Advanced biomethane potential from local sources in Italy

Anaerobic digestion is a mature technology that can provide a domestic source of biomethane, supporting the decoupling of the energy system from imported fossil fuels and advancing the transition towards energy system decarbonization. Additionally, it promotes nutrient recycling in agricultural systems, reducing reliance on fossil-based fertilizers. The main objective of this study is to estimate the Italian technical potential for advanced biomethane production, focusing on feedstocks eligible under the European Union's Renewable Energy Directive for advanced biofuels production. These feedstocks include agro-industrial residues, livestock manure, sewage sludge, cheese whey, and the organic fraction of municipal solid waste. The technical potential represents the maximum amount of biomethane that could be produced from available feedstocks, without considering economic feasibility or competition with other uses. Regional data on processes generating these residues and statistical data on waste streams have been processed and aggregated to create geographically explicit maps of substrate availability. The substrates' availability has been converted into technical potential of advanced biomethane production using specific coefficients. The results indicate a technical potential of advanced biomethane of 5.6 billion m³ in 2022, equivalent to approximately 8 % of Italy's total national natural gas consumption in the same year. This estimate could nearly meet the planned national production targets for 2030 by utilizing only biowaste and residues. Relying exclusively on waste and residues instead of energy crops avoids competition for food, feed, and fibre, and mitigates greenhouse gas emissions and other environmental impacts associated with agricultural practices, including fertilizer and pesticide use. At the same time, nutrient recycling is effectively achieved.