People Are Cooking With Human Poo—and That’s a Good Thing

In Kenya, the future of sanitation may entail turning human waste into fuel.

(Photo: Courtesy Sanivation)

Dec 18, 2014· 3 MIN READ
Jacob Kushner reports on foreign investment and human rights in Africa. His work has appeared in, Newsweek, Vice, Foreign Policy, and

To get the fuel she needed to cook her food and warm her home, Kenyan Nancy Wambui, 54, used to buy charcoal made from chopped-down trees. But recently, she was given a new set of briquettes to try, that looked just like regular charcoal but worked even better. The secret ingredient? Human poop.

“They took a long time to burn off, so you could cook and then still have heat to heat hot water for bathing,” she said of her first experience using the new fuel.

These briquettes just might be a promising new way to curb deforestation, reduce the daily expenditures of low-income families, help solve an energy deficit facing the country, and support sanitation improvements in areas where they are desperately needed. More than 2.5 billion people in the developing world lack access to toilets, and a child dies every 15 seconds from diarrhea, usually the result of food or water becoming contaminated by human waste. Each year, 200 million tons of the world’s poop also goes completely untreated, ending up directly in lakes, rivers, and oceans.

Even in Kenya, one of Africa’s largest economies, $324 million is lost every year due to sickness and missed work hours caused by poor sanitation. Nonprofits and businesses have experimented with what to do with human waste. In Haiti, the NGO SOIL is famous for distributing “composting toilets” that drastically lower the risk of contracting diseases. SOIL collects the poop from the toilets, treats it, and sells it as fertilizer.

Now, a start-up in Kenya is taking SOIL’s model in a new direction: Instead of composting the waste to grow food, it’s turning it into energy to cook it. Sanivation is distributing toilets to local families, emptying them each month, and turning the poop into briquettes. After the waste is collected from toilets around town, it’s put it in a solar concentrator that uses mirrors to heat the waste to temperatures that have been shown by the Centers for Disease Control to kill pathogens, making it safe for reuse.

“We want to be able to dispose of poop safely and affordably,” said Sanivation cofounder Andrew Foote. “Being able to not just dispose of it but to transform it into a product that has high demand is very appealing from a business sense.”

Across Africa and around the world, hundreds of millions of people cook with wood and charcoal. Most charcoal comes from trees that are slowly cooked down in huge earthen ovens, removing the moisture without oxidizing the wood so that it becomes a more efficient source of heat per volume. But the process consumes a lot of trees—four tons of trees produce just one ton of charcoal, according to the U.N. Food and Agriculture Organization—and with populations on the continent rising exponentially, deforestation is only increasting. Already, forest cover in Kenya has fallen to just 2 percent, and the price of charcoal is rising.

Moreover, smoke from burning charcoal indoors can be hazardous for parents, kids, and neighbors: 6 percent of global diseases and 7 percent of disease-related deaths are caused by respiratory infections. Sanivation’s poop briquettes contain one-third less charcoal than normal ones.

Since 2012, Sanivation has been operating in the Kenyan town of Naivasha thanks to grants from the German Aid Coproration and other governmental institutions. The project is still in its early stages—families who opt for a toilet pay Sanivation 600 shillings ($7) a month to remove the waste, and they get a free month each time they refer a friend. So far, 15 toilets have been sold, and 20 families are on a waiting list in Naivasha. The organization has also installed another 32 toilets to serve 300 people in the Kakuma Refugee Camp in northern Kenya, where Sanivation is testing out the model in cooperation with the CDC and the U.S. Embassy. Because improving water and sanitation is one of the most cost-effective uses of aid money—every dollar spent leads to between $5 and $46 in return on investment through increased productivity and reduced health care costs, according to the CDC—Sanivation’s model has a well-funded customer base already built in.

In the near future, the organization hopes to undertake a market analysis to see how locals will receive the idea of the briquettes and to determine the best strategy for distribution. For now, they’re being given away for testing purposes.

Sanivation estimates area residents spend as much as 30 percent of their family income on cooking fuel (globally, the poorest spend 25 percent), consuming about two kilograms of charcoal per day. At only 15 shillings ($.17) per kilogram—a third less than the going rate for charcoal—the briquettes may boost the local economy once Sanivation begins producing them en masse.

To date, nearly two tons of briquettes have been produced by hand, but Sanivation crowdfunded $11,000 to buy a machine capable of cranking out a metric ton of briquettes per hour. Foote says that when people started coming up to him asking if they could use the solar concentrator itself to cook things on, he knew there was a market for affordable energy.

“When you look at the chemical composition of poop, it’s 90 percent organic matter and 40 percent carbon. So not only is there a high demand for fuel, but poop from a chemical composition standpoint already has a great composition to be turned into fuel,” he said.

Others who work on sanitation in developing countries say there’s one major obstacle to Sanivation’s model: the “ick” factor. This, said Sebastien Tilmans, cofounder of Resource Sanitation, which builds toilets for urban environments in the developing world, “is probably the biggest concern” Sanivation needs to overcome. “People have to be OK with cooking with that material.”

So far in Naivasha, people’s reservations tend to disappear as soon as they try out the odorless briquettes for themselves. For Wambui, the proof is in the smell—or rather, lack thereof. She said she tells skeptical friends, “‘Go and [light them] and smell that smoke and see how it feels.’ They see it’s not smelling, it’s cooking good.”