Tata AIG General Insurance Company - Insurer Innovation Award 2024
Domestic biogas in asia1
1. Domestic Biogas in Asia
Dr David Fulford CEnv MEI
www.kingdombio.com
davidf@kingdombio.com
2. 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
3. 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)
4. 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
5. 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
6. 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)
7. 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.
8. 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
9. 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
10. 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
11. 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
12. Tasks involved in running a biogas programme
Construction
Quality
Training
Management
Household Micro Credit,
Marketing
& Sales
Biogas SME
Development
Sector
R&D Subsidy
Extra
services
Ref: Dagmar Zwebe, “SNV Renewable Energy Developments: The Biogas Programme for Animal
Husbandry Sector of Vietnam”, Presentation (May 2012).
13. Project Achievements
Start Built in Built by Invest
Country
Year 2011 2011 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
14. 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
15. 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
16. 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
17. 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
19. 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)
22. 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
23. 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
24. Other applications (3)
• Local authority wastes
• Market wastes
• Office canteen wastes
• Municipal solid wastes
• Food processing wastes
Best example of a biogas plant is a cow. Breaks down biomass (grass) into energy and a waste product. Cattle dung is a good source of the right microbes. Anaerobic = without oxygen. Archaea so old that oxygen in the atmosphere is an innovation to which they have not adapted. If they are in an oxygen environment, they shut down and wait for it to go away. Work best in places such as the guts of animals or in marshes.
SNV did not like me telling them that their project was based on work in which I was previously involved. Many of the ideas which they claim that they developed were actually already used in the previous project. Ideas developed by an American – Sanfred Ruohoniemi, who used to work for USAID. “ What have you done to ‘my’ project?” UMN passed the project to ADB/N (Agricultural Development Bank of Nepal) who had UNDP funding (1985 to 1992). SNV “rescued” the project and made it work more effectively.
Designs based on the Chinese fixed dome design (more later, if people are interested). Most of the plant is underground. See feed pit, the gas pipe and the slurry pit. A Canadian builder, Nick Peters, adapted the Chinese design for Nepal. SNV used this design, but changed it to make it easier to construct (GGC 2047).
Extra income seen in Vietnam comes mainly from the family being able to keep piglets for longer to allow them to fatten up. Previously, they tended to sell the piglets while they were still small because they could not stand the smell!
In “Katcha” houses in India (built of woven bamboo with thatched roofs), people keep their valuables in a bag by the door. If the house catches fire (which happens too often), they can grab them as they run out of the door.
Change of cultural attitudes. Survey in 1991, old people said they did not use the latrine, preferred to use the fields. Younger people, when interviewed on their own, admitted they used the latrine at night, when the old people were in bed. This old couple were very proud of their latrine as well as their biogas plant.
Slurry fresh from the plant is not as good as a fertilizer – contains hydrogen sulphide, needs to be “matured”. Using dry biomass (e.g. straw) to soak up the slurry means that nitrogen is conserved, not allowed to evaporate. Composting means that the dry biomass acts as a sponge and retains the fertilizer in the top layer of the soil.
Many arguments about subsidy. However, need to cover “externalities”. Use of carbon offset finance less of a concern for development philosophers. Users are paid for a “service” – that of saving carbon.
Numbers in other places: China - 42.8 million plants by end 2011; India – 4.4 million by April 2011 under National Biogas and Manure Management Programme (NBMMP). (Enenrgy4all report, downloaded from HEDON website).
Building viable domestic biogas programmes, published by SNV, Oct 2009 available from SNV publications web site.
Sewage plant in a prison in Cyangugu, Rwanda, near the Congo border.
