A particularly gruesome public toilet in China and a guy running a toilet business in Nairobi's slums inspired David to start Sanergy. With co-founders Lindsay Stradley and Ani Vallabhaneni, the Sanergy team saw a better way and came up with a "build–collect–convert" approach to pay toilets.
2.5 billion people lack access to adequate sanitation in the developing world, and sanitation-related disease kills 1.6 million children every year. All over the world, slum dwellers must resort to open defecation and pit latrines. Sanergy's toilets are at convenient points throughout the community, cost about five cents to use, and provide a safe, clean and dignified experience. Sanergy collects the waste each day and converts it into saleable byproducts such as fertilizer and electricity, representing a $177M market in Kenya alone.