4. Biogas extension work
The following chapter describes extension work within the framework of a project dealing exclusively with biogas units. But most of the points are also relevant when biogas extension is promoted within more general development programmes.
The target group of a rural biogas extension programme are farms having at least 50 kg of cattle dung (or 35 kg of pig droppings) available per day' which means they have at least three milk cows or 10 adult pigs fully stable bound, or nine heads of local cattle half stable bound There are several conditions to be fulfilled before a farmer of the target group becomes a customer:
-He has to have enough income to buy a plant or repay a loan.
-He must be educated enough to understand the system.
-He must know about biogas and its suitability for his individual case.
-He must have easy access to sufficient water.
-He has no real fuel alternatives.
Standardization means to define exactly and restrictives the materials, measurements and methods off the work. Given standards must be clear and universalIy adabtibIe.
Technical standardization is needed because it can not be expected that an artisan or farmer will fully understand the essentials of a biogas unit. Biogas plants are easy to construct but difficult to comprehend totally. Artisans must be trained to precisely observe all details and methods of construction. This is especially important for extension programmes that aim at handing-over the construction activities to the private sector, where permanent quality control is difficult. It should also be mentioned, that management training of artisans is needed to improve the efficiency of the enterprise and thus the quality of workmanship).
A farm benefits from a biogas plant if the plant works trouble free, gas and slurry are used profitably and operation of the plant is comfortable and easy. In fact feeding the plant must be less labour intensive than not feeding the plant. This user-oriented approach leads to a standardized biogas plant, if possible, connected to a standardized stable which are integrated as much as possible into the existing farm economy.
The final goal of the extension project is to have independent artisans who construct standardized biogas units on demand of independent farmers against appropriate payment. connection to zero-grazing units is favoured.
Each biogas extension project starts by building demonstration units at selected farms which might be fully subsidized. The farmers must be willing to cooperate with the biogas extension service by allowing potential customers to visit their installations. It is most important that those farmers maintain and utilize their gasplants well.
After sufficient number of demonstration units have been installed, further biogas units are only constructed on demand and against full payment. Payment is usually done in 2 to 3 instalments. It is helpful to have standardized procedures for application, payment and realization of the construction (see sample of forms in the appendix).
When a potential customer first comes to the Biogas Extension Office he is given general informations including a price list. He is asked to file a written request which describes his farm and the proposed site of construction. Then the site is visited by BES-staff, assessments are made, technical details are worked out and a fixed price is given to the farmer.
After a contract agreement has been signed and a 50% down payment has been made, the biogas unit will be erected by trained private contractors under supervision of BES-technicians. When the construction is finished, the plant has been filled. appliances are connected and the final payment has been made, the unit is legally handed over to the customer. The customer receives a user manual, detailed explanations about plant operation, gas and slurry utilization and maintenance in his specific case. The customer is also given a set of tools and equipment for cleaning the stable, chopping the fodder and handling the slurry.
The main points of instruction are:
-to keep the overflow free from slurry
-to check the water trap from time to time, especially when there is no gas available for consumption
-to clean the burner regular like other cooking vessels
-to poke from time to time the inlet and outlet pipe, especially if substrate does not enter the plant
-how to change the mantle of the gas lamp
-the meaning of the slurry level in the expansion chamber
-where to turn to in case of problems the farmer cannot solve himself
The biogas unit is then visited once a month until the persons attending the plant are acquainted with the daily routine work and the utilization of gas and slurry.
As a principle. the farmer should decide freely wether he wants to have a biogas unit or not. Therefore, advertisement means mainly information and awareness building. Image cultivation is also a part of the publicity work. The biogas unit is presented as a clever way of running a modern farm unit. Well operated biogas units are the best advertisement.
Fig.10: A Biogas sticker used by CAMARTEC for advertising
Besides the standard applications for biogas plants there will always be special requests for individual solutions reaching the Biogas Extension Service. Special requests often demand individually designed units which differ either in size or proposed utilization of gas or slurry. The BES has to keep planning and supervising capacity for such services' because they often are requested by VIPs (Very Important Persons) who are important for the support of the biogas programme.
Research and Development
In addition to standardization, research and development needs will arise from the project activities. New ideas have to be tried out which will disturb the standardized routine. To minimize problems and preserve the standard of quality of construction, innovations and modifications should be restricted to a few that really improve the performance of the biogas unit or eliminating severe short-comings.
As for CAMARTEC, the most important research was the development of the weak-ring and the strong-ring. Tests on reducing the requirements for gas-tight plaster are under way. Own appliances have been developed and others from outside have been tested. A bench-scale test has been carried out to define the flow of slurry inside the digester more exactly.