Circular Farming in Action: How Uilenkraal turns Agricultural Waste into Renewable Energy

In the rolling farmlands of Darling in the Western Cape, South African farming brothers Willem and Paul Basson embarked on an ambitious journey to revolutionize energy use on their farm, Uilenkraal. Inspired by a visit to Italy thirteen years ago, where they saw European farmers generating electricity from cow dung, the Basson brothers set out to implement a similar system in South Africa. However, importing a biogas plant from Europe was financially unfeasible due to the weak rand. Instead, they collaborated with a local engineering company, Cape Advanced Engineering (CAE), to develop a cost-effective and locally designed alternative.

A Locally Engineered Solution for Biogas Energy

CAE extensively researched biogas technology from Europe and the United States to design a system tailored to South African conditions. Unlike the traditional dome-shaped biogas digesters commonly used in Europe, Uilenkraal’s system features a rectangular, tent-like structure that better suits the local climate and operational requirements.

Construction of the plant began in 2013, and by mid-2014, the first biogas was produced. By December of that year, Uilenkraal’s two CAE-manufactured generators were running on purified biogas, producing 200kWh of electricity daily. The project quickly demonstrated its potential, reducing the farm’s monthly electricity bill from R110,000 to R45,000, and later to just R12,000 as both generators reached full capacity—a nearly 90% reduction in costs.

Scaling Up: The Impact of Uilenkraal’s Biogas Plant

Since its inception, Uilenkraal’s biogas plant has:

• Generated 15 GWh of renewable electricity and 20 GWh of process heat.
• Processed 827,000 tonnes of dairy cattle manure slurry and wash water.
• Produced a pumpable liquid bio-fertilizer that enhances soil health.
• Utilized South African-developed 250kVA biogas engines, ensuring local economic benefits.

This innovative system not only generates electricity but also harnesses waste heat for additional farm processes, showcasing the broader benefits of biogas beyond simple power generation. The 20 GWh of process heat can be utilized for heating water for dairy operations, or drying animal feed, further improving farm efficiency.

Circular Farming and Regenerative Agriculture

The Uilenkraal biogas plant is a prime example of circular farming in action. The process of converting livestock manure into biogas reduces methane emissions while producing a valuable bio-fertilizer that is returned to the soil, enhancing its fertility.

While some may question whether removing manure from the fields disrupts natural nutrient cycling, the digestate produced from anaerobic digestion remains rich in organic matter and nutrients. This allows Uilenkraal to return essential minerals and organic content to its croplands, supporting soil health and regenerative agricultural practices. Furthermore, integrating precision farming techniques ensures efficient application of bio-fertilizer, optimizing crop yields while minimizing waste.

Addressing Concerns: Antibiotics and Residues in Digestate

One common concern with biogas systems is the potential presence of antibiotics or chemical residues in the digestate. While anaerobic digestion can break down some of these compounds, others may persist. At Uilenkraal, careful manure management and responsible antibiotic use in livestock feeding help mitigate this risk. Ongoing research is being conducted worldwide to better understand how biogas digestion affects pharmaceutical residues and how post-treatment processes can further neutralize any remaining compounds.

A Model for South African Agriculture

Uilenkraal’s biogas plant is more than just a power source—it’s a blueprint for sustainable farming in South Africa. By reducing reliance on Eskom’s grid and lowering operational costs, the farm has gained energy independence while contributing to environmental sustainability. The project also highlights the potential for biogas as a viable renewable energy solution for the country’s agricultural sector.

As energy prices continue to rise—Eskom tariffs are set to increase by 12.74% for direct customers (April 2025) and 11.32% for municipal bulk purchases (July 2025)—biogas presents a resilient alternative for farmers looking to control costs and enhance sustainability.

The Future of Biogas in South Africa

The success of Uilenkraal’s biogas plant underscores the potential for on-farm energy generation across South Africa. As the country seeks to transition towards a greener economy, investments in local biogas technology, research, and policy support will be crucial in scaling up adoption.

Willem and Paul Basson’s story is a testament to how innovation, collaboration, and a commitment to sustainability can drive meaningful change in agriculture. By harnessing the power of waste, Uilenkraal has set a precedent for farms across South Africa to turn challenges into opportunities, unlocking the full potential of circular agriculture.