charge for its dissemination bear the responsibility to deliver a reliable, durable and user-
Appropriate Design: Only appropriate designs will perform satisfactory and will have a
favorable cost-benefit ratio. Existing basic designs of biogas systems have to be adapted to
the following framework conditions:
• climatic and soil conditions;
• the quality of substrate to be digested;
• the quantities of substrate;
• the prioritization of expected benefits;
• the capital available;
• the availability of skills for operation, maintenance and repair.
Official Policy Support: The policies of governments and donor organizations cannot turn
immature technologies and inappropriate designs into success stories, nor can they create
an artificial demand for alternative energy or improved fertilizer. But where a national need
for energy alternatives exists and the increasing burden of water pollution, deforestation and
soil depletion is felt, governments can asupport biogas dissemination by a legal framework
against unsustainable use of natural resources and in favor of green technologies.
Donor organizations can provide take-off funding and initial technical assistance where
biogas technology is hitherto unknown.
The ’Critical Mass’ of Biogas Systems: For small and medium scale farmers, the
investment in a biogas system is a considerable risk. Besides the confidence in the
technology itself, they need reassurance from neighbors and colleagues. Farmers believe
what they see. The more working biogas systems are around, the more they will be willing to
invest. In addition, professional (commercial) advice, maintenance and repair will only
evolve, if a sufficient number - the ’critical mass’ - of biogas systems are established in the