This site was our group’s first chance to examine a domestic biogas system. The total cost was 22,000 rupees ($403 USD) from both KJBF and home owner contributions. The tank itself is lined with brick and cement, which is covered with dirt and built adjacent to the beneficiary’s home. Through an opening at the top of the dirt mound, the tank is filled with a mixture of milled cow dung and water referred to as slurry. Methane produced from the slurry is then piped from a small opening into the home, where it is fitted to a cooking stove. The condensed cow dung seeps out of the tank into a smaller holding container, which is used as fertilizer. This method relieves homeowners from having to source wood from nearby forests, saving both time and labor in addition to conserving natural resources.
Mr. Bajaj noted that only individually owned biogas tanks are successful because it is difficult for village members to take responsibility for a communal structure, which then quickly falls into disrepair (the tragedy of the commons!). But a possible drawback of this setup is the large amount of valuable domestic space that it occupies. I still have lots of questions: how long the tanks last, repair costs, possible slurry contamination, etc. But the greatest difficulty this technology faces right now is simply meeting the citizen demand for biogas systems, an optimistic challenge for KJBF.