Three Maids Renewable Biomethane Facility
The Three Maids Renewable Biomethane Facility is Winchester’s first anaerobic digestion plant. It produces sustainable biomethane, green CO₂, and nutrient-rich digestate, creating clean energy while promoting a circular economy.
By transforming organic by-products into valuable resources, the facility supports local agriculture, strengthens the regional economy, and generates employment opportunities.
As a flagship project, Three Maids contributes to the UK’s renewable energy strategy and plays a key role in the national journey towards net zero.
Project Timeline
- Planning application submitted
- Planning application approved
- Start of construction
- Commissioning
- Start of operation
Project Details
Exact location
51°6'10.33"N,
1°20'35.68"W
Total site area
4.5 Ha
Number of tanks
5
Key information
Technology and Operations
Technology used
Agraferm
Biomethane production
120 GWh per year
Storage and Infrastructure
• Primary and Secondary Digesters
• Post Digester
• Slurry tank
• Leachate Water Tanks
• Digestate tank
• E-box / control rooms
• Gas storage
• Gas Separation Equipment (Upgrader)
• CHPs x 2
• Manure Building
• Separator Building
• Straw Building
• Lagoon x 1
• Switchgear container
• Silage Clamps x 2
• CNG Equipment
• Odour treatment
• Workshop & lab container
• Boiler container
Capacity and Production
Feedstock processed
83,600 tonnes per annum
Households
supplied
9,000+
Grid connection and uses
Injection into the national grid network via virtual pipeline
Environmental Impact
30,000 tonnes of CO₂ avoided annually
The equivalent of 1.2 million planted trees, or 15,000 cars removed from the road
Circular economy contribution
Digestate generated and reused as biofertiliser
Waste valorisation
46,000 tonnes of waste/residues recovered and reintroduced into the economy. 55% of the total facility processing capacity
Socio-Economic Impact
Local economy contribution
Partnerships with farmers, cooperatives, and local businesses. Currently contracted to c. 14 feedstock suppliers
Jobs created as a result of the development
15
Indirect employment
Supporting up to 35 roles within the wider engineering and supply chain ecosystem
Safety and Environmental
Certifications Obtained
Hazardous Substances
Consent
Environmental
Permit