Strengthening the Environmental Benefits of Anaerobic Digestors Through Robust Measuring, Monitoring, Reporting, and Verification

The report finds that methane emissions from anaerobic digestion (AD) systems typically range from 0.5% to 6% of total production, with some plants reaching 41%, which is significantly higher than average levels in the oil and gas industry. Current regulatory frameworks in countries like France and Germany often prioritize worker safety over methane mitigation, and the United States lacks dedicated federal or state regulations for AD methane emissions. The report emphasizes that digestate storage is frequently the largest emission source, particularly in the U.S. where lagoons are often uncovered. It recommends implementing robust, facility-level MMRV, mandatory leak detection and repair (LDAR) programs, and the use of conservatively high default emission factors in carbon crediting methodologies to incentivize actual emission reductions.

• Methane losses in modern anaerobic digestion (AD) plants are estimated to be between 0.5% and 6% of total methane produced, with a mean value just under 5%, while legacy plants exhibit far higher emissions.
• Site-wide measurement studies of AD projects report total methane losses typically between 3.5–6%, though some individual cases have shown emission rates as high as 41%.
• Digestate processing and storage are often the largest contributors to methane emissions, with losses commonly between 2–4% and reaching up to 12-15% during warmer months or at facilities lacking gas-tight storage.
• Biogas utilization and upgrading are major emission sources; methane slip from Combined Heat and Power (CHP) units typically ranges from 1–5%, and upgrading losses range from 0.9% to over 3.0%.
• Regulatory priorities for AD systems vary by country, with many focusing on worker health and safety rather than methane mitigation; notably, the United States lacks federal and state regulations specifically for AD methane emissions.
• Current carbon offset and crediting methodologies, including those from the American Carbon Registry, Gold Standard, and Verified Carbon Standard, rely heavily on default emission factors and have incomplete coverage of AD emission sources.
• Industry associations generally recognize methane losses as an economic issue but often downplay the sector's role as a significant methane source, with the U.S. industry supporting general emission factors over rigorous MMRV.
• The report recommends that carbon crediting methodologies apply conservatively high default emission factors to incentivize the adoption of facility-level MMRV.

APA

Gupta, A., Ferreira, F., Humann-Guilleminot, T., Siegel, K., McCabe, D., Feldman, L., Sosa, Z. T., Hill, L. A., & Herbstritt, S. (2026). Strengthening the Environmental Benefits of Anaerobic Digestors Through Robust Measuring, Monitoring, Reporting, and Verification. Clean Air Task Force. https://www.catf.us/wp-content/uploads/2026/05/Anaerobic-Digestors-Report.pdf

Chicago

Gupta, Abhinav, Fernanda Ferreira, Theophile Humann-Guilleminot, Kait Siegel, David McCabe, Lesley Feldman, Zitely Tzompa Sosa, Lee Ann Hill, and Stephanie Herbstritt. Strengthening the Environmental Benefits of Anaerobic Digestors Through Robust Measuring, Monitoring, Reporting, and Verification. Clean Air Task Force, 2026. https://www.catf.us/wp-content/uploads/2026/05/Anaerobic-Digestors-Report.pdf.

Wikipedia

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BibTeX

@techreport{gupta2026strengthening, author = {Gupta, Abhinav and Ferreira, Fernanda and Humann-Guilleminot, Theophile and Siegel, Kait and McCabe, David and Feldman, Lesley and Sosa, Zitely Tzompa and Hill, Lee Ann and Herbstritt, Stephanie}, title = {{Strengthening the Environmental Benefits of Anaerobic Digestors Through Robust Measuring, Monitoring, Reporting, and Verification}}, institution = {Clean Air Task Force}, year = {2026}, month = may, url = {https://www.catf.us/wp-content/uploads/2026/05/Anaerobic-Digestors-Report.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }