The biogas production process can be simply described as an anaerobic (absence of air) composting. In anaerobic environments a different microbe dominates and metabolizes the organic material available. A by-product of this metabolic process is CH4 (methane/natural gas). This "biogas" can serve as an alternative fuel source for any natural gas appliance. A very important consideration is that the appliance does not need to be modified. Natural gas generators, water heaters and refrigerators are available and very compatible with a biogas system.

While the energy yeilded from this composting discipline is significant, the most important implication of a bio-digester is the fertilizer it produces. In a normal aerobic pile many of the important nitrates are evaporated into the atmosphere. The sealed vessel associated with the anaerobic process retains volatile nitrates that greatly contribute to the fertilizing value of the solid product. In the 1940s when rural china started using bio-digesters to process all of their human, animal and vegetable wastes, they were able to greatly increase their quality of life in a responsible, sustainable manner. Until the biogas, they had been using imported coal for their heating and cooking needs, but once they built the digesters, they stopped importing any coal. Aside from the energy liberation, the pathogens associated with fecal matter were eliminated by the composting. Further, the increased strength of the fertilizer increased their crop yeilds 10-20%. Biogas is much more than an energy solution, its a responsible waste management system that does not require subsidies, in fact the fertilizer is of high value to local gardeners and farmers.