The viability of co-firing biomass waste to mitigate coal plant emissions in Indonesia

Given Indonesia’s abundant biomass resources, co-firing biomass presents an opportunity to reduce coal plant carbon emissions. However, the emissions profile of this strategy depends upon biomass sourcing, which, if derived from non-waste biomass (purpose-grown at plantations), could induce substantial land use change emissions, shifting emissions offset from coal plants to land. Here we use a plant-level supply-demand and combustion-cycle assessment to investigate whether available biomass in Indonesia from agricultural, forestry, and municipal waste alone can meet feedstock requirements for co-firing at various ratios throughout the year and across the archipelago. Our results indicate that incorporating existing biomass waste into coal plants reduces carbon emissions minimally without additional deforestation, meeting co-firing demand only at low ratios. However, competition with alternative uses and limited biomass supply in eastern provinces, where coal capacity is growing, preclude meeting demand at higher ratios without substantial land use change emissions.