Turning leftovers into energy: How food waste powers biogas production

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OPINION

By Dr Patience Tugume

As cities, markets, and households across Uganda struggle with rising levels of food waste, one groundbreaking initiative is showing us that the solution may lie in the waste itself.

At Makerere University, a transformative project is proving that food waste can be a powerful driver of sustainability, energy independence, and economic empowerment. Supported by a prestigious Early Career research grant from the Organisation for Women in Science for the Developing World (OWSD), this project, titled “Bio-innovation of Biogas, Bio-pesticides and Bio-fertilisers Utilising Bio-wastes”, is redefining how the problem of food waste accumulation can be turned into an opportunity.

Instead of letting food scraps rot in landfills, emitting greenhouse gases, and contributing to disease outbreaks, this project is using them from banana and potato peelings to spoiled produce and leftover meals to produce clean, affordable biogas and nutrient-rich bio-fertiliser.

In a country like Uganda, where many households still rely on firewood and charcoal as sources of cooking energy, biogas technology is more than a green alternative but a lifeline.  Unlike traditional biogas production initiatives that depend solely on cow dung, this approach taps into readily available urban and household food waste, cutting down the piles of garbage that choke our communities.

The environmental and health impacts of the initiative are immediate: improved sanitation and waste management in urban areas, reduced deforestation and less indoor smoke pollution that would result from using firewood and charcoal for cooking and improved soil fertility through use of bio-slurry that has no side effects compared to chemical fertilisers. Biogas usage also reduces the burden on women and youth who spend hours collecting firewood.

This initiative is not just a scientific exercise but a real working model. Through a partnership with FREVASEMA Ltd in Biharwe-Mbarara, a spin-off centre of bio-reactors has been established. Women and youth are being trained at the centre to convert waste into wealth, energy, and opportunity. They are empowered with tools and knowledge to produce biogas and bio-fertiliser from food waste, which reduces their dependency on expensive, harmful fuels and gives them a chance at economic independence.

“By introducing clean biogas energy, we're not just saving trees, we're saving lives and building resilient communities,” says Dr Tugume, the Principal Investigator.

This project focuses on three pillars of sustainability:

• Economic: By reducing household energy costs and generating income through biogas and fertiliser production.
• Environmental: By cutting carbon emissions, curbing deforestation, and maintaining cleaner
• Social: By empowering women and youth with knowledge in biogas and biofertiliser production, improving public health, and creating new opportunities for development.

The potential for national impact of this project is enormous given the abundance of raw materials to act as feedstock for biogas production. All that is needed now is investment, awareness and action. Thus, if scaled, this model could shape Uganda’s policies on waste management, renewable energy, and sustainable agriculture and at the same time serve as a blueprint for other countries facing similar challenges.

Given the current global challenges associated with climate change, energy crises, and food insecurity, turning food waste into energy acts as a smart, sustainable solution, and Uganda has an opportunity to lead by example. Hence, the need to stop looking at food waste as garbage but as a powerful resource. After all, the future isn’t just in high-tech laboratories but might just be in the food scraps we throw away.

The writer is a Senior Lecturer, Department of Plant Sciences, Microbiology and Biotechnology, Makerere University.