- Email: [email protected]
Improved stoves in developing countries
Improved stoves in developing countries A critique
Jas Gill
Improved stoves have largely failed to achieve widespread dissemination in developing countries for a number of reasons. Improved stoves were not necessarily more efficient than traditional designs nor were they always smokeless. Improved stove programmes emphasize fuel economy whilst stove users regard versatility and the ability to cook quickly as being more important. Other concerns of villagers such as water supplies and incomegenerating technologies may have a higher priority than the supply of traditional cooking fuels. Moreover, stove programmes are unlikely to significantly reduce deforestation. The likely effects of stove programmes could have been determined and a number of problems avoided had these projects been appropriately monitored.
Keywords: Fuelwood shortage; Traditional fuels; Deforestation Jas Gill is a member of the Energy Research Group, The Open University, Milton Keynes MK7 6AA, England and now a Fellow at the Science Policy Research Unit, University of Sussex, Mantell Building, Falmer, Brighton, East Sussex BN1 9RF. lie firewood and crop residues. 2See D. Earl, Forest Energy and Economic Development, Clarendon Press, Oxford, 1975; E. Eckholm, Firewood: the Other Energy Crisis, Worldwatch Paper No 1, Worldwatch Institute, Washington, DC, USA, 1975; K. Openshaw, 'Wood fuels the developing world', New Scientist, Vol 61, No 883, 31 January 1974, pp 271-72. continued on page 136
Energy supplies and costs hit the world's headlines when the price of oil rose by a factor of four in 1973-74. These events were seen as marking the end of an era of cheap oil and coal and the beginnings of an age of high-cost energy. Whilst it was recognized at the time that the oil-importing developing countries would have problems in adjusting to the higher oil prices, it was only a few years later that the critical importance in their economies of traditionally 'non-commercial' fuels 1 was given widespread attention. 2 The greatest dependence on traditional fuels in developing countries is in the rural areas. In 1975, it was estimated that only 15% of commercial energy consumption in these countries took place in the rural areas) Traditional fuels in rural areas are used primarily for cooking and have usually been gathered by village women and children at no monetary cost. 4 In the mid-19?0s, Eckholm, a researcher with the Washington-based Worldwatch Institute, argued that deforestation in developing countries had led to an acute shortage of firewood in these countries and that continued fuel gathering had led to further deforestation. 5 By the late 1970s this view had come to be accepted by international institutions. 6 Thus, in 1985, the Forestry Department of the United Nations Food and Agriculture Organisation 7 reported that fuelwood supplies have been rapidly depleted and the cutting of firewood has in turn been a major cause of excessive deforestation.
Moreover, the clearance of forest land for agriculture for the food requirements of a growing population was considered to exacerbate deforestation. 8
Intervention strategies Strategies to cope with deforestation and the perceived shortage of firewood are concerned with increasing the supply of firewood and/or decreasing the demand for firewood. One demand-orientated strategy
0301-4215/87/020135-10503.00 © 1987 Butterworth & Co (Publishers) Ltd
1 35
Improved stoves in developing countries continued from page 135 3j. Parikh, Energy Systems and Development: Constraints, Demand and Supply of Energy for Developing Regions, Oxford University Press, Delhi, India, 1980. '=M. Montalembert and J. Clement, 'Fuelwood supplies in the developing countries', FAO Forestry Paper No 42, 1983, p 1 ; D. Hughart, Prospects for traditional and non-conventional energy sources in developing countries, World Bank Staff Working Paper No 346, World Bank, Washington, DC, USA, 1979, p 3. 5Eckholm, up cit, Ref 2. 6FAO, Forestry for Rural Communities, Forestry Department, UN Food and Agriculture Organisation, 1978; World Bank, Energy in Developing Countries, Washington, DC, USA, August 1980, p 38. 7FAO, 'Forestry and food security', Unasylva, Vol 37, No 149, 1985, p 8. 8FAO, up cit, Ref 6; R. Revelle, 'Energy use in rural India', Science, Vo1192, 1976, pp 969-975. 9See T. Kennedy, Bangladesh: the Energy Outlook, EDP No 12, 15 September 1981, Energy Research Group, Physics Department, Cambridge University, p 33; A. Makhijani, 'Solar energy and rural development for the Third World', Bulletin of the Atomic Scientists, Vo132, Pt 6, 1976, p 24; S.P. Raju, Smokeless Kitchen for the Millions, Christian Literature Society, Madras, India, 1957; K.S. Salariya, Energy Conservation in Domestic Consumption, Tata Energy Research Institute, Bombay, 1983, p 4; N. Smith, Wood: An Ancient Fuel with a New Future, Worldwatch Institute Paper No 42, Worldwatch Institute, Washington, DC, USA, 1981, p 15; TERI, Cookstove Handbook: Pilot Edition, Documentation Centre, Tata Energy Research Institute, Bombay, India, June 1982, p 3; World Bank, up cit, Ref 6, p 39. ~°C. Baron, Energy Policy and the Social Objectives of Development, Working Paper No 72, Technology and Employment Branch, ILO, Geneva, 1980; Eckholm, up cit, Ref 2; W. Knowland and C. Ulinski, Traditional Fuels: Present Data, Past Experience and Possible Strategies, USAID, Washington, DC, USA, September 1979; Raju, up cit, Ref 9; S. Siwatibau, Rural Energy in Fiji: A Survey of Domestic and Rural Energy Use and Potential, IDRC, Ottawa, Canada, 1981. l~See T. Acott et al, How to Help Poor Countries Develop Fuel-saving Cookstoves, German Appropriate Technology Exchange, Postfach 5180, D-6236 Eschborn 1, Federal Republic of Germany, 1980; A. Soedjarwo, Yayasan Dian-Desa's Wood Conserving Stove Project, a case study prepared for the Guangzhau Rural Energy Systems Seminar, 6-10 December 1982 (mimeo); UNICEF, New Nepafi Cooking Stoves that Make Smokeless Kitchens and Use Less Firewood, UNICEF, Nepal, September 1982. ~2j.E.M. Arnold, Fuelwood as a Source of Rural Household Energy, paper presented continued on page 137
136
has been to p r o m o t e better cooking stoves for use in the rural sector of developing countries. This strategy assumes that traditional stoves and fireplaces commonly used in developing countries have low cooking efficiencies ~ and are a risk to w o m e n ' s health because of the smoke they produce in the kitchen. "~ In order to eliminate smoke from traditional kitchens and reduce consumption of firewood, much effort has gone into designing and disseminating stoves which are both smokeless and more efficient than traditional designs. These are generally referred to as ' i m p r o v e d ' stoves. Such stove p r o g r a m m e s , it is argued, 11 would improve women's health through their working in a smoke-free kitchen and reduce the time spent in cooking and collecting fuel. Rural women could usefully spend the time saved in income-generating activities. J2 It was believed that if these ' i m p r o v e d ' stoves could be adopted on a widespread scale, then firewood consumption would fall, thereby reducing the pressure on forests 13 as well as decreasing the consumption of crop residues: improved stoves for cooking are of the highest priority given the declining availabilities of crop residues and the dependence of the poor on these forms of fuel for cooking.14 At the same time, such an intervention would increase the chances of success of solutions concerned with increasing the s u p p l y of firewood, eg reforestation, agroforestry, silviculture.
A technical assessment o f 'improved' stoves ~-~ I m p r o v e d stoves can conveniently be grouped into two categories: 1-pot and multi-pot designs. 1~,It is crucial to point out that the performance of various improved stoves within these two categories will be similar. 17 In practice, a potential adopter of any new or improved stove is likely to be interested in a stove which has a low cost (eg monetary terms or construction time), fits in with traditional cooking practices, is simple to use, easy to maintain, has a low fuel cost and produces low levels of smoke if used in an enclosed space, is A s u m m a r y of such features is given for stoves p r o m o t e d as being both 'smokeless and fuel-efficient' (Table 1) and stoves that were 'fuel-efficient' (Table 2). Nearly all the stoves p r o m o t e d as being both fuel-efficient and smokeless were constructed from mud (unfired clay) and generally not portable (Table 1). Most of these stoves had dampers (to control the heat output of the burning fuel). Consequently, they were not simple to use and the cook had to be taught how to use the dampers. The designers of most of these stoves claimed fuel savings of around 50% but gave no field data to substantiate this belief. In addition, a n u m b e r of these stoves were not smokeless in practice. From the mid-1970s attention shifted to designing and promoting stoves which their designers claimed were fuel-efficient (Table 2). A n u m b e r of these stoves were made from fired clay which could be constructed by skilled potters in a few hours. The time to build the fired clay stoves by a skilled potter varies from 1-6 hours (Table 2); however, it is not clear why there should be such a wide time variation, given that these stoves look remarkably similar. It is important to note, however, that whilst these were referred to as ' i m p r o v e d ' stoves, in most cases their designers did not give any figures on the expected reduction in fuel consumption. E N E R G Y P O L I C Y April 1987
Improved stoves in developin[4 countries Table 1. Stoves claimed by their designers to be smokeless and fuel-efficient. Features of stove
HERL Improved chulha Egyptian stove
Singer stoves
GS stove
Ghanaian stove
Nepali chulha
Lorena Magan stove chulha
Approximate year of design Cost (£) Construction time b Fuel savings claimed by designer (%) PHU in lab tests ° (%) Fuel savings in cooking food (in lab) (%) Level of fuel savings observed in field trials Complicated to use/training required to use stove Smokeless in practice Number of dampers Construction material Grate Estimated lifetime (years) Portable version Mass (kg) Number of pot holders
1953 na a na 50 na na na yes no 1 mud no 3 no 150 2-4
1961 na 3-4 days 60-75 20-30 na na yes no 1 mud no na no 1000 2-3
1980 1 na 50 na na na yes na 1 mud no <6 no 70 2
c 1960 na na 50 na na none yes no 2 mud no na no 1000 3
1979 na na 50 na na na yes na 2 mud yes na no na 3
1976 3 na 50 na na none yes no 2 mud no 2 no 200 2 or more
1953 na na 30 4-5 na na yes na 1 mud no na no 300 2
1987 na 2-4 h >50 4-12 na na na na none fired yes 2 yes 100 2 or more
Source: Adapted from Gill, op cit, Ref 32, p 100. ana - information not available. btime in hours refers to construction by a potter to fabricate a ceramic stove, mud stoves are generally to be constructed by the stove user and take several days to build. cpHU - proportion of heat from firewood (expressed as a percentage) absorbed by water heated in a metal pan from around 25°C to boiling point (generally referred to as water boiling tests).
Table 2. Stoves claimed by their designers to be fuel-efficient. Features of stove
Economical Indian chulha TypeA TypeB TypeC
1-pot Louga
Tungku Lowon
Malawi mudstove
New Keren
Tandoor
Approximate year of design Cost (£) Construction time b Fuel savings claimed by designer (%) PHU in lab testsC (%) Fuel savings in cooking food (in lab) (%) Level of fuel savings observed in field trials Complicated to use/training required to use stove Number of dampers Construction material
1978 na a na na 16 na na na none mud + sheet steel no na no 20 1
1981 na na 30-60 na na na na none mud
c 1979 na 2-6 h 50 22-23 na na na none mud
1984 na na 0 na 60 none no none mud
na na 1-2 h ncm e 16-20 na na no none fired clay
1978 na 6h ncm 14-18 na na na one fired clay
no na no 100 1
no 2 no 80 2
no 0.5 no na 1
yes 2 yes 3 1
yes 2 no 30 2
Grate Estimated lifetime (years) Portable Mass (kg) Number of pot holders
1978 na na na 12 na na yes none mud + sheet steel yes na no 20 1
1978 na na na 14 na na yes none mud + sheet steel yes na no 20 1
Source: Adapted from Gill, op cit, Ref 32, p 101. a n a - information not available. bconstruction time in hours by potter to fabricate a ceramic stove. cpHU - proportion of heat from firewood (expressed as a percentage) absorbed by water heated in a metal pan from around 25°C to boiling point (generally referred to as water boiling tests). dncm - no claim of fuel saving made by stove designer.
continued from page 136 at Colloque, L'energie dans les communautes rurales des pays du Tiers-Monde, 5 - 1 0 M a y 1980; S o e d j a r w o , op cit, Ref 11. 13Makhijani, op cit, Ref 9, pp 2 4 - 2 6 ; S a l a r i y a , op cit, R e f 9, p 4. r"R. Bhatia, ' E n e r g y and a g r i c u l t u r e in d e v e l o p i n g c o u n t r i e s ' , Energy Policy, Vol 13, No 4, A u g u s t 1985, pp 3 3 0 - 3 4 . 151n technical terms, f u e l - e f f i c i e n t c o o k i n g s t o v e s require the f o l l o w i n g : all the fuel to u n d e r g o c o m b u s t i o n , a m a x i m i z a t i o n of the heat t r a n s f e r to the c o o k i n g vessel,
continued on page 138
ENERGY POLICY April 1987
Reasons for the 'failure' of 'improved' stoves ' I m p r o v e d ' mud stove p r o g r a m m e s in developing countries have failed to displace traditional designs to any extent. A n u m b e r of reasons to explain this are considered below. (1) 'Improved' stoves in practice were not necessarily more efficient than traditional designs nor were they always smokeless. One reason for the low efficiency of some of the ' i m p r o v e d ' stoves was p o o r or inaccurate construction. TM In Sri Lanka, Lorena stoves had a lower efficiency than the traditional stove, since villagers only used two
137
Improved stoves in developing countries continued from page 137 minimization of the thermal losses from the cooking pot and controllability of the heat output of the burning fuel; G. de Lepeleire et al, A Woodstove Compendium, prepared for the technical panel on the UN Conference on New and Renewable Sources of Energy, held in Nairobi, Kenya, August 1981; P.D. Dunn, Renewable Energies: Conversion and Resources, Peter Peregrinus, London, 1986. 16Dunn, op cit, Ref 15. In 1-pot designs, a cooking vessel is placed directly over the burning fuel - the hot gases liberated from the fuel flow past the bottom and sides of the cooking vessel and subsequently escape. Heat is transferred from the flames by both radiation and convection. In multi-pot stoves these hot gases, after hitting the first cooking vessel, are channelled to other pots. With these latter designs a chimney is sometimes added to increase the draft and remove smoke. In both cases the heat transfer is sensitive to the relative positioning of the fuelbed and pot. The heat transfer from the hot gases to the cooking pot can be increased by having the pot lower in the stove body. Heat losses from the pan can be reduced by insulation or by using a lid. The burning rate of the fire can be controlled by moving the wood in or out of the fire, or through the use of dampers. ~Any difference in fuel economy will be due to variations in critical parameters such as the pot-fuelbed distance (see for example, P. Bussmann, P. Visser and K.K. Prasad, 'Open fires: experiment and theory', Proceedings of the Indian Academy of Sciences, Vol 6, Part 1, pp 1-34, 1983) or the velocity of the hot gases (de Lepeleire et al, op cit, Ref 15). Fuel consumption will also depend on the skill of the stove user and both the size and type of fuel used in the tests. ~SDunn, op cit, Ref 15. ~gS. Joseph, An Evaluation of Lorena-type Stoves Introduced into Villages in Indonesia and Sri Lanka, Intermediate Technology Development Group (ITDG), Reading, UK, 28 March 1980. 2°M. Howes, S. Joseph, Y. Shanahan and W. Stewart, The Sarvodaya Stoves Project: A Critical Review of Developments Since August 1979 and Some Proposals for the Future, ITDG Stoves Project, Shinfield, Reading, UK, March 1983, p 24. roD. French, Design and Testing of FuelEfficient Mudstoves for Use in Rural Areas of Malawi, mimeo, Energy Studies Unit, Lilongwe, Malawi, 31 August 1984. 22D. Shaller and E. Shaller, A Sociocultural Assessment of the Lorena Stove and its Diffusion in Highland Guatemala, mimeo, March 1979. 23L.H. Martin, The Economics of Cooking Fuels in Ghana, MA thesis submitted to the American University, 1979. a4E. Gern, G. Amalfitano and I. Evans, Baan Ak Suuf Cookstoves in Senegal, USAID, Dakar, Senegal, 1981. continued on page 139
138
pot holes out of the four in cooking. 2° Moreover, the fuel consumption of some improved stoves that initially used less firewood than traditional designs increased very quickly with time. 21 Another reason that 'improved' stoves were not more efficient than traditional ones was that traditional modes of cooking were not as inefficient as had been assumed. It is informative to examine the basis of the belief that traditional designs had a low efficiency. Most of the authors who gave low figures of 'efficiency' (ie 5-10%) for traditional stoves, have relied on apparently anecdotal evidence (see Appendix). Whilst data based on experimental work gives a wide variation in the values of 'efficiency', it shows that traditional stoves can have significantly higher efficiencies than has generally been assumed. Some improved stoves produced smoke. Thus, in Guatemala, some Lorena stoves created as much smoke as the traditional 3-stone fireplace 22 whilst an 'improved' stove promoted in Ghana gave off smoke when unused pot holders were not tightly covered. 23 (2) 'Improved' stove programmes emphasize fuel economy, whilst villagers are more interested in stoves that allow speedy cooking and are versatile. Cooking speed is regarded as very important by stove users: villagers in Senegal, 24 Sri L a n k a Y Indonesia 26 and Zimbabwe 27 were more concerned about being able to cook quickly than about fuel efficiency. The desirability of fast cooking has also been reported for charcoal stoves in Tanzania 28 and the slowness of solar cookers is a barrier to their acceptance by Sudanese villagers. 29 Traditional stoves and fireplaces in developing countries are often highly versatile, as they are able to burn different fuels and serve a number of practical and socio-cultural functions. Versatility is important, since a variety of cooking fuels besides firewood are used in traditional stoves. For example, fuels such as crop residues may be used when available. 3° However, crop residues are much more 'bulky' than firewood. Thus the design of traditional stoves in Sri Lanka is such that the distance between the pot and hearth lies between 12 and 17 cm. 31 This distance is much larger than would be the case if only firewood was used, and the main aim of the cook was to minimize firewood consumption. Where there is a very high reliance on crop residues, the gap may be even greater (eg 20-23 cm). However, this large gap allows more crop residues to be placed in the hearth as well as reducing the amount of time spent in tending the fire. In practical terms, traditional stoves produce light, heat and smoke all of which may be considered useful. Heat from the fire can be used for cooking food, brewing beer, providing space heat and drying. Thus in Zimbabwe, the 3-stone fireplace is used to support a large oil drum for brewing beer. 32 Furthermore, after a meal has been cooked, the hot ashes can be used to roast tubers. 33 Space heat considerations can be very important. In Fiji, fires are kept burning all night in the sleeping quarters of old people, and in regions where it is cold. 34 In Guatemala, the major source of resistance to the Lorena stove was that it gave out very little space heat. 35 Whilst some were prepared to put up with this inconvenience, others used the Lorena stove for cooking, and also lit a fire for space heat - the latter practice defeating the primary objective of reducing firewood consumption!
ENERGY POLICY April 1 9 8 7
Improved stoves in developing countries continued from page 138 25Howes et al, op cit, Ref 20. 26Joseph, op cit, Ref 19; Soedjarwo, op cit, Ref 11. 27j. Gill, Fuelwood and Stoves in Zimbabwe: A System in Change, paper presented to the 2nd EEC Conference on Energy From Biomass, held in Berlin, 21-24 September 1982. 2SH.H. Sneiders, 'Jiko la Dodoma - the UTAFITI field test of an improved charcoal stove', GATE Quarterly, No 2, June 1984, p16. 29L. Brattle, Novel and Improved Cookstove Technology for Use in the Sudan: The Application of Home Economics to the Question of Appropriate Technologies, PhD thesis, Dept of Home Economics, University of Surrey, July 1983. a°E. Ernst, Fuel Consumption Among Rural Families in Upper Volta, West Africa, paper (FRC/3-1) presented to the 8th World Forestry Congress, held at Djakarta, Indonesia, 1978; Gill, op cit, Ref 27. 31Howes et al, op cit, Ref 20. 32j. Gill, Traditional Fuels and Cooking Stoves - a Social, Technical and Environmental Assessment, PhD thesis, Energy Research Group, The Open University, England, July 1985. 33lEA, Proceedings of the Workshop on Energy Data of Developing Countries, Vol 1, International Energy Agency, OECD, Paris, France, 1979, p 16; J. Dunkerley, 'Patterns of energy consumption by the rural poor in developing countries', Natural Resources Forum, Vol 3, 1979, p 359. 34Siwatibau, op cit, Ref 10, p 71. aSShaller and Shaller, op cit, Ref 22. The Lorena stove was purposely designed to have a high mass and low thermal conductivity. a6Martin, op cit, Ref 23; Siwatibau, op cit, Ref 10, p 71. aTHowes et al, op cit, Ref 20. ~SShaller and Shaller, op cit, Ref 22; I. Evans, Using Firewood More Efficiently, paper (No FRC/3-4) presented to the 8th World Forestry Congress, held in Djakarta, Indonesia, 16-28 October 1978. 39G.M. Foster, Traditional Cultures, Harper and Row, New York, NY, USA, 1962, pp 80-82; Siwatibau, op cit, Ref 10. 4°D. Brokensha and B. Riley, Forest Foraging, Fences and Fuel in a Marginal Area of Kenya, paper to the USAID Africa Bureau Firewood Workshop, held 12-14 June 1978; J. Stryker, 'Lesotho: renewable energy technology project', pp 219-224, in Proceedings of the Workshop on Energy, Forestry and Environment, Vol 2, Africa Bureau, USAID, April 1982. "1Martin, op cit, Ref 23. 42D. Bajracharya quoted in A. Makhijani, Economics and The Sociology of Alternative Energy Sources, paper presented at the Environment and Development Regional Seminar on Alternative Patterns of Development and Lifestyles in Asia and the Pacific, held 14-18 August 1979, Bangkok, Thailand. continued on page 140
ENERGY
P O L I C Y April 1987
In Ghana, whilst village women made a number of negative comments about smoke from traditional s t o v e s , 36 smoke that is produced is not always regarded as a problem, 37 as it may be used to cure food 3s and to deter insects. 39 Traditional fireplaces may provide a social focus4° as well as have a symbolic value. Thus, in Ghana, the 3-stone fireplace symbolizes a united family4~ whilst in parts of Nepal, villagers believe that a spirit dwells in their traditional hearth. 42 In these latter respects, the concept of high cooking efficiency has little value or meaning. The importance of the multiple functions of stoves and fireplaces has become increasingly apparent. 43
(3) Villagers' priorities may be different from stove promoters' whose concerns go beyond cooking fuel supplies. A study in India 44 examined the reactions of village women to an 'improved' stove that had been provided by extension workers. Whilst the women said that they liked the 'improved' stove, they were not prepared to pay 20Rs (about £1) for it. On the other hand, the women were willing to pay for a spinning device (which also cost 20Rs) as it enabled them to increase their income. Similarly firewood gathering was not a high priority to villagers surveyed in Indonesia where their main concerns after access to water was increasing their income. 45 For villagers elsewhere, access to clean water can also have a much higher priority than fuel supplies. 46 Villagers in Burkina Faso (formerly Upper Volta) were more concerned about the water supplies, provision of education for their children, health care, jobs for young adults, and enough food and income to keep their families together, than about forest products. 47 Overall, however, these considerations and barriers to the acceptance of new stoves do not necessarily mean that villagers will not adopt new stoves. For example, village women in Zimbabwe have spontaneously changed from their traditional 3-stone fireplace to stoves which they considered to be better (in terms of cooking speed, space heat, less smoke and so on) even though they perceived a substantial increase in fuel consumption. 4s In any case, the widespread adoption of these stoves by villagers is unlikely to have any significant impact on deforestation as gathering cooking fuel is not generally a primary cause of deforestation. 49 It would have been possible to avoid a number of such problems as well as to determine the chances of achieving the purported aims of stove programmes (eg reduce firewood consumption, reduce stress on forest resources) had appropriate use been made of project management tools.
Monitoring and the dissemination of decentralized energy technologies Monitoring is one of a number of key tools (viz surveys, needs assessment studies, feasibility studies and project evaluation) which is used by project management. Monitoring is primarily used in project implementation. Surveys and needs assessment studies are carried out earlier and feed into monitoring by providing baseline information and identifying items which are of strategic importance to the project. 5° On 139
Improved stoves in developing countries continued from page 139 43Brokensha and Riley, up cit, Ref 40; P. O'Keefe, 'Case study: Kenya', pp 65-75, in Proceedings of the Workshop on Energy, Forestry and Environment, Vol 2, Africa Bureau, USAID, April 1982; G. Foley and P. Moss, Improved Cooking Stoves in Developing Countries, Technical Report No 2, International Institute for Environment and Development, London, 1983. 44R. Roy, 'User needs and appropriate energy technologies', Appropriate Technology, Vol 11, No 4, pp 7-8, March 1985. 4sJoseph, up cit, Ref 19, p 8. 46j.T. Thomson, 'Firewood survey: theory and methodology', in D. French and R. Larson, eds, Energy for Africa, Washington, DC, USA, 1980. 47M. Hoskins, Community Participation in African Fuelwood Production, Transformation and Utilization, discussion paper to the Workshop on Fuelwood and Other Renewable Fuels in Africa, held in Paris, 29-30 November 1979, p 19; A.V. Desai, (Rural Energy Systems, unpublished report, National Council for Applied Economic Research, India, c 1978) argues that this is because there is no firewood problem and that no studies show an energy shortage being perceived by the rural poor. 48j. Gill, 'Fuelwood and stoves: lessons from Zimbabwe', Proceedings of the Indian Academy of Sciences, Vol 6, Pt 1, pp 79-94, 1983. 49Gill, up cit, Ref 32; J. Gill, The Pofitical Economy of Deforestation in Zimbabwe, paper presented to the Symposium on Environmental Crisis in Africa: Ecology versus Political Economy, held at the Department of Anthropology, London University, 18 September 1985; J. Gill, Stoves and Deforestation in Developing Countries, paper presented to the UK-ISES conference on Energy for Development What Are the Solutions?, held at Reading University, Reading, UK, 13 December 1985; J. Zerbe, J. Laundrie, H. Wahlgren and J. Whitmore, Forestry Activities and Deforestation Problems in Developing Countries, USDA Forest Service, Wl, USA, 1980. S°E. Hommes, Strategic Management of Energy Projects, Course Manual, International Course on Rural Energy Planning, May--June 1984, Technology and Development Group, Twente University of Technology, Enschede, The Netherlands. SlA. Caceres, Stoves and Kilns - Mapping the Progress over the Last Decade, paper to the Bioenergy 84 Conference, pp 65117, in E. Egneus et al, eds, Bioenergy 84, Vol 5 of Bioenergy in Developing Countries, Elsevier Applied Science, London, 1985; French, up cit, Ref 21; Howes etal, up cit, Ref 22; K. Skutsch, Strategic Management of Stove Programmes: a Rational Reconstruction Approach, Working Paper No 25, Technology and Development Group, Twente University of Technology, Enschede, The Netherlands, 1986; Shaller and Shaller, up cit, Ref 22. continued on page 141
140
the basis of a number of findings and assumptions, feasibility studies define the conditions under which the project is feasible, thus identifying key indicators to be monitored. Monitoring can identify and highlight problems and thus reduce uncertainty in the planning process, for example, by ensuring that there are no significant departures from the proposed timetable. Monitoring can also be used to provide information on the achievement of project goals. In practice, monitoring of a project concerned with achieving mass dissemination of any decentralized energy technology could be carried out at a number of levels: • • • • •
determination of the number of devices built or disseminated; determination of the number of devices still operational in the field; measurements of the operational performance in the field; obtaining user feedback; and measurements of the implications/effects (eg social, economic environmental) of the adoption of the devices with respect to the overall goals of the project.
Monitoring in stove programmes has concentrated principally on the number of stoves which had been built or bought and the number still in use. 5~ Field data on the fuel consumption of 'improved' stoves vis-a-vis traditional ones are very limited. Moreover, it was only in the mid-1980s that the health impacts of 'improved' stoves began to be monitored. 52 T o determine their efficacy, stove programmes could have been monitored in a number of ways, for example changes in the level of fuel consumption, effects on the health of rural women, changes in fuel collection time, impact on deforestation rates, and so on. It has not been possible to find any stove programme which monitored some of the expected effects of the adoption of 'improved' stoves such as a reduction in fuel collection time or increased time spent in income-generating activities. In cases where user feedback has been obtained, this has generally either not been integrated into the stoves project or has been carried out in an ad hoc rather than systematic manner. What is remarkable is not so much findings such as that 'improved' stoves were not necessarily more efficient than traditional ones, or that stove users placed a higher priority on cooking speed than fuel consumption, but that it took so long to discover these findings! 53 Had monitoring been carried out systematically in 'improved' stove projects, such information would have been obtained much more easily and quickly.
Conclusions The importance of traditional 'non-commercial' fuels such as firewood and crop residues in the economies of developing countries was not widely known until the mid-1970s. Consumption of such fuels is concentrated in the rural areas of these countries. These fuels have been the primary sources of cooking fuel and traditionally gathered by rural women and children. However, pressure on forests from firewood collection activities and the extension of agricultural land by a growing population are believed to have led to deforestation. One strategy to reduce stress on forests has been the promotion of 'improved' cooking stoves for use by the rural poor. Improved stove programmes have failed to displace traditional modes of cooking to any
ENERGY POLICY April 1987
Improved stoves in developing countries
continued from page 140
52See for example, K. Smith, Biomass Fuels, Air Pollution and Health Evidence from The Third World, Health and Development Programme, East-West Center, Honolulu, Hawaii, USA, 1984; S. Sharma, Concept and Performance of Smokeless Wood Burning Cookstoves, paper to the Workshop on 'Strategic management of rural technology and health programmes in the process of rural transformation', held in Jaipur, India, 3-5 March 1986. 531n this respect, it is important to note that the first 'improved' stove was promoted in India in the 1950s.
significant e x t e n t . O n e r e a s o n for this is the m i s m a t c h b e t w e e n the felt n e e d s o f the rural p o o r a n d the a s s u m p t i o n s o f the i n s t i t u t i o n s and i n d i v i d u a l s d e s i g n i n g a n d p r o m o t i n g i m p r o v e d stoves. F o r instance, villagers m a y be m o r e c o n c e r n e d a b o u t i n c r e a s i n g t h e i r i n c o m e , access to e d u c a t i o n a n d a b o u t w a t e r s u p p l i e s t h a n the s u p p l y of c o o k i n g fuel. M o r e o v e r , e x p e r i m e n t a l w o r k shows that t r a d i t i o n a l stoves and f i r e p l a c e s are c a p a b l e of significantly h i g h e r c o o k i n g efficiencies than a r e w i d e l y q u o t e d in the o p e n l i t e r a t u r e . In this r e s p e c t , most of the c l a i m s that t r a d i t i o n a l stoves w e r e inefficient w e r e b a s e d on a p p a r e n t l y anecdotal data. In p r a c t i c e the design a n d choice of c o o k i n g stove involves a range of issues a n d t r a d e - o f f s , a n d users m a y be p r e p a r e d to sacrifice fuel e c o n o m y for the ability to c o o k m o r e quickly o r for versatility in thc t y p e s o f fuel t h a t can be used. In a d d i t i o n , t r a d i t i o n a l stoves serve a n u m b e r of p r a c t i c a l (eg p r o v i s i o n o f space h e a t a n d light) a n d s o c i o - c u l t u r a l (eg a social focus a n d b e a r a s y m b o l i c role) functions. T h e s e c o n s i d e r a t i o n s have b e e n n e g l e c t e d in stove p r o g r a m m e s to d a t e . M o n i t o r i n g o f s t o v e p r o g r a m m e s has g e n e r a l l y f o c u s e d on the n u m b e r o f s t o v e s d i s s e m i n a t e d a n d o p e r a t i o n a l . T h e r e a p p e a r s to have b e e n very little d a t a c o l l e c t e d to d e t e r m i n e the effects and i m p a c t s of i m p r o v e d stove p r o g r a m m e s with r e s p e c t to the e x p e c t e d b e n e f i t s (eg a r e d u c t i o n in fuel c o l l e c t i o n t i m e , less p r e s s u r e on forests). P r o b l e m s in the a d o p t i o n o f i m p r o v e d stoves c o u l d have b e e n a w f i d e d had a p p r o p r i a t e use b e e n m a d e of s t a n d a r d p r o j e c t m a n a g e m e n t tools such as n e e d s a s s e s s m e n t surveys, m o n i t o r i n g a n d e v a l u a t i o n . O v e r a l l , h o w e v e r , the w i d e s p r e a d a d o p t i o n of i m p r o v e d stoves is u n l i k e l y to h a v e a significant i m p a c t on d e f o r e s t a t i o n since it is a c o m p l e x p h e n o m e n o n to which t h e r e a r e a n u m b e r of c o n t r i b u t o r y factors.
Appendix The basis of stove 'efficiency' data The basis for the data reported in the literature on the 'efficiency' of traditional stoves and fireplaces can be divided into four categories: first, data which are 'anecdotal'; second, where the author refers to another source; third, data obtained by comparing the magnitude of cooking energy consumption in two countries; and finally data based on empirical work. Most of the work cited falls into the first two categories. The figures in these two categories are remarkably consistent, (mostly in the range 510%), and are almost all derived from literature written between 1978 and 1981. One explanation is that these authors have either drawn upon each other or another common source. The first category contains those
ENERGY POLICY April 1987
figures which are apparently anecdotal and have no acknowledged source or direct literature reference (Table 3). This category contains the largest number of efficiency figures given in the literature - 38 in all. Thirteen references fall into the second category (Table 4). Of 13 authors whose sources were checked, there were seven end references (Figure 1). Of these seven ultimate source references, four have relied on published experimental testing methods. Data by Ascough 5a and Franklin et al ss are unpublished and unavailable, despite several requests; both Revelle 56 and the data by Makhijani and Poole 5v are discussed below. Prasad e t a l 5s do not give a source for the efficiency figure, and hence fall
into the category of "anecdotal' data listed in Table 3. Data by N C A E R 5" are given in Table 5. An example of how evidence can get passed on and become part of the accepted wisdom can be seen in the following flow of citations: Arnold ~'' cites Floor < as his reference source, who refers to an earlier paper by himself) e This latter paper refers to Le Developpement Voltaique ~'3 as the ultimate source. However, this does not contain any efficiency data! Floor 64 acknowledges this and cites two other references ('a publication by the Village and Khadi Commission on Gobar gas, and a shorter Makhijani study') from which he obtained the data. There is only one example in the
141
Improved stoves in developing countries Table 3. 'Efficiency' data with no original source given. Cooking method
Author
Quoted 'efficiency' (%)
Baron (1980)
grossly inefficient
MacKillop (1983) Knowland and Ulinski (1979)
10 3-8
Desch (1973) Hayes (1977)
10 9
McGranahan et al (1980) Smith (1981) Stanford (undated)
10 6-8 8
Open fire
Desch (1973) Digernes (1978) lEA (1979) Dunkerley (1979) Gamser (1979) ROCAP (1979) Morgan and Moss (1980) Norman (1981) Hottenroth (1982) Tiwari (1982) Munasinghe (1983) Sodha and Prasad (undated)
10 6-8 5-10 10 10 <10 6-10 5 6 very low efficiency 5 5-10
3-stone fireplace
Club du Sahel (1978) KiZerbo and de Lepeleire (1979) Mnzava (1980) Vita (1980) Norman (1981 ) Smith (1981) Moss and Hall (1981 ) Lequeux (1982) Thomas and Amalfitano (1982)
3-8 3-8 10-12 wasteful on fuel 7 6-8 7-8 <5 wasteful of heat
Mud stoves 'open chulha' 'chulha' 'mud chulha' 'brick chulha' 'open chulha'
Raju (1957) Prasad et al (1974) Gupta (1982) Gupta (1982) Nanda (1982: 58)
'chulha'
Tiwari (1982)
extremely low efficiency 11 very low efficiency very low efficiency (firewood) 17 (cow manure) 11 very low efficiency
Fuel cowdung firewood
Kashkari (1975) Openshaw (1980)
11 7-8
Stoves in general 'stoves in developing countries' 'woodstoves' 'stoves and fireplaces in Third World homes' 'primitive stoves' cooking in developing countries Open fires and variations Hearth
Source: Gill, op cit, Ref 32, p 117.
third category: Makhijani and Poole 65 who give a figure of 5% for the cooking efficiency in India by comparing the magnitude of domestic energy use in rural India - based on work by Revelle 66 - and the USA. According to these data, the domestic energy use per capita figure for India is four times that of the USA, whence, the efficiency of cooking in India is calculated to be one-quarter of that in the USA. In addition, if we assign an efficiency of 20 per cent to gas stoves - somewhat arbitrarily - then the efficiency of rural cooking would be about 5 per cent. (Emphasis added.) 67
142
This is the underlying logic that Makhijani and Poole use to arrive at the 5% figure of efficiency. Assuming for the moment this logic to be valid, then simply altering the value of the assumed efficiency of gas cookers will change the calculated efficiency of cooking in rural India. Values of efficiency68 of gas cookers in the USA vary between 30% and 60% (depending on the power output and type of pan). These figures would mean that the calculated efficiency of cooking in rural India would lie between 7.5% and 15%. However, this method of estimating
efficiencies may c o n t a i n further errors, as there are difficulties in comparing the magnitude of domestic energy in the USA and India. For instance, foods purchased in the USA will tend to be processed, pre- or partially-cooked. All these will reduce the domestic cooking energy demand. Another implicit assumption in this analysis is that the same amount of food is cooked (ie same useful cooking demand). The average US citizen does not eat the same amount of food as the average rural Indian. These would have to be taken into account in any attempt at comparison. Data based on experimental work give a wide variation in the values of 'efficiency' (Table 5) but do show that traditional stoves can be much more efficient than has generally been a s s u m e d . The v a r i a t i o n s in the measured 'efficiencies' of traditional stoves (as with improved stoves) are a consequence of differences in critical physical parameters, operating conditions and test methodologies. The following example illustrates the danger of generalizing from limited experimental work. Revelle 69 obtains a figure of just under 9% for the efficiency of fuel use in India, the empirical basis for which is as follows: two experiments with rice cooking showed that the energy required to bring the cooking water to boiling and to boil away the requisite quantity of water is about 600 kcal/kg, or 17.5 percent of the food energy content of rice.7° Revelle makes the following assumptions: first, other food grains behave similarly to rice (ie they also require 17.5% of their calorific value to be cooked); second, that 75% of the energy 'biomass' (ie firewood, crop residues and animal manure) is available for cooking food. A value of the efficiency of cooking fuel can then be calculated if the food energy intake and energy from firewood, crop residues and animal manure are known. Repeating Revelle's calculation using his data gives a value of 11.6%, which suggests that he has made an arithmetical error. Revelle gives very little detailed information regarding the rice cooking tests he conducted on rice. Popali et a171 obtained values around 1 210 kcal/
ENERGY
POLICY
April 1 9 8 7
Improved stoves in developing countries Table 4. Author refers to another source. Cooking method
Author
Quoted 'efficiency'
Source of data
Floor (1978) Vanin et a~ (1980) Revelle (1980) Pearson and Stevens (1984) Makhijani (1976)
8 10-43 5-10 6 5
Floor (1977) Goldemberg and Brown (1979) Revelle (1976) Makhijani (1976) Makhijani and Poole (1975)
Open fire
Revelle (1978) Goldemberg and Brown (1979) FRIDA (1980)
10 5-10 2.5
Revelle (1976) Franklin et al (unpublished) Ascough (personal communication)
3-stone fireplace
Arnold (1979)
8
(a) Makhijani and Poole (1975) (b) Floor (1978)
Floor (1977)
8
Le Developpement Voltaique No 40 (August 1976)
Morgan et al (1979)
5-10
Goldemberg and Brown (1979)
Bene et al (1978)
5-11
Makhijani and Poole (1975) Prasad et al (1974)
Somasekhara (1978)
11-17
NCAER (1959)
(%)
Stoves in general
'traditional modes of cooking' (closed) 'wood fire' 'wood stoves'
Open fire and variations
Mud stoves
chulha
Source: Gill, op cit, Ref 32, p 119.
kg to cook rice. Using these data would roughly double the value of the efficiency of cooking from 11.6% to 23%. However, the determination of the energy required to cook food items is not so simple since the energy needed is not a constant quantity, but depends on the physical properties of the food, for example the size or degree of
fibrous material, as well as subjective qualities such as when the food item is regarded as being 'cooked'. Food can be cooked much more quickly and use less energy through being cut into small pieces compared to large pieces. Similarly, the energy required to cook pulses can be reduced if they are soaked prior to cooking. E x p e r i m e n t a l work by Islam 72
Citing authors
Arnold (1979) ~-
End source data
Floor(1978) - " i - - F l o o r ( 1 9 7 7 ) ~
Vonin et o~ ( 1 9 8 0 ) ' ~ . ~
Goldemberg and
Morgan eta~ (1979') ~
Brown (1979)
=
Basis of data
Le Developpement Voltoique (August 1976)
No efficiency data given
Franklin ef o~ (1976) unpublished
Experimental
Revelle (1976)
Experimental
Ascough [personal communication)
Experimental
Revelle ( 1980) ~-------__ Revel]e (1978) 4. FRIDA (1980) ~
Prosad ef o~ (1974)
(1984)
Mokhijoni and Poole (1975)
Somoskhero (1978) ,=
NCAER (1959)
No source given Comparison of domestic energy
consumption
Figure 1.
Citation flows for stove 'efficiency' data.
Source: Gill, op cit, Ref 32.
E N E R G Y P O L I C Y April 1987
Experimental
showed that the amount of energy to cook rice depends not only on the type and quantity of rice, but also on the amount of water used and the type of cooking vessel: cooking rice in a pan with a round bottom used about threequarters of the energy required with a pan with a flat bottom.
54j. Ascough, cited in Domestic Energy
and Its Measurement and the Framework for Practical Solutions, FRIDA, London, December 1980. ssC. Franklin, D. Harrjee and J. Goldemberg, Design for Improving the Efficiency of Wood Burning for Heating Water to Boiling at Low Cost, Princeton University, USA (unpublished), 1977. S6Revelle, op cit, Ref 8. 57A. Makhijani and A. Poole, Energy and Agriculture in the Third World, Ballinger Press, Cambridge, MA, 1975. 58C. Prasad, K. Prasad and A. Reddy, 'Biogas plants: prospects, problems and tasks', Economic and Political Weekly, Vol 9, Pts 32-34, pp 1 347-1 364, 1974. 5eNational Council for Applied Economic Research, Domestic Fuels in India, New Delhi, India, 1959. 6oj. Arnold, 'Wood energy and rural communities', Natural Resources Forum, Vol 3, pp 229-252, 1979. 81W. Floor, Energy Options in the Rural Areas of the Third World, paper presented to the 8th World Forestry Congress, Djakarta, Indonesia, June 1978. 62W. Floor, The Energy Sector of the
143
Improved stoves in developing countries Table 5. Source of 'efficiency' data: experimental works, a Cooking method
Author
Quoted 'efficiency' (%)
Cooking in India
Revelle (1976)
<9
Open fire and variations 'fire under 3-legged pot'
Best (1979a, 1979b)
1.3-7.3
3-stone fireplace
Brattle (1979) Visser et al (1979) Joseph and Shanahan (1981) Visser and Verhaart (1980) Ascough (1980) Bussmann et al (1983) Ouedraogo et al (1983)
11.2-25.5 13-26 14-30 11-23 3.5 22-36 4.9-17.4
'Fijian' fireplace
Weir and Richolson (1980) Siwatibau (1981 )
3.8-5.1 5-10
1-pot stoves Indian brick 'U' chula (firewood logs) (small pieces of firewood)
NCAER (1959) NCAER (1959)
13-15 19.1
Indian 'U' chula (firewood) (cow manure)
Salariya (1978, 1983) NCAER (1959)
12.3 10.1-10.7
Indian 'U' chulha + grate (firewood) Sri Lankan 'U' chulha 1-pot Bangladesh chulha
Salariya (1978, 1983)
15.8
Joseph and Loose (1982) Islam (1980)
10.4-16.2 4.3-10.0
2-pot stoves Egyptian design Indonesian design Indonesian design Indian design 2-pot Bangladeshi chulha
Theodorovic (1954) Singer (1961) Joseph (1983) Geller (1980) Islam (1980)
3-4.4 6-7 12-17 6-14 12.6-19.5
3-pot stoves Indonesian design Indian design Indian design
Singer (1961) Geller (1980) Geller (1982)
6-7 8-14 3-9
Sahelian Countries, Policy Planning Centre, Ministry of Foreign Affairs, The Netherlands, April 1977. 63Floor, op cit, Ref 62, which refers to the August 1976 edition of Le Developpement Voltaique (1976). 64W. Floor, personal communication, Policy Planning Centre, Ministry of Foreign Affairs, The Netherlands, 1981. 65Makhijani and Poole, op cit, Ref 57. eeRevelle, op cit, Ref 8. 67Makhijani and Poole, op cit, Ref 57, p 27. 68K. Knapp, E. Jahn and E. Kafka, 'Domestic gas cooking appliances', pp 12/51-12/157, in C. Segeler, ed, Gas Engineers Handbook Fuel Gas Engineering Practices, Industrial Press, New York, NY, 1965. 69Revelle, op cit, Ref 8. 7°Revelle, op cit, Ref 8, p 972. 71S. Popali et al, 'Cooking at low temperatures: energy and time requirements', Proceedings of the Indian Academy of Sciences, Pt 3, 1979. 72N. Islam, Study of the Problems and Prospects of Biogas Technology as a Mechanism for Rural Development: Study in a Pilot Area of Bangladesh, prepared for the International Development Research Centre, Canada, September 1980.
Source: Gill, op cit, Ref 32, p 123. aAll data obtained from water boiling tests except for Revelle (1976) who conducted two experiments cooking rice (see text).
144
ENERGY
POLICY
April 1 9 8 7
Jas Gill
Improved stoves have largely failed to achieve widespread dissemination in developing countries for a number of reasons. Improved stoves were not necessarily more efficient than traditional designs nor were they always smokeless. Improved stove programmes emphasize fuel economy whilst stove users regard versatility and the ability to cook quickly as being more important. Other concerns of villagers such as water supplies and incomegenerating technologies may have a higher priority than the supply of traditional cooking fuels. Moreover, stove programmes are unlikely to significantly reduce deforestation. The likely effects of stove programmes could have been determined and a number of problems avoided had these projects been appropriately monitored.
Keywords: Fuelwood shortage; Traditional fuels; Deforestation Jas Gill is a member of the Energy Research Group, The Open University, Milton Keynes MK7 6AA, England and now a Fellow at the Science Policy Research Unit, University of Sussex, Mantell Building, Falmer, Brighton, East Sussex BN1 9RF. lie firewood and crop residues. 2See D. Earl, Forest Energy and Economic Development, Clarendon Press, Oxford, 1975; E. Eckholm, Firewood: the Other Energy Crisis, Worldwatch Paper No 1, Worldwatch Institute, Washington, DC, USA, 1975; K. Openshaw, 'Wood fuels the developing world', New Scientist, Vol 61, No 883, 31 January 1974, pp 271-72. continued on page 136
Energy supplies and costs hit the world's headlines when the price of oil rose by a factor of four in 1973-74. These events were seen as marking the end of an era of cheap oil and coal and the beginnings of an age of high-cost energy. Whilst it was recognized at the time that the oil-importing developing countries would have problems in adjusting to the higher oil prices, it was only a few years later that the critical importance in their economies of traditionally 'non-commercial' fuels 1 was given widespread attention. 2 The greatest dependence on traditional fuels in developing countries is in the rural areas. In 1975, it was estimated that only 15% of commercial energy consumption in these countries took place in the rural areas) Traditional fuels in rural areas are used primarily for cooking and have usually been gathered by village women and children at no monetary cost. 4 In the mid-19?0s, Eckholm, a researcher with the Washington-based Worldwatch Institute, argued that deforestation in developing countries had led to an acute shortage of firewood in these countries and that continued fuel gathering had led to further deforestation. 5 By the late 1970s this view had come to be accepted by international institutions. 6 Thus, in 1985, the Forestry Department of the United Nations Food and Agriculture Organisation 7 reported that fuelwood supplies have been rapidly depleted and the cutting of firewood has in turn been a major cause of excessive deforestation.
Moreover, the clearance of forest land for agriculture for the food requirements of a growing population was considered to exacerbate deforestation. 8
Intervention strategies Strategies to cope with deforestation and the perceived shortage of firewood are concerned with increasing the supply of firewood and/or decreasing the demand for firewood. One demand-orientated strategy
0301-4215/87/020135-10503.00 © 1987 Butterworth & Co (Publishers) Ltd
1 35
Improved stoves in developing countries continued from page 135 3j. Parikh, Energy Systems and Development: Constraints, Demand and Supply of Energy for Developing Regions, Oxford University Press, Delhi, India, 1980. '=M. Montalembert and J. Clement, 'Fuelwood supplies in the developing countries', FAO Forestry Paper No 42, 1983, p 1 ; D. Hughart, Prospects for traditional and non-conventional energy sources in developing countries, World Bank Staff Working Paper No 346, World Bank, Washington, DC, USA, 1979, p 3. 5Eckholm, up cit, Ref 2. 6FAO, Forestry for Rural Communities, Forestry Department, UN Food and Agriculture Organisation, 1978; World Bank, Energy in Developing Countries, Washington, DC, USA, August 1980, p 38. 7FAO, 'Forestry and food security', Unasylva, Vol 37, No 149, 1985, p 8. 8FAO, up cit, Ref 6; R. Revelle, 'Energy use in rural India', Science, Vo1192, 1976, pp 969-975. 9See T. Kennedy, Bangladesh: the Energy Outlook, EDP No 12, 15 September 1981, Energy Research Group, Physics Department, Cambridge University, p 33; A. Makhijani, 'Solar energy and rural development for the Third World', Bulletin of the Atomic Scientists, Vo132, Pt 6, 1976, p 24; S.P. Raju, Smokeless Kitchen for the Millions, Christian Literature Society, Madras, India, 1957; K.S. Salariya, Energy Conservation in Domestic Consumption, Tata Energy Research Institute, Bombay, 1983, p 4; N. Smith, Wood: An Ancient Fuel with a New Future, Worldwatch Institute Paper No 42, Worldwatch Institute, Washington, DC, USA, 1981, p 15; TERI, Cookstove Handbook: Pilot Edition, Documentation Centre, Tata Energy Research Institute, Bombay, India, June 1982, p 3; World Bank, up cit, Ref 6, p 39. ~°C. Baron, Energy Policy and the Social Objectives of Development, Working Paper No 72, Technology and Employment Branch, ILO, Geneva, 1980; Eckholm, up cit, Ref 2; W. Knowland and C. Ulinski, Traditional Fuels: Present Data, Past Experience and Possible Strategies, USAID, Washington, DC, USA, September 1979; Raju, up cit, Ref 9; S. Siwatibau, Rural Energy in Fiji: A Survey of Domestic and Rural Energy Use and Potential, IDRC, Ottawa, Canada, 1981. l~See T. Acott et al, How to Help Poor Countries Develop Fuel-saving Cookstoves, German Appropriate Technology Exchange, Postfach 5180, D-6236 Eschborn 1, Federal Republic of Germany, 1980; A. Soedjarwo, Yayasan Dian-Desa's Wood Conserving Stove Project, a case study prepared for the Guangzhau Rural Energy Systems Seminar, 6-10 December 1982 (mimeo); UNICEF, New Nepafi Cooking Stoves that Make Smokeless Kitchens and Use Less Firewood, UNICEF, Nepal, September 1982. ~2j.E.M. Arnold, Fuelwood as a Source of Rural Household Energy, paper presented continued on page 137
136
has been to p r o m o t e better cooking stoves for use in the rural sector of developing countries. This strategy assumes that traditional stoves and fireplaces commonly used in developing countries have low cooking efficiencies ~ and are a risk to w o m e n ' s health because of the smoke they produce in the kitchen. "~ In order to eliminate smoke from traditional kitchens and reduce consumption of firewood, much effort has gone into designing and disseminating stoves which are both smokeless and more efficient than traditional designs. These are generally referred to as ' i m p r o v e d ' stoves. Such stove p r o g r a m m e s , it is argued, 11 would improve women's health through their working in a smoke-free kitchen and reduce the time spent in cooking and collecting fuel. Rural women could usefully spend the time saved in income-generating activities. J2 It was believed that if these ' i m p r o v e d ' stoves could be adopted on a widespread scale, then firewood consumption would fall, thereby reducing the pressure on forests 13 as well as decreasing the consumption of crop residues: improved stoves for cooking are of the highest priority given the declining availabilities of crop residues and the dependence of the poor on these forms of fuel for cooking.14 At the same time, such an intervention would increase the chances of success of solutions concerned with increasing the s u p p l y of firewood, eg reforestation, agroforestry, silviculture.
A technical assessment o f 'improved' stoves ~-~ I m p r o v e d stoves can conveniently be grouped into two categories: 1-pot and multi-pot designs. 1~,It is crucial to point out that the performance of various improved stoves within these two categories will be similar. 17 In practice, a potential adopter of any new or improved stove is likely to be interested in a stove which has a low cost (eg monetary terms or construction time), fits in with traditional cooking practices, is simple to use, easy to maintain, has a low fuel cost and produces low levels of smoke if used in an enclosed space, is A s u m m a r y of such features is given for stoves p r o m o t e d as being both 'smokeless and fuel-efficient' (Table 1) and stoves that were 'fuel-efficient' (Table 2). Nearly all the stoves p r o m o t e d as being both fuel-efficient and smokeless were constructed from mud (unfired clay) and generally not portable (Table 1). Most of these stoves had dampers (to control the heat output of the burning fuel). Consequently, they were not simple to use and the cook had to be taught how to use the dampers. The designers of most of these stoves claimed fuel savings of around 50% but gave no field data to substantiate this belief. In addition, a n u m b e r of these stoves were not smokeless in practice. From the mid-1970s attention shifted to designing and promoting stoves which their designers claimed were fuel-efficient (Table 2). A n u m b e r of these stoves were made from fired clay which could be constructed by skilled potters in a few hours. The time to build the fired clay stoves by a skilled potter varies from 1-6 hours (Table 2); however, it is not clear why there should be such a wide time variation, given that these stoves look remarkably similar. It is important to note, however, that whilst these were referred to as ' i m p r o v e d ' stoves, in most cases their designers did not give any figures on the expected reduction in fuel consumption. E N E R G Y P O L I C Y April 1987
Improved stoves in developin[4 countries Table 1. Stoves claimed by their designers to be smokeless and fuel-efficient. Features of stove
HERL Improved chulha Egyptian stove
Singer stoves
GS stove
Ghanaian stove
Nepali chulha
Lorena Magan stove chulha
Approximate year of design Cost (£) Construction time b Fuel savings claimed by designer (%) PHU in lab tests ° (%) Fuel savings in cooking food (in lab) (%) Level of fuel savings observed in field trials Complicated to use/training required to use stove Smokeless in practice Number of dampers Construction material Grate Estimated lifetime (years) Portable version Mass (kg) Number of pot holders
1953 na a na 50 na na na yes no 1 mud no 3 no 150 2-4
1961 na 3-4 days 60-75 20-30 na na yes no 1 mud no na no 1000 2-3
1980 1 na 50 na na na yes na 1 mud no <6 no 70 2
c 1960 na na 50 na na none yes no 2 mud no na no 1000 3
1979 na na 50 na na na yes na 2 mud yes na no na 3
1976 3 na 50 na na none yes no 2 mud no 2 no 200 2 or more
1953 na na 30 4-5 na na yes na 1 mud no na no 300 2
1987 na 2-4 h >50 4-12 na na na na none fired yes 2 yes 100 2 or more
Source: Adapted from Gill, op cit, Ref 32, p 100. ana - information not available. btime in hours refers to construction by a potter to fabricate a ceramic stove, mud stoves are generally to be constructed by the stove user and take several days to build. cpHU - proportion of heat from firewood (expressed as a percentage) absorbed by water heated in a metal pan from around 25°C to boiling point (generally referred to as water boiling tests).
Table 2. Stoves claimed by their designers to be fuel-efficient. Features of stove
Economical Indian chulha TypeA TypeB TypeC
1-pot Louga
Tungku Lowon
Malawi mudstove
New Keren
Tandoor
Approximate year of design Cost (£) Construction time b Fuel savings claimed by designer (%) PHU in lab testsC (%) Fuel savings in cooking food (in lab) (%) Level of fuel savings observed in field trials Complicated to use/training required to use stove Number of dampers Construction material
1978 na a na na 16 na na na none mud + sheet steel no na no 20 1
1981 na na 30-60 na na na na none mud
c 1979 na 2-6 h 50 22-23 na na na none mud
1984 na na 0 na 60 none no none mud
na na 1-2 h ncm e 16-20 na na no none fired clay
1978 na 6h ncm 14-18 na na na one fired clay
no na no 100 1
no 2 no 80 2
no 0.5 no na 1
yes 2 yes 3 1
yes 2 no 30 2
Grate Estimated lifetime (years) Portable Mass (kg) Number of pot holders
1978 na na na 12 na na yes none mud + sheet steel yes na no 20 1
1978 na na na 14 na na yes none mud + sheet steel yes na no 20 1
Source: Adapted from Gill, op cit, Ref 32, p 101. a n a - information not available. bconstruction time in hours by potter to fabricate a ceramic stove. cpHU - proportion of heat from firewood (expressed as a percentage) absorbed by water heated in a metal pan from around 25°C to boiling point (generally referred to as water boiling tests). dncm - no claim of fuel saving made by stove designer.
continued from page 136 at Colloque, L'energie dans les communautes rurales des pays du Tiers-Monde, 5 - 1 0 M a y 1980; S o e d j a r w o , op cit, Ref 11. 13Makhijani, op cit, Ref 9, pp 2 4 - 2 6 ; S a l a r i y a , op cit, R e f 9, p 4. r"R. Bhatia, ' E n e r g y and a g r i c u l t u r e in d e v e l o p i n g c o u n t r i e s ' , Energy Policy, Vol 13, No 4, A u g u s t 1985, pp 3 3 0 - 3 4 . 151n technical terms, f u e l - e f f i c i e n t c o o k i n g s t o v e s require the f o l l o w i n g : all the fuel to u n d e r g o c o m b u s t i o n , a m a x i m i z a t i o n of the heat t r a n s f e r to the c o o k i n g vessel,
continued on page 138
ENERGY POLICY April 1987
Reasons for the 'failure' of 'improved' stoves ' I m p r o v e d ' mud stove p r o g r a m m e s in developing countries have failed to displace traditional designs to any extent. A n u m b e r of reasons to explain this are considered below. (1) 'Improved' stoves in practice were not necessarily more efficient than traditional designs nor were they always smokeless. One reason for the low efficiency of some of the ' i m p r o v e d ' stoves was p o o r or inaccurate construction. TM In Sri Lanka, Lorena stoves had a lower efficiency than the traditional stove, since villagers only used two
137
Improved stoves in developing countries continued from page 137 minimization of the thermal losses from the cooking pot and controllability of the heat output of the burning fuel; G. de Lepeleire et al, A Woodstove Compendium, prepared for the technical panel on the UN Conference on New and Renewable Sources of Energy, held in Nairobi, Kenya, August 1981; P.D. Dunn, Renewable Energies: Conversion and Resources, Peter Peregrinus, London, 1986. 16Dunn, op cit, Ref 15. In 1-pot designs, a cooking vessel is placed directly over the burning fuel - the hot gases liberated from the fuel flow past the bottom and sides of the cooking vessel and subsequently escape. Heat is transferred from the flames by both radiation and convection. In multi-pot stoves these hot gases, after hitting the first cooking vessel, are channelled to other pots. With these latter designs a chimney is sometimes added to increase the draft and remove smoke. In both cases the heat transfer is sensitive to the relative positioning of the fuelbed and pot. The heat transfer from the hot gases to the cooking pot can be increased by having the pot lower in the stove body. Heat losses from the pan can be reduced by insulation or by using a lid. The burning rate of the fire can be controlled by moving the wood in or out of the fire, or through the use of dampers. ~Any difference in fuel economy will be due to variations in critical parameters such as the pot-fuelbed distance (see for example, P. Bussmann, P. Visser and K.K. Prasad, 'Open fires: experiment and theory', Proceedings of the Indian Academy of Sciences, Vol 6, Part 1, pp 1-34, 1983) or the velocity of the hot gases (de Lepeleire et al, op cit, Ref 15). Fuel consumption will also depend on the skill of the stove user and both the size and type of fuel used in the tests. ~SDunn, op cit, Ref 15. ~gS. Joseph, An Evaluation of Lorena-type Stoves Introduced into Villages in Indonesia and Sri Lanka, Intermediate Technology Development Group (ITDG), Reading, UK, 28 March 1980. 2°M. Howes, S. Joseph, Y. Shanahan and W. Stewart, The Sarvodaya Stoves Project: A Critical Review of Developments Since August 1979 and Some Proposals for the Future, ITDG Stoves Project, Shinfield, Reading, UK, March 1983, p 24. roD. French, Design and Testing of FuelEfficient Mudstoves for Use in Rural Areas of Malawi, mimeo, Energy Studies Unit, Lilongwe, Malawi, 31 August 1984. 22D. Shaller and E. Shaller, A Sociocultural Assessment of the Lorena Stove and its Diffusion in Highland Guatemala, mimeo, March 1979. 23L.H. Martin, The Economics of Cooking Fuels in Ghana, MA thesis submitted to the American University, 1979. a4E. Gern, G. Amalfitano and I. Evans, Baan Ak Suuf Cookstoves in Senegal, USAID, Dakar, Senegal, 1981. continued on page 139
138
pot holes out of the four in cooking. 2° Moreover, the fuel consumption of some improved stoves that initially used less firewood than traditional designs increased very quickly with time. 21 Another reason that 'improved' stoves were not more efficient than traditional ones was that traditional modes of cooking were not as inefficient as had been assumed. It is informative to examine the basis of the belief that traditional designs had a low efficiency. Most of the authors who gave low figures of 'efficiency' (ie 5-10%) for traditional stoves, have relied on apparently anecdotal evidence (see Appendix). Whilst data based on experimental work gives a wide variation in the values of 'efficiency', it shows that traditional stoves can have significantly higher efficiencies than has generally been assumed. Some improved stoves produced smoke. Thus, in Guatemala, some Lorena stoves created as much smoke as the traditional 3-stone fireplace 22 whilst an 'improved' stove promoted in Ghana gave off smoke when unused pot holders were not tightly covered. 23 (2) 'Improved' stove programmes emphasize fuel economy, whilst villagers are more interested in stoves that allow speedy cooking and are versatile. Cooking speed is regarded as very important by stove users: villagers in Senegal, 24 Sri L a n k a Y Indonesia 26 and Zimbabwe 27 were more concerned about being able to cook quickly than about fuel efficiency. The desirability of fast cooking has also been reported for charcoal stoves in Tanzania 28 and the slowness of solar cookers is a barrier to their acceptance by Sudanese villagers. 29 Traditional stoves and fireplaces in developing countries are often highly versatile, as they are able to burn different fuels and serve a number of practical and socio-cultural functions. Versatility is important, since a variety of cooking fuels besides firewood are used in traditional stoves. For example, fuels such as crop residues may be used when available. 3° However, crop residues are much more 'bulky' than firewood. Thus the design of traditional stoves in Sri Lanka is such that the distance between the pot and hearth lies between 12 and 17 cm. 31 This distance is much larger than would be the case if only firewood was used, and the main aim of the cook was to minimize firewood consumption. Where there is a very high reliance on crop residues, the gap may be even greater (eg 20-23 cm). However, this large gap allows more crop residues to be placed in the hearth as well as reducing the amount of time spent in tending the fire. In practical terms, traditional stoves produce light, heat and smoke all of which may be considered useful. Heat from the fire can be used for cooking food, brewing beer, providing space heat and drying. Thus in Zimbabwe, the 3-stone fireplace is used to support a large oil drum for brewing beer. 32 Furthermore, after a meal has been cooked, the hot ashes can be used to roast tubers. 33 Space heat considerations can be very important. In Fiji, fires are kept burning all night in the sleeping quarters of old people, and in regions where it is cold. 34 In Guatemala, the major source of resistance to the Lorena stove was that it gave out very little space heat. 35 Whilst some were prepared to put up with this inconvenience, others used the Lorena stove for cooking, and also lit a fire for space heat - the latter practice defeating the primary objective of reducing firewood consumption!
ENERGY POLICY April 1 9 8 7
Improved stoves in developing countries continued from page 138 25Howes et al, op cit, Ref 20. 26Joseph, op cit, Ref 19; Soedjarwo, op cit, Ref 11. 27j. Gill, Fuelwood and Stoves in Zimbabwe: A System in Change, paper presented to the 2nd EEC Conference on Energy From Biomass, held in Berlin, 21-24 September 1982. 2SH.H. Sneiders, 'Jiko la Dodoma - the UTAFITI field test of an improved charcoal stove', GATE Quarterly, No 2, June 1984, p16. 29L. Brattle, Novel and Improved Cookstove Technology for Use in the Sudan: The Application of Home Economics to the Question of Appropriate Technologies, PhD thesis, Dept of Home Economics, University of Surrey, July 1983. a°E. Ernst, Fuel Consumption Among Rural Families in Upper Volta, West Africa, paper (FRC/3-1) presented to the 8th World Forestry Congress, held at Djakarta, Indonesia, 1978; Gill, op cit, Ref 27. 31Howes et al, op cit, Ref 20. 32j. Gill, Traditional Fuels and Cooking Stoves - a Social, Technical and Environmental Assessment, PhD thesis, Energy Research Group, The Open University, England, July 1985. 33lEA, Proceedings of the Workshop on Energy Data of Developing Countries, Vol 1, International Energy Agency, OECD, Paris, France, 1979, p 16; J. Dunkerley, 'Patterns of energy consumption by the rural poor in developing countries', Natural Resources Forum, Vol 3, 1979, p 359. 34Siwatibau, op cit, Ref 10, p 71. aSShaller and Shaller, op cit, Ref 22. The Lorena stove was purposely designed to have a high mass and low thermal conductivity. a6Martin, op cit, Ref 23; Siwatibau, op cit, Ref 10, p 71. aTHowes et al, op cit, Ref 20. ~SShaller and Shaller, op cit, Ref 22; I. Evans, Using Firewood More Efficiently, paper (No FRC/3-4) presented to the 8th World Forestry Congress, held in Djakarta, Indonesia, 16-28 October 1978. 39G.M. Foster, Traditional Cultures, Harper and Row, New York, NY, USA, 1962, pp 80-82; Siwatibau, op cit, Ref 10. 4°D. Brokensha and B. Riley, Forest Foraging, Fences and Fuel in a Marginal Area of Kenya, paper to the USAID Africa Bureau Firewood Workshop, held 12-14 June 1978; J. Stryker, 'Lesotho: renewable energy technology project', pp 219-224, in Proceedings of the Workshop on Energy, Forestry and Environment, Vol 2, Africa Bureau, USAID, April 1982. "1Martin, op cit, Ref 23. 42D. Bajracharya quoted in A. Makhijani, Economics and The Sociology of Alternative Energy Sources, paper presented at the Environment and Development Regional Seminar on Alternative Patterns of Development and Lifestyles in Asia and the Pacific, held 14-18 August 1979, Bangkok, Thailand. continued on page 140
ENERGY
P O L I C Y April 1987
In Ghana, whilst village women made a number of negative comments about smoke from traditional s t o v e s , 36 smoke that is produced is not always regarded as a problem, 37 as it may be used to cure food 3s and to deter insects. 39 Traditional fireplaces may provide a social focus4° as well as have a symbolic value. Thus, in Ghana, the 3-stone fireplace symbolizes a united family4~ whilst in parts of Nepal, villagers believe that a spirit dwells in their traditional hearth. 42 In these latter respects, the concept of high cooking efficiency has little value or meaning. The importance of the multiple functions of stoves and fireplaces has become increasingly apparent. 43
(3) Villagers' priorities may be different from stove promoters' whose concerns go beyond cooking fuel supplies. A study in India 44 examined the reactions of village women to an 'improved' stove that had been provided by extension workers. Whilst the women said that they liked the 'improved' stove, they were not prepared to pay 20Rs (about £1) for it. On the other hand, the women were willing to pay for a spinning device (which also cost 20Rs) as it enabled them to increase their income. Similarly firewood gathering was not a high priority to villagers surveyed in Indonesia where their main concerns after access to water was increasing their income. 45 For villagers elsewhere, access to clean water can also have a much higher priority than fuel supplies. 46 Villagers in Burkina Faso (formerly Upper Volta) were more concerned about the water supplies, provision of education for their children, health care, jobs for young adults, and enough food and income to keep their families together, than about forest products. 47 Overall, however, these considerations and barriers to the acceptance of new stoves do not necessarily mean that villagers will not adopt new stoves. For example, village women in Zimbabwe have spontaneously changed from their traditional 3-stone fireplace to stoves which they considered to be better (in terms of cooking speed, space heat, less smoke and so on) even though they perceived a substantial increase in fuel consumption. 4s In any case, the widespread adoption of these stoves by villagers is unlikely to have any significant impact on deforestation as gathering cooking fuel is not generally a primary cause of deforestation. 49 It would have been possible to avoid a number of such problems as well as to determine the chances of achieving the purported aims of stove programmes (eg reduce firewood consumption, reduce stress on forest resources) had appropriate use been made of project management tools.
Monitoring and the dissemination of decentralized energy technologies Monitoring is one of a number of key tools (viz surveys, needs assessment studies, feasibility studies and project evaluation) which is used by project management. Monitoring is primarily used in project implementation. Surveys and needs assessment studies are carried out earlier and feed into monitoring by providing baseline information and identifying items which are of strategic importance to the project. 5° On 139
Improved stoves in developing countries continued from page 139 43Brokensha and Riley, up cit, Ref 40; P. O'Keefe, 'Case study: Kenya', pp 65-75, in Proceedings of the Workshop on Energy, Forestry and Environment, Vol 2, Africa Bureau, USAID, April 1982; G. Foley and P. Moss, Improved Cooking Stoves in Developing Countries, Technical Report No 2, International Institute for Environment and Development, London, 1983. 44R. Roy, 'User needs and appropriate energy technologies', Appropriate Technology, Vol 11, No 4, pp 7-8, March 1985. 4sJoseph, up cit, Ref 19, p 8. 46j.T. Thomson, 'Firewood survey: theory and methodology', in D. French and R. Larson, eds, Energy for Africa, Washington, DC, USA, 1980. 47M. Hoskins, Community Participation in African Fuelwood Production, Transformation and Utilization, discussion paper to the Workshop on Fuelwood and Other Renewable Fuels in Africa, held in Paris, 29-30 November 1979, p 19; A.V. Desai, (Rural Energy Systems, unpublished report, National Council for Applied Economic Research, India, c 1978) argues that this is because there is no firewood problem and that no studies show an energy shortage being perceived by the rural poor. 48j. Gill, 'Fuelwood and stoves: lessons from Zimbabwe', Proceedings of the Indian Academy of Sciences, Vol 6, Pt 1, pp 79-94, 1983. 49Gill, up cit, Ref 32; J. Gill, The Pofitical Economy of Deforestation in Zimbabwe, paper presented to the Symposium on Environmental Crisis in Africa: Ecology versus Political Economy, held at the Department of Anthropology, London University, 18 September 1985; J. Gill, Stoves and Deforestation in Developing Countries, paper presented to the UK-ISES conference on Energy for Development What Are the Solutions?, held at Reading University, Reading, UK, 13 December 1985; J. Zerbe, J. Laundrie, H. Wahlgren and J. Whitmore, Forestry Activities and Deforestation Problems in Developing Countries, USDA Forest Service, Wl, USA, 1980. S°E. Hommes, Strategic Management of Energy Projects, Course Manual, International Course on Rural Energy Planning, May--June 1984, Technology and Development Group, Twente University of Technology, Enschede, The Netherlands. SlA. Caceres, Stoves and Kilns - Mapping the Progress over the Last Decade, paper to the Bioenergy 84 Conference, pp 65117, in E. Egneus et al, eds, Bioenergy 84, Vol 5 of Bioenergy in Developing Countries, Elsevier Applied Science, London, 1985; French, up cit, Ref 21; Howes etal, up cit, Ref 22; K. Skutsch, Strategic Management of Stove Programmes: a Rational Reconstruction Approach, Working Paper No 25, Technology and Development Group, Twente University of Technology, Enschede, The Netherlands, 1986; Shaller and Shaller, up cit, Ref 22. continued on page 141
140
the basis of a number of findings and assumptions, feasibility studies define the conditions under which the project is feasible, thus identifying key indicators to be monitored. Monitoring can identify and highlight problems and thus reduce uncertainty in the planning process, for example, by ensuring that there are no significant departures from the proposed timetable. Monitoring can also be used to provide information on the achievement of project goals. In practice, monitoring of a project concerned with achieving mass dissemination of any decentralized energy technology could be carried out at a number of levels: • • • • •
determination of the number of devices built or disseminated; determination of the number of devices still operational in the field; measurements of the operational performance in the field; obtaining user feedback; and measurements of the implications/effects (eg social, economic environmental) of the adoption of the devices with respect to the overall goals of the project.
Monitoring in stove programmes has concentrated principally on the number of stoves which had been built or bought and the number still in use. 5~ Field data on the fuel consumption of 'improved' stoves vis-a-vis traditional ones are very limited. Moreover, it was only in the mid-1980s that the health impacts of 'improved' stoves began to be monitored. 52 T o determine their efficacy, stove programmes could have been monitored in a number of ways, for example changes in the level of fuel consumption, effects on the health of rural women, changes in fuel collection time, impact on deforestation rates, and so on. It has not been possible to find any stove programme which monitored some of the expected effects of the adoption of 'improved' stoves such as a reduction in fuel collection time or increased time spent in income-generating activities. In cases where user feedback has been obtained, this has generally either not been integrated into the stoves project or has been carried out in an ad hoc rather than systematic manner. What is remarkable is not so much findings such as that 'improved' stoves were not necessarily more efficient than traditional ones, or that stove users placed a higher priority on cooking speed than fuel consumption, but that it took so long to discover these findings! 53 Had monitoring been carried out systematically in 'improved' stove projects, such information would have been obtained much more easily and quickly.
Conclusions The importance of traditional 'non-commercial' fuels such as firewood and crop residues in the economies of developing countries was not widely known until the mid-1970s. Consumption of such fuels is concentrated in the rural areas of these countries. These fuels have been the primary sources of cooking fuel and traditionally gathered by rural women and children. However, pressure on forests from firewood collection activities and the extension of agricultural land by a growing population are believed to have led to deforestation. One strategy to reduce stress on forests has been the promotion of 'improved' cooking stoves for use by the rural poor. Improved stove programmes have failed to displace traditional modes of cooking to any
ENERGY POLICY April 1987
Improved stoves in developing countries
continued from page 140
52See for example, K. Smith, Biomass Fuels, Air Pollution and Health Evidence from The Third World, Health and Development Programme, East-West Center, Honolulu, Hawaii, USA, 1984; S. Sharma, Concept and Performance of Smokeless Wood Burning Cookstoves, paper to the Workshop on 'Strategic management of rural technology and health programmes in the process of rural transformation', held in Jaipur, India, 3-5 March 1986. 531n this respect, it is important to note that the first 'improved' stove was promoted in India in the 1950s.
significant e x t e n t . O n e r e a s o n for this is the m i s m a t c h b e t w e e n the felt n e e d s o f the rural p o o r a n d the a s s u m p t i o n s o f the i n s t i t u t i o n s and i n d i v i d u a l s d e s i g n i n g a n d p r o m o t i n g i m p r o v e d stoves. F o r instance, villagers m a y be m o r e c o n c e r n e d a b o u t i n c r e a s i n g t h e i r i n c o m e , access to e d u c a t i o n a n d a b o u t w a t e r s u p p l i e s t h a n the s u p p l y of c o o k i n g fuel. M o r e o v e r , e x p e r i m e n t a l w o r k shows that t r a d i t i o n a l stoves and f i r e p l a c e s are c a p a b l e of significantly h i g h e r c o o k i n g efficiencies than a r e w i d e l y q u o t e d in the o p e n l i t e r a t u r e . In this r e s p e c t , most of the c l a i m s that t r a d i t i o n a l stoves w e r e inefficient w e r e b a s e d on a p p a r e n t l y anecdotal data. In p r a c t i c e the design a n d choice of c o o k i n g stove involves a range of issues a n d t r a d e - o f f s , a n d users m a y be p r e p a r e d to sacrifice fuel e c o n o m y for the ability to c o o k m o r e quickly o r for versatility in thc t y p e s o f fuel t h a t can be used. In a d d i t i o n , t r a d i t i o n a l stoves serve a n u m b e r of p r a c t i c a l (eg p r o v i s i o n o f space h e a t a n d light) a n d s o c i o - c u l t u r a l (eg a social focus a n d b e a r a s y m b o l i c role) functions. T h e s e c o n s i d e r a t i o n s have b e e n n e g l e c t e d in stove p r o g r a m m e s to d a t e . M o n i t o r i n g o f s t o v e p r o g r a m m e s has g e n e r a l l y f o c u s e d on the n u m b e r o f s t o v e s d i s s e m i n a t e d a n d o p e r a t i o n a l . T h e r e a p p e a r s to have b e e n very little d a t a c o l l e c t e d to d e t e r m i n e the effects and i m p a c t s of i m p r o v e d stove p r o g r a m m e s with r e s p e c t to the e x p e c t e d b e n e f i t s (eg a r e d u c t i o n in fuel c o l l e c t i o n t i m e , less p r e s s u r e on forests). P r o b l e m s in the a d o p t i o n o f i m p r o v e d stoves c o u l d have b e e n a w f i d e d had a p p r o p r i a t e use b e e n m a d e of s t a n d a r d p r o j e c t m a n a g e m e n t tools such as n e e d s a s s e s s m e n t surveys, m o n i t o r i n g a n d e v a l u a t i o n . O v e r a l l , h o w e v e r , the w i d e s p r e a d a d o p t i o n of i m p r o v e d stoves is u n l i k e l y to h a v e a significant i m p a c t on d e f o r e s t a t i o n since it is a c o m p l e x p h e n o m e n o n to which t h e r e a r e a n u m b e r of c o n t r i b u t o r y factors.
Appendix The basis of stove 'efficiency' data The basis for the data reported in the literature on the 'efficiency' of traditional stoves and fireplaces can be divided into four categories: first, data which are 'anecdotal'; second, where the author refers to another source; third, data obtained by comparing the magnitude of cooking energy consumption in two countries; and finally data based on empirical work. Most of the work cited falls into the first two categories. The figures in these two categories are remarkably consistent, (mostly in the range 510%), and are almost all derived from literature written between 1978 and 1981. One explanation is that these authors have either drawn upon each other or another common source. The first category contains those
ENERGY POLICY April 1987
figures which are apparently anecdotal and have no acknowledged source or direct literature reference (Table 3). This category contains the largest number of efficiency figures given in the literature - 38 in all. Thirteen references fall into the second category (Table 4). Of 13 authors whose sources were checked, there were seven end references (Figure 1). Of these seven ultimate source references, four have relied on published experimental testing methods. Data by Ascough 5a and Franklin et al ss are unpublished and unavailable, despite several requests; both Revelle 56 and the data by Makhijani and Poole 5v are discussed below. Prasad e t a l 5s do not give a source for the efficiency figure, and hence fall
into the category of "anecdotal' data listed in Table 3. Data by N C A E R 5" are given in Table 5. An example of how evidence can get passed on and become part of the accepted wisdom can be seen in the following flow of citations: Arnold ~'' cites Floor < as his reference source, who refers to an earlier paper by himself) e This latter paper refers to Le Developpement Voltaique ~'3 as the ultimate source. However, this does not contain any efficiency data! Floor 64 acknowledges this and cites two other references ('a publication by the Village and Khadi Commission on Gobar gas, and a shorter Makhijani study') from which he obtained the data. There is only one example in the
141
Improved stoves in developing countries Table 3. 'Efficiency' data with no original source given. Cooking method
Author
Quoted 'efficiency' (%)
Baron (1980)
grossly inefficient
MacKillop (1983) Knowland and Ulinski (1979)
10 3-8
Desch (1973) Hayes (1977)
10 9
McGranahan et al (1980) Smith (1981) Stanford (undated)
10 6-8 8
Open fire
Desch (1973) Digernes (1978) lEA (1979) Dunkerley (1979) Gamser (1979) ROCAP (1979) Morgan and Moss (1980) Norman (1981) Hottenroth (1982) Tiwari (1982) Munasinghe (1983) Sodha and Prasad (undated)
10 6-8 5-10 10 10 <10 6-10 5 6 very low efficiency 5 5-10
3-stone fireplace
Club du Sahel (1978) KiZerbo and de Lepeleire (1979) Mnzava (1980) Vita (1980) Norman (1981 ) Smith (1981) Moss and Hall (1981 ) Lequeux (1982) Thomas and Amalfitano (1982)
3-8 3-8 10-12 wasteful on fuel 7 6-8 7-8 <5 wasteful of heat
Mud stoves 'open chulha' 'chulha' 'mud chulha' 'brick chulha' 'open chulha'
Raju (1957) Prasad et al (1974) Gupta (1982) Gupta (1982) Nanda (1982: 58)
'chulha'
Tiwari (1982)
extremely low efficiency 11 very low efficiency very low efficiency (firewood) 17 (cow manure) 11 very low efficiency
Fuel cowdung firewood
Kashkari (1975) Openshaw (1980)
11 7-8
Stoves in general 'stoves in developing countries' 'woodstoves' 'stoves and fireplaces in Third World homes' 'primitive stoves' cooking in developing countries Open fires and variations Hearth
Source: Gill, op cit, Ref 32, p 117.
third category: Makhijani and Poole 65 who give a figure of 5% for the cooking efficiency in India by comparing the magnitude of domestic energy use in rural India - based on work by Revelle 66 - and the USA. According to these data, the domestic energy use per capita figure for India is four times that of the USA, whence, the efficiency of cooking in India is calculated to be one-quarter of that in the USA. In addition, if we assign an efficiency of 20 per cent to gas stoves - somewhat arbitrarily - then the efficiency of rural cooking would be about 5 per cent. (Emphasis added.) 67
142
This is the underlying logic that Makhijani and Poole use to arrive at the 5% figure of efficiency. Assuming for the moment this logic to be valid, then simply altering the value of the assumed efficiency of gas cookers will change the calculated efficiency of cooking in rural India. Values of efficiency68 of gas cookers in the USA vary between 30% and 60% (depending on the power output and type of pan). These figures would mean that the calculated efficiency of cooking in rural India would lie between 7.5% and 15%. However, this method of estimating
efficiencies may c o n t a i n further errors, as there are difficulties in comparing the magnitude of domestic energy in the USA and India. For instance, foods purchased in the USA will tend to be processed, pre- or partially-cooked. All these will reduce the domestic cooking energy demand. Another implicit assumption in this analysis is that the same amount of food is cooked (ie same useful cooking demand). The average US citizen does not eat the same amount of food as the average rural Indian. These would have to be taken into account in any attempt at comparison. Data based on experimental work give a wide variation in the values of 'efficiency' (Table 5) but do show that traditional stoves can be much more efficient than has generally been a s s u m e d . The v a r i a t i o n s in the measured 'efficiencies' of traditional stoves (as with improved stoves) are a consequence of differences in critical physical parameters, operating conditions and test methodologies. The following example illustrates the danger of generalizing from limited experimental work. Revelle 69 obtains a figure of just under 9% for the efficiency of fuel use in India, the empirical basis for which is as follows: two experiments with rice cooking showed that the energy required to bring the cooking water to boiling and to boil away the requisite quantity of water is about 600 kcal/kg, or 17.5 percent of the food energy content of rice.7° Revelle makes the following assumptions: first, other food grains behave similarly to rice (ie they also require 17.5% of their calorific value to be cooked); second, that 75% of the energy 'biomass' (ie firewood, crop residues and animal manure) is available for cooking food. A value of the efficiency of cooking fuel can then be calculated if the food energy intake and energy from firewood, crop residues and animal manure are known. Repeating Revelle's calculation using his data gives a value of 11.6%, which suggests that he has made an arithmetical error. Revelle gives very little detailed information regarding the rice cooking tests he conducted on rice. Popali et a171 obtained values around 1 210 kcal/
ENERGY
POLICY
April 1 9 8 7
Improved stoves in developing countries Table 4. Author refers to another source. Cooking method
Author
Quoted 'efficiency'
Source of data
Floor (1978) Vanin et a~ (1980) Revelle (1980) Pearson and Stevens (1984) Makhijani (1976)
8 10-43 5-10 6 5
Floor (1977) Goldemberg and Brown (1979) Revelle (1976) Makhijani (1976) Makhijani and Poole (1975)
Open fire
Revelle (1978) Goldemberg and Brown (1979) FRIDA (1980)
10 5-10 2.5
Revelle (1976) Franklin et al (unpublished) Ascough (personal communication)
3-stone fireplace
Arnold (1979)
8
(a) Makhijani and Poole (1975) (b) Floor (1978)
Floor (1977)
8
Le Developpement Voltaique No 40 (August 1976)
Morgan et al (1979)
5-10
Goldemberg and Brown (1979)
Bene et al (1978)
5-11
Makhijani and Poole (1975) Prasad et al (1974)
Somasekhara (1978)
11-17
NCAER (1959)
(%)
Stoves in general
'traditional modes of cooking' (closed) 'wood fire' 'wood stoves'
Open fire and variations
Mud stoves
chulha
Source: Gill, op cit, Ref 32, p 119.
kg to cook rice. Using these data would roughly double the value of the efficiency of cooking from 11.6% to 23%. However, the determination of the energy required to cook food items is not so simple since the energy needed is not a constant quantity, but depends on the physical properties of the food, for example the size or degree of
fibrous material, as well as subjective qualities such as when the food item is regarded as being 'cooked'. Food can be cooked much more quickly and use less energy through being cut into small pieces compared to large pieces. Similarly, the energy required to cook pulses can be reduced if they are soaked prior to cooking. E x p e r i m e n t a l work by Islam 72
Citing authors
Arnold (1979) ~-
End source data
Floor(1978) - " i - - F l o o r ( 1 9 7 7 ) ~
Vonin et o~ ( 1 9 8 0 ) ' ~ . ~
Goldemberg and
Morgan eta~ (1979') ~
Brown (1979)
=
Basis of data
Le Developpement Voltoique (August 1976)
No efficiency data given
Franklin ef o~ (1976) unpublished
Experimental
Revelle (1976)
Experimental
Ascough [personal communication)
Experimental
Revelle ( 1980) ~-------__ Revel]e (1978) 4. FRIDA (1980) ~
Prosad ef o~ (1974)
(1984)
Mokhijoni and Poole (1975)
Somoskhero (1978) ,=
NCAER (1959)
No source given Comparison of domestic energy
consumption
Figure 1.
Citation flows for stove 'efficiency' data.
Source: Gill, op cit, Ref 32.
E N E R G Y P O L I C Y April 1987
Experimental
showed that the amount of energy to cook rice depends not only on the type and quantity of rice, but also on the amount of water used and the type of cooking vessel: cooking rice in a pan with a round bottom used about threequarters of the energy required with a pan with a flat bottom.
54j. Ascough, cited in Domestic Energy
and Its Measurement and the Framework for Practical Solutions, FRIDA, London, December 1980. ssC. Franklin, D. Harrjee and J. Goldemberg, Design for Improving the Efficiency of Wood Burning for Heating Water to Boiling at Low Cost, Princeton University, USA (unpublished), 1977. S6Revelle, op cit, Ref 8. 57A. Makhijani and A. Poole, Energy and Agriculture in the Third World, Ballinger Press, Cambridge, MA, 1975. 58C. Prasad, K. Prasad and A. Reddy, 'Biogas plants: prospects, problems and tasks', Economic and Political Weekly, Vol 9, Pts 32-34, pp 1 347-1 364, 1974. 5eNational Council for Applied Economic Research, Domestic Fuels in India, New Delhi, India, 1959. 6oj. Arnold, 'Wood energy and rural communities', Natural Resources Forum, Vol 3, pp 229-252, 1979. 81W. Floor, Energy Options in the Rural Areas of the Third World, paper presented to the 8th World Forestry Congress, Djakarta, Indonesia, June 1978. 62W. Floor, The Energy Sector of the
143
Improved stoves in developing countries Table 5. Source of 'efficiency' data: experimental works, a Cooking method
Author
Quoted 'efficiency' (%)
Cooking in India
Revelle (1976)
<9
Open fire and variations 'fire under 3-legged pot'
Best (1979a, 1979b)
1.3-7.3
3-stone fireplace
Brattle (1979) Visser et al (1979) Joseph and Shanahan (1981) Visser and Verhaart (1980) Ascough (1980) Bussmann et al (1983) Ouedraogo et al (1983)
11.2-25.5 13-26 14-30 11-23 3.5 22-36 4.9-17.4
'Fijian' fireplace
Weir and Richolson (1980) Siwatibau (1981 )
3.8-5.1 5-10
1-pot stoves Indian brick 'U' chula (firewood logs) (small pieces of firewood)
NCAER (1959) NCAER (1959)
13-15 19.1
Indian 'U' chula (firewood) (cow manure)
Salariya (1978, 1983) NCAER (1959)
12.3 10.1-10.7
Indian 'U' chulha + grate (firewood) Sri Lankan 'U' chulha 1-pot Bangladesh chulha
Salariya (1978, 1983)
15.8
Joseph and Loose (1982) Islam (1980)
10.4-16.2 4.3-10.0
2-pot stoves Egyptian design Indonesian design Indonesian design Indian design 2-pot Bangladeshi chulha
Theodorovic (1954) Singer (1961) Joseph (1983) Geller (1980) Islam (1980)
3-4.4 6-7 12-17 6-14 12.6-19.5
3-pot stoves Indonesian design Indian design Indian design
Singer (1961) Geller (1980) Geller (1982)
6-7 8-14 3-9
Sahelian Countries, Policy Planning Centre, Ministry of Foreign Affairs, The Netherlands, April 1977. 63Floor, op cit, Ref 62, which refers to the August 1976 edition of Le Developpement Voltaique (1976). 64W. Floor, personal communication, Policy Planning Centre, Ministry of Foreign Affairs, The Netherlands, 1981. 65Makhijani and Poole, op cit, Ref 57. eeRevelle, op cit, Ref 8. 67Makhijani and Poole, op cit, Ref 57, p 27. 68K. Knapp, E. Jahn and E. Kafka, 'Domestic gas cooking appliances', pp 12/51-12/157, in C. Segeler, ed, Gas Engineers Handbook Fuel Gas Engineering Practices, Industrial Press, New York, NY, 1965. 69Revelle, op cit, Ref 8. 7°Revelle, op cit, Ref 8, p 972. 71S. Popali et al, 'Cooking at low temperatures: energy and time requirements', Proceedings of the Indian Academy of Sciences, Pt 3, 1979. 72N. Islam, Study of the Problems and Prospects of Biogas Technology as a Mechanism for Rural Development: Study in a Pilot Area of Bangladesh, prepared for the International Development Research Centre, Canada, September 1980.
Source: Gill, op cit, Ref 32, p 123. aAll data obtained from water boiling tests except for Revelle (1976) who conducted two experiments cooking rice (see text).
144
ENERGY
POLICY
April 1 9 8 7