Role of Biogas in Energy Security and Energy efficiency

Role of Biogas in Energy Security and Energy efficiency
-- Leena Mehendale

The question of energy security has become a major

important agenda of the Government. With far higher

cry for rural power, and high fluctuations in the

international crude prices, the search for alternative

fuels has become more urgent.

A real boost to the solution for energy security however,

lies in efficiency, rather than in higher supply.

This aspect struck me greatly when recently I had a

chance to look at the Integrated Energy Policy - a

document prepared some two years back by Planning

Commission of India. Let us look at some of the

numbers mentioned therein.

Our annual consumption of energy is nearly 450 Million

Tonnes of Oil Equivalent (Mtoe). Out of this 110 Mtoe,

that is, nearly one fourth, comes from non-commercial

resources and only 340 Mtoe is commercial, in the form

of electric power, Petroleum and Coal. The non-

commercial sources are wood, biomass and cowdung

cakes.

For the urban elite, it is rather difficult to comprehened

that the highest use for domestic fuel is still wood &

cowdung cakes. Out of our 135 Mtoe domestic fuel, only

5% is clean fuel, namely, LPG and a miniscule of

electricity. Another 15% comes as Kerosene and coal.

About 20% is cowdung cake and nearly 60% is wood.

We use annually, 80 Mtoe of wood and 30 Mtoe of

cowdung cake, while Kerosene is nearly 10 Mtoe.

Programs like India Shining or Bharat Nirman are

creating rosy pictures of India becoming world super

power by 2030. This is not possible without energy

security. Our growth rate of economy which is 8% for

last 3 years and which we want to take to double digit

will require tremendous amount of energy inputs by

2030. Our electricity demand will rise from 1.2 L

Megawatts to 4 L Megawatts, However out of our

indigenous coal stock of 100000 crore tonnes, only

50,000 crore tonnes is extractable and at an increasing

cost. This whole coal will also be sufficient for only 30%

of our need for electricity generation.

It is therefore high time that we relook at these fuels

and also at our methods of burning them. Much higher

burning efficiency can be brought in our methods by

spreading proper education and providing services to

the rural areas.

Let us start with gobar. We use 133 Million tonnes of

gobar in rural areas and 8 Mt. in urban areas totaling

to 141 Mt (which is Equivalent to 30 Mt of oil). The

standard method is to make dry cowdung cakes which

are then easy to store or transport if need be and use

them in traditioned Chulhas for daily cooking.

Efficiency of these Chulhas is very low - only 8%. This

means that most of our precious fuel is wasted - not to

speak of resulting smoke, pollution and innumerable

diseases suffered by women folk. Asthama, bronchitis

and eye problems are the most common.

Improving chullha efficiency can give good dividend.

The burning efficiency can go upto 22%. However

converting gobar in usable gobar gas can increase fuel

efficiency upto 50%. Thus the same fuel can perform 6-

7 times better job.

Cost of putting up a domestic size gobar gas plant of 2

meter cube size comes to nearly Rs.20,000. In last 40

years programs for subsidized gobar gas plants were

taken in surges when agencies pushed for targets but

without any program for maintenance of the assets

which have been created. Sufficient emphasis was on

constructing gobar gas plants - but the equally

important emphasis on creating trained manpower who

could repairs or make improvements was completely

missing. When the plants went into disuse for lack of

even minor maintenance, no attention could be paid to

them. The farmer whose family women were the real

beneficiaries was himself not too concerned. Rather he

was reluctant for paying money for repairs and the

women had practically no voice. The food could always

be cooked one way or other.

Today can we learn from these lessons when we are so

concerned for energy sources and alternatives? Let us

re-draft our gobar gas strategies in such a way where

these gaps are taken care of.

Over last 40 years, many plants were built. Many new

techniques have been invented and the program can be

given a push once again. This requires first and

foremost a change in the attitude and priorities of our

policy makers. Our priority cannot be to construct

more and more plants - with or without subsidy - small

or big, commercial or non-commercial. Our priority has

to be to create trained manpower - equipped to work as

a service provider at a cheap cost, when the local gas

plant goes into disuse for want of minor repairs. We

need to ensure the ready availability of such a person

who can get for himself an annual maintenance

contract. Alongwith this it is worthwhile to invest once

again in major repairs of some of the revivable plants

and a few thosand totally new plants.

Very early in my service I was associated with scheme

for gobar gas. In the years 81-83 when I was CEO in ZP

of Aurangabad & Sangli, the GoI had launched a

massive program for construction of gobar gas. Since

then I have watched the development of various

techniques, the good and not so good aspects of

program implementation

On the technical side, the very early KVIC models used

to have floating domes - later the fixed dome technology

came and today we can use both for domestic sizes. To

parry the problem of bad smell, water jacket technology

was used. There were many experiments about dome

material. As some complaints arose that the cement

domes developed cracks, people experimented with

fiber – glass and other material and this issue now

stands successfully trackled. Some companies

experimented with pre-fabricated ferrocement plants

too. All these designs have their own success stories for

show-casing.

The common digester sizes started from 2 meter cube

for domestic purpose. A farmer having 4 cattle would

get sufficient cowdung for meeting the daily

requirement of gas in his kitchen, for a family of 6-8

members. In 1986 I visited a farmer who used 20%

diesel and 80 % biogas in his diesel pump for pumping

water in the farm. In 1992, I visited the Anandwan

Justitute of Shri Baba Amte where he ran a Leprosy

rehab centre. It had around 500 inmates and 3 gobar

gas plants of 35 meter cube each which ran on nightsoil

and cowdung and daily supplied enough gas for the

entire kitchen activities.

These are some examples of successful plants. However

a large percentage of gobar gas plants then constructed

through Government subsides have gone into disorder.

Some years back TERI conducted a survey which

showed that about 80% of plants went into disorder and

disuse.

Today, when the need to reassess the situation and once

again build up the stock of our assets for renewable

resources and revitalize the program, I think we should

focus on those 20% plants which are still being used

successfully.

The action plan can begin with an experience sharing

seminar of those households where gobar gas plants are

still working, and those where the plant failed, those

technical experts who are constructing biogas plants

and those who are in the job of framing policies. Such

experience sharing will tell us about the do’s and dont’s

of the new program. Another point of action is to start

training rural youth in gas plant maintenance. Yet

another action is to undertake a survey of gobar gas

plants built over last few years and the reasons of their

failure or success. Then, a repairs program needs to be

taken up in right unrest.

The question of fire wood is also of crucial importance.

The estimates of IEP state that we burn 180 million

tonnes of wood for domestic fuel. Another estimate

states that for all uses put together, we burn nearly 220

million tonnes of wood and 130 million tonnes of bio

waste thus taking the total to 350 million tonnes.

(Nearly half for domestic and half for other purpose -

mostly industrial).

The efficiency of our traditional chullhas is very low -

nearly 8%. It means when we burn 100 kg of wood, we

get the real value of only 8 kg. The rest - nearly 12 times

of what is burned - goes as waste. Hence improving our

chullhas and small units of traditional bhattis eg. gur

bhatti, is very essential.

Two such experiments are worth quoting. In Udaypur

the KVIC developed a new model of chulhas in which a

pre-tested iron mould is used as a base material. The

dimensions of the mould have been finalized after lot of

trial - errors and improvements. The mud plus cement

chullhas are constructed around this mould and the

mould is taken out. It can be used over and over again

upto nearly 15000 chullhas. The chullha so made has

two compartments connected with a pipe and a chimney

is also fitted, which takes the smoke up and away. With

this chullha, the burning efficiency is found to increase

upto 22% which means straight saving of at least 25%

of our today’s wood consumption and consequential

environment pollution. The cost of mould is around Rs.

500 while that of chulha is around Rs. 1500. I was then

Executive director of PCRA (Petroleum Conservation

Research Association) and we decided to sponser this

chulha through an Action Research project. Under this

we funded the training of 5 masons, giving them moulds

and paying them 50% of wages for the chulhas so

constructed. In first phase we sponsored 2000 such

chulhas in Rajasthan. In the 2nd phase some more have

been sponsored. In yet another Action Research project

we sponsored a lab-to- field trials of fuel efficient Gud-

bhattis developed by Indian Institute of Petroleum.

PCRA has very good technical video films made on

these two subjects (and many more films relating to

energy efficincy). These can be used seminars and to

educate the end user.

In yet another experiment, I visited a small village

Odenthorai near Coimbtore. Here, with the leadership

of DRDA officials and the village sarpanch, power

generation is done from wood. First the firewood is

dried and chopped to small pieces. They are burned

with low oxygen supply in a small scale gassifier.

Carbon monoxide so produced is filtered with water

and taken to burn alongwith diesel in a diesel motor

where it produces electricity. All the village water

pumping is done by using this electricity. This is a far

efficient way of burning wood. This experiment has

been repeated in some neighboring villages who are

using excess electricity for street lights upto 10 pm in

the night. Thus the villages which used to be in the grip

of darkness after sunset are now active and bubbling till

10 pm. With power cuts having become so common in

rural areas, this locally generated electricity opens up

new dimensions of enterprise. A video films on this is

also made by PCRA and is available in our clip-bank.

Sources like solar energy, wind, bio-diesel are being

talked about a lot. It is high time we also pay attention

to the aspect of fuel saving and efficient burning of

biomass - be it cowdung or wood or farm waste.

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