Energy Security and Efficiency : Role of Bio-Gas.
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 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.
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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.
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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 ShriBaba 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-bhattisdeveloped 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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Some more info on these subjects can be seen on following site.
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