Hourly emission inventories for air toxic emissions for eastern Australian electricity generators derived from energy distribution data

Abstract

Emission inventories are a fundamental input for atmospheric chemical transport models in order to accurately simulate air pollution and its impacts. In Australia, emission inventories are currently not available for electricity generators at high temporal and spatial resolutions. In this study, a new high spatial and temporal resolution inventory for Australian power plant emissions has been developed. The emissions from coal- and gas-fired power plants have been estimated using 5-min electricity generation time-series data and emission factors. The emissions are estimated from 2010 to 2019 for sulfur dioxide ($\hbox {SO}_2$), nitrogen oxide ($\hbox {NO}_{2}$), particulate matter (PM) and mercury (Hg). We estimate that, for 2019, the coal-fired power plants in Australia emitted significant amounts of $\hbox {SO}_2$ (485.7 kTonne) and $\hbox {NO}_{2}$ (452 kTonne), as there are no sulfur dioxide or nitrogen oxide controls in place. In contrast, PM emissions are mitigated by particulate matter control devices and coal-fired power plants emit an estimated 27.48 and 13.46 kTonne of $\hbox {PM}_{10}$ and $\hbox {PM}_{2.5}$, respectively. Coal-fired power plants were responsible for an estimated 3.13 tonnes of Hg emissions. Gas-fired plant emissions are significantly lower than coal-fired power emissions for all pollutants. Temporal analysis showed that coal- and gas-fired power plant emissions vary quite markedly during the day and over the week. There is a strong diurnal cycle in the gas-fired emissions, which, if ignored by assuming constant emissions (such as is routinely done), will lead to significant errors in modeled air pollution.