Biogas is a gas produced by the breakdown of bio-degradable organic matter in the absence of oxygen. Bio Projects Biogas is one of the key renewable energy sources, produced by the anaerobic degradation (or fermentation) of biodegradable materials such as food waste, garden waste, energy crop waste, Biogas is mainly constituted of methane and carbon di-oxide and also contains traces of hydrogen sulphide. The combustion Of these components releases energy which allows biogas to be used as alternate fuel for cooking, can also be converted to electricity and can be compressed to form a 'biofuel'