The dependence on fossil fuels as primary energy source has led to global climate change, environmental degradation, and human health problems. Moreover, the recent rise in oil and natural gas prices may drive the current economy towards alternative energy sources such as biogas. Security of energy supply especially sustainable energy and reduction of CO₂ emission are priorities and biogas fuel helps to reduce greenhouse gas emissions. Domestic biogas installations can reduce greenhouse gas (GHG) emissions in three ways: by changing the manure management modality; by substituting fossil fuels and non-renewable biomass for cooking (and to a smaller extent for lighting) with biogas, and; by substituting chemical fertilizer with bio slurry. Utilizing biogas as an alternative to fossil based fuels reduces the net amount of carbon dioxide emitted to the atmosphere. Biogas is regarded as carbon neutral fuel because CO₂ released is utilized by plants for photosynthesis which creates organic matter from it. The use of renewable energy sources can contribute to solve the present and future energy problems. Among the alternative energy sources, biogas production from green energy crops and organic wastes has world wide application as it yields a good quality fuel and fermented slurry, which may be used as a manure or soil conditioner.