Anaerobic Digestion
Livestock slurry releases methane and nitrous oxide into the air.
Anaerobic digestion captures these gases and turns them into clean, renewable energy.
The Climate Issue
Slurry isn’t just waste. It’s a major source of emissions. Left in open tanks or lagoons, it breaks down anaerobically and releases methane, a gas over 80 times more potent than CO₂ in the short term.
Even with careful spreading, slurry contributes nitrous oxide and ammonia, harming air quality and raising the farm’s footprint. Yet this organic material contains valuable energy, if captured before it escapes.
Today, most of that energy is lost into the atmosphere.


The Solution: Anaerobic Digestion
Key Benefits applying Anaerobic Digestion
Cut Methane
Renewable Energy
Fertiliser Use
Digestate is more plant-available than raw slurry, easier to handle, and releases fewer emissions when spread.
Impact of Applying Anaerobic Digestion
Anaerobic digestion delivers both energy and emissions savings. It turns a problem, manure emissions, into a solution: renewable fuel and better fertiliser.
Based on EU and Teagasc models, AD systems using 5,000–10,000 tonnes of slurry per year can:
- Cut methane emissions by 65–90 %
- Reduce GHG per kg milk by 0.05–0.10 kg CO₂-eq
- Generate 200–400 MWh/year in energy
- Deliver net benefits of €12,000–€20,000/year
The table below shows typical farm-scale AD impact across adoption levels.

Scenario
|
Slurry sent to AD
|
Net Farm Benefit
|
GHG Emissions
|
% GHG Reduction
|
---|---|---|---|---|
0% sent to AD |
- |
- |
0.960 kg CO₂-eq/kg milk |
0% kg CO₂-eq/kg milk |
50% sent to AD |
50% |
€12,000 |
0.911 kg CO₂-eq/kg milk |
5.1% kg CO₂-eq/kg milk |
100% sent to AD |
100% |
€20,000 |
0.870 kg CO₂-eq/kg milk |
9.4% kg CO₂-eq/kg milk |
Considerations
Capital Investment
Feedstock Volume
Operational Expertise
AD plants require skilled management. Gas handling, digestate storage, and system maintenance are essential for safety and efficiency.

Implementation
- Assess suitability. Farms with high livestock numbers and sufficient slurry volume are best suited. Consider site access, zoning, and integration with current systems.
- Explore funding. Look for CAP, EU Innovation, or national renewable energy grants. Group investment with neighbours can help reach viable scale.
- Plan for digestate use. Ensure spreading and nutrient plans make full use of the digestate, replacing synthetic fertiliser and closing nutrient loops.
Behind the Research
ODOS Tech was founded by Cian White and Alejandro Vergara, two sustainability specialists with deep expertise in agricultural climate action.
Cian, a researcher at Trinity College Dublin with a background in environmental science, works on restoring nature to increase biodiversity on farms by using satellite images to track trees, hedgerows, and other habitats. Alejandro, a PhD researcher at University College Dublin, helps farmers measure their carbon emissions footprint and implement mitigation strategies to reduce their impact.
Together, they helped lead the carbon and nature-based work for the Farm Zero C project at Shinagh Farm, one of Europe’s first net-zero dairy pilots. At ODOS, they build smart, science-based tools to help agri-food businesses protect the environment and restore nature.

Research
Teagasc MACC
Farm Zero C Pilot
EU Renewable Energy Strategy
The EU views AD as a key pillar of the Renewable Energy Directive. It supports biomethane development and offers policy incentives for on-farm installations and grid injection.
Ready to reduce emissions through Anaerobic Digestion?
Talk to our Carbon Footprint & Biodiversity experts on how we can help.