Emissions intensity across the National Electricity Market (NEM) has fallen significantly in recent years, driven by the continued rollout of renewable energy projects.
Analysis of Open Electricity data by Windlab principal wind engineer David Osmond shows that average NEM emissions intensity has declined to around 510 kg CO₂-equivalent per megawatt-hour (MWh) over the past 12 months. This represents a 25 per cent reduction since 2020 and a 40 per cent drop compared to 2015 levels. The figures include emissions linked to electricity imports.
South Australia is leading the transition, with emissions intensity dropping below 200 kg CO₂-e/MWh over the past year. This marks a 28 per cent decrease since 2020 and a substantial 68 per cent decline since 2015.
The state’s progress has been particularly notable since the closure of its last coal-fired power station at Port Augusta in May 2016. Between February 2016 and February 2018, emissions intensity nearly halved, reflecting a rapid shift towards cleaner energy sources.
Over the past year, South Australia has sourced approximately 64 per cent of its electricity from wind, 25 per cent from gas, and 7 per cent from solar, according to data from the Australian Energy Market Operator (AEMO). These figures exclude rooftop solar contributions, which would further increase the share of renewables.
Victoria remains the largest contributor to NEM emissions, with an average intensity of just over 600 kg CO₂-e/MWh as of February 2026. However, the state has made considerable progress over the longer term, down from nearly 1,200 kg CO₂-e/MWh in February 2010.
Despite this improvement, Victoria continues to rely heavily on brown coal, which accounted for around 60 per cent of its electricity generation over the past 12 months. Wind contributed 27 per cent, while solar made up 5 per cent.
Queensland has recorded the slowest pace of emissions reduction among NEM states. Emissions intensity has fallen by less than 20 per cent since 2020 and under 30 per cent since 2010. The state’s electricity supply remains dominated by black coal, which provided about 70 per cent of generation over the past year. Solar contributed 12 per cent, while wind accounted for 9 per cent.
The data highlights both the progress made and the uneven pace of decarbonisation across the NEM, as states continue to transition away from fossil fuels towards cleaner energy sources.