Closing the Loop: The Circular Economy Behind a Western Cape Dairy Farm

Every day at Uilenkraal, a dairy farm near Darling in the Western Cape, 1 700 cows are milked three times a day, producing more than 40 litres of milk per cow.

The scale is impressive. Yet some of the farm’s most valuable output never leaves the farm in a milk tanker.

Beneath the operation, manure collected from the dairy sheds is fed into a bio-digester. There, naturally occurring bacteria break down organic matter to produce methane gas. The gas is used to generate electricity, while the nutrient-rich by-product is returned to the soil as bio-fertiliser.

What was once considered waste has become a source of energy, productivity and long-term resilience.

The economics of dairy farming leave little room for inefficiency. Feed remains the single largest cost component, accounting for between 50% and 75% of the value of milk produced. Each cow consumes more than 40kg of balanced feed daily, including silage, grains and concentrates, much of it grown on the farm itself.

Any improvement in soil health, crop yields or fertiliser efficiency therefore has a direct impact on profitability.

The cows produce manure. The manure produces methane. The methane generates electricity. The digester’s by-product becomes bio-fertiliser. The bio-fertiliser is applied to fields that produce wheat, potatoes and silage, much of which returns to the dairy operation as feed.

The result is a closed-loop system that reduces dependence on external inputs while extracting greater value from resources already available on the farm.

The scale of that opportunity is considerable. Uilenkraal captures more than 110 tonnes of manure and urine every day. Rather than becoming a disposal challenge, that resource is converted into renewable energy and fertiliser that supports the wider farming operation.

“The biggest financial impact is the saving on electricity,” says Paul Basson of Uilenkraal. “Biogas generation is cheaper than Eskom.”

The benefits extend well beyond electricity.

According to the farm, fields treated with bio-fertiliser have achieved yield improvements of around 20% compared with fields that do not receive it. At the same time, reliance on conventional fertilisers, particularly phosphorus and potassium, has declined significantly.

For Wynand van Zyl, the area head for Business Banking at Standard Bank, the significance of the project lies in the way it closes the loop between energy generation, soil health and agricultural productivity.

“Manure is converted into biogas, which generates electricity. The by-product is then returned to the soil, improving fertility, water retention and long-term productivity,” he says. “The client is not only reducing energy costs but building a more sustainable farming system.”

The energy system itself has also evolved.

Uilenkraal recently received approval to export excess electricity to the national grid, allowing the farm to bank surplus power generated during periods of lower demand and use those credits when consumption rises.

The farm has now embarked on an upgrade of the biogas facility to replace ageing equipment and improve operational performance. The investment is expected to extend the life of the plant for at least another decade.

Looking further ahead, Uilenkraal sees opportunities beyond electricity generation. Basson believes future growth may come from selling biogas directly, potentially creating an additional revenue stream while further reducing reliance on traditional energy sources.

The commercial benefits are already becoming apparent. Electricity generated through the biogas system contributes the equivalent of approximately 2.8% of the value of milk production while offsetting the cost of manure processing and energy generation. When combined with lower fertiliser requirements, improved yields and greater resource efficiency, the integrated system has the potential to reduce overall milk production costs by around 10%.

“This project aligns directly with our sustainable finance strategy,” says Zaid Railoun, Specialist: Power and Sustainable Solutions at Standard Bank. “It demonstrates how circular economy principles can be applied in a commercial agricultural setting while helping clients reduce costs and improve resilience.”

The project’s viability was strengthened by a combination of factors: a proven farming operation, a reliable feedstock source in the form of manure, specialist technical expertise provided by Cape Advanced Engineering, and a banking relationship that stretches back more than a century.

“We’ve been doing business with Standard Bank for over 100 years,” says Basson. “Our business has grown because Standard Bank has always been willing to support opportunities that made sense.”

Agriculture is increasingly being asked to produce more with less: less water, less energy, fewer emissions and tighter margins. In that environment, waste streams are becoming valuable assets and sustainability is becoming inseparable from profitability.

At Uilenkraal, manure is no longer simply a by-product of dairy farming.

It is electricity. It is fertiliser. It is a source of future revenue.

And it is a reminder that some of agriculture’s most important innovations are not about producing more, but about making better use of what already exists.