Acorn’s Winchester AD plant receives environmental permit

Acorn Bioenergy Operations Limited has been granted an environmental permit to run a new anaerobic digestion (AD) plant at Three Maids Farm, just outside Winchester in England.
The approval, issued by the Environment Agency on 1 August 2025 under permit reference EPR/BP3326SD/A001, allows the company to treat up to 94,000 tonnes of feedstock per year.
Materials to be processed will include maize and whole-crop silage, straw, animal manures and certain non-hazardous liquid wastes.
The 4.45-hectare site sits near the A34/A272 junction, approximately 4km north-west of the city.
The plant will generate biogas through the controlled breakdown of organic matter.
This biogas will be upgraded to biomethane for injection into the national gas grid, while captured carbon dioxide will be purified for industrial and commercial uses.
Two combined heat and power units, running on biogas or natural gas, will provide heat and electricity to the plant, maintaining digester temperatures and powering pasteurisation equipment.
The facility is designed so that by-products such as digestate fibre and liquid are re-used as biofertiliser on local farmland.
The permit sets strict environmental controls. These include measures to prevent odour, noise and vibration pollution, monitoring of emissions and robust systems for drainage and containment to protect local watercourses. There are also fire prevention, pest control and accident management plans in place.
Acorn Bioenergy’s application process began in July 2024, involving multiple rounds of additional information and updated technical documents, including air quality modelling, odour and noise assessments, and bioaerosol risk analysis.
Environment Agency official Peter Maksymiw authorised the decision, confirming the plant can only begin operations once all pre-operational requirements are satisfied.
The company says the project will contribute to renewable energy generation, reduce greenhouse gas emissions, and provide sustainable fertiliser for agriculture in the region.