Methane Emissions from 31 European Biogas Plants: Measurements, Mitigation, and Policy Implications

Biogas offers substantial low-carbon energy potential, but significant uncertainties remain regarding methane emissions which would hinder this benefit. This study addresses this uncertainty through a mixed-method emissions survey across three European countries, combined with environmental assessment, mitigation option analysis and regional policy comparison. Our findings reveal that methane emissions from biogas production average 14.4 kg/h per site (5.4% of methane produced) with a range of 1.3-57 kg/h (2%-21.7%). These values exceed previous estimates, yet 59% of emissions could be eliminated at no net cost. When considering full supply chain emissions, methane emerged as the dominant greenhouse gas – accounting for 47% (17-93%) of GHGs at GWP100 and 60% (32-93%) at GWP20. We advocate for revisions in EU and national policies to better account for methane’s role in biogas’s GHG footprint and enhance emissions monitoring, highlighting the need for policy interventions that incorporate recent advancements in methane measurement along with cost-effective mitigation strategies.