Councillors tour Winchester’s first biomethane facility

Acorn Bioenergy, a leading UK-based renewable energy company focused on the production of biomethane, invited Winchester councillors to tour its Three Maids Hill anaerobic digestion (AD) site, to learn more about the city’s first AD facility before it becomes fully operational later this year.

Expected to create 50 engineering, rural and infrastructure jobs within the wider supply chain, the site will start producing green biomethane gas in the summer of 2025, in support of the government’s net zero ambitions and strategy to quadruple biomethane by 2030-2035.

Situated a few metres from the A34, the facility sits within the city’s emerging “renewable hub”, in between the Three Maids Hill solar farm and InstaVolt’s EV superhub.

Once up and running, the facility will produce enough green gas to heat more than 9,380 homes. This will deliver greenhouse gas emissions savings equivalent to taking 16,500 cars off the road or planting 1.2 million trees.

The site utilises a natural process where organic materials, such as agri-based waste and rotational feedstocks are broken down by microbes in an oxygen-free environment to produce biogas. The gas is then upgraded to biomethane and either injected into the national gas network or used as a renewable fuel for heavy goods vehicles (HGVs). It also generates green CO₂ for use in sustainable industries and creates nutrient-rich bio-fertiliser as a byproduct. This natural fertiliser can be used on local farms to reduce reliance on carbon-intensive, imported alternatives.

The visit brought together representatives from Winchester City Council, Hampshire County Council and local parishes, to discover more about the AD process and how it can support the UK's food and energy security.

Representatives from Headbourne Worthy Parish Council and surrounding parishes attended the visit alongside Winchester City Councillors, including Cllr Kelsie Learney, Cabinet Member for Climate Emergency; Cllr Jackie Porter, Cabinet Member for Place and Local Plan; and Cllr Caroline Horrill, Leader of the Conservative Group.

Councillor Jackie Porter, Cabinet Member for Place and Local Plan, Winchester City Council, said: “The Three Maids site in Winchester is well situated because it’s near a major road system, the Instavolt EV charging station and a solar energy site; meaning it has become a renewable energy hub for the city.

“I'm very pleased to know that green methane prevents us from taking fossil fuels out of the ground. This is methane that would have been created on farms anyway, however, we’re now channelling it into producing green energy for the city and community to benefit from.”

Commenting on the visit, Belinda Baker, Clerk, Headbourne Worthy Parish Council, said: “Anaerobic digestion is a technology that has been used in other countries very successfully. In Winchester, we have a growing industry on a site which is overseen by the Environment Agency, which uses waste products to create renewable energy. The Parish Council thinks this is a very exciting project.”

As well as creating renewable energy opportunities in rural communities, Acorn’s closed-loop approach helps UK farmers at a time of market volatility. The Three Maids AD plant uses a supply of rotational feedstock as part of its input, which helps extend the growing season and harvest period of farmers in the surrounding areas. In return, farmers receive a steady income as well as a supply of digestate from the facility; this helps improve soil health and provides a local, organic replacement for imported, carbon-intensive synthetic fertilisers.

Local farmer Nick Rowsell, who is supplying feedstock to the plant, emphasised how it will help his farm become more economically and environmentally sustainable: “As well as supporting our energy security, the AD facility also helps to protect the UK’s food security”.

“In addition to providing a steady income stream, it can help farms like ours manage risk by extending our harvest season and reducing fertiliser costs, which is critical in an increasingly uncertain economic and environmental climate.”

Alister Veitch, Head of Business Development at Acorn Bioenergy, said: “The UK’s transition to clean power by 2030 and net zero by 2050 will require bold innovation, collaboration and pragmatic solutions, which is exactly what we’ve seen from stakeholders in Winchester.

“The Three Maids Hill facility will become a real flagship hub for us. Alongside our dozen sites in development, it is a big step towards our ambition to supply 25% of the UK’s biomethane as the country’s leading producer. Following the site’s approval in May 2023 – which received no objections from statutory consultees – we’re excited to complete on-site to begin producing our first biomethane later this year”.

“The seamless process with Winchester has accelerated the city’s net-zero ambitions whilst creating renewable career opportunities and real value for farmers and the environment. We look forward to continuing to collaborate with the council, stakeholders and local communities as the site becomes operational this year.”

For more information on Acorn Bioenergy, please visit the website.