Estimating unit production cost, carbon intensity, and carbon abatement cost of electricity generation from bioenergy feedstocks in Georgia, United States

In Georgia, the coal-based electricity generation emitted about 26% of the total greenhouse gas (GHG) emissions in 2016. Considering the availability of biomass resources in the state and advent of emerging technologies like torrefaction, biomass-based feedstocks could be directly used in existing coal-based power plants. We performed economic and environmental analyses of electricity derived from nine feedstocks (loblolly pine, corn stover, cotton stalks, bermudagrass, switchgrass, napier grass, giant reed, energycane, and miscanthus) over 25 years relative to coal-based electricity in Georgia. We assumed processing biomass via torrefaction before using the same to substitute coal at the power plant. Pine chips were the least expensive ($113 MWh−1) and the least GHG intensive (134 kg CO2e MWh−1) option for generating electricity, with the lowest abatement cost ($17 t CO2e−1). Based on sensitivity analysis, the abatement cost could be as low as $8 t CO2e−1 for a 900 MW power plant, the most common capacity of coal-based electricity generating units in Georgia. Between the two agricultural residues, cotton stalk ($26 t CO2e−1) had a lower abatement cost than corn stover ($34 t CO2e−1). Among perennial grasses, switchgrass and giant reed had the lowest carbon abatement cost (about $25 t CO2e−1) because of their low unit production cost of electricity. Other perennial grasses had comparable abatement costs, ranging between $28 and $30 t CO2e−1, except napier grass and energycane, which had the highest abatement cost (about $38 t CO2e−1). A carbon tax of $40 t CO2e−1 could make bioenergy feedstocks found in Georgia competitive against coal for reducing carbon emissions from the electricity sector.