Biogas is a mixture of different gases produced by the breakdown of organic matter under anaerobic condition. Biogas can be produced from different raw materials such as agricultural waste, plant waste, municipal waste, sewage and food waste. It is a renewable energy source which can be produced with less capital investment and in less time. Biogas can be produced by anaerobic digestion with anaerobic bacteria, which digest material inside a closed system, or fermentation of biodegradable materials. Biogas is composed of methane (CH4) and carbon dioxide (CO2) and may have small amounts of hydrogen sulphide (H2S), moisture and siloxanes. Biogas can be compressed, like natural gas is compressed to CNG, and used to power motor vehicles.