Modelling the technical production potential of biomethane from anaerobic digestion to decarbonise the gas grid

With global natural gas demand reaching a record high in 2024, meeting Net Zero targets requires strategies that rapidly decarbonise the gas grid. One alternative is to substitute natural gas with biomethane produced from anaerobic digestion (AD) technologies. While recent work has modelled the global production potential of biomethane from AD, much of the literature is limited to analyses of specific geographies or feedstocks. This work contributes to this literature by modelling the technical production potential of both biomethane and digestate that considers a broader set of technical efficiency limitations across the AD system. By applying this modelling approach to the United Kingdom, for the first time, this study models the technical production potential of biomethane for injection to the gas grid together with the corresponding amount of digestate. The results show that biomethane from AD could only displace about 5 % of current domestic demand for natural gas. It demonstrates that biomethane production should target applications that are difficult to decarbonise with other technologies. This can also support the primary benefit of AD as a waste management strategy. Policy development should focus on maximising the production of biomethane from existing waste and target specific applications that support a Net Zero economy. • New model for the technical production potential of AD biomethane and digestate. • Including broader technical efficiency limitations informs AD sector development. • UK analysis shows biomethane cannot significantly displace natural gas in the grid. • Use limited biomethane in specific applications that are difficult to decarbonise. • Focus the development of AD technologies as a waste management strategy.