|Boiling Point No. 26 - December 1991 (ITDG Boiling Point, 1991)|
Summary of a study by P. M Sadaphal, R C Pal and Veena Joshi of the Tata Energy Research, Delhi
Ed Note: India is the first and most prolific developer of improved stoves for the third world. Many new designs have been produced and used in different parts of the country and bodies such as NPIC, DNES, CORT, TERI etc. have tried to monitor their efficiency and spread information about them. India is facilitating technology transfer by certification and encouraging standardization so far as local circumstances permit. African countries and other parts of Asia may be able to learn from this.
The National Programme on Improved Chulhas (NPIC) was initiated in December 1983 by the Department of Non-conventional Energy Sources (DNES).
· to conserve and optimize the use of fuelwood in rural areas,
· to create and train a work force particularly of women, to construct improved cookstoves,
· to accelerate research and development activities to design more improved stoves.
The dissemination involved certification of models of improved cookstoves having a thermal efficiency of at least 20% and their subsequent installation in relatively large numbers in selected villages all over India through a multi-agency approach. The majority of models are made of mud with 2 pot holes and have chimneys of asbestos. By March 1990 a total of 8.4 million stoves were installed.
TERI was entrusted with the task of evaluating the impact of the NPIC programme till l 987 in the states of Rajasthan, Tamil Nadu and West Bengal.
Cooking System: There are significant differences in the cooking systems used in Rajasthan, Tamil Nadu and West Bengal. Roti is a major food item in Rajasthan whereas rice dominates the food habits in the other two states. In West Bengal, an additional predominant activity is preparing puffed rice for which cookstoves are invariably installed in the open. One pot mud cookstoves are predominantly used in West Bengal and two pot pottery lined mud stoves most often in Tamil Nadu. None of these traditional cookstoves have chimneys.
In terms of fuels, twigs of local trees are commonly used in Tamil Nadu and Rajasthan whereas in West Bengal one often finds leaves, crop residues and dung cakes.
Improved Stove Models and Strategy of Dissemination: models chosen
for dissemination in the three states were - Kallupatti chulha for Tamil Nadu,
Sahyog chulha for Rajasthan and Nada/Seva chulha for West Bengal.
The dissemination of the stoves and training of villagers were entrusted to the concerned block development officers in all states except West Bengal where this function was entrusted to voluntary agencies. The training of the trainers was undertaken at the technical back-up units set up by the DNES at educational institutions located in different regions.
The stove model used in Rajasthan and West Bengal was of mud with cement chimneys. In Tamil Nadu, however, a large variation was found with respect to the materials for stove construction and flue pipe construction. In some villages, pottery stoves had been installed whereas the mud version was seen in other places. Similarly, some villages had cement pipe flues whereas others had pottery flues. The flues, particularly the pottery ones, were found to be broken in most cases and leakages were prevalent in most of those which were intact. By and large, the pottery stoves were found to be in better condition than the mud stoves, indicating that it is easier to maintain them.
Acceptability of Improved Cookstoves: A numerical count of the stoves has revealed that except for Tamil Nadu in 1984-85 and West Bengal, the extent of usage of improved cookstoves was in most cases of the order of 50%. A large proportion of these had been modified in various ways by the users to suit their specific requirements. Common changes observed were:
· modification of the first pot-hole to U-shape,
· construction of projections on the pot-holes for vessel support,
· blockage of tunnel to second pot-hole,
· removal of dampers,
· removal of baffle,
· blockage/removal/shortening of chimney.
Perceptions of stove users: The major reasons for stove adoption were smoke removal, improved health and cleaner kitchens. A large variation was found in the number of people reporting fuel saving from district to district. (Tamil Nadu: 24-67%, Rajasthan: 21-100%, West Bengal: 20-100%). In Rajasthan, the stove was found unsuitable for"roti" preparation and in West Bengal it was found to be unsuitable for"moodi" (puffed rice) making when using local fuels (i.e. leaves and dungcakes).
The fuel consumption, based on field experiments, was observed to be higher for the improved stove than for the conventional cookstove in Tamil Nadu and Rajasthan. In West Bengal, however, the experiments indicated a lower consumption by the improved stoves than by the traditional cookstoves. This could be due to higher fuel consumption in traditional cookstoves in West Bengal compared to Tamil Nadu and Rajasthan. There is also a greater variation in fuel consumption in traditional stoves than that in improved cookstoves.
Opinions of Non-owners: The non-owners of improved stoves in the three states seemed to appreciate the smoke removing capability of the stoves but were apprehensive about their fuel saving capability. They were aware of the unsuitability for some applications like roti baking and were hesitant to adopt one due to possible fire hazards. In all three states, more than 50% of the respondents thought that the Improved Cookstove was better than the traditional cookstove.