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Waste to energy to innovation

In Uganda, students see opportunity to fuel sustainability and public health

Winter/Spring 2013 | By Amanda Lucas

Could the solution to some of the developing world’s energy, health and conservation challenges lie in a landfill?

Nelson Institute graduate students Aleia McCord and Sarah Stefanos think so. They’ve teamed up with partners in Uganda to develop a business model that converts human waste, animal manure and food scraps into fertilizer and biogas through an anaerobic digester.

Waste to Energy team
The W2E team (left to right): Vianney Tumwesige,
Sarah Stefanos, Aleia McCord and Alex Tumukunde.

“An anaerobic digester is essentially a giant concrete stomach,” explains McCord. “Millions of microbes, like the ones that live in our stomach, eat organic matter and burp methane. The organic matter becomes a high-quality organic fertilizer, and the gas – the methane microbes produce – becomes an opportunity for energy use.”

McCord and Stefanos, both pursing master’s degrees in Environment and Resources and participants in the Certificate on Humans and the Global Environment (CHANGE) program, studied anaerobic digesters as part of a CHANGE capstone course. Traveling to Germany, they learned how biogas is widely produced and used.

They brought their findings to Uganda, where the students then began imagining the potential of smaller-scale systems in a country where unmanaged waste degrades urban conditions and quality of life. Makeshift landfills and a lack of public restrooms have created haphazard and unhealthy conditions in many of Uganda’s crowded urban areas. 

All that waste represented an opportunity to McCord, a microbial ecologist, and Stefanos, a rural sociologist. They joined forces with two graduate students at Makerere University’s Centre for Research in Energy and Energy Conservation, engineer Vianney Tumwesige and conservationist Alex Tumukunde. The diverse and imaginative team created a unique business model and launched a new company called W2E, an acronym for their waste to energy concept.

Cutting health risks

Uganda faces three struggles common in developing countries: insufficient public hygiene, severe energy inequalities and limited options for agricultural expansion. W2E works to transform each of these obstacles into a socially responsible business initiative.

For starters, McCord says, turning waste into energy helps divert it from streets, where careless dumping is common, attracting vermin and polluting water. W2E gives Ugandans a purpose for their waste and a place to put it (the program will provide neighborhood dumpsters), minimizing human-animal disease transmission and water-borne illnesses. 

Uncollected waste in Uganda
Uncollected waste from a Ugandan slum clogs drainage
channels and creates a risk of flooding. Converting
waste to energy will help divert it from the streets.

It also provides an alternative to the charcoal and firewood Ugandans use as cooking fuel in their homes, both of which harm local forests and human health. According to McCord, an estimated 1.5 million Ugandans die each year from indoor air pollution. Women and children, who spend most of their days indoors, are disproportionately affected by chronic lung problems.

The long-term goal of W2E is to produce electricity for the national grid, a significantly cleaner and safer source of energy that produces emissions with less particulate matter. Shifting from indoor use of charcoal and firewood also dramatically lowers the rate of lung disease, says McCord.

In addition to cleaner energy, the project also turns the waste into fertilizer, which has the potential to help feed Uganda’s growing population and even help preserve its forests. Uganda is under constant pressure to increase food production, but poor farming techniques, high rates of soil loss and a lack of fertilizer leave only one option: move to new cropland.

As a result, according to McCord, many Ugandan farmers turn to the forest for new cropland, an ongoing process that drives widespread deforestation. Many of the country’s most precious natural resources are being depleted – and in some cases, destroyed completely. Uganda’s forests are home to several critically endangered species, including some of the last remaining populations of mountain gorillas.

“We want to provide a product that helps farmers improve yields and protect their soils, so they can increase yields on the soil they have, and they don’t have to cut down more forests to make more food,” McCord says.

Boosting Uganda’s economy

W2E is currently in a pilot stage, with an anaerobic digestion system in place at a rural Ugandan school. The team is collecting data and assessing the project’s impact on waste management and public health. They plan to eventually introduce their process in urban centers across Africa.

“Our vision is to take
what is currently a grant-
dependent project and turn
it into something that is
truly financially sustainable,
and to demonstrate that you
can have a profitable, commercial
venture that at its core is a
sustainable vision for the future.”

The digesters at the heart of W2E can be implemented for $10,000 each, which, though costly, is much more affordable than many of the digesters deployed in the United States. 

To date, W2E has been funded primarily through grants and prizes. The team won two student innovation competitions, the Wisconsin School of Business Burrell Business Plan Competition and the Nelson Institute-hosted Global Stewards Sustainability Prize. It also received grants from the Swedish International Development Agency for its innovations in fighting poverty, and from the Grand Challenges Rising Stars in Global Public Health, a Bill and Melinda Gates Foundation program.

Now registered as a for-profit company, W2E could also provide desperately needed jobs in Uganda. Waste must be collected and transported to the digester facility, where it will be sorted by local waste pickers who receive benefits and fair wages. The locally produced biogas will serve as a more affordable, renewable source of energy, sold for 20 to 30 percent less than competing fuel products. 

A volunteer from the Kasiisi Primary School fills a bottle that will be used to build the biodigester latrine wall
A volunteer from the Kasiisi Primary
School fills a bottle that will be used
to build the biodigester latrine wall.

“Poverty is one of the strongest motivators for innovation – innovation by necessity,” McCord says. “Our vision is to take what is currently a grant-dependent project and turn it into something that is truly financially sustainable, and to demonstrate that you can have a profitable, commercial venture that at its core is a sustainable vision for the future.” 

“The forces that are driving our global economy are corporate forces,” she continues. “It’s important to envision alternatives that engage with for-profit models in a way that has positive environmental and societal outcomes.”

Next, W2E envisions flipping the traditional perception of innovation on its head, transferring a technology originating in a developing country to the developed world. 

According to McCord, the W2E model has the potential to be implemented in places like Wisconsin. Anaerobic digesters are now used on some Wisconsin farms, but the multi-million dollar systems are only feasible for very large agricultural operations. However, most dairy farms in the state have fewer than 100 cows. Scaling down the technology to something similar to that being implemented in Uganda may create new opportunities for biogas production. 

“Ideally, some of our Wisconsin farmers would see the work we do in Uganda and be inspired to meet the needs here,” McCord continues. 

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