 2017 to 30 June 2018 - updated 06 November 2017 13 November 2017 (82 KB, xlsx)
• Regional Boundaries and Marginal Loss Factors for the 2016–17 Financial Year - updated 05 January 2017 (2.2 MB, pdf)
• 2016–17 MLF Applicable from 1 July 2016 - updated 05 January 2017 (92 KB, xlsx)
• Regional Boundaries and Marginal Loss Factors for the 2015–16 Financial Year - (2.08 MB, pdf)
• Regional Boundaries and Marginal Loss Factors for the 2014–15 Financial Year - (1.94 MB, pdf)
• Regional Boundaries and Marginal Loss Factors for the 2013–14 Financial Year - (1.69 MB, pdf)
• Regional Boundaries and Marginal Loss Factors for the 2012–13 Financial Year - (1.15 MB, pdf)
• Regional Boundaries and Marginal Loss Factors for the 2011–12 Financial Year - (996 KB, pdf)
• Regional Boundaries and Marginal Loss Factors for the 2010–11 Financial Year - (1.11 MB, pdf)
• Regional Boundaries and Marginal Loss Factors for the 2009–10 Financial Year - (404 KB, pdf)
• Regional Boundaries and Marginal Loss Factors for the 2008–09 Financial Year - (1.05 MB, pdf)

• Distribution Loss Factors for the 2019–20 Financial Year (697 KB, pdf)
• Distribution Loss Factors for the 2018–19 Financial Year (695 KB, pdf)
• Distribution Loss Factors for the 2017–18 Financial Year (673 KB, pdf)
• Distribution Loss Factors for the 2016–17 Financial Year (657 KB, pdf)
• Distribution Loss Factors for the 2015–16 Financial Year (253 KB, pdf)
• Distribution Loss Factors for the 2014–15 Financial Year (230 KB, pdf)
• Distribution Loss Factors for the 2013–14 Financial Year (561 KB, pdf)
• Distribution Loss Factors for the 2012–13 Financial Year (404 KB, pdf)
• Distribution Loss Factors for the 2011–12 Financial Year (392 KB, pdf)
• Distribution Loss Factors for the 2010–11 Financial Year (552 KB, pdf)
• Distribution Loss Factors for the 2009–10 Financial Year (784 KB, pdf)
• Distribution Loss Factors for the 2008–09 Financial Year (503 KB, pdf)

Archived loss factor documents may be obtained upon request from the AEMO Information & Support Hub.

Interested parties may on occasion require marginal loss factors (MLFs) under conditions that differ from the Forward Looking Loss Factor (FLLF) methodology. Examples include:

• A proponent may wish to assess the potential impact on published MLFs if a generating unit is installed or upgraded at a particular connection point.
• A market customer may wish to assess the impact on the published MLF at a connection point without the contribution of a nearby generating unit.
• A market participant may wish to assess the MLF of an embedded generator for which AEMO does not normally calculate and publish an MLF.

To assist interested parties with such requests, AEMO currently provides a service to calculate indicative MLFs under non-standard assumptions for a nominal fee.The following document provides details of the indicative MLF calculation process, including fees and data requirements.

• Provision of Indicative Marginal Loss Factors - 25 July 2018 (206 KB, pdf)

AEMO conducted an indicative extrapolation study to assist generators in determining whether the historical generation data used by AEMO is reasonable for the 2019-20 MLFs calculation.

Indicative extrapolation input data for 2019-20 Marginal Loss Factors:

• Indicative extrapolation input data for 2019-20 loss factors (458 KB, docx)
• Indicative extrapolation results for 2019-20 loss factors (106 KB, xlsx)

Indicative extrapolation archive

In August 2018 AEMO held several information sessions to seek feedback from participants and interested parties on the current MLF calculation process.

Specifically, AEMO asked:

• Whether the current MLF calculations are fit for purpose.
• Potential improvements to MLF calculations that AEMO can make through a market consultation to amend the Forward Looking Loss Factor Methodology.
• Potential improvements to MLF calculations that require changes to the National Electricity Rules.
• Ways AEMO can increase the transparency of the MLF calculation process and improve the ability of participants and intending participants to forecast MLFs.

The slide pack presented at the sessions is available here: MLF Engagement Session (1.33 MB, pdf)

The high-level notes of the discussions are available here: Marginal Loss Factor (MLF) Engagement session notes (232 KB, pdf)

AEMO will be continuing this review in 2018 and 2019.

This document has been prepared by AEMO as required by clauses 2A.1.3 and 3.6 of the National Electricity Rules (Rules), and has effect only for the purposes set out in the Rules. The Rules and the National Electricity Law (Law) prevail over this document to the extent of any inconsistency.

• List of Regional Boundaries and Marginal Loss Factors the 2015–16 Financial Year (2 MB, pdf)