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Project
Proposal: Biogas Generator
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Full description of problem/need |
In Pabal, there are
multiple power cuts during a day. Businesses
that rely on electricity become less
efficient and lose profits as a result
of power losses. The government has
no short-term plans to address the electricity
problem in rural India so an alternative
power solution is needed to alleviate
the problems caused by power cuts.
Biogas is a reliable, cheap and sustainable
alternative to, or creator of electricity.
About fifteen years ago, there was a
government-level biogas drive, but the
government only made generators available
at a cheap rate and did not provide
proper advice and maintenance, without
which the generators were misused. The
generators relied on cow dung, which
presented an extra problem in Pabal,
Maharastra. Due to the severity of the
dry season (January - May), the local
farmers must transport the cows to a
nearby village, which has a wetter climate.
This meant that there was no cow dung
available for the generators for four
months of the year. As the generators
require 21 days start up time (where
the bacteria in the dung can build up
to a sufficient level), the generators
became hard work to use. The generators
would be non-functional for about 5
months in a year. Any farmers that did
try the generators ended up stopping
their usage. Another factor was that
farmers also wanted to use cow dung
as free fertiliser for their crops.
Because of this cow dung is not a viable
main fuel source for a biogas generator.
A small-scale biogas generator needs
to be developed, so that it can run
on different forms of biomass and
serve a household in a localised situation.
A small generator would be the most
sustainable solution, as less power
and energy would be wasted than if
a community-based, larger generator
was designed. The localised small
biogas generator would limit any losses
from electricity and/or biogas distribution.
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| How will the local community use the
proposed solution? |
| The community can
use biogas generators to convert organic
biomass into biogas. The NGO located
near to Pabal, Vigyan Ashram, has experimented
in the past with biogas generators.
They concluded that large-scale community
generators (which are bigger than 20
m3) are not practical, as providing
service to the whole community creates
extra costs and requires the use of
more materials. This is because the
biogas or electricity produced by the
community biogas generator must then
be supplied to the community via gas
lines, electricity cables or a compressor
and canisters.
A sustainable design would therefore
be small enough for a farmer to use
permanently as a generator and back-up
for power cuts. A design has been
developed that uses half a kilogram
of spoilt flour. The flour grains
can be black and this is a good example
of an appropriate solution. The design
of a sustainable generator should
take size into account: the biogas
generator should be designed to cater
for a typical Indian household of
6-10 people. Such a generator would
allow families to use the biogas plant
for their own individual needs and
they would be able to create biogas
in a small rear garden or even a kitchen
if the design is small enough.
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| Estimate of the economic
benefit anticipated and plans for training
of the local community? What are the
major impacts on such a project? |
| An implemented project
would bring constant electrical power
to the community. With the power cuts
that are present throughout the vast
majority of rural India, a design for
a cheap biogas generator (providing
power for a family/business) would provide
a reliable power source for much of
the population. The power cuts lead
to a loss of trade for many businesses
and slow down the technological growth
of the community, causing much of the
rural population to want to migrate
into cities. A back-up power supply
would be really useful in bringing direct
economic benefit to many businesses
in Pabal.
If a cheap design is proposed it
could be implemented in many places.
This would require a large amount
of biomass, involving the use of 'oil
cake' (see below) or crops directly
from the fields. There would be encouraged
demand in the manufacture of oil cake
and/or farming, either way potentially
increasing jobs within the area and/or
profit for those community sectors.
If a truly effective design were to
be reached, it could benefit the community
to completely replace its connection
to the electrical grid with power
generation from the community's own
biogas generator. If such a solution
can be reached then the pay back time
on the initial investment should be
deduced, as an offer for the local
community.
Other economic benefits are also
present. Large-scale biogas generators
have the capacity to produce ethanol.
If a small-scale biogas generator
is designed and can collect a supply
of ethanol, it may have the following
benefits:
- It could be used as a fuel for gas
powered cookers or in addition to
the biogas in the generator.
- It could possibly be mixed with
used cooking oil and a form of biodiesel
can be created and then used.
- It could be then made into a fertiliser
(with the appropriate technology)
and would be very useful to the rural
population of Pabal, where the soil
has very little organic content with
in it.
The building of trial and then commercial
biogas generator can be done at Vigyan
Ashram using local materials and skills.
The construction of such generators
can be incorporated into the curriculum,
taught to the students. The NGO could
then teach the local community how
to maintain the generators and how
to optimise them. As they are a non-profit
organisation, this would all be done
at low or no cost.
The major impacts of implementing
a biogas generator solution to Pabal
would concern safety primarily. The
generators would need to be safe,
easy to use and easy to teach about,
as any major accidents attributed
to the generator failure would be
unacceptable. The generators would
have to have a long working life,
as such a generator would be a large
investment for most family in Pabal.
Another impact of using biomass could
be that the price of crops and 'oil
cake' would increase. This could possibly
make it harder for the community to
buy food. The 'oil cake' is currently
used as cattle feed and an impact
of using it in biogas would be that
farmers would have to find another
cheap source of cattle feed.
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| Full description of the local situation
(e.g. social, economic, geographical,
political) |
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Vigyan Ashram has experimented with
the use of other organic, cheap material
in the biogas generator. Paper (Rs.
1 /kg) was tried, but was found to be
too slow to work when shredded and when
treated with enzymes to break down the
paper. 'Oil cake', a waste product from
the peanut oil milling industry (see
Optimisation of Pabal Peanut Oil Mill
Project Proposal), (Rs. 11 - 13) was
found to work well in their generator.
There are many seeds and starch-based
plants grown in the area. For a biogas
generator to be sustainable and practical,
the organic substance used needs to
be grown within a season, otherwise
the farmer/owner of the generator would
have to wait a long time (maybe even
years) before he can use the generator.
The floating head generator has also
caused problems, as there the gas
is produced at atmospheric pressure.
This means that the supply of the
gas often fluctuates (often a person
has to stand on the floating head
to get gas out). Therefore, for a
generator to be really useful this
design flaw would have to be optimised
by operating the generator at a higher
pressure or by another method, which
would give a constant production and
collection of gas that may be used
when required, i.e. when the power
cuts occur.
The NGO's generator is 1 m3 in size
and has a 'floating dome' top to it
(as opposed to a 'fixed dome'). This
means the gas can expand and occupy
extra space in the roof. Vigyan Ashram
has also commissioned the building
of a biogas generator in a nearby
village. This is a larger scale generator
(15 m3). A similar generator has been
built on a local farm and serves a
number of farms which are clustered
together. This solution works, but
an optimised solution could be created
on a smaller scale to provide for
single-family households, which are
more common.
 Biogas
Generator Used at Vigyan Ashram
In a nearby village to Pabal, a biogas
generator has used human excrement
as a power source. This option could
be researched as the design feature
of such a generator would have to
be modified. This could be linked
to the human waste disposal project
proposal.
 Biogas
Generator used in a local farm
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| Full description of relevant infrastructure
available locally and/or internationally |
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Materials:
Concrete
Sheet Steel
Used Petrol Oil Barrels
Peanut Oil Cake: Rs. 11 - 13 /kg
Pipes
Generator engines
Seeds in Oil mill, their Marathi
names and English (given when known).
Odid
Toor
Bajri
Gawu
Kaddhanya
Methi
Carla
Maka
Rajma (kidney beans)
Black Rajma (black kidney beans)
Jawari
Chauli (black eyed peas)
Soya beans
Mohri
Puri
Howri
Herberra
Watana (peas)
Natni
Rice
Urda dal
Peanuts
Sugar
Chintsa-tam-arind
Used oil barrels are in abundance
throughout the village |
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