Question

how is biogas a renewable source of energy

Answer 1

Biogas is a fuel gas - a mixture consisting of 65% methane (CH4) and of 35% CO2. It is a renewable energy resulting from biomass. It is released during the anaerobic (without oxygen) fermentation of biomass. Since biomass - the primary ingredient in producing biogas is renewable source and is not under threat of extinction, biogas is a renewable source of energy.