Carbon Dioxide Equivalent Intensity Index

The Carbon Dioxide Equivalent Intensity Index (CDEII) is calculated under a formal framework contained within the National Electricity Rules. It replaced the informal Greenhouse Intensity Index published by AEMO’s predecessor NEMMCO.

The CDEII calculation combines sent out metering data with publicly-available generator emission and efficiency data to provide a National Electricity Market (NEM)-wide CDEII. This is calculated on a daily basis and published weekly to the AEMO website, in accordance with the timing of the issue of preliminary statements.

AEMO CDEII Procedure

This AEMO CDEII Procedure document describes the methodology used to calculate the CDEII.

CDEII results – current year

The Summary Results File below, for the current year, contains the daily summarised regional and NEM-wide CDEII results. Emission factors used in calculating the CDEII from June 2014 are based on NGER data.

CDEII results – historical

The Summary Results Files below contain the daily summarised regional and NEM-wide CDEII results. Emission factors used in calculating the CDEII to May 2014 are based on estimated data. Emission factors used in calculating CDEII from June 2014 are based on NGER data.

Emission Factor Data Source

Where available, Emission Factor data is sourced from the latest published Planning Database.  The current version can be found at:

In previous years,  NTNDP data was used to calculate the CDEII:

Available Generators File

List of all available generating units for electricity production in the current CDEII reporting week.

CDEII input data change – June 2014

From 1 June 2014, the emission data used in calculating the CDEII changed from estimated to actual emission data, obtained through the National Greenhouse and Energy Reporting (NGER) scheme. An impact assessment performed for the 2012/–13 financial year indicates that this new data source would have resulted in the CDEII result being on average 2.5% higher than the published CDEII. The change to data source should be taken into consideration when analysing the change to CDEII over time. Further detail on this change can be found below under the heading CDEII input data change – June 2014.

AEMO produced an impact assessment on using a new source of emission data from June 2014, and proposed next steps to integrate this source into planning activities and calculation of the CDEII.

This CDEII information update provides guidance on the structure and application of the CDEII from June 2014.

CDEII historical snapshot data

The links below contain a snapshot of historical data for daily summarised regional and NEM wide CDEII results to June 2011, based on the following underlying assumptions.

The data is:

  • Calculated based on emission factors as at June 2012.
  • Only representative of generators in service as at June 2012.
  • Calculated based on the historical generated energy of those generators in the NEM at the time of the snapshot period (that is, data for Tasmania is only from 29 May 2005).

The data published here may not be accurate or complete and AEMO accepts no liability for reliance on it. For more details please view our full disclaimer.

2010   2009
2008   2007
2006   2005
2004   2003
2002   2001

*The 2011 data set includes data for the dates 1 January 2011 to 18 June 2011. CDEII data for 19 June 2011 to 31 December 2011 is provided above in CDEII results – historical.

For enquiries regarding any of this documentation, please contact the AEMO Information & Support Hub.

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