Phase 1

Phase 1 of our work in Indonesia evaluated mercury emissions from every coal-fired utility unit >100 MW on a unit-by-unit basis. By focusing on mercury emissions per GWh of plant operation it became clear that some plants were emitting more mercury per GWh than others, by order of magnitude. The emission rates were associated more with plant capacity and operating rate than with coal type or plant configuration, although there were some anomalies.

The figure above shows the top 30 Indonesian coal units in terms of estimated remaining lifetime emissions of mercury.

The data presented in the figure above assume that plants will operate at the same rate and efficiency as they did in 2019/2020 until they close at 40 years old. The red dots show estimated sulphur emissions from each unit over the remaining plant lifetime. This information will be useful when decisions are made on potential multipollutant control strategies for these units.

The results of this work suggest that there are 15 coal-fired units in Indonesia which, over their remaining predicted lifetime, could emit half of the predicted mercury emissions from the entire fleet (>100 units). This is critical information for an informed emission reduction strategy – it could be significantly more cost-effective for Indonesia to focus mercury strategies on certain plants rather than apply a blanket reduction requirement across the fleet. Based on these results, three high-emitting units have been identified for closer study during Phase 2 of this project.

There were significant assumptions made in preparing such estimates, and these must be transparent for the results to be useful. A full description of the analysis is given in the report from Phase 1, which can be downloaded here