The electricity sector remains the largest emitting industry in Australia. Stanwell is a significant contributor. In the 2017/18:
While our emissions rates are consistent across recent benchmarking periods and are within allowable ranges; these rates are unfavourable to the NEM average due to increases in renewable generation. This presents significant challenges. Going forward, as our renewable energy generation assets transfer to CleanCo Queensland (31 October 2019), our coal-only portfolio will be more unfavourable to benchmark levels for emissions, particularly NGERS reporting.
We report our emissions annually to the National Greenhouse and Energy Reporting Scheme (NGERS), an initiative of the Australian Government’s Clean Energy Regulator, as well as the Australian Federal Government’s National Pollutant Inventory (NPI).
We used real-time data (known as continuous emissions monitoring system or CEMS data) to inform our 2017/18 NPI report for Stanwell Power Station as this is considered a more transparent and robust method of reporting. Previously, we had used generic emissions factors to report our emissions at Stanwell Power Station, as permitted under the NPI guidelines and in keeping with the practices of the majority of generators in Australia. The voluntary move to CEMS provides greater transparency of air emission data that will be used to further optimise our operations and improve coal ignition efficiencies.
In the case of NOx at Stanwell Power Station, there was an increase of 99.5 per cent between the use of the previously used generic emissions factor and the real-time measured data for the 2017/18 period. Year on year, Stanwell Power Station’s actual emissions have remained relatively unchanged, in line with the amount of electricity our power station has generated. What has changed is the methodology we use to report the emissions. As part of our commitment to transparently report air emissions and develop continuous improvement initiatives, a $2.0 million CEMS was also installed at Tarong power stations in early 2019. From 2019/20, emissions from Tarong power stations will be reported using the new system.
We also conduct comprehensive air quality monitoring at Tarong and Stanwell power stations. During the 2018/2019 period we made significant improvements to the electrostatic precipitator rapping procedure at Tarong power stations. This has helped to reduce airborne particulate concentrations released to the surrounding environment. At Stanwell Power Station, we have undertaken extensive work on optimising combustion of the boilers to control emissions, as well as installing low NOx burners on all four of the generating units. This has helped to reduce the formation of NOx during the coal combustion process.