At present energy and fertilizer requirements of the developing countries are largely met by locally available non-commercial sources, such as firewood and farm wastes. Extensive use of firewood can lead to deforestation. When organic farm wastes are burnt soil nutrients, which should return to soil, are lost and this can severely affect agricultural production. The problem of efficient utilization of these locally available resources, therefore, needs to be studied in a systematic manner. As an option for efficient utilization of local resources, bio-gas plants in which animal dung and agricultural byproducts are utilized, to obtain both methane and fertilizer through anaerobic fermentation, are considered taking India as a case study. This is an example of appropriate technology for rural environment which requires low investment, does not need highly skilled labor and could be constructed with local materials and self-help in the 576,000 villages of India. The economic benefits to a family of a family bio-gas plant and the impact of its widespread acceptance on a national scale are evaluated. However, the scope of such bio-gas plants is likely to be limited for a number of reasons. For fully realizing the potential of bio-gas, village plants of approximately 6000 cft capacity for approximately 100 families are suggested instead.

The introduction of such seemingly sensible new technologies has failed in the past for want of appropriate management and organizational structures to ensure social participation by persons of various income groups in the successful operation of such community plants. A pricing policy for purchase of farmwastes and distribution of gas fertilizer is developed as an essential tool to ensure that no-one is worse off by the introduction of bio-gas plants. The idea with a different organization scheme could be also tried out for the urban area for maintaining sanitation.

The impact of full scale adoption could mean that by 2000 A.D. almost 90% of rural energy requirements of domestic sector could be met; at present this is about 45% of the total energy consumption in India. The consequent reduction in firewood consumption would prevent deforestation. In addition organic manure containing 2 million tons of additional nitrogen would be available every year to enhance soil nutrients and hence boosting food production and helping to solve the problem of sanitation at the same time.

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