Financial assessment of integrating anaerobic digestion with cattle farming for biomethane production – Implications for farm economics and the supply chain

Integrating anaerobic digestion (AD) into agriculture can support carbon neutrality and circular bioeconomy. However, economic benefits for stakeholders are crucial for implementing full-scale AD. This study assessed the financial implications of producing grass silage for AD on beef farms. It also assessed the financial viability of full-scale AD plants co-digesting grass silage and cattle slurry for biomethane, focusing on competitive grass silage pricing and support schemes. Results indicate that a grass silage price of €245/t dry matter (DM) is needed for competitiveness with beef production; this requires a biomethane certificate price of €0.12/kWh for the AD plant. At current prices (€0.098/kWh), the AD plant could afford €164/t DM for silage, requiring farm subsidies of €893/ha to cover price gaps. Methane yield of AD silage, along with biomethane certificate and silage prices, are key variables affecting the 20-year net present value of the AD plant. This study underscores the government's critical role in fostering a low-carbon livestock sector. • The economic viability of integrating AD within a beef farm should be addressed. • Pricing strategy for producing grass silage for AD on a beef farm was assessed. • AD silage price afforded by AD plant highly relied on biomethane certificate price. • Farm subsidies are needed to offset AD silage price gap between AD plant and farm. • Methane yield of AD silage, along with biomethane certificate and grass silage prices, are key drivers of the overall NPV.