Sintex's Biogas Digester Converts Human Waste to Energy
Indian plastics and textiles manufacturer, Sintex Industries is experimenting with human waste as a source of energy. Its new biogas digester may help satisfy two of India's major needs: energy and sanitation.
The biogas digester can turn human or cow (or any, really) excrement and kitchen garbage into fuel that can be used for cooking or generating electricity. The digester uses bacteria to break the waste down into sludge which can be used as fertilizer. In the process the bacteria emit methane that is stored in a canister rather than pumped into the atmosphere. A one cubic meter digester can convert the waste generated by a four person family into enough fuel to cook all its meals. A device that size would cost about $425. The Indian government has agreed to subsidize about a third of the cost of these units.
The government plans to end open defecation by 2012 and believes biogas plants are a good solution. A.R. Shukla, a scientific advisor in the Ministry of New and Renewable Energy, says India could support 12 million such plants, but only 3.9 million - mostly pricier models big enough to accommodate entire villages - have been installed to date.
An excellent example of an efficiently working biogas plant can be found in a South Delhi neighborhood where around 1,000 people use a public toilet constructed by a nonprofit foundation, the Sulabh Sanitation Movement. The biogas digester attached to it provides enough gas for a 600-student school and vocational-training program the foundation runs.
Although Sintex has only installed about 100 digesters, they plan to increase investment and production tenfold this year.