Poop-to-Energy Project Provides Clean Cooking Fuel in Kenya

Sanitation workers, public health officials and entrepreneurs are working together in Kenya to tackle two huge challenges: deal with human waste safely and provide clean cooking fuel for local residents.

A project in Nakuru, the fourth-largest city in Kenya, is collecting human poop from toilets in selected areas of the city and turning it into biochar briquettes that can be used for tasks ranging from cooking meals at home to keeping chicks warm at poultry farms.

Leading this effort is Nakuru’s local sanitation company, which aims to cover 95 percent of the city and surrounding area with this program. The Nakuru Water and Sanitation Services Company is building its own value chain, starting with the construction of 5,000 toilets in neighborhoods where sewage systems are lacking.

Waste from those toilets, in addition to what can be collected from pit latrines and septic tanks, is eventually taken to a processing facility. Similar in design to that of a greenhouse, waste dries out in these sheds during a two- to three-week process. That sludge is then fired, or carbonized, at a temperature of 700° Celsius. Additional materials such as banana stalk fiber and sawdust are then added; that material is then heated again at 300°C.

Next, the mixture is formed into briquettes, resulting in a charcoal-like product. According to the sanitation company, this fuel has no odor, and also burns far more safely and efficiently than conventional charcoal. Various media sources report that despite initial fears over what the smell of these briquettes may impose, the carbonizing process removes pathogens and they burn cleaner than wood-based alternatives; additives such as molasses, a binding agent, even lend a sweet-smelling aroma (and help users forget the source of this fuel).

In the meantime, the sanitation company is promoting hand-washing and other personal hygiene tactics to improve public health in and around Nakuru, which is home to over 400,000 people.

The project’s leaders hope to attract more funds to expand the program, which would create more jobs while also generating other products such as fertilizer for local farmers. Production capacity is currently limited to two tons a month, but local officials say investment could help quintuple the amount of poop processed into fuel by the end of this year.

On one hand, the project could improve sanitation in this western Kenyan cities, as well in other areas across the world where providing a safe place to use the bathroom while maintaining safe water supplies is often close to impossible. Furthermore, the project also could offer a clean form of fuel cookstoves, the household tool by which meals are prepared in much of the developing world - and also creates its own set of health and environmental problems.

The quest to find alternative sources to burning wood in cookstoves, which contributes to deforestation, has been an ongoing challenge. Some carbon offset programs have focused on finding alternative fuel sources for these cookstoves, as well as finding ways to improve these contraptions’ design - but those efforts have at best witnessed mixed results.

Human waste, however, is a renewable resource. And consumers are slowly but surely getting over the “ick” factor - witness the success of Orange County’s water recycling program in California, for example.

The briquettes appear to be popular with Nakuru’s residents: Quartz reports that the fuel is currently sold for 50 cents a kilo (2.2 pounds).

Other entrepreneurs in Kenya have been trying to harness human waste into fuel, as many residents lack reliable access to sewage systems. One student, for example, designed a biodigester that could turn human waste into clean-burning biogas. And a Kenyan startup has launched a system similar to what is used in Nakuru, but it runs on solar power.

Image credit: Nakuru Water and Sanitation Services