When considering community biogas, the large quantities of cow-dung and other organic waste in rural areas can be used to produce significant amounts of biogas in an organised way. Using biogas in this way or “biogas farming” has the potential to counter the rising prices of crude oil and could emerge to be an alternative to fossil fuels whose stocks will soon be depleted.
Salasar Agrotech Pvt. Ltd. developed the Balaji biogas plant which is a good example of hydraulic biogas system. This plant is made with the help of a steel mould, and by concreting the complete plant in sections. This modular construction approach means a series of identical biogas plant can be produced in a relatively short time frame.
The viability of a particular community biogas plant design depends on the particular environment in which it operates. The Chinese and other Indian systems mentioned earlier can be scaled up to cater for a small community needs.
There is also benefit when considering systems of this size to consider alternative systems, which may in the future be more appropriate. For instance, gasification using biomass (wood, waste from crops, vegetable, etc.) is heated in an air-lean environment to produce a gas which can then be used to run engines. Apart from running engines to generate electricity, Gasifiers can also power vehicles like cars and trucks.
In designing a community biogas system the reliability of the system depends on providing adequate supplies of feedstock to keep the plant operative. If the physical resources are not constantly available, a backup source of fuel (for cooking stoves etc) should be included which of course has additional costs to the overall biogas system.
Although there are a number of large biogas plants in various countries few can be said to be truly community biogas plants. One Indian ‘mini’ community system was operated between 1969 and 1970 in Khiroda Panchayat, near Bhusaval, Maharashtra. There is a great site with a page called back-yard biogas in China which contains many photos and commentary by Florita Botts showing how community biogas can work and also be ascetically pleasing. It is interesting that Florita sees much of the aid going to countries, “does not go to the people for whom it is intended”. It is for this reason I hope the www.build-a-biogas-plant.com is useful as it provides information at no cost that can enrich lives.
The idea of community biogas plants provides the potential to bring the benefits of biogas systems within reach of the poorer sections of the rural population. Unfortunately, most cooperative ventures seem to only succeed when there is positive leadership (individual or institutional) and once cooperation is absent, a system soon appears to fail.
An innovative approach to community systems might come from the Loowatt system. The Loowatt toilet uses a mechanical sealing unit to contain human waste within biodegradable film with apparently low odours. The waste is stored in a cartridge beneath the toilet, for emptying, weekly or daily, depending upon level of usage and capacity. A pilot system operates in Antananarivo, Madagascar, which utilises the waste to produce biogas. The aim is to increase the value of toilet ownership, produce some biogas while fertilizer products will feed value back into the whole system.
If you are interested in a community biogas system, you made need to put together a business plan or a proposal in support of the idea. The Faculty of Engineering and Industrial Sciences at Swinburne University of Technology developed a Biogas Plant Proposal for Devikulum in India, which may provide some ideas on how to develop your own. Also check out the Community Biogas plans page which provides a lot of information on designing systems for villages or larger groups of people.