FarmersJoint.com

This biogas something is very interesting. Like what size of biogas tank will be ok for a family of 5?

it depends on what your primary aim is

From http://www.farmersjoint.com/thread-187.html, a family of 5 will need 1m3 daily. This can be generated from 43.5kg cow manure or 25kg pig manure or 15.4kg chicken manure. A 4m3 biogas digester can handle this.

Thanks a lot Henlus. Pls how did u arrive at those values - the math behind them. tnks.