Biogas typically refers to a gas produced by the biological breakdown of organic matter in the absence of oxygen (anaerobic digestion). Biogas offers highly cost effective, renewable and decentralized energy production for domestic and commercial consumers. Pakistan did tried biogas production in Seventies but it could not succeed due to lack of technology and awareness among the communities. Recent technological advancements in biogas digesters especially the Dome Shaped Digester has greatly helped in developing highly efficient, economically viable, environment and user friendly biogas plant, which is successfully being developed and operated using indigenous construction material and equipment. It is successfully being used in China, many other countries including Pakistan for biogas production using cow dung and biomass. Biogas is extensively produced in China and India using anaerobic digestion techniques and currently over fifty million households are using dome shaped digesters in China.
Domestic biogas plants of various sizes (5-20 cubic meter) and commercial biogas plants above 20 cubic meter can easily be developed using dome shaped biogas plants. Biogas at household level is used for cooking, heating, and small scale power generation, whereas commercial biogas plants are used for power generation, water lifting, vehicle fuel and other such uses. The decomposed organic manure produced during fermentation process in the biogas digester is a rich source of soil fertility. The decentralized biogas energy production using animal dung is highly sustainable as it is economically viable, socially acceptable besides being environment friendly. A rural household possessing an average of five livestock heads can produce 10 m³ of biogas sufficient for their daily domestic energy need besides producing decomposed humus as a rich source of organic manure. It has been observed that an average size domestic biogas plant can save Rs. 10000/- per month as a replacement cost of LPG and chemical fertilizer and health and hygiene benefits. Pakistan being the 5th largest livestock and dairy producing country can easily adopt these simple technologies at domestic and commercial scale to ensure energy security in rural areas.