Turning garbage into gold
By Tracey Grose
Some of the fastest-growing cities in the world are in Africa. According to the United Nations, there will be over a billion people living in slums in Africa by 2050. This concentration of humanity with little clean water and no sanitation yet with a surplus of refuse presents growing public health hazards. What signals are there of new solutions to meeting these urgent issues?
Trash has long been used as a cheap building material, but what if it could fuel a community? The Community Cooker addresses multiple challenges of slum living and produces multiple benefits. For starters, the cooker is fueled by rubbish. Plentiful around slums, trash is a cheaper fuel source than charcoal, gas or kerosene. And burning trash instead of wood protects dwindling forests. It also prevents the garbage from contaminating waterways. The cooker is shared by residents and contributes to the sense of community. The Community Cooker Foundation has piloted this project in Laini Saba Kibera near Nairobi, Kenya and has plans to set up cookers in other parts of the city and country.
An even trickier topic, what can be done about sanitation needs? There are many ideas for innovating on the toilet. The Gates Foundation has awarded innovations that not only safely manage the waste but also produce different forms of power and clean water.
In another example, a company called Sanergy promotes entrepreneurship. In Kenya, Sanergy offers small business opportunities to franchise operators of its Fresh Life toilets. For roughly $575, a person can buy a toilet block outfitted with toilet roll, a solar lantern and a mop. Operators are incentivized to keep the toilets clean. The air tight collection containers are emptied on a daily basis. The waste is processed centrally into biogas for electricity generation, and the output from the biogas is processed into organic fertilizer and sold to farmers.
An innovation the sprung out of the Lagos Maker Faire, three Nigerian teenage girls have developed a urine-powered generator. Using an electrolytic cell, one liter of urine can generate six hours of electricity. While there is still much progress to be made on this concept, invention is underway on the most critical issues facing urban dwellers today. For more examples, see the Financial Times Urban Ingenuity Awards.