LOWER SIXTH - KGP SCHEDULE, WEEKS 2-9 - ENERGY
MODULE 1 THE DYNAMICS OF CHANGE
10.2 PEOPLE AND THE ENVIRONMENT -POPULATION AND RESOURCES
RENEWABLE ENERGY - HEP
NON-RENEWABLE ENERGY -OIL
   
BIOGAS
What is Biogass? · Biogas originates from bacteria in the process of bio-degradation. · The conditions for this must be anaerobic (without air) · Methanogens (carbon producing bacteria) are a link in a chain of microorganisms which degrade organic material. · In this process biogas in generated as a source of renewable energy.
Composition and Properties of Biogas · Methane; 40-70% · Carbon dioxide; 30-60% · Others; 1-5% (including hydrogen and hydrogen sulphide) · Calorific value of biogas is about 6KWh/m3 (equivalent to about half a litre of diesel oil) · Methane is the valuable component which can be harnessed in biogas as a fuel.
Fuel and Fertiliser · Dung burnt in LEDC's for cooking. Chemical fertilisers imported. · Dung contains 8 times as many phosphates & nitrates as chemical fertilisers. This is wasted when it is burnt. · Biogas is an effective tool for making maximum use of scarce resources. · As the above diagram shows, after the extraction of useful energy in the form of gas, resulting sludge is a good fertiliser, supporting general soil quality as well as high yield crops.
Benefits and Costs · Heat, light, electricity and high quality fertilisers are all produced. · Reduction of workload, mainly for women in firewood collecting and cooking. · Renewable resource that requires only an initial capital investment but once running does not need large subsidies for energy or imported goods to sustain the system. · Biogas requires high initial capital investment. This can often not be afforded although recent efforts have led to research to cut construction costs · Biogas general not considered in MEDC's because of the high availability of other fuels.

BIOGAS PROCESSING
CASE STUDY - NEPAL
Background · Total domestic energy demand in Nepal; 248 million GJ in 1990/91. · 35% of revenue from export used to import petrol and coal, which accounts for 8% of the total energy demand. · 91% of the energy demand is met by traditional sources (wood and animal wastes) · Pioneer of Biogas in Nepal was B.R. Sauboll, and his work impressed the department of agriculture, which invested money in 250 biogas generators in 1975/76. · Since then government and bank incentives have promoted investment in biogas.
Government policies for the promotion of biogas · 1974/75: Government provided interest free subsidies for biogas plants · Throughout the eighties many more promotional policies were pursued to increase the use of biogas. · 1992: New government objective to gradually replace imported fuels by indigenous energy sources that could be locally exploited · By 1998 a 90 000 biogas plant instillation target was set, to be completed by 2003
Success, and why · The national biogas program has been considered one of the most successful programmes in Nepal, reasons for this are…. · Biogas generators produce no significant waste material. The 2 products are the gas and slurry, both of which have valid applications. This allows the people of Nepal to gain maximum efficiency from their precious resources. · High quality design of biogas generators. · Effective promotion by means of leaflets, posters and manuals. · Proper channelling of loans means more plants have been created with the money provided by the government which lowers the countries dependency on imported fuels · Government policies have been improved and effective monitoring and good co-ordination have made this venture a success.
Four Concluding statements on the success of biogas
1. "Availability of both loan and subsidy funds to ensure implementation of the programme makes biogas more attractive."
2. "Privatisation of biogas with the involvement of several recognised biogas construction companies and commercial banks for financing make the programme attractive."
3. "Quality control mechanism and slurry extension approach have made the biogas programme a success."
4. "A proper survey has been made of the potential as well as demand of biogas in the country and promotion awareness activities have been carried out." Similarly technical capacities have been assessed. A good organisational networking has made the national biogas programme a success in Nepal.

PROCESSING BIOGAS
RENEWABLE ENERGY - HEP
NON-RENEWABLE ENERGY -OIL