Biomass-based electricity 74-85% cleaner than coal, new study finds
According to a study by the University of Illinois, USA, carbon emissions throughout biomass process are 74-85% lower than coal-based electricity.
The paper - 'Carbon savings with transatlantic trade in pellets: accounting for market-driven effects' - examines the greenhouse gas (GHG) intensity of pellets exported from the US using either forest biomass only or forest and agricultural biomass combined.
Professor of Agriculture Madhu Khanna and her team analysed multiple scenarios considering variables like pellet demand fluctuations, greenhouse gas intensity, land use and milling residues.
"Across different scenarios of high and low pellet demand that can be met with either forest biomass only or with forest and agricultural biomass, we find that the GHG intensity of pellet based electricity is 74% to 85% lower than that of coal-based electricity. We also find that the GHG intensity of pellets produced using agricultural (i.e. miscanthus and switchgrass) and forest biomass is 28% to 34% lower than that of pellets produced using forest biomass only", said Professor Khanna.
"Greenhouse gas (GHG) effects due to induced direct and indirect changes in forest carbon stock caused by changes in harvest rotations, changes in land use and in conventional wood production account for 11% to 26% of the overall GHG intensity of pellets produced from forest biomass only; these effects are negative with the use of forest and agricultural biomass."
"Our study demonstrates that low GHG-intensive supply-chain management practices for pellet production are possible by avoiding extended storage of biomass. It provides a framework for determining the effects of market-driven direct and ILUCs (Indirect Land Use Change) on GHG intensity of pellets in the US", concluded Professor Khanna.