[Sdpg] biogas bonanaza
Wesley Roe and Marjorie Lakin Erickson
lakinroe at silcom.com
Wed Jun 22 07:44:54 PDT 2005
-------- Original Message --------
Subject: [SANET-MG] biogas bonanaza
Date: Tue, 21 Jun 2005 15:14:17 -0400
From: jcummins <jcummins at UWO.CA>
Reply-To: Sustainable Agriculture Network Discussion Group
<SANET-MG at LISTS.IFAS.UFL.EDU>
To: SANET-MG at LISTS.IFAS.UFL.EDU
http://www.i-sis.org.uk/BiogasBonanza.phpISIS Press Release 20/06/05
Biogas Bonanza for Third World Development
Biogas, a by-product of farmyard waste-treatment, has emerged as a major
boon for Third World countries, bringing health, social, environmental, and
financial benefits Dr. Mae-Wan Ho
Sources for this report are available in the ISIS members site. Full
details here
Biogas energy, readily available, cheap and decentralized
The United Nations Development Programme (UNDP) 1997 Report, Energy After
Rio: Prospects and Challenges [1] identified community biogas plants as one
of the most useful decentralized sources of energy supply. Unlike the
centralized energy supply technologies, such as power plants based on
hydroelectricity, coal, oil or natural gas, that have hitherto been the
only choices open to rural communities, biogas plants do not require big
capital to set up, and do not pose environmental problems that excite
public opposition. Instead, in most cases, they offer solutions to existing
environmental problems, and many unexpected benefits besides.
The organic materials needed for producing biogas in an anaerobic digester
are readily available in developing countries. These include firewood,
agricultural wastes and animal wastes. Many countries have large cattle and
buffalo herds producing tonnes of manure. Traditionally, these wastes are
carefully collected in India and used as fertilizer, but the increasing
scarcity of firewood has forced many villagers to burn dung-cakes in
cooking their food.
As biogas plants yield good quality sludge fertilizer, the biogas fuel
and/or electricity generated is an additional bonus. And this has motivated
the large biogas programmes in a number of developing countries, starting
with China.
Overcoming early obstacles
China began mass adoption of biogas in 1975 under the slogan "biogas for
every household". Within the first few years, 1.6 million digesters were
constructed annually, but these were of low quality; and by 1980, half of
all digesters were not in use and the rate of adoption had slowed. By 1992,
only 5 million family sized plants were still operating, many of them
redesigned to avoid leakage [2].
In India, as in China, a too-rapid implementation policy in the early 1990s
exceeded the capacity of India's research and development organizations to
produce reliable designs and to optimise digester efficiency. The situation
has improved since, especially with the introduction of a low-cost
polyethylene tubular digester. Now, everyone in India installing a biogas
plant has the right to an allowance paid by the central government [3].
In a report, Biogas in India: A Sustainable Energy Success Story [4], the
authors identified women and children as the major beneficiaries of biogas
in India, where every year, 200 000 families turn away from the traditional
fireplace and have a biogas plant installed to provide energy for cooking
and lighting. By 2000, more than 2 million biogas plants have been built in
India and almost 200 000 permanent jobs created.
India's early difficulties and recent success is being replicated in
countries such as Nepal [5], Sri Lanka [6] and Vietnam [2].
In Vietnam, as in other developing countries - Colombia, Ethiopia,
Tanzania, Cambodia and Bangladesh - the polyethylene tubular digester was
promoted to reduce production cost by using local materials and simplifying
installation and operation. The resulting low-cost digester has been well
received by poor farmers, especially when farmers participate fully in the
necessary maintenance and repair work. Within ten years, more than 20 000
polyethylene digesters were installed and mainly paid by the farmers
themselves. However, the digesters are still not fully integrated into the
farming system, as there is only limited use of the effluent as fertilizer
for fish and crops ("Dream farms", this series). There are also potentials
for improving the digester for greater efficiency, ease of maintenance and
durability. More cooperation between scientists and farmers and credit
systems for poor farmers to install digesters will also help to increase
the adoption rate.
In Sri Lanka, biomass accounts for 45% of the country's energy needs, with
petroleum and hydroelectricity supplying 41% and 14% respectively [7]. Sri
Lanka's economy is still largely based on agriculture. A major constraint
to production is the increasing cost of fertilizer, while solid waste,
mainly organic, is collected and disposed at a large number of unprotected
sites, affecting the health of the poorest.
Although biogas digesters have been introduced in Sri Lanka since the
1970s, poor design, lack of maintenance skills and insufficient capacity to
deal with the problems meant that only a third of the 5 000 units installed
functioned properly [6]. The Intermediate Technology Development Group
(ITDG) started a project in 1996 to improve the success rate of the units
on a national level by setting up demonstration units to help spread
information, restoring abandoned units and training users to operate and
maintain them. In addition, individual farmers get help to install biogas
units on their farms to make use of the manure from their cows.
Mr. Ratnayake is one of the lucky farmers. With nothing more than cow dung,
he now has enough power to cook with, iron the laundry and provide heat and
light for his home without using a single piece of wood. All he has to do
is to collect the manure from his cows in a specially adapted cattle shed
where they feed, mix it with water and leaves it to ferment in a large
concrete tank or pit. The gas produced is collected in a simple storage
tank, from where it is piped into his house to use.
The women and children, freed from firewood collection and from cleaning
smoke-blackened utensils and the disposal of animal waste, gain some two
hours a day for other activities. About 80% now use this time to earn extra
income that currently accounts for approximately 24% of the family's
monthly income. Another advantage of using biogas is that there is very
little waste from the process and it is environmentally friendly.
The dried manure left after biogas is generated is richer than ordinary
manure and makes a fantastic organic fertilizer for Mr. Ratnayake's crops,
which he can sell at a higher price as organic produce.
Biogas brings numerous benefits
The many benefits of biogas are now generally recognized. It has resulted
in a smoke-free and ash-free kitchen, so women and their children are no
longer prone to respiratory infections, and can look forward to longer,
healthier lives. Women are spared the burden of gathering firewood, a load
of 60-80lb per week, which can take up to one day a week. That, and the
practice of containing livestock for manure collection, which might
otherwise graze in the forest, both contribute to protecting the remaining
forests and allowing the forests to regenerate.
The sludge remaining after digestion is richer in valuable nutrients than
the animal manure, providing vegetables, fruits and cereals with a top
quality fertilizer that guarantees better crops.
In rural areas where there is otherwise no electricity supply, biogas has
enabled women to engage in evening study, literacy classes and other home
and community activities.
Cattle dung is no longer stored in the home, but is fed directly to the
biogas digester along with toilet waste. The anaerobic digestion process
also destroys pathogens. As a result, sanitation has greatly improved.
Carbon trading bonanza
There are other benefits for countries that decide to adopt biogas. The
United Nations Framework Convention on Climate Change has set up a Clean
Development Fund, and the World Bank has put together a Carbon Finance Unit
to allow rich countries, which are pumping more carbon into the atmosphere
than is allowed under the Kyoto Protocol, to buy emissions that poor
countries prevent through conserving forests or promoting renewable energy.
An article in the Nepali Times [8] pointed out that Nepal's successful
biogas programme not only brought farmers a non-polluting fuel, conserved
forests and provided high quality fertilizer for crops; it can make the
rest of the world pay hard cash for not burning firewood to release carbon
dioxide into the atmosphere.
About 85% of the fuel used in Nepal comes from biomass sources like
firewood, animal manure and agricultural residue. The remainder, kerosene,
diesel or liquefied petroleum gases. Its biogas programme would not have
been possible if the users had not received subsidies. Each biogas unit
costs $300 to set up, but the government pays one-third of the amount.
Nepal's biogas programme is internationally regarded as a model for
successful use of alternative energy for the rural Third World. Nepal has
now overtaken China and India in the number of biogas plants per capita.
Each of its 125 000 functioning digesters prevents five tonnes of carbon
dioxide equivalents from being pumped into the atmosphere every year. This
'saved' greenhouse gas is what rich countries are buying to offset their
own emissions, and is worth US$5 million. This money can be invested back
into clean energy that would make Nepal eligible to trade even more carbon
offset to rich polluters.
"We have an initial agreement with the World Bank," said Sundar Bajgain,
executive director of the Biogas Support Project, which has played a
leading role in installing biogas plants in private houses in 66 districts
across the country. The biogas model can be applied to other renewable
energy sources such as hydropower (under 15MW, as recommended by the
International Panel on Climate Change) and solar power to reap rewards from
carbon trading.
Admittedly, paying cash to poor countries not to burn firewood is a measure
of desperation for rich countries like the United States, which, at 4.6
percent of the world's population and growing, is responsible for 25
percent of global greenhouse gas emissions due to human activities [9]. It
would make much better sense for developed countries to cash in on the
benefits of biogas themselves ("Bug power", this series), as they also have
greater capacity for research and development to optimise the production
and use of biogas.
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