Speaking at the Bio360 Africa expo and conference at Gallagher Convention Centre in Johannesburg earlier this week, Kondwani shared lessons from real-world project development and operation.
He stressed that while investors and developers often focus on technology and financing, feedstock quality ultimately determines whether a biogas plant succeeds or struggles.
“You can have amazing technology and the funding to get the project going, but if you don’t have quality feedstock, the project will struggle,” Kondwani explained.
According to him, feedstock management is one of the single biggest determinants of project performance. While many developers focus on securing sufficient volumes of feedstock, quality is equally important, if not more so.
He added that feedstock contamination is another challenge since waste streams are often not separated at source. “Unreliable feedstock supplies can damage project economics and negatively affect digester performance.”
To mitigate these risks, developers need strong relationships with suppliers, effective quality control procedures, and robust logistics planning.
Kondwani noted that South Africa’s diverse waste streams create both opportunities and challenges. “Seasonal fluctuations in feedstock availability can affect plant performance, requiring facilities to be designed with flexibility in mind.
“During periods when fresh produce waste is not readily available, for example, operators may need to increase the proportion of manure or brewery waste in their feedstock mix. Plants therefore need sufficient storage and holding capacity to blend materials and maintain consistent feedstock quality.”
He said technology selection should be driven by the available feedstock rather than the other way around. “Businesses will often first look at the technology side and then at the available feedstock. But the feedstock needs to be considered first so the plant can be designed accordingly.
“Waste streams differ significantly between regions, making it essential for plants to be designed around local conditions and be capable of handling varying feedstock compositions.”
Kondwani also cautioned developers against underestimating operational and management costs, which begin accumulating during the development phase rather than after construction is completed.
“Skills shortages need to be anticipated early, while access to spare parts can present challenges because many components must be imported. Designing plants for operational simplicity can help reduce downtime and improve reliability.”
Another common mistake is treating digestate, the nutrient-rich material remaining after anaerobic digestion, as a waste product rather than a valuable co-product.
“If you don’t plan for digestate management, then you plan to fail,” Kondwani added.
“Digestate requires storage, handling, and transport infrastructure, which are often underestimated during project planning. While digestate can be sold as an organic fertiliser, market adoption remains relatively limited, meaning projects should not depend on this revenue stream to ensure profitability.”
His final lesson was that technology alone does not guarantee project success.
“Diversified revenue streams improve project resilience, while long-term offtake agreements strengthen bankability. Producing multiple products can also reduce exposure to fluctuations in any single market,” he concluded.
