| Main knowledge bank page |
Recent additions |
Recent changes |
What links here |
Categories |
Category cloud How-to guides | Organisation profiles | Project profiles | |
Improved cookstoves in India
The two direct advantages of the improved chulhas are
Since these models consume less fuel, they not only save trees but also reduce the efforts spent by the rural housewife in collecting firewood. Reduced consumption of agricultural biomass and cattle dung allows more of these residues to be used as manure. Reduction in pollutants in the indoor atmosphere contributes to better health of the householders. In order to demonstrate the improved chulhas to the users, the NPIC also undertakes large scale demonstrations of the improved chulhas. In Maharashtra (a state in India) alone about a hundred thousand to hundred fifty thousand such chulhas are installed in rural households every year under this programme. In this way, the NPIC also offers an opportunity to rural potters, masons and unemployed persons to earn a livelihood by fabricating and installing the improved chulhas. At the present moment, about 50 chulha entrepreneurs, trained by Appropriate Rural Technology Institute, are collectively earning annually about Rs.2.5 crores, through this activity in the state of Maharashtra. [top] [end]Models of improved chulhasThe National Programme on Improved Chulha had popularised only durable chulhas having a potential life span of at least 5 years, and provided with a chimney. The reasons for disseminating only such chulhas is that the improved chulhas are costlier than the traditional chulhas and therefore they have to last longer than the average life of just two years of a typical mud chulha, and that the harmful flue gases and smoke are taken out of the house by a chimney.Because these models are costly, NPIC provides a subsidy to their users. There are however several other chulhas that are being offered outside the NPIC by chulha entrepreneurs and potters in Maharashtra. Some of the popular models are Laxmi, Parvati, Grihalaxmi and Bhagyalaxmi. They are generally made of unburnt clay, but the same models can also be fired or made by using cement concrete. These models are described below in brief: Laxmi: This chulha accepts two pots at a time. It is also provided with a chimney. There are no pot raisers, and because the pots sit flush on the potholes, the flue gases do not escape into the kitchen, but are taken out of the house. Out of the total heat generated by the fuel, about 60% is available at the first pothole and 40% at the second pothole. It is thus possible to cook food simultaneuously on both the potholes. The disadvantage of a two pot chulha is that a part of the heat is wasted if the second pothole is not used.  Bhagyalaxmi: This is a chimneyless version of Laxmi.  Grihalaxmi: This is a single pot chulha without a chimney. It is provided with a top grate which acts as a flame concentrater. All the above models are provided with a cast iron bottom grate.In 2007, a study was conducted to provide an insight into the facilitators and constraints that influence the utilisation of improved stoves like Bhagyalaxmi stove in a rural village in Maharashtra, India, and discuss ways in which the utilisation can be improved.  Parvati: This is a two pot chulha with a chimney. It does not have a bottom grate, but the firemouth is deliberately kept large to provide more air to the burning fuel. In this model, about 80% of the total heat is delivered at the first pothole and only 20% at the second pothole. As a result, only the first pothole can be used for cooking, while the second pothole serves only to keep the food warm.  Adhunik: This chulha has a single pothole. It does not have a chimney. This chulha is supplied by the manufacturer in the form of a kit, consisting of two terra cotta parts, a cast iron bottom grate and a cast iron top grate. One of the terra cotta parts serves as the tunnel which provides air to the fuel burning on the grate, while the other part acts as the firebox. The user assembles the parts himself to install the chulha in his own kitchen.  Portable metallic chulhas: The most popular model in this category is the Priyagni chulha developed by Central Power Research Institute, Bangalore. It is used primarily to burn small pieces of wood.  Harsha: A model developed by the Central Fuel Research Institute in Dhanbad, can be used for a multitude of fuels, including coal and charcoal.  There also exist models specially designed for burning light biomass. Light biomass is filled tightly into these chulhas, leaving a central unfilled vertical lumen in the biomass. In both these models, the biomass is gasified, and the gas flame emerges from the pothole. Navjyoti: In a model called Navjyoti, the charred biomass remains as a residue in the stove.  Vivek: In this model called Vivek, even the char is burnt, leaving only ash behind. As a result, Vivek has a higher efficiency than Navjyoti. [top] [end]Fabrication and installation of improved chulhas as a rural enterpriseIn Maharashtra, about 10 million rural families cook their food on chulhas. Assuming that the life of an unfired mud chulha is about 2 years, and that a good chulha costs about Rs.150 per piece, the annual business potential of producing and selling chulhas can be estimated to be about Rs.750 million in Maharashtra alone. However, purchasing a readymade chulha from a potter is prevalent only in Western Maharashtra. In the Vidarbha region of Maharashtra, chulhas are made by the housewives themselves. Rural domestic chulhas are traditionally made of unfired clay, but under the National Programme on Improved Chulha, the Ministry of Non-Conventional Energy Sources introduced chulhas made of cement concrete, in order to increase their durability.However, sale of clay chulhas by individual potters or private enterprises is not banned. Preparation of clay is an important part of the fabrication process of a clay chulha. Black cotton soil, technically called vertisol, occurs naturally and abundantly in the fields of Maharashtra, but it is not suitable for making the clay chulha, becasue this clay cracks while drying. Red laterite clay, clay from an anthill, silt from a lake bed or river bank, are better suited for making a chulha. The above mentioned clays, or their mixture, to which volumetrically about half the quantity of horse dung or donkey dung (cattle dung, or sheep/goat dung are also acceptable) has been added, is wetted with adequate water and kneaded by trampling it underfoot to make a doughlike mass. This mass is cured for about 5 to 6 days, whereby it is kneaded twice a day by trampling over it. Traditional potters know how to prepare the clay, and also where to obtain the clay from. However, cement concrete can also be used for fabricating a chulha. A cement chulha with two pot-holes requires 7kg Portland cement, 22kg stone grit and 16kg stone powder. Adequate water is added to this mixture to make the cement mortar. Ideally, the chulha should be fabricated in a workshop and then installed into the client's kitchen. In this case, the client can start using the chulha right from the day of its installation. Alternatively, the chulha can also be fabricated in situ. For this type of fabrication, the mold and the raw material are taken to the client's house, and the chulha is fabricated in situ. The latter process has the advantage that client's wishes regarding the position of the fire mouth, position of the ash portal/air portal etc. can be taken into consideration while producing the chulha, but there is also a disadvantage in this process. The new chulha must dry out completely. In the case of a cement chulha, curing of the cement concrete is of utmost importance. If the chulha is not properly cured, it would fall apart while in use. The clients often get impatient and start using the chulha before it has dried out or cured properly. Apart from clay and cement concrete, a chulha also requires a grate. If the client desires to install a chulha with a chimney, an asbestos-cement pipe and a terra cotta cowl to fit on top of the chimney would also be required as additional accessories. All the components must conform to the norms and standards laid down by MNES. Only chulhas having the correct shape and dimensions show the desired efficiency. It is difficult for even a skilled artisan to maintain these parameters, if he were to produce the chulhas without using a mold. Use of a mold ensures the correct shape and the correct dimensions, and it also speeds up the manufacturing process. The mold consists of several removable parts made out of sheet iron and steel rods. Filling of the mold, insertion of individual parts into it, and dismantling the mold, are all conducted in a sequential manner. It is not possible for an artisan to learn the technique of using the mold just by reading its description. He would have to attend a ten day course to learn the correct technique. Appropriate Rural Technology Institute offers the necessary training through courses conducted all over Maharashtra. After he has learned the technique of making improved chulhas, he receives a certificate which makes him eligible to participate in the work of chulha fabrication and installation under the National Programme on Improved Chulha. The chulha workers also attend refresher courses, whenever there are any changes in the existing models, or when new models have been introduced into the programme. After he has worked for a couple of years under this programme, he can attend another course, called the Entrepreneurship Development Course, also conducted by Appropriate Rural Technology Institute. In this course, he learns how to set up an independant business of fabricating and marketing improved chulhas. This is a more comprehensive course, which includes such aspects as operating an enterprise, salemanship, laws governing a business enterprise, account keeping, advertising, etc. ARTI conducts a special programme of chulha installation for the benefit of the trained entrepreneurs. After the budding entrepreneurs have worked for a couple of years under ARTI's tuteledge, they can start an enterprise of their own. The independant operators cannot claim subsidies on the chulhas installed by them under their own programmes. [top] [end]Economics of chulha enterpriseA facility producing 6000 chulhas in a year, would occupy a plot of land measuring about 100 sq.m., of which 50 sq. m. should be covered by a shed. The shed would cost approximately Rs 100,000. The tools and equipment (sieve for sand/stone grit, barrels to store water, buckets, metal baskets, shovels, trowels, etc. and chulha moulds) would cost about Rs. 10,000. Thus the capital expense of setting up the business comes to about Rs. 110,000. The chulhas are nowadays made of cement concrete, so the entrepreneur would have to buy cement, sand, stone grit, stone powder, grates, chimney pipes and cowls for the chimney. The costliest chulha model is a two pot hole chulha with chimney . Its production cost would be about Rs. 200 and the sale price Rs.220 per piece. If the entrepreneur were to keep about 500 chulhas ready for sale at any given time, about Rs. 100,000 would be permanently locked up in inventory. Annual interest on Rs. 2,10,000 at the rate of 15% would come to Rs. 31,500. Assuming that his sales comprise entirely of this one chulha model, and he sells annually 6000 chulhas at a price of Rs. 220 each, the annual turnover of the entrepreneur would be Rs. 13,20,000, and a net annual profit of about Rs. 90,000.[top] [end]Related topics[top] [end]External links and referenceshttp://www.teriin.org/case/stove.htm http://www.teriin.org/pub/books/bmass.htm [top] [end]ContributorsUser:Karabi Dutta 20 October 2003 | |
Page created:
17 November 2003; Last edited:
15 February 2008; Version: 3 | |
Pagename: ImprovedCookstovesInIndia @HEDON: KHAA | |
