The Lt-AD solution produces a methane rich biogas as a by-product of the process. The biogas produced has an average methane content greater than 80%, exceptionally close to natural gas quality. The Lt-AD system uses minimum energy input for the pumping of wastewater. The Lt-AD does not require the biogas generated to heat the process (unlike other AD technologies) as the process runs at low temperatures. This allows the biogas that is generated to be utilized on site for heat or electricity reducing external on site energy requirement, therefore reducing energy costs and also reducing GHG emissions.