If generating methane from manure, collect dung for several days to
determine average daily dung production.
On this basis, the appropriate
size biogas digester plant can be calculated.
For example, where
55 kg of dung a day is available a 8 m3 plant is warranted; where it’s
only 6 kg of dung a day, a 1 m3 plant will suffice.
For a family of 8 with a few animals (say 8-10 cows), a 10m³ digester is a commonly used size in India, with 2 m³ gas storage.