domestic biogas in asia1
TRANSCRIPT
What is biogas?
•Anaerobic Digestion (AD) breaks down wet biomass to gas and compost
•Relies on microbes (bacteria and archaea) in animal dung
•Several possible applications
•Talk focuses on biogas in rural areas for domestic uses, with dung as feed
Background• SNV (Netherlands Development Organisation)
Asia Biogas programme - focus on rural domestic biogas fed by animal dung.
• Started in Nepal (1993) - extended to Vietnam, Bangladesh, Cambodia and Laos
•Based on previous programme set up Development and Consulting Services of United Mission to Nepal (1976 to 1984)
Technology
• Dung mixed with water and allowed to flow into underground pit lined with masonry
• Plants built for individual households• Need 3 to 6 cows or 6 to 12 pigs• Gas piped to kitchen for cooking
•Slurry from plant collected
•Can be used as a fertilizer after some processing
•Removes smell
Benefits (1)• Clean gaseous cooking fuel• No smoke• Instant availability • Does not need constant attention• Reduced danger of burns
•Resource (dung) available from animal sheds
•No need to walk to collect firewood
Benefits (2)• Cooking pots easy to clean (no soot)• Saving of time (3 hours a day)• Saving of firewood (2,000 kg a year)• Reduced deforestation (1,000 biogas plants
saves 33.8 ha forest from clear felling)
•Much reduced smell from the animal sheds
(in Vietnam, pig sties are close to the house)
Benefits (3)• Biogas can be used for lights• Reduced smell from kerosene lamps• Savings of 32 litres kerosene a year• Reduced risk of house fires• Saving of carbon (4,900 kg a year)
•Since gas available in the morning, children get cooked breakfast before school.
Benefits (4)• A latrine can be attached• Improved sanitation• Reduced transfer of pathogens (especially if
slurry is properly processed)
•Reduced risk to women (who go out at dawn or dusk to use the fields)
•Reduce incidence of snake bites
Benefits (5)• Slurry is a good quality compost (better than
raw dung)• Liquid slurry should be absorbed in dry
biomass and composted for 1 month
•Compost even better if use vermi-culture
•Growers prepared to pay cash for vermi-compost
Economics• With so many benefits, what is drawback?• Cost - most cost:benefit analyses show
financial benefit as marginal• BUT high value for “externalities” - e.g.
saving forests, health benefits etc.
•Biogas becomes attractive with subsidy
•SNV Asia Biogas Programme offered reliable subsidy
Asia Biogas Programme • Involve people at all levels, from government
policy makers to masons who build plants• Promotion, Education and Training• Emphasis on quality of technology• Use a local design, but ensure it works well
•Train staff to check quality of construction
•Release subsidy for each plant only when it meets specification
HouseholdBiogas Sector
Quality Management
Marketing & Sales
Construction
Subsidy
Extra services
R&D
Training
Micro Credit, SME
Development
Tasks involved in running a biogas programme
Ref: Dagmar Zwebe, “SNV Renewable Energy Developments: The Biogas Programme for Animal Husbandry Sector of Vietnam”, Presentation (May 2012).
Project Achievements
CountryStartYear
Built in 2011
Built by 2011
Invest Cost $
Nepal 1992 19,246 250,476 663
Vietnam 2003 23,372 123,714 621
Cambodia 2006 4,826 20,756 488
Bangladesh 2006 5,049 14,972 430
Laos 2007 439 2,405 448
Total 52,932 412,323
Based on: Brief progress and planning report the Working Group on Domestic Biogas under the Energy for All Partnership as per May 2012
Starting a Programme
• Find a group interested in biogas to manage programme (or set up a group)
• Involve people from government and encourage renewable energy policy
• Design a subsidy & micro-finance scheme
•Develop a local design that works well
•Use local companies to build plants
•Train staff regularly
Subsidy Issues (1)
• Who funds externalities? i.e.• Who pays to save forests, improve people’s
health, reduce carbon emissions? • National governments - but other priorities• International Community
•Bilateral Aid (SNV, KfW, DANIDA, USAID etc)
•UN agencies:World Bank, ADB, UNDP,
UNEP, UNFCCC•Danger of corruption
Subsidy Issues (2)
• WWF puts high value on certain habitats: e.g. tiger ranges - pay extra
• CDM designed to fund carbon offsets - CER certified emissions reductions
• Also VER - voluntary emissions reductions
•Carbon offset trading under voluntary market mechanisms
(Big companies want to look “Green”)
•Complex - large nos. needed
Carbon Offset Biogas
• New Charitable Company established• Foundation SKG Sangha - based on biogas
programme in South India• Aim: to use voluntary carbon offset finance to
encourage biogas projects elsewhere
•Also interest in other renewable energy projects
•First project in Egypt funded by UNDP
Thank you
Technical Aspects • Underground dome made from masonry
(bricks or concrete)• Gas stored by displacing slurry into
reservoir tank• Volume 4 m3 (2 m3 to 10 m3)
Biogas Displacement Principle
Thank you
Other applications (1)• Sewage Treatment • KIST project in Rwanda processing sewage
from prisons (10,000 people)• Saves 50% of wood fuel for cooking• Volume 100 m3 x 10 = 1,000 m3
Other applications (2)• Urban biogas to process food wastes• Volume 1 m3, food waste gives more gas• Family’s own food waste saves 25% LPG• Use extra food waste from local shops• Can use sewage in addition
Other applications (3)• Local authority wastes• Market wastes• Office canteen wastes• Municipal solid wastes• Food processing wastes
Thank you