The Centre of Science for Villages (CSV), Wardha, Maharashtra, has developed a microbiogas plant with a battery of 300 litres clay jars, which is known as Ranjan biogas plant. The biogas plant is a large clay pot churned on the potter's wheel that is utilised for storing water during summers. Ten Ranjans provide four hours of non-stop cooking gas. The plant produces nearly 35 litres of biogas from one kg of cowdung, says Devendra Kumar, director of the CSV. The daily need of an individual is around 270 litres. In that case, eight kg of cowdung and same amount of water could generate sufficient quantity of gas to meet the needs of a single person everyday, he says. The biogas slurry takes up 12 litres of the total jar volume daily for 40 days, which is the retention period of a Ranhan biogas plant. Hence, it requires 480 litres of total jar-space. Since the gas is produced only in the upper one-fourth portion of the plant, it requires a total gas production space of 120 litres.