SUPPORTING TECHNICAL PAPER: National Energy and Emissions Audit, July 2018
CALCULATING GREENHOUSE GAS EMISSIONS ARISING FROM ELECTRICITY GENERATION IN THE NATIONAL ELECTRICITY MARKET.
Emissions are calculated on an annual basis as the sum of emissions arising from each thermal power station supplying the National Electricity Market (NEM). This is the procedure used by the Australian Electricity Market Operator to calculate, on a daily basis, its Carbon Dioxide Emissions Intensity Index (CDEII)1. AEMO calculates emissions from each power station as the product of electricity sent out from the station by the sent out emissions intensity of the station.
This study uses the AEMO sent out emissions intensity figures, in t CO2-e/MWh sent out, for each power station (most of which are calculated from individual power station NGER reports). AEMO’s list of power station emission intensities are summarised in an Excel file entitled Available Generators, accessible on the website. AEMO’s calculation uses the metered sent out data for each power station, which AEMO gathers as a key input to its market settlement procedures. However, these data are commercially confidential and not publicly available. This study therefore uses AEMO’s published data on power station output as generated, accessed through NEM-Review. The conversion from as generated to sent out uses AEMO’s list of estimated power station auxiliary load factors. AEMO uses these values as an input to its annual National Transmission Development Plan process. Values for each individual power station were compiled for AEMO by ACIL Allen, and are available in a workbook entitled Emission Intensity Values.