The Contribution of Biogas Technology to Conservation and
The conversion of waste material into fertilizer and biogas helps protect the environment in
five principal ways:
• The generated biogas can replace traditional energy sources like firewood and animal
dung, thus contributing to combat deforestation and soil depletion.
• Biogas can contribute to replace fossil fuels, thus reducing the emission of
greenhouse gases and other harmful emissions.
• By tapping biogas in a biogas plant and using it as a source of energy, harmful effects
of methane on the biosphere are reduced.
• By keeping waste material and dung in a confined space, surface and groundwater
contamination as well as toxic effects on human populations can be minimized.
• By conversion of waste material and dung into a more convenient and high-value
fertilizer (’biogas slurry’), organic matter is more readily available for agricultural
purposes, thus protecting soils from depletion and erosion.
Farmers, industrial estates, municipalities and governments have diverging concepts of
development. They can use biogas technology in different ways to contribute to their own
Farmers may want to substitute inputs such as fertilizers, household and engine fuels by
biogas slurry and the biogas itself. A biogas system can relieve farmers from work that they
have formerly spent on dung disposal or dung application on their fields. By using biogas for
cooking, lighting and heating, life quality for the whole family can improve. Improved stables,
if they are part of the biogas system, can increase the output of animal husbandry. Improved
farmyard manure may raise the yields of plant production.
Industrial estates can, by processing their waste in a biogas plant, fulfill legal obligations of
waste disposal. They can, at the same time, generate energy for production processes,
lighting or heating.
Municipalities can use biogas technology to solve problems in public waste disposal and
waste water treatment. The energy output of biogas digestion is usually not a priority, but
may respond to public energy demands such as street lighting, water pumping and cooking
in hospitals or schools.
National Governments have macro-economic interests that may render biogas technology
an interesting option in overall development plans. On a national scale, a substantial number
of working biogas systems will help reduce deforestation, increase agricultural production,
raise employment, and substitute imports of fossil fuels and fertilizers. If macro-economic
benefits are obvious and quantifiable, a government may even consider to subsidize biogas
systems to bridge a micro-economic profitability gap.
Craftsmen, engineers and maintenance workers have long been overlooked as a target
group for biogas promotion. Not only does biogas technology open market niches for
masons, plumbers, civil engineers and agronomists, they are often the most effective
promoters of biogas technology.
Under which conditions can biogas technology contribute to development and
Mature technology: A positive contribution of biogas technology can only materialize, if the
technology works. The development of biogas technology has passed the experimental
stage. Trials with uncertain outcome can only be accepted if the costs of failure are not to be
paid by the end-users. Whatever the chosen design of the biogas plant may be, those in