In August 2015—after a couple of years of testing—a company in Kenya began commercially treating human poop with the sun’s heat to create an environmentally friendly fuel source. This week, Sanivation plans to turn on a new continuous-flow system that will help it scale up to support many more customers than it could previously.
“We can treat thousands and multi-thousands of peoples’ shit continuously,” says Sanivation CTO Emily Woods.
In developing countries, the International Energy Agency estimates that about 2.5 billion people cook with biomass: charcoal from forests, agricultural waste, animal dung, and other sources. In Kenya, charcoal provides about 82 percent of the energy in urban households and 34 percent of the energy in rural households, according to the Kenya Forest Service. Yet its use is leading to major deforestation—2013 research found that the demand for charcoal was about 16.3 million m3, but there was only a supply of about 7.3 million m3. Not to mention that the air pollution from inefficiently burning solid fuels such as charcoal can kill about 4.3 million people a year.
One solution to these problems could be switching to cleaner cooking stoves, but some research points out that new technology adoption is difficult. Instead of swapping stoves, changing fuel is another possibility—research by the United Nations University Institute for Water, Environment, and Health concluded that the electricity generated from the world’s collective human feces could power up to 138 million households, for example.
And that’s where Sanivation steps in—providing an alternative cooking-fuel source to local small businesses and restaurants. Woods says Sanivation’s sun-treated poop fuel briquettes can burn two times longer than normal charcoal, yet release about one third of the carbon monoxide and particulate matter emissions. Each metric ton of the briquettes saves about 88 trees yet they are “comparable” in cost even with charcoal’s rapid price fluctuations.
Before this week, the team of about 50 was able to process about 2 metric tons of waste every month in batches. In the new continuous-flow system coming online this week in Naivasha, Sanivation estimates it will be able to process 6 to 8 metric tons of waste every month, decreasing the amount of physical space required for processing, and increasing the number of customers from hundreds to hopefully many more.
The process starts with fecal waste that the company collects from latrines and ends with a fuel briquette.
