In accordance with section 2.27 of the WEM Rules, by 1 June of each year Western Power must calculate and provide to AEMO Loss Factors for each connection point in its network. Where Western Power fails to provide AEMO with the Loss Factors by 1 June, AEMO must continue to use the equivalent Loss Factors from the previous year until such time as Western Power has provided AEMO with the new Loss Factors and those Loss Factors have taken effect.

AEMO must publish the Loss Factors within two business days after receiving them from Western Power. AEMO must also publish the time from which the Loss Factors will apply.

A Market Participant may apply to AEMO for a reassessment of any Loss Factor applying to a Scheduled Generator, Non-Scheduled Generator, Curtailable Load, Interruptible Load, Dispatchable Load, or Non-Dispatchable Load registered by that Market Participant in accordance with section 2.27.15 of the WEM Rules.

Loss Factors 2018 - 2019

The links below provide further information on the Loss Factors which apply from 1 July 2018.

• Distribution Loss Factors 2018-19 (10 KB, csv) - 26 June 2018 
• Transmission Loss Factors 2018-19 (6 KB, csv) - 06 June 2018
• 2018-19 Loss Factor Report (921 KB, pdf) - 26 June 2018

Previous Loss Factors

The links below provide further information on the Loss Factors which apply from 1 July 2017.

• Distribution Loss Factors 2017-18 (6 KB, csv) - updated 16 June 2017
• Transmission Loss Factors 2017-18 (6 KB, csv) - updated 16 June 2017
• 2017-18 Loss Factor Report (252 KB, pdf) - updated 16 June 2017

The links below provide further information on the Loss Factors which apply from 1 July 2016.

• Distribution Loss Factors 2016-17 (6 KB, csv) - updated 2 June 2016
• Transmission Loss Factors 2016-17 (6 KB, csv) - 2 June 2016
• 2016-17 Loss Factor Report (1.05 MB, pdf) - updated 2 June 2016

The links below provide further information on the Loss Factors which applied from 1 July 2015.

• New Distribution Loss Factor 2015-16 QBBW  (4 KB, csv) - updated 6 November 2015
• New Distribution Loss Factor 2015-16 QCTE  (4 KB, csv) - updated 6 October 2015
• Distribution Loss Factors 2015-16  (6 KB, csv) - updated 29 June 2015
• Transmission Loss Factors 2015-16  (6 KB, csv) - 3 June 2015
• 2015-16 Loss Factor Report (1.75 MB, pdf) - updated 29 June 2015

The links below provide further information on the Loss Factors which apply from 1 July 2014.

• New Distribution Loss Factor 2014-15 QCMA (107 bytes, csv) - 24 July 2014
• Distribution Loss Factors 2014-15 (6 KB, csv) - updated 9 July 2014
• Transmission Loss Factors 2014-15 (6 KB, csv) - 30 May 2014
• 2014-15 Loss Factor Report (1.8 MB, pdf) - updated 9 July 2014

The links below provide further information on the Loss Factors which apply from 1 July 2013.

• Distribution Loss Factors 2013-14 (6 KB, csv) - updated 3 July 2013
• Transmission Loss Factors 2013-14 (6 KB, csv) - 2 July 2013
• Western Power 2013-14 Loss Factors Report (201 KB, pdf) - 2 July 2013

The links below provide further information on the Loss Factors which apply from 1 July 2012.

• New Distribution Loss Factors 2012-13 QDWF (95 bytes) - 21 February 2013
• New Transmission Loss Factors 2012-13 TMBA (96 bytes) - 04 December 2012
• New Transmission Loss Factors 2012-13 TMDP (110 bytes) - 21 August 2012
• New Transmission Loss Factors 2012-13 TMGS (113 bytes) - 21 August 2012
• New Distribution Loss Factors 2012-13 QWHF (93 bytes) - 07 August 2012
• New Distribution Loss Factors 2012-13 QANF (91 bytes) - 07 August 2012.
• Distribution Loss Factors 2012-13 (7 KB) - 06 June 2012
• Transmission Loss Factors 2012-13 (6 KB) - 06 June 2012
• Western Power 2012-13 Loss Factors Report (201 KB) - 06 June 2012

The links below provide further information on the Loss Factors which apply from 1 July 2011.

• New Distribution Loss Factors 2011-12 QZSC (106 bytes) - 21 May 2012
• New Transmission Loss Factors 2011-12 WCTE (88 bytes) - 08 November 2011
• New Distribution Loss Factors 2011-12 QTES (16 KB) - 18 August 2011
• Distribution Loss Factors 2011-12 (15 KB) - 08 August 2011
• New Transmission Loss Factors 2011-12 WCGW (95 bytes) - 08 August 2011
• Transmission Loss Factors 2011-12 (6 KB)
• Western Power 2011-12 Loss Factors Report (204 KB)

The links below provide further information on the Loss Factors which apply from 1 July 2010.

• New Transmission Loss Factors 2010-11 WCWG (95 bytes)
• New Distribution Loss Factors 2010-11 QMBW (105 bytes)
• New Distribution Loss Factors 2010-09 QRGP (115 bytes)
• New Distribution Loss Factors 2010-09 QFLM (117 bytes)
• New Distribution Loss Factors 2010-08 QHVI (96 bytes)
• Distribution Loss Factors 2010-11 (5 KB)
• Transmission Loss Factors 2010-11 (6 KB)
• Western Power 2010-11 Loss Factors Report (167 KB)

The links below provide further information on the Loss Factors which apply from 1 July 2009

• New Distribution Loss Factors 2009-10 QR12 (122 bytes)
• New Transmission HV Loss Factors 2009-10 WGNN (94 bytes)
• New Distribution Loss Factors 2009-10 QTMH (93 bytes)
• New Distribution Loss Factors 2009-10 QPHG (94 bytes)
• New Distribution Loss Factors 2009-10 QHFM (96 bytes)
• Distribution Loss Factors 2009-10 (5 KB)
• Transmission Loss Factors 2009-10 (6 KB)
• Western Power 2009-10 Loss Factors Report (166 KB)

The links below provide further information on the Loss Factors which apply from 1 October 2008. New Loss Factors or Loss Factors amended after 1 October 2008 apply as per the dates in each file:

• New Distribution Loss Factors 2008-09 QDMS (97 bytes)
• New Transmission HV Loss Factors 2008-09 WGNI WPLD (123 bytes)
• New Distribution Loss Factors 2008-09 QBGM (100 bytes)
• New Distribution Loss Factors 2008-09 QBMA QBMB (147 bytes)
• New Transmission HV Loss Factors WBGM TBLB (137 bytes)
• New Transmission HV Loss Factors WNGK (91 bytes)
• Transmission HV Loss Factors 2008-09 (4 KB)
• Distribution Loss Factors 2008-09 (4 KB)
• Western Power Letter to IMO (85 KB)
• Western Power Distribution Loss Factors Report (131 KB)

The links below provide further information on the 2007/08 Loss Factors which applied until 1 October 2008:

• Transmission Loss Factors 2007-08 (5 KB)
• Distribution Loss Factors 2007-08 (4 KB)
• Western Power Letter to IMO (50 KB)
• Distribution Loss Factor Report December 2007 (154 KB)

The Loss Factor procedure can be found here .

This web page is published in accordance with Market Rule 10.5.1 (l).