From Cow Dung to Daily Energy
Purpose-built biogas systems for small dairy farms with two or more cattle — converting a daily waste burden into a daily cooking fuel and soil resource.
Discuss a Farm SystemBuilt for Small-Scale Dairy Farmers
Many of the world's dairy farmers manage between two and twenty cattle — a scale that generates significant daily waste without the infrastructure to convert it into value. Terra Digester systems are engineered for exactly this context.
"Small-scale dairy farmers manage waste every day. Our systems are designed to turn that daily burden into a daily resource — clean cooking gas and organic fertiliser. The same waste that once required disposal now produces morning fuel for the kitchen and nutrition for the fields."
From Dung to Daily Energy
Four steps. One sealed system. Daily cooking gas and free fertiliser — every single day.
Load Livestock
Manure Daily
Fresh cow dung is collected from the farm and mixed with water to create a slurry. This organic slurry is fed into the Terra Digester through the sealed inlet — a simple, daily task taking just minutes. Two to twenty cattle generate enough input to run the system continuously.
Anaerobic Digestion
Inside the Bag
Inside the sealed Terra Digester bladder, naturally-occurring anaerobic bacteria break down the organic slurry in a completely oxygen-free environment. Over 15–30 days of retention time, microorganisms convert organic matter into methane-rich biogas that accumulates at the top of the bag, and nutrient-rich digestate that settles at the bottom.
Daily Clean
Cooking Gas
Biogas collects at the top of the Terra Digester bladder and flows through a simple pipe to the kitchen stove. It burns with a clean blue flame — smoke-free, odourless, and directly replacing expensive LPG cylinders or harmful firewood. A farm of four cattle can produce enough gas for a family's daily cooking needs.
Nutrient-Rich
Liquid Fertiliser
As fresh slurry enters the system daily, digested effluent flows out from the outlet as a nutrient-rich liquid digestate. This bio-fertiliser — rich in nitrogen, phosphorus, and potassium — is applied directly to fields, pasture, and kitchen gardens. It replaces expensive synthetic fertilisers with a completely free, daily output from the same waste that powered the stove.
What the System Delivers to Farmers
Four tangible daily outcomes from a system engineered for the small farm context.
Daily Cooking Gas
The system generates biogas on a continuous basis, providing a reliable daily source of cooking and heating fuel — reducing dependence on purchased LPG, firewood, or charcoal.
Free Organic Fertiliser
Digestate — the nutrient-rich byproduct of anaerobic digestion — serves as an effective organic fertiliser for pasture, crops, and kitchen gardens, reducing spending on synthetic inputs.
Hygienic Waste Management
The sealed system contains dung and associated odours within a managed process, improving farm hygiene and reducing the manual labour associated with daily manure handling and disposal.
Reduced Fuel Dependency
Replacing purchased fuel with on-farm biogas production reduces household expenditure and insulates farmers from fuel price volatility — an important benefit in rural and off-grid contexts.
Systems That Grow With Your Farm
Systems are designed with modular expansion in mind. As your herd grows, the system can grow with it — from two cattle to twenty and beyond. Each additional module integrates with the existing installation, protecting your initial investment while increasing gas and fertiliser output proportionally.
Common Questions
Everything dairy farmers ask before getting started with biodigestion.
Dairy manure is loaded into the inlet, mixed with water, and fed into the sealed digester bag. Anaerobic bacteria break down the organic matter over 15–30 days, capturing methane for cooking gas and releasing liquid bio-fertiliser from the outlet — rich in nitrogen, phosphorus, and potassium.
Cow, pig, and horse manure all work well. Dairy cow manure is particularly effective due to its high organic content and naturally present anaerobic bacteria. The system processes up to 50 litres of slurry per day at farm scale.
After the initial load — typically manure mixed with water — the system requires 2–3 weeks for the bacterial colony to fully establish. No additional feeding is needed during this period. Once active, gas is produced daily as long as manure is added regularly.
Farm-scale systems produce enough biogas for up to 6 hours of cooking per day depending on unit size and manure volume. Gas output scales with the amount of organic matter fed in — consistent daily feeding means consistent daily gas.
Yes. Anaerobic digestion does not destroy nutrients — it concentrates them. The liquid digestate is enriched with amino acids, biostimulants, minerals, and beneficial microorganisms that are immediately bioavailable to crops. It outperforms raw farmyard manure in plant uptake efficiency.
Farm systems produce 50–150 litres of liquid fertiliser per day, yielding over 30,000 litres annually. Dilute at 1:3 (fertiliser to water) before applying. Storage impact is minimal — the fertiliser retains its quality for at least a week after collection.
Choose a flat, sunny area within 50 m of the kitchen or gas point of use. The system sits above ground and requires no civil works or pits. Keep the biogas pipe run under 50 m for optimal pressure. Installation typically takes one day.
Very little. Replace the gas filter every 8–12 months. Clean only the exterior with water. The bag does not need emptying — digestate flows out continuously as new manure is added. Expected system lifespan is over 10 years.
Manure digesters work well from around 10 °C (50 °F) upward. Below this, slow feeding by half to match reduced bacterial activity. In colder climates, insulate the bag or shelter it from wind to maintain stable temperatures and consistent output.
Yes — and this is one of its most important environmental benefits. Dairy manure stored in open lagoons releases methane directly into the atmosphere. The Terra Digester captures 100% of that methane and converts it into usable cooking energy, reducing your farm's climate footprint significantly.
Discuss a Dairy Farmers System
Tell us about your farm — herd size, location, and current energy situation — and we will outline the right system configuration for your context.
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