Water Footprint in Bioenergy Generation: South Africa’s Perspective

***ALTERNATIVE ENERGY: South Africa is at a crossroads in its energy transition. As the country seeks cleaner alternatives to coal, bioenergy has emerged as a promising solution.***

South Africa is at a crossroads in its energy transition. As the country seeks cleaner alternatives to coal, bioenergy has emerged as a promising solution. But there’s a catch—bioenergy production, particularly from crops and biomass, has a significant water footprint. Can South Africa afford to invest in a water-intensive energy future in a nation where water scarcity is already a pressing issue?

The concept of a water footprint measures the total freshwater used in producing goods and services, including bioenergy. Water is consumed at every stage, from growing feedstock crops like maize and sugarcane to processing biofuels.

Studies have shown that some biofuels require more water per unit of energy produced than fossil fuels. In South Africa, where periodic droughts and water crises are a reality, this raises concerns about competition for water between energy, agriculture, and human consumption.

The Hidden Cost of Bioenergy

Bioenergy is often hailed as an environmentally friendly alternative to fossil fuels. While it does reduce carbon emissions, its impact on water resources cannot be ignored. The cultivation of biofuel crops demands irrigation, and large-scale production could divert water away from food production. If bioenergy is not carefully managed, we could swap one environmental crisis for another.

Take sugarcane and maize, for example, two potential biofuel feedstocks. These crops are water-intensive and require significant irrigation. South Africa already struggles with water allocation for food crops. Introducing large-scale bioenergy farming without a sustainable water strategy could worsen food security concerns.

BIOENERGY OPTIONS: Vast hectares of land are being irrigated in Zimbabwe. The writer says that instead of growing crops specifically for biofuels, South Africa can focus on converting organic waste—like agricultural residues, food waste, and wastewater—into energy. Photo: TV BRICS/Istock

Rethinking Bioenergy: A Water-Smart Approach

So, does this mean bioenergy has no place in South Africa’s energy mix? Not at all. But we need a smarter approach that prioritizes water efficiency and sustainability. Instead of growing crops specifically for biofuels, South Africa can focus on converting organic waste—like agricultural residues, food waste, and wastewater—into energy.

Biogas, for example, has a much lower water footprint than bioethanol and biodiesel. We should invest in research on non-irrigated, hardy feedstocks like drought-tolerant grasses, invasive plant species, or algae, which require minimal water input.

Technologies allowing biofuel production facilities to recycle and reuse water can significantly reduce overall consumption. Closed-loop water systems should become the industry standard. South Africa needs policies that align renewable energy goals with water conservation strategies. Before approving bioenergy projects, a thorough water impact assessment must be conducted to ensure responsible resource management.

Global Best Practices in Bioenergy

South Africa is not alone in its pursuit of sustainable bioenergy. Countries like Brazil, Sweden, and Germany have successfully integrated bioenergy into their energy mix while managing environmental concerns. Brazil, for instance, is a global leader in bioethanol production, primarily derived from sugarcane.

JUST ENERGY TRANSITION: Matimba Power Station near Witbank, Mpumalanga, is one of Eskom’s coal-fired power stations. Studies have shown that some biofuels require more water per unit of energy produced than fossil fuels. In South Africa, where periodic droughts and water crises are a reality, this raises concerns about competition for water between energy, agriculture, and human consumption, says the writer.

The country has achieved efficiency in water use through precision irrigation techniques and policies that promote sustainable biofuel production.

By incorporating wastewater treatment and water recycling in processing plants, Brazil has managed to reduce the water footprint of its bioenergy industry.

Sweden, on the other hand, has focused heavily on waste-to-energy strategies. Nearly 50% of its bioenergy comes from forest residues, organic waste, and industrial byproducts rather than dedicated energy crops. This approach significantly reduces water demand while ensuring efficient resource utilization.

Similarly, Germany has prioritized biogas production using agricultural waste and livestock manure, reducing reliance on water-intensive biofuel crops. These nations showcase how combining technological innovation, policy incentives, and sustainability planning can make bioenergy viable without exacerbating water shortages.

South Africa can learn valuable lessons from these global leaders. Adopting Sweden’s waste-to-energy model, expanding biogas infrastructure like Germany, and integrating Brazil’s irrigation efficiency strategies could help South Africa achieve a sustainable and water-conscious bioenergy future. Policymakers must focus on creating incentives for low-water bioenergy options while ensuring that water security remains a priority.

POWER CRISIS: Protesters marched on Eskom’s offices, demanding an end to load-shedding. The writer says that adopting Sweden’s waste-to-energy model, expanding biogas infrastructure like Germany, and integrating Brazil’s irrigation efficiency strategies could help South Africa achieve a sustainable and water-conscious bioenergy future.

The Way Forward

Bioenergy has the potential to play a role in South Africa’s sustainable future, but only if we acknowledge and address its water footprint. Energy security is critical, but not at the cost of water security.

The country must take a balanced approach, embracing water-efficient bioenergy solutions while prioritizing policies safeguarding water for agriculture and communities.

The conversation on renewable energy should not just be about reducing carbon emissions, but also water sustainability. Otherwise, we risk solving one crisis while creating another.

South Africa must take a balanced approach, embracing water-efficient bioenergy solutions while prioritizing policies safeguarding water for agriculture and communities.

Dr. Mariam Adeoba is a highly accomplished researcher and educator with extensive experience in zoology, environmental management, and renewable energy. She holds a Ph.D. in Zoology from the University of Johannesburg (UJ). Dr. Adeoba has a solid academic background and a passion for addressing pressing environmental and sustainability challenges. She writes in her personal capacity.