Biomass Cofiring: A Transition to a Low-Carbon Future

The fact sheet describes biomass cofiring—the simultaneous combustion of biomass and a base fuel, typically coal—as a practical bridge to a renewable energy future. It highlights benefits including linear reductions in CO2 and SO2 emissions, lower capital costs for retrofitting existing boilers, and support for sustainable forest management by creating markets for hazardous fuels. However, it identifies barriers such as feedstock preparation costs and ASTM standards that prevent the sale of biomass-contaminated fly ash. The document suggests that replacing 5% of U.S. coal with biomass could reduce total U.S. emissions by 1.5% within 5-10 years.

• Biomass cofiring involves burning biomass fuels—such as crop residues, municipal waste, and energy crops like switchgrass—alongside a base fuel, usually coal, typically with the biomass comprising less than 20 percent of the energy content.
• Cofiring reduces air pollutants; CO2 and sulfur dioxide (SO2) emissions decline linearly as coal is replaced by biomass, and cofiring wood at 7 percent of total heat input can reduce nitrogen oxides (NOx) emissions by up to 15 percent.
• The technology supports sustainable land management by creating a market for thinning fire-prone forests; in the western United States, 28 million acres of forest currently require thinning.
• Cofiring is economically advantageous due to low capital costs for boiler retrofits and potential annual fuel savings between $60,000 and $100,000 for an average-sized federal facility boiler.
• A 2006 experiment in Iowa known as the Chariton Valley Project used switchgrass to produce 19.6 million KWh of electricity over 1,675 hours, reducing carbon emissions by 50,800 tons and generating 19,600 renewable energy credits.
• Economic barriers include retrofit costs ranging from $50 to $300 per kW of biomass output and a regulatory barrier where ASTM standard C618 prevents the sale of biomass-cofired fly ash for use in cement.
• Replacing 5% of coal in U.S. power production with biomass could reduce total U.S. emissions by 1.5 percent within 5-10 years, offering a more cost-effective carbon mitigation path than cellulosic ethanol.

APA

Caputo, J., & Hacker, J. (2009). Biomass Cofiring: A Transition to a Low-Carbon Future. Environmental and Energy Study Institute. https://www.eesi.org/files/cofiring_factsheet_030409.pdf

Chicago

Caputo, Jesse, and James Hacker. Biomass Cofiring: A Transition to a Low-Carbon Future. Environmental and Energy Study Institute, 2009. https://www.eesi.org/files/cofiring_factsheet_030409.pdf.

Wikipedia

{{cite report |last1=Caputo |first1=Jesse |last2=Hacker |first2=James |title=Biomass Cofiring: A Transition to a Low-Carbon Future |publisher=Environmental and Energy Study Institute |date=March 2009 |url=https://www.eesi.org/files/cofiring_factsheet_030409.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{caputo2009biomass, author = {Caputo, Jesse and Hacker, James}, title = {{Biomass Cofiring: A Transition to a Low-Carbon Future}}, institution = {Environmental and Energy Study Institute}, year = {2009}, month = mar, url = {https://www.eesi.org/files/cofiring_factsheet_030409.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }