The adoption of small-scale anaerobic digestion (AD) using slurry and manure in the UK has been slow, largely due to a lack of governmental support. However, advancements in technology and a shifting market landscape suggest it might be time to revisit the benefits of this approach. This article explores the potential advantages of on-farm AD systems.
Increasing regulations around slurry management and storage are pushing farmers to invest heavily in their infrastructure. Coupled with high energy prices, there is a growing interest in finding on-farm energy solutions that also reduce greenhouse gas emissions.
A Multi-Solution Approach
Christine Parry, Product Innovation Expert at AB Agri, proposes small-scale, on-farm anaerobic digestion as a solution to these challenges. She highlights the multiple benefits, including improved slurry management and energy generation, which contribute to a sustainable and circular farming operation.
The Circular Economy
Parry suggests that on-site AD could be highly beneficial for UK dairy farmers. Energy generated from slurry and manure can be converted into heat, electricity, and vehicle fuel. Additionally, the residual digestate serves as an effective fertilizer, fostering a circular economy and reducing reliance on fossil fuels. Upcoming legislation on slurry store coverage, alongside the challenges posed by wet weather, makes AD an attractive option for more efficient slurry storage.
Currently, only 3% of the UK’s livestock slurry is processed through AD. Parry points out the opportunity to derive value from manures and bio-residues, reducing emissions and enhancing nutrient availability for crops. Producing on-farm energy also improves the sustainability of dairy herds.
Technology and Market Evolution
Despite limited success in the past, particularly due to incentive schemes favoring crop feedstocks over manures, the UK AD market has evolved. The current focus is shifting towards smaller, modular systems that better align with dairy farm needs. Parry notes that the technology is now established, operational, and can significantly reduce a farm’s carbon footprint.
Anaerobic digesters add value to existing farm materials, generating income and improving nitrogen management. Addressing carbon emissions involves tackling enteric methane, optimizing feed, and managing methane from stored slurry. On-farm AD can significantly mitigate these emissions by using methane to produce renewable energy.
Future Considerations
Parry emphasizes the need for dairy farmers to consider on-farm AD as part of their nutrient management strategies. By converting nutrient management issues into opportunities, AD can help address slurry storage challenges. AB Agri and Kite have already implemented successful small-scale AD plants on client farms, demonstrating the feasibility and benefits of this technology.
Call for Government Support
Richard Gueterbock, director at Foodchains, stresses the importance of government support for the success of on-farm AD. He points out that the current Green Gas Support Scheme (GGSS) excludes smaller AD systems, limiting their potential. Gueterbock urges the government to reassess the role of AD in slurry management and provide grants or incentives for farmers to invest in farm-scale AD systems. This support is crucial for improving nutrient management and reducing the environmental impact of farms.
The potential for on-farm AD to increase energy security and reduce environmental footprints is significant. As the industry responds to government consultations on biogas and biomethane, the hope is that more supportive policies will emerge to facilitate the adoption of this sustainable technology.
