Digesting past lessons: China's experience with biogas is starting to pay off

China's efforts to use biogas as an alternative fuel in the 1970s have matured to make biogas a reliable, inexpensive source of fuel for lighting, cooking and agriculture. Research into standard designs and training for farmers on biogas techniques have resulted in construction of nearly 5 million biogas digesters in rural areas. Digesters are being used for sewage treatment and supply 64,000 urban families with biogas. The residue from the digestion process makes excellent fertilizer.