Prospects for Traditional and Non-Conventional Energy Sources in Developing Countries SWP346 World Bank Staff Working Paper No. 346 July 1979 FILE COPY Prepared by David Hughart Energy Department Central Projects Staff Copyright () 1979 The World Bank 1818 H Street, N W Washington, D C 20433, U S A The views and interpretations in this document are those of the auth' __ and should not be attributed to the World Bank, to its affiliated L E [ f organizations, or to any individual acting in their behalf X- The views and interpretations in this document are those of the author and should not be attributed to the World Bank, to its affiliated organizations, or to any individual acting in their behalf. r1, . .. L I.7 WORLD BANK L[ i 1 u 1985 Staff Working Paper No. 346 1;, ;Z-tC,W.0AtL Dl-!- . .oa July 1979 Crtc,i. i).C. 2Al- i PROSPECTS FOR TRADITIONAL AND NON-CONVENTIONAL ENERGY SOURCES IN DEVELOPING COUNTRIES A Background Study for World Development Report, 1979 This paper reviews the prospects for traditional and non-conventional energy sources in the developing countries through 1990. The evidence cited indicates widespread shortages of the traditional fuels on which an estimated one-half of the world's population relies for cooking and other energy needs. Collection of these fuels, which include firewood, charcoal, dung, and the inedible portions of agricultural crops, has become in some areas an important demand on the labor and cash resources of low-income groups as well as a threat to the soil resources on which agricultural development depends. Estimates of traditional fuel supply and demand are presented, but the data base in this field is too weak to allow much confidence to be placed in them. Non-conventional energy technologies, including biomass conversion, solar, wind and small-scale hydro are surveyed. It is suggested that many developing countries could usefully consider programs to increase fuelwood production, improve charcoal production techniques, raise cooking equipment efficiencies, survey and exploit wind and small-hydro resources, and utilize combustible residuals from agro-industrial and forest-industrial plants. Prepared by: Copyright J 1979 David Hughart, Energy Department The World Bank Central Projects Staff 1818 H Street, N.W. Washington, D.C. 20433 With material prepared by: U.S.A. Meta-Systems, Inc. and the Overseas Development Council Table of Contents Page No. NOTE ON UNITS ....................................................... ii I. INTRODUCTION ................................................. 1 II. ENERGY SOURCES AND USES IN TRADITIONAL SECTORS . . 8 A. Generalizations .......................................... 8 B. Case Studies ................................. 17 III. NATIONAL AND REGIONAL STATISTICS AND PROJECTIONS . . 34 IV. TECHNOLOGICAL ALTERNATIVES .................................,. 44 V. RECOMENTNATIONS ..............................,.,.,. 55 A. Substantive Programs ........................ 55 B. Research Needs ., 58 UNNXES I. STATISTICS AND PROJECTIONS,...,,,,,,,,,,,,,,,, .. . 62 II. NON-CONVENTIONAL ENERGY TECHNOLOGIES ......................... 110 -ii- NOTE ON UNITS The energy unit used in the paper is the gigajouleD abbreviated GJ0 A joule is one watt-second9 and a gigajoule is one bill-ion (10 ) joules. The gigajoule is approximately equivalent to: 280 kwh, 0O95 million btu, 0O24 million kcal, 34 kg of coal, 0O17 barrels of crude oiL, 26 liters of kerosene, 67 kg, 150 lbs, 0O093 m3 or 3.3 cu0ft. solid or O0,4 3 or 5.0 cu.ft. stacked air-dried wood, 34 kg or 75 lbs of charcoal, or the energy required to llft 1000 tonnes 100 meters,* that needed to bring 3000 liters of 200C water to a boll,* or to boil away 440 liters of water at 1000C.* * At 100% efficiency. I. INTRODUCTION 1. This paper discussed the prospects for traditional and non- conventional energy in the period to 1990 under three general headings: (a) energy and basic needs, (b) energy and modernization, and (c) non- conventional energy sources for the modern sector and developed countries. 2. Heat for cooking is the most important energy requirement at the basic needs level. The traditional fuels, including firewood, charcoal, dung, and crop residues, are used for cooking by over half the world's population. A widespread pattern of local and regional problems in the supply of these fuels has developed. Scarcities of these fuels have increased the share taken by fuel collection and purchases in the time and cash budgets of many of the world's poorest people. Perhaps more important in the long run is that fuel scavenging has in some areas contributed to deforestation and/or desertification which degrade the resource base on which agriculture depends. Projects and programs to increase the supply of and decrease the demand for woodfuels (firewood and charcoal) are especially important in the mountainous catchment areas of agriculturally important river basins and in arid and semi-arid zones. 3. Modernization virtually requires the use of electricity and mechanical energy from machines, yet the cost of these technologies is too high to permit their rapid extension through the developing world. The only simple resolution to this dilemma is to deny the possibility of providing modern means of production and amenities to most of the world's population in the foreseeable future by continuing to rely solely on conventional electrification and internal combustion engines. At least three alternative approaches should be pursued: making more effective use of draft animals, developing technologies that may permit economic use of locally-available wind, hydro, and solar energy in some areas, and improving the return on electrification projects by attaining a better understanding of the circumstances under which they can contrib:'.-e _o increasa3 in incomes sufficient to justify the investimer't requiredc and &ss-gn-i.g ar;c implementing them accordingly, 4. Developed economies and the modern sectors oc developf- economies need to move away from dependence on petroletm over the cominVCig 6.cadesL Tnhe prospects, however, for non-conventional energy sources playing an importavr. rolc in this transition appear poor at least through 1990 Developing countries can expect to share in the use of technolpg-ies developed in the industr-ialized countries for the use of solar and wind energy, but probably need to take the lead in evaluating and developing mcans of tapping the enormous potential of humid tropical areas to produce biomass fucls. 5. The energy forms most used in the traditional sectors of developing countries, both rural and urban, are ofteD refer.red to as `non-comnercial," although in fact they are widely bought and soldc The most impo-trant forms are firewood, charcoal, plant and animal residues, human and animal effort, and solar energy. Wind and hydro power are also used in tsraditional sector-s !rn some areas. Many of these same energy sources are also cailed "'non-conventioalt17 in the context of discussions of alternatives for the supply of energy to the modern sectors of both developed and developing countries. The differe.ces between traditional and non-conventional enexgy are moire in the techno1og i es used for energy collection and transformation T.han in the nature of the ietrgy source. 60 Developing countries vary widely in their degree of re_-°ance on traditional energy sources. It has bszn estimated tha'; non-cormlrirciaL energy forms supply over ninety percent of total energy demand i.i such countr-ies as Nepal, Tanzania and Mali. In Africa (e'xcluding South Af-rica) m ao>e than sixty-five percent of toal energy consumed is non-commercaia; so0,'2 ten per- cent is agricultural residues while ove.r fifty-five percent is r.:.zlwood. In - 3 - the Far East, excluding Japan, energy use is probably divided about equally between modern and traditional energy forms. In Panama, however, traditional fuels make up only an estimated 20 percent of the total energy sources. 7. Our working hypothesis is that in late 1981, when the world's popu- lation is expected to be 4.5 billion, about two billion people will be eating food cooked with commercial energy, one and one-half billion will rely prin- cipally on woodfuels, and one billion will be eating food cooked with agricul- tural residues including dung. These figures are based on the estimates by geographic region and population group shown in Table 1. 8. Traditional energy supply and demand patterns are frequently integ- rated into complicated agricultural and socio-economic systems. In many agrarian ecosystems, virtually no agricultural product is wasted in the sense of not being put to some productive use, and fuel is produced either jointly or as an alternative to other valued outputs. The right to collect fuel in a given area is sometimes separate from rights to grow crops or build there, and fuel-collection rights are sometimes lost in the transition from tradi- tional to modern land tenure systems. Fuel-gathering is typically women's work, and women are generally responsible for using it in cooking as well. 9. In many of the most densely populated parts of the developing world, forests have been reduced to insignificance as a result of land-clearing for agricultural purposes and scavenging for fuelwood. This leads not only to the use of dung and crop residues to meet basic energy needs, but also to shortages of wood for other essential purposes such as housing, and, in some areas, environmental damages that compromise the soil and water resources on which future food production depends. .-4-4 TABLqE 1 World Population by Princi4pal Caokin- Fuel, 1976 (millions) Commezcial Dung anet Total Energy Woodfuels Crop Wastes Afriea South of Sahara 340 35 215 90 Urban non-poor 30 25 5 Urban poor 20 20 Rural 290 10 190 90 India 610 60 290 260 Urban non-poor 60 40 20 Urban poor 70 - 40 30 Rural 480 20 230 230 Rest of South Asia 205 25 95 85 Uzban non-poor 20 15 5 Urban poor 15 10 5 Rural 170 10 80 80 East Asia-Developing 265 95 110 60 Pacific Urban non-poor 55 40 15 Urban poor 30 15 15 Rural 180 40 80 60 Asian CPEs 855 1i90 435 230 UrDban 205 150 55 Rural 650 40 380 230 M-'Lddle East - North Africa 200 105 35 60 Urban non-poor 70 70 Urban poor, 20 10 10 - Rural 110 25 25 60 Latin America & Caribbean 325 230 85 10 Urban non-poor 145 145 Urban poor 50 25 25 Rural 130 60 60 10 North America - OECD Pacific 365 365 0 0 Western Europe 400 400o 0 0 European CPEs 340 340 0 0 ¶lotal 3905 1845 1265 795 -5- 10. Deforestation and desertification are destroying the resources on which large numbers of people depend for food as well as fuel. In some cases, mountain slopes are cleared of trees for fuel and other uses as demand exceeds regrowth. The soil is then exposed to the elements and often washes away quickly. The loss of the soil not only makes it more difficult or impossible to re-establish forest production on the areas affected, but may cause problems downstream as well. The eroded soil may be deposited in reservoirs (shortening their lives), irrigation canals (raising maintenance costs) or riverbeds (increasing the flood level associated with any given volume of water). 1/ In addition, the upland water storage capacity of the eroded soil is lost, so runoff becomes more irregular, which both decreases useable water resources and increases flood potential. 11. Desertification occurs when the carrying capacity of arid or semi- arid areas is exceeded and vegetative cover is reduced to meet forage and fuel needs. The soil may then be carried away by the wind. 12. Fuel gathering is an important contributor to deforestation, but clearing of land for agricultural purposes and browsing by animals are at least as important. Whatever the causes, deforestation forces people to spend as much as a fourth of their time and/or income obtaining the fuel they need to cook their food. Fuel scarcity also complicates efforts to re-establish forests by making it difficult to prevent seedlings from being uprooted to meet immediate needs. 1/ Controlling floods by building levees without at the same time dealing with siltation can result in the riverbed being built up above the level of the surrounding countryside. The classic example of this is the Yalu River in China. 130 Fuel scarcity can also affect agricultural productivity by £orcing people to stop using animal dung and crop residutes as fertilizers and soil conditioners. In some areas this may be of minor importance, wh:'ne in areas where poor soil is cropped it reduces productivity markedly. 140 We do not know the magnitude of these environmental costs with any precision, but we do know that they are serious and that the inc-:easing pressure of population on resources will prevent the simple continuation of fuel gathering and usage practices that have evolved over centuries and form an integral part of the socio-econcmic-'agricultural structure of many com- munities. At the current rate of deforestation, the tropical forests of developing countries, which now cover half of their aggregate la-Ld area, would disappear in about 60 years0 150 While meeting household energy needs in a manner that is consistent with maintaining and increasing food production is perhaps the most serious energy problem facing many countries, it is not always seen as sucho This is partly because the supply of non-commercial energy is generally taken for granted, and in any case does not have an easily measured effect on variables such as GDP or the balance of paymentso On the other 'nand, there is a clear link between modernization and the use of inanimate forms of mechanical energy,-/and the goal of development in the sense of introduction of modern technologies and means of production often takes precedence over that of maintaining and improving the viability of traditional systems in the interim0 - Per capita horsepower of mechanical prime-movers was sometimes used as an index of economic development before national accountsvcice invented and estimated. -7- 16. The increased price of petroleum and other modern sector energy forms has made the process of modernization generally more expensive and hence more difficult. In order to increase food, fiber, and fuel production and to increase non-agricultural employment opportunities, more energy in the forms of fertilizer, water lifting, seed and crop drying, and mechanical power is required. Although we often assume that this means more electrification, chemical fertilizer, diesel and electric pumps, and tractors running on petroleum products, the time period that would be required to provide these things to the vast numbers of people who must otherwise depend on themselves and on animals for mechanical power and fertilizer may prove to be so long that it is worth considering alternative technologies. There are perhaps 0.3 billion households without electrical service. It may be technically feasible to provide connections to these households at an average cost of $1,500 but the cost would be $450 billion. It may prove more practical in some cases to improve the utilization of locally available energy resources, including the sun, wind, and running water. While costs restrict the present economic usefulness of these non-conventional technologies to a relatively narrow range of conditions, they are already cheaper than conventional power supply alternatives in some areas. Thus, it seems safe to say that when inanimate mechanical energy does come to many areas, it will be provided by small-scale solar, wind and hydro systems or by engines running on locally produced fuels rather than by an electric grid or a diesel generator operating on "imported" fuel. In the meanwhile, there may be scope for making more and better use of draft animals through improvements in animal breeding and health and with improved equipment. The use of rubber tires too worn for further use on automobiles has already reportedly multiplied the load-carrying capacity of an ox-cart by a factor of four in some areas. 1IL ENERGY SOURCES AMD USES -M.N 7'ADITIONAL SECTORS A. GER1EIAIZAEIONS 170 Demand for traditional fue:ls is neav°est in rural areas and dominated by household uses, primar7Ly cookignc but there is also consider- able use in urban areas and by a number of ladus-ries, some on G large scale. 180 iHost rural communities in developing countries are largely closed systems with respect to energy0 A se: of estiuates constructed for rural India, for example, indicates that apz.oxcimatcly ninety percent oc the energy used is from local sources: human (ten percent) and animal (fe;:-.teen) work, wood (forty) crop residues (ten), and cattle dung (sixteen). Only ten percent of rural Yndia's energy is "imported f.Mom the modern sector as petroleum, coal, or electricity. Table 2 presen.s est;hates of hors each of these energy forms is used. Estimates constructed for a pzoto-typical v:.llage in Northern Nigeria indicate it derives about one percenat cf its total energy (including animal and human labor) from commercial so-zrces and xwoodfuel provides some 80 percent of the total, essentially all c'- w.hich is used in household activi- ties. Agriculture accounts for some _5 pezcent of energy demand Lnd domestic uses Zor\eighty percent. 19o Table 3 summarizes a set of estimates £or energy balances of six such proto-typical communities represeeting important regions in the develop- ing world0 It is important to note, however, that these estimates were constructed from a variety of secorda/y sou,ces supplemented Wi^t-- educated guesswork0 Very little reliable quai'titative data exists in this field0 20 Household activities account for -he Largest amounts of- traditional energy demands0 The chief use is for cooking (including the boiling of water, -9- l~ Ln 1-H Cl) cn 11 ,n4 '4t C'J 4 ft L ILIn C C C) u* s I * * * r N sru Ic. 0 o '4 4 I~~CC) 1r4 CD C 4i ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~ CO Co < o4 C C IC Co If -4 C O ' 1 ° 44 * * * * I 0 -4 ,4 - - -4 \C C~ C; C; C 1- H V CO CJ02c I 1r< 4J '0 0) 0CO * I %~~~~~ > U) aq 0 er P. SCo Co IC C c- Ea 0 P .0 a)~'. 4-i 444 E-4 .4 V V CO c) C~~~~~~C P 0 C; 4- HCo I-4-) -,q coW C - r . .. I .. o *co I oo w : 0 1 Cn IC oo n O I C- C 4 o I JH o oo ¢ 0 to 4 o4- CE Co C o~0 @ C i -42C b42C *H OI ZI fX ) C CW o o XC C C C C C4 a)4 ~20O rO 3w C IUOgO H X t ,q ac to : X O sd ^' al~~~cq 0)~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~2~~~~~~~~~ ~ ~ ~ 0 ~~~~~~~~~~~~~~~~~~~~~~~~~4~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~~~'4 S C o 3 1 > c) o * Eq gi w En 44 E -10- TABLE 3 Hypothesized Energy Budgets of Six Agricultural Settlements (GJ per person per year) BIhar, Hunan, Plateau, Northern Northern Ances, India China Tanzania Nigeria iiexico Bolivia Sources 15.2 32o4 2601 1904 56C2 48M7 Woodfuels 1.0 23.0 15.7 34.8 14o9 Crop residues 1.0 20.9 - Dung 2. lj CQal, oil products 40.05 301 -- z0.05 9o9 -w Electricity -- - -- 203 - Human energy 301 301 301 3.0 3,7 305 Animal energy 7.9 52 -- 0.8 704 10.4 Uses 15.2 32,4 26,1 19.4 56,3 48,7 Domestic 4,2 23,9 23.0 1507 17.8 3408 Agricultural 7,4 8,2 2,4 2.9 34,7 7/0 /1 Other 3,5 3,3 0.8 0.8 3,8 6,9 Detail may not add to total due to rounding errors, '/ Includes transportation and crop processing. Source: Makhijani and Poole, 1975, -11- baking and brewing of beverages). Cooking was found in surveys in The Gambia and Thailand to account for about 75% of total woodfuel consumption. Cooking fuel in rural areas is almost always derived from biological sources, such as wood, dung and crop residues. In fact, aside from kerosene, which is used fairly widely in Latin America and less frequently elsewhere, wood, dung and crop residues constitute virtually the only sources of household fuels acces- sible to the non-rich in rural areas of developing countries. 21. An important factor in the choice among biomass fuels is their relative accessibility. According to an Indian survey, 1/ a pattern which appeared typical of many areas is that where forests are no more than 10 km from a village, between 70% and 100% of fuel requirements will be obtained from them. Beyond a distance of 15 km however, fuelwood use virtually stops. Crop residues and dung are then gathered locally or charcoal is brought from more distant areas, or kerosene is used when available and affordable. Similar patterns have been reported in Bangladesh, Northern Nigeria, Sudan and Nepal, although people in some areas go much further for wood. Other food preparation tasks often make use of solar and wind energy. A variety of crops, species and fruits are sundried in order to preserve them. The wind is widely used to help separate grain from chaff and sometimes also for drying meat and hides. Space heating, where practiced, has traditionally relied on biomass fuels in combination with architectural adaptations. Use of thick stone or adobe walls and roof overhangs are the most common examples of the latter. The household use of wood, dung and crop residues is often 1/ R. Mathur, 1975 cited in J.E.M. Arnold, 1978 World Forestry Congress Paper. *12- much greater in the mountainous areas of cievQic'iThg countries t17,= in tropical lowlands0 One recent study 1/ fo-und Lhat household fuelwood requ rements differ between lowland and highland areas by as much as a factor of 4. The bulk of this variation is presumably due to space hestingc 22. Hauling water and gatherinig fuel az,e essential domestic tasks re-' quiring considerable arduous labor Palost altmays done by women and children0 Agricultural tasks in traditional ruz1al settTigs awe usually performed using animate energy. Numerous country studies end cbservations indicate that most of the human and animal labor available to rural families is used in 'these tasks and that outside of parts of La-in America and South Asia, mechanization is uncommon0 Soil preparation, chiefly by plowing, is done wherever possible with bullocks. In some areas, especially in shifting tropical forest agricul- ture, soil preparation is done by hand6 arTd -includes tasks such as tree-felling and stumping. Both men and women (the lattez especially in Africa) perform this task. Planting and cultivating is almosi: universally done by hand0o iT;is includes the application of fertil-°ze£s a2no pesticides where used0 Irrigatio-n generally relies on gravity or commercial onecgy. Traditional energy forms are less often used for irrigation, but in some countries technol-ogies such as the animal-powered Persian wheel, the hand- owered counter,balancz "'shadoof" of North Africa and West Asia, windmills in scattered sites and, occasionally water wheels are used to provide mechanf caci pownro 23. Fertilizing is not a universal practice in the poorer developing countries, though it is far from uncommon0 On mocern farms commercial ferti- lizers may be used. On small, traditional, end subsistence farms fertilizer, 1/ K. Openshaw, Tanzania -13- if used, usually takes the form of animal wastes. Harvesting and initial processing, such as grain threshing or sugar cane crushing and other tasks such as husking, shucking, shelling or grinding, typically involve great outlays of human and draft animal labor. Again, the proportion of animal labor depends largely upon how much is available. Draft animals are uncommon in Central and West Africa because of the prevalence of the tsetse fly. In much of Asia, most draft animals are owned by the better-off village residents and not available to the bulk of the rural population. In any event, harvest- ing requires mostly human labor since animal-drawn harvesting equipment is not available or is very costly. Marketing of foods that may be surplus to the farmer's needs takes energy. In some areas cash crops are carried to market on foot. More often it is brought on the backs of animals or in carts drawn by them. Rural industry and commerce employ primarily human labor and wood fuels. Some of the most important of these activities in terms of energy use include metal working, commercial food preparation, brickmaking, and drying and curing of food and crops such as tobacco, tea, and coffee. Tobacco curing in Malawi is estimated to account for 17% of that country's total energy consumption. 24. In some rural areas, but more typically in larger towns and urban areas, community services such as schools, clinics, local government, reli- gious centers, public markets, transportation, communication, and electric power enter into energy demand. Most of these needs are met with commercial forms of energy. Public transportation is probably the most important of these services in terms of numbers of users and quantities of energy used. It is highly dependent on petroleum fuels. Electric service reached as of 1970 about 10-15% of the population of low-income and about half of the households of middle-income developing countries. -14- 25. Much of the above description of energy needs and tasks applies to urban areas as well, particularly for domestic needs and communit:y-related services. However, the density of demand and hence pressure on resources is much greater. Urban dwellers typically rely less on fuelw^ood tikan their rural counterparts, but consume more charcoal and commercial fuels than rural populations. 26. Charcoal is a widely-used fuel in the households and informal/small business sectors in many urban areas because it is more easily transported than an equivalent amount of wood and is more convenient to use. As the urban component of developing country population grows, charcoal use can be expected to increase in importance. While 70-80% of the energy value of wood is lost in traditional charcoal productions this is generally roughly compen- sated for by the much higher efficiency of charcoal stoves. 27. Where demand is high and supplies tight, wood fuel depzndency can lead to hardships. Fuel purchase was estimated to take 20-30% of the average worker's family income in Ouagadougou, Upper Volta and Niamey, Niger in the early 1970so 280 Traditional fuels are not used exclusively by the poor0 Among the highest income group in a Thailand study, comprising 6% of the population, more than 70% of households are predominantly wood fuels0 Tne fraction of households using woodfuels has been estimated from survey data to be 99% in The Gambia, 98% in Tanzania, and 97% in Sudan and Thailand0 However, among the middle and upper classes, a gradual transition to petroleum-based fuels or electricity is evident, though tradition continues to favor charcoal for cooking in some areaso Because overall consumption increase with income, a positive income elasticity of demand for wood fuels has been found by some -15- studies, so that with gradual rises in income, more wood fuels rather than less may be consumed. 29. A major element in the choice of cooking fuels is the cost of an appropriate stove. Wood is often used without a stove of any sort and simple braziers produced by artisans are frequently used for charcoal, whereas LPG or electric stoves represent substantial investments. Investment costs re- quired for the use of various fuels in Ouagadougou, Upper Volta have been estimated as follows: Fuel Investment Required Cost (US$) Fuelwood some stones 0.00 Charcoal stove 0.80 - 4.00 Kerosene stove 10.00 - 14.00 Butane or Propane (LPG) stove + bottle ca. 52.00 Electricity stove + utility deposit ca. 120.00 30. Fuel prices vary greatly from area to area. Kerosene, the most internationally traded of the fuels listed above, was sold in world markets until recently at about US$0.10 per liter, or about US$7.50 per capita per 1/ annum for basic household requirements. If crude oil prices settle around $20/barrel, kerosene can be expected to cost about $0.15 per liter in major export refinery markets, bringing the foreign exchange cost of cooking with kerosene to about $11 per capita per annum. 31. Lighting, another essential domestic need, is met by a variety of sources, including kerosene lamps and candles. Most of the urban poor cannot afford the high cost of electricity even when available. 1/ Retail prices were less than half the figure quoted in mid 1977 in the capital cities of Indonesia, Bolivia, Ecuador, Mexico, Peru, and Venezuela and more than US$0.20 per liter in those of Brazil, Ethiopia and Uruguay. The prices in twenty-five other developing country capitals was between US$0.05 and US$0.20 per liter. 320 Other household activities such as food preparation and clothes making and washing are done by hand; irons zaL' neated with fuel u'fhare electri- city is not used. 33. A host of cottage industry End s:maDl-scale enterprises employ traditional fuelso Small bakeries, cafe-baco. streets-de food vzacdors, blacksmiths9 and briclmakers all ccmmonly use toodfuclso As in the uLban household sector, charcoal is a preferred fuel. These same enterprises often employ a great deal of semi-skille6 ½bDor. la Afr ca, it is not uncommon to find open air shops operated by semri-killed entrepreneurs. These wsorkers may use wood or charcoal fires to recycle scrap rnotal into items such as bicycle parts or kerosene lanteens wh'nch can be sold directly to the public (usually the urban poor) or to other small: businesses for resale. 34. Other informal sector activ`;ties substitute labor for activities thaL in the more developed countries would take modern energy0 1,.cusehold members and domestic servants make the frequent trips to market (partly in lieu of refrigeration), do the manual clothes washing and house^work', the carrying of water and fuels, and nunerous other essential daily tasks by hand0 35. Some formal sector enterprises utilIze traditional fuels50 3efore the oil price increases of the seventi_es this was decreasing steadily0 Indi- cations are that for some industries this trend &ay have halted or even reversed. One example of using traditional fue '6s in the modern sector is the use of charcoal for steel making in the PhiXippines, Brazil and other countries. The Ugandan tea industry uses wood fo- curing and Thailand's railroads are starting to revert back to their earl-ier use of wocd fuels0 Wood fuels are also used to brew beer, dry fisb, tobacco and lumber, make bricks, and manufacture cemento -17- 36. The case studies that follow are intended to illustrate the point that traditional energy supply and usage patterns cannot in most cases be understood except in the context of the eco-agricultural and socio-economic systems of which they are a part. B. CASE STUDIES (1) Rural Energy in the Context of Agricultural Systems: Dhanishwar, Bangladesh 37. Traditional energy systems are difficult to analyze not only for lack of data but because they are often part of complex agricultural systems. In terms of output, high technology agriculture in developed countries is often much simpler than traditional subsistence agriculture in developing countries. While the only valued ouput from a corn field in a developed country may be grain, each crop in Bangladesh typically fulfills multiple, explicitly-recognized purposes. 38. Another characteristic of this agricultural ecosystem's that vir- tually nothing is wasted. The term "crop wastes" is inappropriate since virtually every product of cultivation is put to use in some way. In a materials sense subsistence economies are "tight." 1/ 39. This complexity and "tightness" makes the process of understanding the energy system contingent on an appreciation of the agricultural and live- stock systems. The high degree of "connectedness" between different sectors means, for example, that an intervention in the agricultural sector (such as 1/ FAO Soils Bulletin 40, China: Recycling of Organic Wastes in Agriculture (Food and Agriculture Organization of the United Nations; Rome 1977) also illustrates this tightness. the introduction of high.yielding crop varieLies which produce a Jower ratio of straw to grain) will also affect the energy and livestock sec^crs and vice-versa. 40. The intricacy of fuels supply and usage patterns in a nearly-closed agricultural system is illustrated in Figure 1, an energy-related resource flow diagram for the village of Dhanishwar in Bangladesh. Food and fuel balances for the village of 422 people are shown in the lowcr left corner of the figure. The village economy is approximately balanced at a subsistence level. Energy flows in Dhanishwar are related to the production of cash crops, livestock, food and materials for home building. 410 A single crop may perform several complementary functicns0 An example of this type of crop is doinshah, a leguminous plant which is sown before the monsoon on the small ridges which separate individual plots. As the fields become flooded by monsoon waters, doinshah fulfills the first of its tasks by preventing water hyacinth from entering the plot and damaging the growing paddy. At the same time the plant is enriching the soil by fixing atmospheric nitrogen, a function hinch is explicitly recognized by the farmers. The leaves of the doinshah plant are harvested for cattle fodder. Finally, at the end of the monsoon the fibrous stem is pulled out of the ground and provides an excellent source of fuel0 This fuel is particularly valuable since it becomes available during the period of acute fu2l shortage preceding the amon harvest0 42. Not only do most crops produce multiple complementary products, but there are often alternative, competing uses to which each product may be puto This is best illustrated by the most important crop in the area, deep--water amon paddy0 This crop is sown before the monsoon, grows in four to nine feet 0 ~ ~ ~ ~~~~1-C . 1 .0 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ t ,80 C~~~~~~~~~~~~~~~~ E 0 U, C 0)~~~~~~~~~~~~~~~oU C c . n OG C'4H1 ~ IC N f 0 W 0 U'w E - 04 U] C-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~U to CE -C a) .~~~~~~~o -.0~~~c ( -- C 00 .C 'C _ U, 0~~~~~~~~~~~~~~~~ LO 0C a CL. ~ ~ ~ ~ ~ ~ ~ a 0~~~~~~~ 00 . 0 N C *~ U, U, C C -O~~~~~ 00 cc . a) N -. a) U]J C-E 'C C- .0 > "I 0 0~~~~~~~~~~ CN C%j~~~~~~~ 0 0~~~~~~~~~~~~~.- 0 0 OL~~~ U) 0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~C 'a~~~~~~~~~ )C U,0 t C', - N >~~~~~~~~C U G~~~ 0 ON Ul ~ ~ ~ ~ O N 1-f .2 U') o..- -W 'n = 0 ~ ~ ~ ~ 0 .. 0 . ' cu Cj CL o v .0 ~ ~ ~ ~ ~ ~ ~ ,~C E a) 0 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~a) o tn 0 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~I n0 Ii of water and is harvested after the monsoon waters recede. The wost signi- ficant purposes served by the cultivation or amca paddy can be iJ_ustrated as follows: Use Product Human food Fodder Fuel Fertilizer Construction Leaves Grain Husk nara 1/ straw kher 2/ straw (Legend. ** predominant use; ** used commonly but not frequently; 8 used but uncommonly). 1/ nara is the tough straw which remains in the field after the paddy is harvested o 2/ kher is the more tender straw which is carried from the field with the harvested paddy and which remains alter the threshing of the grain. 43. All village activities depend on so1ar energy0 Total s-,nlight falling on the cultivated area can be considered constant from year to year at about 60OOO GJ/year while the efficiency of photosynthetic utilization may increase or decrease depending on varietal, soil, and cultivation changes0 44. Seventy-two percent of the labor available for agricultural work is utilized in cultivation and crop processing0 During peak seasons this becomes 100 percent. A shift to more intensive agriculture may be prevented unless more power can become available through mechanization of agricultural activities or shifting of labor from alternative occupations such as fuel -21 collection. Alternatively, as fuel becomes scarce and more time is required for its collection, agriculture may suffer. 45. Draft animals provide between one-half and two-thirds of the over- all mechanical energy input to agriculture as well as being used in transpor- tation. A change in livestock numbers would thus affect crop production operations as well as alter the balances of straw and dung. 46. Chemical fertilizers contribute little to crop production at pre- sent. Most of the fertilizer applied to this village's fields is cow dung. It is estimated that in this village 62 percent of all dung produced is used to fertilize cultivated land and 13 percent is used as fuel. Twenty-five percent is not collected and probably uncollectable. If dung use for fuel were to increase, its availability for fertilizer would decrease and crop production would suffer unless a replacement source of nutrients and soil conditioners is provided. 47. Agricultural outputs are processed and supplied to the homesteads and to the cash economy outside the village. This village is close to a balance between local food supply and demand with a modest sale of cash crops suffucient to pay for the barest necessities of clothing, taxes, and small amounts of food (salt, spices, sugar) from outside the vi4lage. 48. Food and cash come from agriculture together with three other essential products: animal feed, cooking fuel, and material for house cons- truction. It is estimated that about one-half of the jute sticks (materals left after the fibrous "cash crop" is removed) is currently used as construc- tion material. Where competition is keen for jute stick as fuel, housing suffers. This has already been reported to be happening in some parts of Bangladesh. 49. Rice is the staple food of Bangladesh. Rice straw is zn important source of cattle feed and provides three-quarters of the fuel used for cook- ing. Jute sticks provide another 15 percent of cooking fuel. Clearly any decline in the amount of rice straw produced, whether because of production or varietal changes, will force (1) a cooking fuel shortage, (2) pressure on jute stick supply for fuel9taking them away from construction, (3) pressure on the few trees from which fuel-wood can be taken, and/or (4) reduced use of rice straw for animal feed with animals as a res-ult producing less draft power and dung. Fuelwood in Dhanishwar supplies only about seven percent of household fuel requirements. 50. Poor landowners head 20 out of the 77 familiesp xeitil 100 out of 422 peopleo They work 6o5 of 60 hectares of land and own six of the 101 cows and bullocks. Another 12 families are landlesso Table 4 shows the distribu- tion of population and principal resources among households by income levelo Table 5 shows the resulting food and fuel balances0 51. The poor use no chemical fertilizer and have a supply of dung of only 6 tonnes per year: less than their demand for fertilizer alone0 The richest 10 percent of families have , however, a relative surplus of dung, part of which they use for cooking0 52. Furthermore, the poor have a food deficit and insufficient rice straw to meet cooking needs0 The poor and landless gather twigs, leaves, and firewoods and obtain food and fuel from the rich in exchange for labor at times of peak demand0 -23- Table 4 Distribution of Population and Resources by Income Group in Dhanishwar Class Landless Poor Middle Rich Village Total_________ ____________ Totals Total Population 40 100 222 60 422 Numbers of Families 12 20 37 8 77 # of persons/ family 3-1/3 5 6 7-1/2 Available Agricultural 1 1-3/4 2 2-1/4 Work Unit/Famil Farm Resources Per Farm: Land (acres) .8 2.25 6 Labor (agricultural work units, in days/year)' 315 360 405 Bullock2 .3 1 3 Cows3 0 .5 2 By Class Land(acres) 16 83.25 48 147.25 Labor(agricultural work units/year)' 35 74 18 1394 Bullock2 6 37 24 67 Cows3 0 18.5 16 34.5 1Each agricultural work unit is assumed to represent 180 days of ten hours/day work. This figure is the one used by Revelle in Science article. 2Each bullock is available in 1,000 hours of work per year (Makhijani and Poole). Each one also produces six pounds of dry dung daily (BES) and eats 26.0 GJ. Each cow produces 4.5 pounds of dry dung daily (BES) and eats 19.3, GJ of straw yearly. Cows are assumed not to perform any agricultural work. 4Includes landless workers. w -l LOi N r; 91 ri: ° > (7\ vD fco t9 2) r- X S tS cDtDtDe tO Vo (t)t)~~~~~~~~o r O [ (: tn 67 ) t ,-(CO f (I L) rD _ -o :3 .S J , aSl C. C 1r4C 1 XC y . m u v9 ~~0 N kg O * rQ ;~~~~A4 f 4 en co>°9 n . s s YJ Z p 0 vl C) 3n Z : IV o. 6 , ° ') F-4 z h ;d cm 34J = O fd O (d vi j U tv S l *~~~~~~~Ai ( 4gDa> F4 4;a n o 3J C) co~~~~ 'F _ 9t4 C4 n Ho'4 - : pq ~ ~ ~ ~ ~ f OD F4 F4(a sS fj > t° g= f B O V 4 144 fE < h .fCl red V- C~~~~U) ,l ( P14 ~ ~ ~ a 0 ° r OOOQ .3 C < -25- (2) Energy in the Contest of Traditional Socio-Economic Systems: Fatehpur, Bangladesh 53. All the important energy sources in village Fatehpur, Bangladesh, are derivatives of either crop production, tree cultivation, or animal hus- bandry. Over 40 percent of the village population is landless, perhaps 80 percent have no cattle, and significant numbers of trees are owned only by the more wealthy villagers. In short, the command of energy resources in the village is highly skewed, with perhaps 50 percent of the population commanding virtually no fuel-generating resources. When we look at energy use rather than production, however, we know that all families do cook their food despite the fact that so many command so few fuel resources. This dis- tribution of fuels is mediated by a system of social relationships. These relationships are central to the distribution of energy resources within the village, the probable reaction of different groups to attempts to introduce new energy technologies, and to the effects that adoption of such technologies would have on the various groups within the village. 54. Social equilibrium in the Indian-subcontinent has historically been maintained through communal organizations and through vertical relationships between powerful patrons and peasants. Since the introduction of private ownership of land by the Permanent Settlement Act of 1793, patron-client relationships have stemmed directly out of the possession of differential rights in land. All those who worked for a landownever, either directly as tenants, servants or laborers or indirectly as artisans or service sup- pliers, tended to become clients. Landowners leased out land to tenants and sharecroppers in part to reduce their management problems and in part to ensure a supply of labor during planting and harvesting when labor shortages -25- are common. A client was also a loyal follower in village affairs, adding to the patron's power in the endemic factionalism characterizing village politics, and as a helper on ritual occasions and times of crisis. 55. The distribution of scarce energy resources is governed by the social mechanisms which control the distribution of food and othor valuable commodities. Thus, after meeting his ot-n needs for fuel, a traa-tional land& owner may neither compost all residual rice straw nor burn the straw _n the fields -- the ash is a valued fertilizer -- but may allow clients to clear a prescribed area of the harvested paddy field. Similar privileges may be extended for the collection of cow dung from the cattle of the rfch. 56. These systems persisted because t'ie patron-client relationship was the only vehicle which satisfied the objectives of both rich and poor. The system acquired an apparent stability, with the regulations governing the appropriate behavior of patron and client embedded in the social norms of the community. Now, these once stable systems are changing rapidly in Bangladesh, India, and other parts of the world0 57. Among the causes of this change in Bangladesh are the adoption of high-yielding crop varieties and the mechanization of agriculturc, the in- creased importance of non-agricultural sources of income (includ:tng govern- ment employment), a decline in the availabiliLy of certain resources (such as fisheries) and the consequent forcing of groups depending on these resources in other pursuits, a reduction in the demand for agric-ultural labor, and an enormous increase in the supply of agricultural labor0 580 These social changes manifest themselves in several ways in the energy system of the village0 Farmers who have acquired land through recent purchases, who farm their own land and who pay exclusively money tiages -27- frequently burn the crop residues which they cannot use themselves. Ten years ago no villagers had difficulty in obtaining sufficient crop residues from a landed person. Today the procurement of sufficient fuel is a critical problem for many families. While there are instances in which families simply cannot cook their food for lack of fuel, these are still uncommon. What is common, however, is a complete breakdown in the distributive mechanisms. Many families in the village collect rice straw from others' paddy fields at night when they cannot be detected. Disputes between landlords and share- croppers over crop residues are frequent and often vehement. The number of village trials resulting from disputes over fuel is rising rapidly. 59. An awareness of these distributive mechanisms is essential for successful planning. A program for the utilization of dung from a farmer's cows and the straw from fields may not be attractive to a traditional farmer since benefits may be insufficient to warrant the risk of damaging customary relationships on which he depends for labor or other services. 60. Where new technologies are adopted and the use of organic resources improved in a thermodynamic sense, the adoption of these technologies may hasten the deterioration of the resource base of the poor. This is apparently the case with the biogas program in India. The average gas-plant owning family in Gujarat has twenty-six acres of land and ten head of cattle. The poor can no longer, as in the past, collect much of the cow dung from the cattle of the rich. (3) Deforestation and Energy Needs in a Mountainous Area: Nepal 61. Examination of one of the world's best known environmental problems provides insight into the difficulties of intervention in a village ecosystem 28- without sufficient attention to socia;. 'ealiies; in this case the desperate condition of the poor. 62. Tne slopes of the HimalayEc- aze zin wiany areas -being vmshed away0 By some estimates, it will only take anothez decace ox two befce these mouzn- tains will be so completely stripped oF the'ir tree cover that erosion, already severe, will be virtually unrestrained0 fkhie irplicztions of such? a develop- ment for both the Nepalese and for the populations dowunstream in Bangladesh and India are appalling. 63. Just a day's walk north ir..o the hIlls above the Kathmandu Valley, the effects of deforestation on soil quality, erosion, and water supply are strikingly visible. The trail benesth trees is rich, moist, dgrk earth full of humus and spongy. But where trees bave b2en cut aw-ay, the soil is dry and sandy, crumbling underfooto Whole mozintainsides can be seen to have fallen away in landslides0 Stream beds are dry or run £ bare trickde between down- pours as there is little soil to sto:re moisture, Where slides hLve started, there is no vegetation to stop the eazth, xAhich smothers any trees below^ and increases the bare surfaces0 Nowhere can thiere oe seen a tree o-: bush un- scarred by axes, knives, or browsing domestic an5imals0 The imprint of people searching for fuel and fodder is to be seen everywinere0 64. There are three main causes of the deforestation which follows people into the hills: expansion of agricultural land, demand for f-odder to feed domestic animals through the winter months, and demand for -irewocd0 In the search for agricultural land on which 'to groW food, people are clearing hillsides and practicing the traditional terracing used in the lower valley areas0 Many terraces are narrow and sloped outware, inviting lardsilides which can subject whole mountainsides to erosion, -29- 65. Although much of the fodder needed by the dense population of domestic animals in Nepal is provided from pastureland grazing, there are some months during the winter when animals must be brought from the high pastures to the villages for safekeeping. During these months, fodder gathered from trees is fed to the animals. 66. All domestic space heating and cooking in hill households is with wood. It is estimated that firewood consumption is three-quarters of a ton per person per year. As fuel becomes scarcer, it takes more hours per day to collect the household's supply, and areas of the forest never before exploited are now subject to the woodcutter's axe. 67. Combined, agricultural expansion, fodder and fuel gathering are removing Nepal's forests at a rate that could be sustained only twelve to thirteen more years. As more forest is removed for farming, the potential for regrowth reduced even further. 68. Figure 2 outlines energy flows in a typical Nepal hill village. Land use in such a situation would divide approximately as follows if forests were harvested at their sustainable yield rates: Cultivated 29 ha Pasture 43 ha Fuel Woodlot 73 ha Forest Fodder 50 ha Total 195 ha = 0.78 ha/person, which is approximately the per capita land availability for all of hill Nepal. 69. Clearly a village is in difficulty if its per capita share of land in forests is not available because of physical or political conditions, de- forestation, or inaccessibility and it therefore has to exploit its forests at a rate that cannot be sustained. This is unfortunately the case for a Figure 2 Farm System in the Hills of Nepal con-i4una:lly Fam fami owiied @OK@ resouXcCs 183 tons 73ha woodlot for 1 materialsl 250 people in sustained produc Lion 48 FOREST LAND HOMESTEAD and WATERSItED C . _ -+5Oha forest fort9 n2 ~ >5 28.7 ha CUJLTIVATED LAND - '% | (valley and hill terraces) s50 tons rice and maize ~~~ _E ~Wa~ur _______e _ Hy>' >S rs ~~ fi O d U 04 :a' grid o: generating It locally with small diesel setso S-in milarIy2 , idnl s w : b found competitive with conventional pumps in many areas w-'nece avz:ag2 e Jnd speeds are at least 15 kcm/h and costs o' electricIty or diesel c:: gcassline fuel and maintenance are relatively iilgh. 127. Mill wastes include sugarcane bagasse, sawdust aœd ti'. shellsD pulp, husks and other materials that are often byproducts of ooc; ana crop processing operations. In many cases these materials are used p.^sductively and efficiently while in others they are dumped, incinerated or inde utilized. Countries in which these industri-es are importantt shcd consider investigating the possible uses of byproducts as fuels, Includi-3 possibi- lities such as driers to raise the fuel value of bagasse, pyrolysis units thaL produce gas and char oil for in-plant use and charcoal for sale, r-evision cf electricity tariff terms to encourage cc generation, and machines to producc briquettes or pellets from loose material in order to produce a .-uel suitable for domestic uses. B. RESEARCH MEEDS 128. The recommendations outlined below include research of oroblem identification and analysis, technical research, development anad demonstration of promising technological approaches, and research and trial of prfloject desigsi and implementation techniques. 129. In problem identification and analysis three general a.es are especially important: - 59 - (1) Surveys of traditional energy supply, trade, and use are needed to establish base-year numbers and the order of magnitude of response to increasing scarcity, price and income changes. We feel that investigation of survey methodology and possibilities for cross-checking and inferring figures from agricultural and forestry data and remote sensing techniques is needed as well as sample surveys of households and other users. (2) Estimates are needed of environmental damages associated with alternative levels and patterns of traditional energy use. Much of the concern for this subject stems from the apparently serious consequences of deforestation (erosion, siltation and flooding downstream, desertification) and burning of crop and animal wastes (loss of soil conditioners and nutrients) in many areas. Sufficient research needs to be done on the cost in terms of agricultural production of these damages and the role of fuel collection in producing them to establish priorities. (3) Identification of policy and investment priorities might also be improved through research into the role of electricity and inanimate mechanical energy in rural development. Mechanization and electrification are widely identified with development by governments and the argument is made that evaluation criteria such as those used by the Bank do not give credit for the dynamic effects on the development process of projects such as rural electrification. Studies to date have indicated the issue is a valid one but have not developed the tools needed to adequately quantify these effects to allow an accounting for them in project assessment. 130. Technical research. Most of the technical research and development being done on renewable energy is directed toward the major energy problem of - 60 developed countries': finding alternatives for limited petroleum resources. Developing countries with their growing urban-modern-industrial'sectors stand to benefit from this research as the technologies are improved and conventional energy prices rise. However, the ecological differences between the tropics and temperate zones give many developed countries significantly different possibilities than those being studied for developed country use, especially in terms of biomass production. Much of the technical R&D on small scale technologies for developing country environments is focused on providing inanimate mechanical power and/or electricity for stationary applications. We feel that much emphasis should be placed on the problem of cooking, including fuels, stoves, utensils, and solar cookers. Improved use of draft animals also appears to be a relatively neglected field. 131. International cooperation in R&D efforts can help to avoid duplica- tion of effort and provide for cross-fertilization and cross-checking of ideas. The form of cooperation that is most appropriate for a given technology or'group on technologies varies from case to case. Basic research may not need to be repeated in a large number of countries, although such replication may be a worthwhile means of transferring technology. Adaptation of designs to local materials and requirements is almost necessarily done in local institu- tions, although the process may be accelerated by improving communication among workers in different countries. Work on some technologies such as solar cookers might usually be concentrated in a relatively small number of institu- tions because to date designs have not been developed that could serve as the basis for successful adaptation efforts in many countries. In general, the number of centers working on a.given technology should increase as progress is made from theoretical understanding of first principles to engineering of - 61 - equipment and as a function of the need to develop different design approaches and make different materials choices in different countries. 132. Project design and implementation trials will be needed to learn how and how not to attempt to move technologies out of laboratories and into homes and communities. Improved woodstoves appear to be a technically simple, low-cost solution or partial solution to fuel shortages in many areas. They have been adapted to local conditions in a number of countries, but successful extension techniques have not been proven on a large scale. ANNEX X -62- STATISTICS AND PROJECT&XOŽS 1. As the discussion in the main text indicates, there is con- d:e2ble uncertainty regarding both the demand and supply sides of the ,-e of traditional fuels. Although potential supply can be estimated from aggregate forestry, agriculture and livestock information, basic fuel needs are strongly influenced by cultural, nutritional and enviyormental factors. Actual utilizvtion or demanad for traditional fuels is strongly influenced by access to supplies, and to a lesser extent by incoyri level. Consequently, neither the overall utilization nor the compositicn of fuels can be estimated accurately from information on the nation-lal level. Firewood may be available on the national level, but If the nearest woodstand is 100 km away, a shift to cereal siraw and/or dung is quite likely. Site specific surveys and measurement are necessary ano. for most countries such information is lacking. The available survey data is summarized in Table I-lo 2. Nevertheless, in order to estimate the magnitude of traditional fuel use and availability in all countries and to indicate pro^olsm areas, baseline figures and projections were constructedo The results of thls exercise must be viewed keeping in mind the data difficulties described above, as yell as the masking of regional, economic class and seasonai variations in traditional fuel use and availability involved in wYorking with data at the national level0 -63- TABLE I-1 HOUSEHOLD USE OF TRADITIONAL FUELS: SURVEY DATA (GJ/capita/yr) Percent of Total Firewood Agri- National National Traditional and Animal cultural Population Average Fuel Use Charcoal Residue Residue Using Tradi- Traditional Country Locale Year - (For Traditional Fuel Users Only tional Fuels Fuel Use I/ Bangladesh 2/ national 1973/74 2.56 .41 .77 1.38 91% 2.32 Gambia 3/ national 1972 17.3 17.3 99% 17.3 India 4/ rural 1970 7.16 4.38 1.77 1.02 Kenya 5/ 1960 10.9 10.9 Nepal 6/ national 1974/75 8.5 8.2 .1 .2 99% 8.5 Nigeria 3/ northern, 1972 10.5 10.5 n.a. urban Peru 7/ national 1976 17.7 15.1 --2.6-- 60% 10.8 Sudan 3/ national 1964 14.2 14.2 99% 14.2 Tanzania rural 8/ n.d. 29.9 29.9 national 9/ 1961 12.3 12.3 national 10/ 1970 23.2 23.2 99% 23.2 Thailand 3/ national 1972 14.2 14.2 97% 14.7 Uganda 5/ 1959 10.9 10.9 Upper Volta 11/ rural 1977 4.2 2.3 1.9 Note: Conversions to energy units were made as needed assuming wood fuel specific gravity of 0.725 and energy content of 15 GJ/metric ton, agricultural residues at 13 GJ/ton at 20% moisture, and dung at 15 GJ per dry ton. 1/ The relationship between the national average for per capita traditional fuel use and the traditional fuel user average is based on the percent of the total population which uses such fuels. Specifically the national average is the product of actual use estimates and the percentage of users. 2/ Data are from Bangladesh Energy Study. 3/ Information is from a study referenced in K. Openshaw, Wood Fuel -- A Time for Re-Assessment (stencil) 1977, p.4. 4/ Roger Revelle, "Energy Use in Rural India, "Science," vol. 192, no. 4243 (1976), p. 973. Of the animal residue use 0.71 GJ per capita is for cottage industrial use (brick making, pottery, etc.). Many other Indian energy studies have been undertaken; however, some of the best recent work was only on a regional basis. The Revelle paper was used because it conveniently presents India-wide results. 5/ FAO-assisted study quoted in J.E.M. Arnold, Wood Energy and Rural Communities, Eighth World Forestry Congress, 1978, p.6. 6/ Energy Research and Development Group, Tribhuvan University, Nepal -- The Energy Sector, November 1976, p.15. 7/ Meta Systems Inc., Traditional Energy and Rural Development Issues and Recommendations for Peru, prepared for Brookhaven National Laboratory and the U.S. Department of Energy (September 1978). 8/ p. and A. Fleuret, Fuelwood Use in a Peasant Community. 9/ An FAO study quoted in FAO, Present Consumption and Future Requirements of Wood in Tanzania, based on the work of K. Openshaw, Rome, 1971, p.21. 10/ The results of a more recent FAO study on Tanzania, Ibid. 11/ Elizabeth Ernst, Fuel Consumption Among Rural Families in Upper Volta, West Africa, July 1977. 30 Estimates of animal and agricultur&aj rc '`u-- s uzl use are Il E bls I .f'z a few countries. These are shown -i TlDbe -2, l'otuntt'.l SUpp-y C',s, imates aan, however, be developed for mos_ LotzntLi`s, 4. Fuelwood and charcoal product:on -nfoLA.t- is avalilaolc .om t^ FAO Yearbook of Forest Products althouga th2 accuracy of suc'- c--£ De questioned. The figures are generally offKci-K. g-s from 'fi' ons > governments, and in some cases they : d 1.t.y productiox fro- 'laniagzo. forests. 5. Nevertheless, the FAO informatico will be used as the bas§t fo:. the estimates of present and future tradiui.ov.l fuel use. Besi6es '.;'e &.ovs difficulties, however, it must be not_a ': at .'27O ooes not eisagg._zgci:e industrial and domestic fuelwood and chiarcce'L use. 60 Unlike agricultural and livestoc:c sa, . nPatistics coverin8 FoTsst, woodlot and tree stand inventories and yicIds sre rarely availa&L.e. In addition, accessibility factors Etre clific. t to ascert. *Torest and woodland area data are presented in the, )TAC Production Year'Dooo.t but the data are approximate and do not usi.aliy iDclu6s such wco6 sources as small woodlots, fruit trees, trees alc.sg roies, v*cd sc&.tereL : .:r-es. Furthermore, the FAQ figures sometilires include lan.d WtliIch may b'o c:sforssted in the future and does not always caoture the reduc-:4on of foree- 1 E-6d due to wood use and land clearing. 7> The projections presented here ofov56c ar) i'tJdicatf o-ft of ';9_ poLentiai of residues as an energy source, bu: clo 'no' 1ae 3eo eCCOUnf: i'-: Qegi8ee to which residues are required for use as fori.iliZe:, ft,dd£r9 or cC%SZL:UC`ion Burning these residues can bring a'ocut several proBle,-!,s concez.ni-.ng, for example, soil fertility, farm yielcds, andl 'ivestock he,lth. T'n efore the -65- TABLE I-2. ESTIMATES OF AGRICULTURAL AND ANIMAL RESIDUE FUEL USE (million GJ) Total Agri- Total Total Animal cultural Residue Country Year Residue Use Residue Use Fuel Use 1/ Bangladesh 1973/74 53 95 148 P.R. ChinaZ/ 1970 960 960 India (rural)3/ 1970 779 448 1227 Nepal4/ 1974/75 1 2 3 Pakistani/ 1973/74 106 81 187 Peru&/ 1976 --25-- 25 Upper Volta7j 1977 9 9 TOTAL 2559 Notes: Bagasse is not included in these estimates. Unit conversions as necessary were made using same assumptions as for Table I-1. 1/ Bangladesh Energy Study, 1975. 2/ V. Smil, China's Energy (Praeger: New York, 1976), p. 101 estimates agricultural residue fuel use by netting out fodder from potential supply and then assuming that one-half of the remainder is used as fuel. All animal residues appear to be used as fertilizer. 3/ R. Revelle, "Energy Use in Rural India," Science, vol. 192, no. 4243 (1976). 4/ Energy Research and Development Group, Tribhuvan University, Nepal -- The Energy Sector, 1976. 5/ Brookhaven National Laboratory, A Preliminary Analysis of Energy Supply and Consumption in Pakistan, Draft, December 1, 1977, p. 19 referencing a survey by the Energy Resources Cell of the Ministry of Fuel and Power in Pakistan. 6/ Meta Systems, Inc., Traditional Energy and Land Development Issues and Recommendations for Peru, prepared for Brookhaven National Laboratory and the U.S. Department of Energy (September, 1978). 7/ Elizabeth Ernst, Fuel Consumption Among Rural Families in Upper Volta, West Africa, July, 1977. -66- energy potential of residues must be considered in light of thz Competing uses and potential damaging effects. 8. The traditional fuel use and availability estimates and project-ions required a range of agricultural, Livestock and forestry statisss:.c and projections as well as a set of residue and wood yields and sne: y content factors. There is little consensus in published literature as to the precise value of most of the required information0 9. Before presenting the complete table of traditional fuel setimates and projections, it will be useful to presenS an expanded form of the table for a few countries as well as some figures which illustrate several points concerning this exercise. Table Y-3 presents rough estimevtes of present and future use and potential supplies of the types descr3bed above; in addition some estimates of traditional fuel consumptio-" are presented other than the FAO fuelwood and charcoal figures, The domestic demand range entries reflect judgements based on the literature about the level of traditional fuel consumption by that fraction of h'-- population which primarily uses such fuel0 Tnis range is based oa rural consumption studies, and the relationship between this range and &iational averages is primarily a function of the availability and relative cost of commercial fuels (primarily kerosene and electricity), the degree of urbanization and the accessibility of traditionai. fuel supplies, 10. These effects can be clearly seen in the case of Peru. Baseci or a recent survey of traditional fuel use and estimates of the number of trEditLonal fuel users, actual annual use of fuelwood and charcoal and of small auiounts of residue was estimated to be about 18 gigajoules per traditional fuel user0 -67- 1-4 ~ C U 4r -r- o 0 oa o . 0 5- : H O l -( o N U I N X a)OU) -W.I1-H a) Ifl Lf LAL LA (LA o .O@t S S N 0P40 HO ~~~~ CU~~~~fl 04(1 0~~~~C)-4 WLfl C'4n 4J 4J r o a) 1-4 kD k0 CS O 4 U' a L a u) C LACUn I-T o - fo o -4 Q~ I a)- 004 r CUv ) oc (li ~o fLA 0 4J IN U1 -4 -4 L A1 OLAcof) O-O on la .1 *Wf t °s \ HO u v) i0 * 4 C4 34 0 U 0 -)- ~ 0 N-4CO 1001 OLA 01 -Q A o4 3W u 44 OH O - W- or 4i coU N o 0 4.W || LO Ln 00) 000 C0 00 4-4 3 °)-4 . - P4 :J0 N4-n LO LALA LA Lt -4 L A V I U) a) E 4- -W ~ ~ ~ ~ N o; a o~ C4UC 0 04 ( ~ 6 1 14 NN 0401 C C CA a) 00O CU4 .0 4 HC) 0 nI -4 04 (.4 0 CU mH>,m) 1 0 4- (a L ~~-4 '4-, a) u )C .14~~~~~~~~~~~~~~~~~~~~~~- U) i *HW ON -4 tO LA 0)~~~~~~~~~~LnL to * LA a' LA CU- NtO N-4 NCCONN NUA A co IV co~~~~~~~L CUILA co 040 1.4 0 Ln rn~~~~~~~- .-' Q) ~~~~~~~~~~~~~0I Q) (a 0)m (3)O'~ 0) 0oll - ')O J()ON CON) CU Na'~~~- -4 - -a' )4a a'-0-a Ua a) a'0C 0a'a' U)a'O' a'a' 0a'a' ~~~~~~~~~a'O L __68= NOTES FOR TABLE Y3 1, The ranges are based on supply, geog.raphical and cultual. factors and were assumed constant over time. The survey est:i':Utes indicate rural domestic use estimates fron published suzveys. These demand figures represent per capita use f7or tcaditional fue3. Users. As a result, there is an inconsist.ency between the dema.d zanges and the fuel wood consumption and residue supply :Ugures A.n t'hat these figures are per capita potential avai biU.ties based on total population not the population of kraditiona' fuel use,.s. The number of traditional fuel users is rarely available ancd in most: cases does not equal only the rural popula'tion. 2. These figures generally zepresent the fuel.wood portion of the consumption estimates from survey wor]k present in tho Oomestic Demand Range column. 3. The figures are based on the differeAce between total zound wood production and fuelwood and charcoal production in the FAQ Yearbook of Forest Products 19760 4. Increments were based on forst types and yields in fi.gure 4-2 and Table 4-3 of D. E. Earl, Forest Xnerqy & Economic_Development (Oxford: Clarendon Press, 1975) pages 44-460 5. These figures are from the Bangladesh Energy Study. 6. These figures are tentative f:i.gures f:o.r 1976 fzom the UtNDP Peruvian National Energy Balance P3roject. 7. These figures are from Ei2abeth Ernst Fuel Consumption Among Rural Families in Uppe-r Volta, West Africa. 8. The 1990 projections for agricultural. residues includes bagasse projected at 2.0 percent per annum for Bangladesh and at 106 percent per annum for Burma. -69- However, due to the relatively high degree of urbanization in Peru and the availability of subsidized kerosene, only about 50-60 percent of the total population uses traditional fuels for domestic purposes. Therefore when a national average for fuelwood and charcoal is calculated, the per capita use becomes about 9.2 gigajoules annually. The disparity between these figures is particularly high due to the particular situation in Peru; most Third World countries have much lower degrees of urbanization and non-subsidized or unavailable commercial fuels for domestic use. II. For Upper Volta and Bangladesh the difference between domestic demand estimates and non-FAO fuelwood and charcoal use estimates is less a function of the fraction of the population which uses traditional fuels and more a function of the use of agricultural and livestock residues in addition to wood. In Bangladesh significant amounts of these residues are used, and they are the largest energy sources for domestic purposes. In Upper Volta, millet straw appears to be the most readily available fuel and fuelwood is used only when millet straw is not available. Unfortunately even this gross breakdown of traditional fuels consumption is available for only a few developing countries; thereby forcing most general work to rely on FAO figures. 12. The Peruvian information also illustrates the point concerning the questionable accuracy of the FAO charcoal and firewood use figures. The FAO figure is approximately 'the same as official Peruvian forestry statistics but is about one-third of the estimate from the household consumption survey. A disparity between FAO figures and other survey results is also apparent in the case of Bangladesh where FAO figures are many times higher than the results of the special study undertaken for the Bangladesh Energy Study, even taking into account industrial use. 13. An additional example of problems evident in the FAO fuelwood and charcoal statistics is a comparison of the results for Burundi and Rwanda. It is difficult to explain the nearly fouz fold diJfxtErenc-. in suchtraditional fuel consumption in light o£ the geographic-' proximity and thecultural similarity of these two countries. -x:.on,h some of the variations in fuelwood use can be attr:Lbuted to d .:erent levels of industrial use, urbanization, and wood availability, e.:.16 'to differences in diet and climate, it is sti.l hard to 32Cp; 'ei comparisons of some of the FARObased resu2.ts. 140 Another point which can be made using ,he Peruvian inforziacLion is the one regarding the inadequacy of national averages due to, in this case, regional disparities in resource endon^tmenL,W The potentiFl. sustain- able forest yield for Peru is extremeiy high reflecting the facL that over half the land area is forested. However due to Peru:s geogradhy and climatology, the spatial distribution of wood and population hardly coincide. This results in local wood shortaqas, increased foraging time requirements, use of animal dung, and to acological dm.age due to &eZoieestation. 15. One final point is that it is wisleading to directly comp;eFr the potential agricultural and livesto&z residue avai.bi.ities and the levels of domestic demand. This co-aIqarison does *lot tF_kc2 into aconnt the magnitude of competing non-fuel uses .or these resources. .'n Bangladesh these non-fuel residue requiretments resulL in neari.Y total utilization of residues and are significantly larger than the fuel use of residues. This situation underlines the need to explore al.' resource flows and requirements in a unified systematic rcinner. -71- 16. Figure I.1 presents a view of the traditional fuel situation in Bangladesh, a country for which there is relatively more information on traditional fuels and in which traditional fuels provide about 70 percent of the overall national energy input. The estimated range of utilization indicates that energy use is quite low in Bangladesh. In fact, the best information available suggests that utilization is most likely at the lower side of the worldwide range -- that is, less than three gigajoules per capita annually. Comparison of this utilization with supplies illustrates a number of points. First, Bangladesh is clearly a situation where it isn't possible to rely on firewood for domestic use; other traditonal fuels must be utilized. The Bangladesh Energy Study (BES) estimated that firewood provides a small percentage of domestic fuel requirements. Curve 1 is an estimate of actual firewood consumption and is based on particular survey and study information used in the BES. It also points out the errors that can evolve from use of more widely available data. In this case, the fire- wood supplies that are implied by curve 1A based on FAO statistics suggest that firewood is potentially available to meet most traditional fuel requirements in Bangladesh; however, based on detailed study of this issue, this is clearly not possible. 17. Curves 2-4 indicate potential agricultural and livestock residue supplies. Utilization requirements are being met by use of these residues but the extent is somewhat unclear. Although overall supply potential is in excess of utilization, significant residue use can create serious problems because these residues have fodder and fertilizer value -720 V oU a) - U) *r 1 +, + -4i : + 4 -- - O4 1 4 W -h [ . ' J . -1 ; V C H ' VP 0 _o U ) 04- 'J * )U'C*,\-'- 0 L ~~~~~I CJ0 .~~~~~~~~~~~~CV~~~~0 -4~~~~- s_, s, V: -o h V. tuJ 3 it _ C G Co OOlQ.J O I I ~~~~~~~-4 ct~~~~~~~~~~~~~~~~~~~~~~~~~- I 0 _ :~~~ H $.~~~~~~~~~~~~- H _6. _ n l~~~~C4 -73- and are being utilized. One of the reasons fuel utilization is low may be a supply restriction reflecting fodder and other competition for the traditional fuel sources. Furthermore, overall per capita potential supplies are decreasing; therefore conditions will be getting worse especially for the landless poor. There will be less fuel, less construction material, less fodder, and less fertilizer (and subsequently less production) based on present population and production projections. 18. Figure I-2 presents similar information for Burma, however, significantly different inferences can be drawn. The estimated range of traditional fuel use is more uncertain than in Bangladesh since no Burma-specific information is available and the range was estimated from information elsewhere. The fuelwood and charcoal consumption estimate based on FAO statistics (no others available at this writing) suggests that wood may be meeting most if not all of the domestic utilization. However, two points should be noted regarding the FAO consumption estimates: (i) some of this is undoubtedly going to industrial use, but likely a small percentage, hence, most utilization is likely domestic and (ii) if these estimates understate actual wood and associated branches, twigs and leaves use, then firewood may be supplying all of the domestic fuel requirements. Overall, potential supplies, curves 2-4, seem to allow for any requirements not met by firewood to be easily met from residues. In addition, Burma, clearly differs from Bangladesh in that overall potential supply is much greater and that the per capita availability of agricultural residues are increasing over time. -74-- U .4i *u+ U .0 "1 .~ : O r :En . .. c.J ',1 '-. U +* W- Q) 0r u x'- la u 1 l _j +C , En c + 0 w -4 + We) cC ) r o L 1- p H eo * H C CIj' * 3 Ue 0 CC a) " a) r:: -4 W, r- -A E Cr: u m- 0) D C1- Q) w < U E~ _ 1 H 0) 00 3 -4 0 fn ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~L Wa 4 F "g < G : FU IO O q /O e'J .-4 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~(7 - CH 0~ -75- 19. Tables I-4 and 5 show traditional fuel supply and demand estimates by country. Due to the lack of domestic demand estimates on a widespread basis, these tables focus primarily on the availability and use of wood and on the potential availability of agricultural and livestock residues. Table 1-4 shows estimates of sustainable forest yield, use of wood for fuel and other uses, and availability of livestock, jute and cereal crop residues /1 and bagasse on a per capita basis for 1976/77 and 1990. Table 1-5 shows woodfuel consumption estimates and projections for 1976, 1980, 1985, and 1990 by country. 20. The agricultural residue figures are divided into two parts: one for cereal and jute residue, the other for bagasse. These two groups were separated because bagasse is rarely, if ever, used as a domestic fuel whereas the cereal straw and jute stick are commonly used as such. These estimates of agricultural residues are very conservative in that they do not reflect the fact that in large segments of the developing world tubers, vegetables and fruits are major crops. Cotton was not included in the calculated residue availabilities because it rarely forms a major portion of a country's agricultural residues. In one major producing country, Sudan, it is legally mandated that cotton bushes be burned in the field as a method of pesticide control. 1/ Wood and forestry figures refer to 1976, residue and bagasse estimates to 1977. -76- 21. Table E4 permits a comparison o, toL_ ,_zsd uses, bo;h fuel and non-fuel related, with an estiinpae ;s5: '-X forest wood yields for 1976 and 1990, It must be noted agE.-Xl .'L' is comparison on & national level does not capture the regional .d eoo7iu ic c:lasc variatiois in accessibility to these fuel resources :hu-etharnore the very appcoximate and uncertain basis oF these figures 'ist- be Yxzall:ed, 7-owever bsased on this comparison, some qualitative hyoo'9`rv- c:£s be suggested concerning the extistence of a firewood crisis 1f T:hi sustzi,able forest yield is much larger than the wooce. use such - Av h : Yi; neroojo.. or Zaire, then except for regional distribution i3suco, x - so e 'n can grow at i ts present rate or even expand. Where the sustiYnxbie'j o ,77.d is fa`rly close to present or projected wood use, it becomes U7skLZ in as to whether projected use levels are attainable. In these cas^s 'Lh~z issues concerning accessibility and accuracy become 7nsr^ lt'uor; t in determining the actual situation. For those countries wheyr p-ere o projected use exceeds sustainable yields then it seems likzely -:het L,-ere exists a serious and widespread firewood proolem0. 22. This diagnostic procedur^ - et ',^ E vary cruce too:l for assessing the traditional fucl situat-on. P msre r2e2labi e and meaningful examination of this situation would 'cequ,r- a maucn ~more sxtensive research effort. For countries falling into the lati:tez tw'o groups where the sustainable yield is approximately less than twicz.e the wxo6 asz- t:he figures are marked by a set of asterisks. The asterisks ind')ra,s^ a range of possible to severe fuelwood shortages. In these cases -he projec.-foos n7ist be viewed with greater uncertainty. -77- 23, Overallit appears that at least twenty-five percent of all developing countries are presently or will be experiencing fuelwood availability problems. This estimation is most likely conservative. In Nepal)for example, the deforestation problem is clearly severe, but the results of this exercise indicate only a possible problem. In this instance, the national averages cover up the severity of regional deforestation and the geographical inaccessiblity of much of Nepal's forests. A similar situation exists for some of the Sahelian countries where a low national population density disguises the fuelwood availability problems around population centers. In addition, a significant portion of fuelwood use is unreported or unrecorded if actual consumption surveys are not undertaken. On the other hand, there are cases such as Kenya, where the magnitude of the problem seems overestimated. 24. The results also indicate the significant role played by population growth in affecting resource availability. For a majority of countries the forest and woodland areas projections did not significantly change; this is more a function of information gathering problems than of actual land use trends. As a result the often large decreases in per capita sustainable forest yields are due to projected population increases. 25. Finally, although the per cgpita use estimates are declining, national fuelwood use is increasing though generally at a rate less than population growth. However these per capita fuelwood decreases are in many cases not large and could reflect numerous trends such as urbanization or an industrial shift to commercial fuels as their availability becomes more reliable. rb - 79_ U) I W) ( I 0 (3 pi o i I I I I I I I r |n U k l l v v s v s v v~~~* o) rnJ o NJI U nX 1) I tT " U c 'U W ~4 R mI S D - - Ln Ln O 0z LI) *4 51 I CY) U 0 r) rl U U - OD U) L U) Q 4 rn D0 U) Is UD Ur) U r O H N K - N Cd ~~ ~~u -. I U) 0 * I C tO 'J LI tO t 0 _1C C NI U)~ ~ ~~~~~~~~~~~~~U 04 >1 WH ,~ o Cu *4 0 S rs sk vx>*-*B4c H 'd> (U Cl (D|D n N) O OI N a N N_ H H H CO N t 'M ~ ~ C H N OO LI CO 0) H LIH O 0 ) L d C) cn H _ H N N U O i c4J L 0 O O c C oN CO Dl A r H % S~~~~~4 r. oN o !r (3) o) o' o o N k. t O- ON OOO OD ,-1 0 U)Q 0 0 H H U) 4-))r *0~ X 'aO °q H VI****H : 3) I C: (J iN 0) N- v 0) 0 GI O O 0 °I tO H 4J , 0 0 0 0 a) I~~~~~~4I bh St _ L l 0^(ad I CO tO 0) ^ @ (NJ 0n > t CN L G O Co N N 0 H |nJ co r * -H N4 H °l N tO < CO NN (N CO 0 zO 4 _ CO N 4 e J L i (NJ 0 0 | CO O ( N I OO LI | UQU)~l4H 0 I 0 40 I 4 >q z - - -- Co) Dt or DI ob ° ul- ° or Vo 0C0 Hco (D LI| t G I CO Cl ( j CO C l H G rI I N) > 0 r. O > 0 H C IO ) ( COCO 1 GI 0 H G I 0o G'. I G LO C I O as Go Q-I 04.-4 I { H 1 o 4 N r 0k 1 o I o o |) (NJN | o I H ,0 L ' ~ 7 ji 4) NO tON 0 tO -i m r0 LO OtO OtO 01 tN 0o _ II :3 Q 4 _] , 4|- l i ) C fu ~ 1a o 8 Il u (H 0 o 0 0n 0 - - i U I O D tlN 40 ,~ u) j I n0 LI) 0 1 l) t N ) 20 0N o 8 in U L O c ro *H 08 U oo o: c oHH>x,o r) 0 ! h4 r0 4 bB N 0 Q CC Co H H N '~' .-: .CA ia :J O X = ffi z x ao O rl Oj 0. 00 U0 U. U:l U) U?z C i 0 Ic r-I C NL CJ2l l X U l O U U U O t) U 0 ~JJ m) Ooi 1- ' O' O CC Oo (N tj o H uLA LA i 4J C > N o~ o'j o CC ' Co o( 4^N m O LA OJ 0 Q) I 0 fo a.-4 . (N N (N LA H (Y CII ,> S \> yO H 1 H H H ( i V 04 ~~ H 0 4 0 I 4H H I I .( NL CC 0 (d to c CV- 0 O I 0 0 0t0 0 0 0 ( U)i 0. 04 ( IH NI 0 ' H CC14C A m c4 o o <' ( ( H H m 0 U)~ 4 °I H C) C 0 0 ) 1 cl) C) it- ° ) HC U)8 Hl 0o | s 1 LA LA) CC ON ( LO Hi 0 9 I .a-1 4 I i I 0 i I 1 °; °~ |; Ln u| v > I 0 0 H jaitDD | r-lO NP 0 o| N1v NQ nl' mJ rt 4fio o HJ 0 0 El~ 00 8l~~~~~~~~~~~~~00O :J0U)~ 8 |~ ~~~~L 'n r, ; Zv - i t! *{ O <)1unlu -l* n °) - t|Sl 8r4I 0 I i 11 1 1 1 1 1 i 0" 'r n H~'I0 - m in N a' ( Ctl ) : | 9 11 XDor- ol MolF o to o mo r- oo 0o00 o1 0 0 0 0 0 0 j 0- 04d H '0 (N r- O t- H oiC t- ON Li N t- L A CC 0) t-N N 0 e) o n N C) 0 OI 01 in ~ N C ) N a ) O N N0 0 C i n i N in N 051 u 11I4 1 1 1-1 Ci NN 0 0 1i o N§ 0o NN 0" NN *,1 NN S4i N ' N Col 0 m I O " I W I C I 4 I iI b . to rH 3 Q ll a) | w | r3 | rG | 4 | < | & i~~~~~Oll ~ r'I ~~~~~~~~~~~~~(a 6) 0 Nj 0 U) r i U ai (1C) rd (d -81- U) r I * I ', r ) * | NJ * rNJ r n r (U 0 Il I * *: . * * a) _U I U) ° I U rn U ci - 0 4 rn ) Or a Cr) _ -X W4 >: O) O~ I N v 0 CO Xf H O 0XLA ( L) 0 I L *r ; U) I U) U) UU O ~-4 I o S W I Us U) U) rN rNUrr)nrN 0 It - S 1 Ln co s n ~ ~~~4 rnl _l ,o i 0 a I U) O) a , U o) 4r I ' 0 r- , -n L N LA r r rN 0 > _1 In a _. NJ 00 L' O U CO rn (NJ H H rO o 3 o I N 0' H nN Hn rn LA , r- 0: Sk 1 k0 r- O xD t t O v9 r- o v9 r- o co'L. r- O 91 4i (L) (0 ') H U) rZ44 - 0r I 0) (' a O LA C ' ) O1' ' la Q I Ik - 4 4 I rI % o ) .- 4n r n OD .I a W > N r-) -'U 0 tn I N~ CO LA H H :J 0 U) rz 1 0 U)X4 '-o0 U o 0~ U) H H .14 0 M M M~0 L O") H, H LA (UM'M 0) M0 a CAON M U *H~~~~~11- - H I '0 0 0 0 VQ) - I~~~~ Z ) - ~ *-44~ 0 g )0 N A C 0 0 a a' 1 r C' HH~~~ ) Iqa f 1c U)(U4JU) 9 0)~E -lO En CO L H N 0 ~ N LA CD co i L n UN ~~~~iH~~~~~~~ I__ ~ ~~1.~, 05 -V m 0 ~ ~~ ~~~~~~~~~~~~~~~~ M 0--0 '- 0- 0) l;Q 0~~j crl) , 0 .1 n en : 0 n in C C) c' () N Cl o' \ , H ( o) C) INI in ,.I-0* Cj El I)U I 1e - T 0 kJo 0 L~~~~n en % en U 14 V U) U, I 4 C) r- Lo m n ( m N-C% en n H!w e >C II < >4 v ~ ~ ~ in r- CC I) 0 inen) -44J I'. ~~, (N H 0LO (N ICN e o n N 0 Cl) m Ln (0 CI 0 ml HN C) ; ( -.o en 0 nm 00 I 0 ~ ~ ~ - (N 0 en en~~~~~~N r 0 ~0 4i 0~I o H I~ -0: .-I- 3 I~~~~~~0( ~~~~~X4 U ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~)U 001; ~ ~ CN .; R f . I0 O n ;, c n r | - _ 1 | i O fj | -83- a) 4i I tJ O 0l . d I I ND fNI | l f () ' I I in C Cd 0 I 0 ED _J I fJ l t ~~~~~~~O U N I_f C Nf4fZt -tO fQa t G <) 0 3 I f) L Ca 1 cow N(N 1 H 1 fO f - I _i i 0d 4 0 I U) I IXX u)~ ~ ~~~C (N r- r- m II fC') I' r- 11 0) 1- 4L) - I H f 0 C fN 0 fN rl 1 fN ,' N fN fO a' H a) E _ a) .a I 0 U t fd f'I N~~~~~~~~~~~~~J rq4 > 4 P4 04 P4 4 4 l I - = fN E f U) 0 ° ° - C - - I a) U) I COUUUUco CO 0 43 I N C H N a f (N N N rN (N N LO O~~~~~L :Jc _ o *n4~ < Cl l. < ' ~ i l~ O H a U) 0 Cd . fd * l < ~a 0 a) Cl O(N N CO (Nl H HN ( H .I .l CL (N in 14~~C Cl w nl, t < O f H H f f f f fN NL ' - Cd id * t * ,O f 4~4 O4 4 U a)3 -1 Cd l N f _ < [ N fl f S N 1-4 Ha) H N. 0 Oft f4 41 N - r i co fD) OC a) r- fN 00 ( N o|fN > v a f D 0 4- C)C~ r~C; 4 i *.. U 0 En D 4 'In N CO Cl C a ' H in H fN CO Cl , 0 H d4J (N5 , N ,N i a i cO CO CO '4 H H L4l i (dU) - 4 o 4 o * o * o . O :3~ ~ ~~~: tD I r- > co>1 8 zr c l n tl c 1 n [-1 - ,f fN I 0 N () f N f lIn fn CCl N (N ( 0 H H H H H HC)0 0 0 C Ha) I c 0 ,~~: -,0 (N Cl (N a' H- (N ON N' * * i n C . 19 ~' i '. gI fd (N H4 H , a' N d rd '. . O i rl J4 -4 -,4 C4 4- Q- ,4 --I w I 0 1 5 1 I -, EP FQ ~H~U (N H Cl ( 0 9' z Cd Cd HD H ' _ C4 C)i I'.0 ~' H- co Na Q N ( 0(E N 1O a' COI CO Q H " *, k -i n 0 uz a) '.CjN 0 '.olr- 0 '.~N 0 ~N 0 t) 0 4.) 4.3 *'4U ~~~4 .14 ~ ~ ~ ~ ~ . .4 a 0 ~ ~ ~ 4 ~ ~ 4 00 C r) 4 ,) -84- C I I LA * (N U. I II * 0 r I I * * ril I C)) Cl7) 1) I u u hD O N ( v U 3l U1 n D 1 U I H0 0 Og U) U U) h) U I, 0 v . ' co 4-.I) I C N Cl 0 Ul Cl N 0 N- LI) (N CN Cl) o I * * )C I4 (N (N J A L A l C f Cl) 0 1 U :3 44 PCO la 2 < S4a s > I §~~~~L -1 Cl A &z .t *> O *4 I - S S * aU) Cl U) 5 N_ 1ZO .1 f 0 Oi - . S S S H < < r l ~~I 09>mOSN t S OSH H I U~~~U 4J ° N- 0o Cl) HO LA a, a O O .0 aO a . D U)N ( H LA '. N C UL a, N (N LA LA 0 ) 0 C) * _ >I*H h 1 ;1 I O'H a, 0 CD Cl (N LA '0 V .H 1° N C H (N H 4.) 04 '- HO H U'N U' >" : 11 -,4 4J '.D Cl ) N H LA) N rdU] | ~ a 0 N Cl 0 || X A0 O 4-i 0z C .N U)~ ~ 4 C1~~~~~~~~~~~~~~~~~~~~~~~~ 0 TI co~ ~~~~~ C Ij~~~~~~ ~-85- 02 - '.0 w~~~~~~~~~~~co 0 0 0) 1) I C ~4 $4 I 4 *H 0 a) 1- 4 I ' C) U) I - It Gd) 0) 4 (n 0 I - - 0) U) I) >) >0 02 N ( 4-0) 4.)- z .1. -4 0 U) .~~~~~~.d> $4 1 0 0 ru~~~~~~~~( 4-IC 00~4 0 0~~~~~~~~~~~~~~~~~~~~~~~~~~~o 0 HO) H~~~~~~~~~~0 02 02 0 C~ 0 .0 I 0 ri -I I 0. cJ v0 ) 'o- I02 2 OCOHO ~~~~~I ,- c 3 -4r~ '. N 02) dl d H4-i I) '0 0 m $4V'0 I I1 m IID :30 0 '~ ~~~14~~~ "fl 0) '.D 0 4-) ~~~~~~~~>4 0 4-4 ~~~~~~~~>1 4.)4 0~~~~~~ 04- -86- t,~~~~~i 'X J _gi_ I I vo W 1, f O t m | u u l mI I | ) I _ II* nr>U | 68 0 I j U) Ui L ) L o t r n n L n H. 0 i Nkx> a~ ~~ v-~ i I ~ cl u ~ u N r | V o ~ ~ ~ c~ O 7 sS 7n O _ G X G LA LO oA o LA Ii~~~~~~~~~~~~~~~~~~~~~p sU / C) ON C, al) U) 0 U C) U I Or 6~~~~~~~C J °N co 00 00 hn Ln e O O O nn v Ho~~~- a _ _-4S r-' a N fI ( aO t N IC) 0 O tN4 LA ' 0 d C) 0 e) (' 4N H H ,4 H U A ~ ~ L ' 0 C I~ ~r N. iiH H EI4 0" 0 0 t N 0" (N -4 G| U 0'> dLi Z n)) LAON 0 O r0LO N U) N CO l | °t °o 4)1 0 fA I C) I ° I 0 'jj1 LA n 0 0 0 k I H Ho LA ( H H4 r~~~~~~~~~~~o Imco cI nr 00 '~~~~~~ 0 0 ~~~~~ 0 0) 0 0 0 0 0 0 0 La 00 ~5dN N C)C) 0 O 0 N N A C0 i *d4 J I HHNU)o CO N 0 0 0 '0 ti 0 0 (n H ( I , _ 4 '0 '.0o o1,1 r- I C-) u 0 NO C', (N LrA H Ln CO (N C) ;3 .0T'i r col r 0 rX H nCI O Lr)C cN >co co rON N ol .11 -4 LO LA4 COO' 'm O ' NN L-JA N ) 0 0D 0, (NC HH(N o', IC'N) LA 0 HH (N H j ) () ( ) m (10 1 0 LON C) AN 0 U)N~~- 0 U)Nr 0 '0N 0 WI 0 0 .44) H (el 0)En 0 0) E-4 9 I-.I ~ Q . j) E- -87- :: o i I -' (' !C c~ I I I I I Id 0 * I , _ , I Ii c GI 3 I Q) U ta ~ ~ ~ ~ c N co Ol U: ;4 m 3 uI 13 4 0 I u ~ 4. IULl 0i''0 ~ N C c t I a) C. I u : - , U *, 2 I 2 c U U m c a -4 =1C r50 m 0 I - -- ' KO 0o (1) U hU W ul I (ci C X ,d O E-4~- Eq ~ ~ -, I - - - o °d 4O.,) O 1 4J 4.) 'i ° 0 ' ' H-q 4n 0 O 0 ' - 0 0 N 2 0 t2) ~ ~ ~ ~ ~ ~ c NJ Ot '. Lf H Hi Hl it - O O O O O ) tN V ; 4 r -d | i rK ~ ~ U r ~ U' CN Lf c d *n N I) ) IV 0N r- 0 r -A t- ,<~~~a R~ 3 C|t C C 2 rdO '0 WH« *-a Ct | . a) <.) r-d 0 r3° 0d SJ Ul) In 0 .i . HD CN _ t.0 N* E-4D O 4: -J : O O O O OC - Wl 0 C PI, 00H C~ . 0 4- a) O '0 N '0 ~ 0 '' L c I o 3 ! I r-d r-d N it) |. HJ ) cd! d r- N 0 q - 0 H (N( a- I O) 0 I DZD (aciI H H- 0 0 0 H 0 0 | N -4 4-) 1 w ST N H 1 Ci c N -A~ - a 040 U |- V. |4 0 S EQ~~ ~~ ~~ H H1 CO 4 4 | CO .4- ) ciU- - 4~~1 ci *~ ci It N- i) ia ) N 0 0 cq 0 *z r LN Cc :% 0 -0 CO4 '00 Cc n O H O CO0 CO~ Nr~ '.0 1 ID4 -H - i ' ' H 0 N N* * Cc N WCO4-)W I c0 0 0 0 0 0ci c H H iI~~ rci~~ H Hu~. H olo r 0 c o r- ':' o wlr N ci NN 4it) HO ) - LAIcW r N 0 0) N- 00 N - L'0) i (1Hci * -* -I 4-3044 HCcCi'H H 0~~~~0- Ia4~~~~~~ C.) - ~~~~.J 4-l O 0. I O. N 'fN 0 0 ~4C >111 0 ~ ~ ~ ~ ~~0r .4 ~~~~~~~~~~~~~4P Cla) H I j d 0 I ,l z4 lI to I I) w I o0* 5~~~: U I s, , WN3~ ' 1@ , l ) _ 0 O U) U) 4 OD U Lf OU SS 414 0 0' 0 l Qr) O , Atx > 1 - tD| '0 NiV F-q U) I L4 oo4 p _ 40 C 10 C) -I I ) H 4J 4 .QH 1I m~~~~ C U OU (U D I|D 0 (U H I 1 "I 0CU)I 00i 4 Ii " 'U En -. I w -H1J I ~~o~~~0 I~0 (U ~~~~~r D mzirl on o ~0 0i 04. a4~~~~~$ 0) I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~O lC l ' -I IDN 0 ON 0 1O r- 0 1~~~~~~~~~~~~~~~. 0~~~~~~~~~~~~', a) 0~~~~~$ a)~e Ui4 H~~~~~~~; - 1 )f -89- tn I - * i I , . I I I .N .1 co . I.U D H (9 I I H U I I I I -4 (1 CO C m~~~~~ - * II I I I t H o C) O ~~~~ ~~LO) L') L1n D t Ln 1- 1_ OD 1 1- WD Lo W ru i :5 I. I - '0 l L u P 4 u) 1o : En- 0 I U) U) I 4 4 S (N L 0 Ct n 'N L(N LO LA Ln H CI H C) ) XI N) _ CO tH OD c CO N C D O H 00 0 Ln > I L L LA CO C L N N N C O L C .r __4 - IA U ~ : 0 O U )0 H w' W I U~~~ U U U U , .1 4J 00 O- 0 tD ml rSl rd ds rd r4 R rI - f ~U) I0 I d V - - I mr 0 -I 1- )i O) _ U)n :5 C H H CO CO cd' al 0 ( Aq .1 CO t L^, .) a C q Cl CN N 'A Ld L LA |O L C C 0 0 _ .r ° ° ° ° ° ° ' °° ° ° ° -4 C)~~~~C <7B q 1 OD L a r OD rl t~~~~~~~f a n r Wm L) (d I 1 I '0~~~ rr )H. -. Cd ~ C 0C ~ a a 1 1; !L} v a o q r O H ) H I _, 4J II 3 nr qNr Cd>4 Cd~~~~~~~~~~~~~~~~~ CdU) - Cd A N - LH LClr-' C o Ln r- CO H|m H 'D NI, CO ID Hr 115 4 L co ) f Jl0 ) | r- W O9 C 04 | |o | ri * | rC Q * O 0 |~ 14Cd r ' | CH N | H r | L | q | 0 0) H 0 4J _ rQ' 0 CO ND (N HQ r. LA H | H| ra kDIz ol tDIz o kDIz o tDIt- o s11~~~~~~~~~~~~~~~o o - ol ksor ol DI- o J I S |I~~~~~~~$ r-Ir- a5 r, r a WN vrI- v r > -r VlrI Cl~~~~~ H H Cl (N 4 H He i HO) UIU | z Q) < J l H H H1 IC I~~~>1 c Cl) d N O CO H C LA d' 4N CO N L CO Cd' LA N LA CO CO C Cd' C 0 0 '00) -~~~ I2a p0 OCOHO I IC IC IC 44 C 0~~rd'H~~ I O d CO H 0 4 -90- zl* r'U (U (N ( Ua - II2 Zco m Ln C) . (Q) ,>~~~~~~~L m r- m IV Ln CN I C ) r4 0 U) U) I >- 7 ! sq sH s N O U (N t < o° !< t t |C 4 O t ese (U -tolrI in (N O Cl IO(N ( I) (U 'q|$ 1 2|I || t 0i|r c n|r -, | h o a -o I~ 11 Nl ,| t tli |l °f in cA o n C) 0 I . - W C 4 Ln 0) C) Io I CN I C I - 0 | 41~ ~ Q 11 {3 l3rd l| r _ ) cn cI | Un l H C-) a4 GI o 4.) cI,4C; 1 ~ C 1 U ) rX4 Cd' (N C C A -: 0 Y H C) 0 C)l 'I *'-I (U CD 0) HC H - H H4 C)t' 0 O U l A ' 0 H C::: .4JC)~- 40 I * 0 4 1-1 -i ~4 En I 0 H .i CO 0 CO- '.o HC) pi 'i'VH C) U) 0C C ( ,J 0 d *1-( - 0 O r N l: I ~ L Jt04 0 C) C) CCD)5) CL ,oPIrl *~~~~~~~C) -LO C 0L L1 C HH0 ) O IV 00 C .oC Nq r4 H Ln ( r4 '-I Im0 0 r)c l 0 4 U)l (N H Cl 'A - ( ' C'O I 0) ON C, c m C~~~~~~~~~~~~~~~~~~~~~ C") ON o') U% m Cl ON O,,~~~~~~~~~~~~~~~~~~~~~'~l ~ COA l A 0' i In f Clj :3 ..14 AHH iHH (U~~~~~~~~~~~~~~~~~U _~ C | l| t * G N1 *|' * .| rN .j H U) 0 rri O l | u rU (N I rN r C r W l 3) U) U U Ca C) I I v I U' ) 7s 0 4 I1 - - 'C E I' k tvs>* *d 0 I ) U) I n -E I a) I~C~ r °~~ ~ H Hd W t'l ~ a) 0 O -u I ~~~~ u~~~~ U) 0 I a) U) I 4) (r*(' U) () (N co U 0m H IT (N H) 0l C~ 0 rr r( rn O U) U) 9) (n ND rn r rN a) 0 a)' > r1CLf r HN m ! r' 4.) '0 $4 t l04 u fo Ua) '-4 - (d 'T 00 m I r Ha) H C)~~~~~~~~~~~~~C ~ ~ C C) U~ ~4 - UH _' H ~~~ .,H. ,> 1a * {|N N (N | tn V NO c'1 s H N lO U) U) H l h I) - :. N O0 ( 0 0*1 U 0 09 U) 0 rn N n 0 0 H Hrn H H H I 1- Ha)D _ I- OO 0 a) C 0.o 0 (N U) o N ' ON U) 0 _ 1 0} 11 0 5 , r ,< W 0I c N W W IO Cy o n " . O e r s' ) rs U) (N I r Jl D-4 55 .'C 0 55 1 4 1 1 - 514 0 0 a 0 I U ' H tN O a. ( ) 4j 0 11 U U V t t U) t D - 1 4 o 0 10 | H H 1- ri' I nJW I O) N1 (N U) rl 0 US H OH N 1U Ur !1 0D tn .: I 2 r0 D 1 5 '40 0 0 '0 _ _ _ _ _~~ (a 4.)~~~~~~~~~7 :5 0 0 .10 - 0~ a)C ~ C~1 ~ 14 1 41 co -4 C r, C H *H~~~ *H *d 04 C4 ., 4.) H~~) m -, 0 H) U n m ) I* m 040 0 ~~~04-E H C) Ca raw~~~.1 () : -92- a 0 0 X la :: . - id I I > 3 U N 0:: 4 J C ' :4O4 Ol O Z ~~~~U kD LO 0' O | -14 0 (5 q)s t 11 4 -H °> 4j jn CN0 U) U) U) - e 0 aH Ij i o H 'I :DI H o o <1 I I 0 u1' -'- 0 I 0 0U) 0I C Z) U)3 - o -i _ C IfI Q 4-J 0) l U) Ei ID L' ' ~ U)4( : 0 0 -4 V 0 14'- 4 N H , u4 LI' C 'J t~ 0 4J HO)~~~~~~~~~~~~C C:~ ~ ~ ~ 'DI 0~~~~ UN~~~~~( ~~ 0 0 0 40 0 U)H U ~ I. 00U)~~ ~ 0000 $4'd'd I~~ | Ul I t i n ., m co . ) rs 3 | as I O n m nS~ rt N OL I LN O 1 I m _ m N l3 l CO(N cn _n CN ( N r o o I U) U) U m) C) i - - a) 3 l I u U *H 0 U) U I ) L) L)c i~ a) _- II H -- I Co to N in in to w ' (N i H CO H (N AS 4W I |i in in LC t H m H H CO .-I C~3 0 C) C~~~~~~~~~~~~~ I .4r,)4 C4 C Ua) 0 1 in I O -O l I P 1h 4PU) U) A4 -a C O I * - - - .^ 3C I U)=zu '0 1- I I u -n=U f X 5 I U ) U U) >) 0 I co * - r- O e) 0) l) U 1 - t >I * < ~ ~~~~~~ U) U ° @ L O ) r 2 ~ ~~- ( 1- ma t | ~ °~ r°m (N in) Nt ,o H m to o S H ~ U O ) og N (N O O ) O tO 0 Oi O O CO in n m '0 CO Ha) H C CO O~ 1- _ N O.-44J 1) N in O .;r to N N in co H (N , I) CD U U) -, co t.o N (N 0 ,N 0- N H in H in H in .4iae) Q 0 La ( 4 4 J 0 0 1 H 01 m N _~ in NF H - , ;j 0 3 (N4 (N CN co N 0) in H H'IT Ott .) E -o 0 00 in (N Hi (N H- >4 0 O 4 0) H _ a I f I I r 9 0 ° tN-i ' H COD ° 1r t°1 m * o to o !o g 0 N CO 0 (N I 0 H 0 d (N CO H 00 0 0 0 tO C 0 0 N i 0 0 . ia I o U)H C) . *4- in m mn in) ml 0'n mn ml H4 kto m IH1-4U) (N H H4 -1 O CO CO 4 O. nS CO 0 to ::s U 4 'i I --I 0 i t H CO(CN H- ICn 0 0lC r - N HN q (N o r0 H T oD H- NO (N oO~ 0~ 1To HO C! O ~O ~ COO (N 1 O'( 0 .0 C r- N Ole) CT (N (N " (N )ONO V O O1-4-4 H' HI H N N Cl'- '0 I a to> tON~0 . C) - ______ -- ~~~~~~~~~ON C toiN o toNe ~~~lr- o , NN r- oo 4)~~~~~~~~~~~~~ 0 H 14~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ C) '~~~~~~~~~~0 0 0 co U --I8 -94.- C I * W Y L LAn L n .9n o: r- co ,° r 1 ur _C) ILA U L lIt4 HO O LA LA LA: n A C in A t in nA rt nd o I v LA 0) CI.) in N 0) , I * U 4J Gi S I | n i- _n n r co L UN O co rq j O co r0) 0 I '] - t t in° Ln i 9 0 - co o a 4 Pt sS~~~~~~1 ° 3 uc u 1 i~~~~~~-1 Sn .S O', - co co # # 1c ,a -^ I LA| co ON r LA A L An rLO t - 0. ,a~~~~~0 a) ° I r- # -;# C.) (a_)4i# U U) Uu U, 0 .~~~~~~m 1 0 c C..co - - - - O ) U) U O r U iqStn tU nL)°|r OS n; mc ;I . C -' L0 co co (0 Cd LA 0 - iA < ~ U2 CL4 Cd L C' 0 LA NcLA 0 i ( a --I !~~~~~~~~~~~~~~~1 ' iJ LI I W 01 In. 0) 0 a)' 0 CO t0 ' C in I OA O | Ln r | Cn O) | 0 C L L N in iO LA H cn (0 |N Si' t IP 0 f II UC "h t H H H-1lGolHsl H I 0 0 in 0 0 I 0 I - 3z H ij4-)( C' L~ in C LA ( LA Cd; H~ (0 N 0 ri 00 z (NI N U ~~~!rol :5 0 0 0 * 0 4(0 i ( 0 0 L H i C 0 L o r- o! r- o )r LA %' H (0 0 H I *'-~~~~~~~~~~~~~ 0 . * 0~~~~~~~~~~~I'Dr 0 0i, : 40,: I~~~~~~ Ca~~~~~~~~~~~~~~dC LA LA L A A f 23 ' i 04 -H0 -95- tO o iii Cd in LA Cl LA 0 i .n nA LA C d r ~ 0 I . . 5p I N ii N N1 N N LA ur N Cl in $.1 : LA, 5- i,j;I 1~ r4 : - ~ II--0 AL D~~~~5 -- - 3 l 01 I LA 0 U i h U . m X CN o u a)~~~~~~~~L C7 a) Cu u ~ u'14 *H 0 I - -m - I U~~~~~~~~~~~~~~~~U H - cn LA |l cn in H N N N LA in Cd 4. I LA O LA Cd LA H H; i. 0 H Ns LA h4 O t LA i NS N N LA LA LAI LA Cl v C -, 0 a 07N Ol V Y l- I (d O aN r7) 0L7 0D r- r C. c Ln L A _ 0) 0) I _ > UV I LA NA C ON K4 ~~-,- ~ 4 I / 0 A AL | , 0 \ - N O 0O* 1 C vt ~ O N N HI rI H>g | o 0l t o r|N U O|r o o|H w w wtD 01 0 Ul N|N m 0l N |O| o 0n 0J 0 _ ll H C H N wo l Co cn | (N | in N L 0 e ~~4-' C)4 C n1 ~ 1 U 4, I Cd N cl vib cnn 'O n I r LN cn 0) LA 'Tc C ) Ln 0 r!) cn S * .N + c , La 0 0 A N in0 LALA Cd L C 4 1 11 1 I I 4e I0 H~~~C/ IO H $4 | N || h T z X l h t Cn | < Cd>-' Cd ~~~~0 00 X4 La I ~ ~ * A 0 tn~l d ALA L n L C I N L 0 C L a" in o 0~ If CN AmCd 0 0) 0N LA %d rti -1 LA Cl C ~C H~ H H 0 r O 00 U H H H~f-4U ~~ Cl ~~Cl 0 %LA LnH N ~ l I- 0 LA N N d r~~~~~g 0~~~~~C 0 *U) O 0 00C z I 0)~~~~~~~~~~~~~ L)C O~~)CdH I N LA in LA Cd'~~~~~~~~~~ N Cd Cl LA N1 0 in ~ H4-) Cd' Cd' LA in Cr' LA LA N Cl C A C HH$4C0~~~$ I * * NO HI LAO in HLA LA ~~~~~~~~m 0 in N O N NHaN N 0~~~~~~0 '0 _ _ _ _ _ _ _ _ _~~~~~~4 04- 0) inN OWN 0 in1N 0~~~~~~~~~Z3 WN 0 NOW H C) HIH H HH H HIH H HH H HH) H HH H H >1 >1 0~~~~~~~~~~~~~~~~~~~L zm0 H - | ! .1 tc ) o, v U -96- uD ^lCI v -4 En I fX ., o , I z z BI:- Z) )U I Fo W U O i | U . o o . o o O m |~~~~- 0 Cg IO00 C~~~~~~ U) B ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ U 0) ft 4. ij 0 (Ii H) O I I i 03 I 0 $ ifl N 04 0) 0 Vo . , o _ . > I:i f I < ~ ~ ~ 0 0) O - ) >| ) >|N G C~~~I m m~~IP. Cq ) Ul) l U) 0 4. a ) V., UU P4 > - I UO , ~~~~I O. o t.) E E-4 ~ U : 0 ~ C ~ ~ - 0 V) -4 r-) IN - i 4I d ID (a- - H - .-I m 0 *?-, 4 ft '1 ro N N 4 - ,-I i ~4 LI) I 0) (Z 4) . - 0 U) -4 OI D04 u:l (0 4 ft r4 0) I ) 0 1-4 I t t f U C') o-4 UT ) in in I 0 *~~~~~- r- * O OD C - 0 0 -,I 0 - - Z r 'do -.~a I4 ,,- i- - 0 U) C) B~~~~C)'D0'or, 0r,C 4i ~ 0~0 rZ ~ ~ Z 4) j* ' )i ' '-~H>4U) I -4 ra N 4 0)ft.1~~~~)0) 4I0 Cz~~~O~ 0 I39 1-4 c mu ~ t ' c4 (' nm Hft w~~~~~~~~~- = N) I tyl~. C I C1 H I I ,1 U) o i N I o o I l l m01 I1 V I I U ) tn c4 I - U4 co N W = QH 0 I U) U ) U' U4u J) C I$4 CO tD v kS O En I A ) N U j H U H N 0 r C) 0 H H > I - - >~~~~ UD I 1° - I -! 0 coU) I O) U H I) I o1 4- -i CIV) cl 4-i C 5-l 0 . sr k L n U) ~4 f l - r) C 0 0 0 J O H H a- 0 U) >44 a,LA *-4 Cd N 4 U) 4 o -i H '~~~~~~~~ oa HO) H U ° oHe O _~- c)r v v C m U) LA Or 0 flO 40~ ~ dU 1>2 H 0 H Nq LA C. OOQ 0 QVNL 0 c 0 n <~~~~~~ ~~~ coi 114 00 0 p4 HO)~~~~~~~~~4 E I H 4-) ) I i >4 I k N H 0 C. N |4 C C K C I 0 0 0~~~~~Z) 0: c N C. I-q ~ I U I~~~~~~ P4 I I 03 ~ 0~C- I %o ) H H~~~~~~~~U) I% ) '~o ~~ .c~~~~ *H1 0 0~~ -98- Notes for Table I-4 n.a. - not available * - indicates possible fuelwood problem 1. The population figures are from the World Book, Population Projections: 1975-2000 (April 1978). 2. These figures are based on the 1976 Yearbook of Forest Products. The baseline per capita estimates are for 1976. The 1990 figures are trend projections based on a linear regression of the historical data in the 1976 Yearbook, except in a few cases where an exponential growth model was used. Projected figures in parentheses are the result of regressions which explain less than half of the variance (r2 A. 0.5). Original data converted to energy units assuming wood density of 0.725 kg/m3 and energy content of 15 GJ per metric ton. These per capita use estimates were based on FAO fuelwood and charcoal production estimates. As a result there is some distortion because imports and exports were not taken into account, however, this error is small since international trade of fuelwood and charcoal involves less than one half of one percent of total production. Furthermore, the FAO figures pose a problem in that imports and exports do not balance: total world imports are 80 percent larger than world exports. 3. These figures are based on the difference between total roundwood production and fuelwood and charcoal production in the 1976 Yearbook of Forest Products. The baseline per capita estimates are for 1976. The 1990 figures are trend projections based on the per annum growth rate from 1970 to 1976. In some cases where this procedure lead to a very high or low growth rate for non-fuel wood use, total roundwood production was linearly regressed. Then the difference between projected roundwood and projected fuelwood and charcoal was taken to be the projected non-fuel wood use. This procedure was used for Ivory Coast, Liberia, Malaysia, Nicaragua, Papau-New Guineau, Peru, Swaziland, Tanzania, and Uruguay. ,4. The sustainable forest yields are above ground annual wood increments based on (i) forst types and yields in Figure 4.2 and Table 4.3 of Derek E. Earl, Forest Energy and Economic Development (Oxford: Clarendon Press, 1975) and (ii) forest and woodland area from 1977 FAO Production Yearbook. 5. the baseline figures are based on the 1977 FAO Production Yearbook; the 1990 figures are based on FAO projections of the number of cattle and sheep and goats. The sources are listed in order of decreasing residue contribution. The sources and ranking are constant between 1977 and 1990. The source codes and the annual residue (0% moisture content) produced per animal used are as follows: Animal Code Annual Residue (ton/head) cattle, buffalo, camel C 1.00 horses, donkeys, asses H .75 sheep, goats s .15 pigs p .30 chicken, fowl F .005 The energy content of dry dung was taken to be 15 GJ per metric ton. -99- For projecting livestock residues, the basic projection in FAO Commodity Projections 1985, Meat: Supply; Demand and Trade Projections 1985 (June 1978) was utilized. In this source cattle numbers and sheep and goat numbers are projected to 1985 for geographical and other groupings: Latin America, Africa, Near East, Far East, Asian centrally planned economies, and other developed regions. Based on these figures two sets of projected annual growth rates were determined: for cattle and for sheep and goats. These rates were used to calculate 1990 livestock residue total availability by selecting for each country a livestock residual growth rate equal to that of the animal group which produced the most dung in 1977. This procedure was not changed when either cattle or sheep and goats were not the largest dung producers, although this was rarely the case. In nearly all countries cattle (including buffalo and camels) were the largest dung producers. 6. The baseline figures are based on the 1977 FAO Production Yearbook); the 1990 figures are based on World Bank, International Food Policy Research Institute and FAO projections. The sources are listed in order of decreasing residue contributions. The sources and ranking is constant between 1977 and 1990. The source codes and the residue (at field moisture content) to grain ratio used are as follows: Grain Code Residue-grain ratio rice R 2.00:1 corn/maize C 2.50:1 sorghum S 2.50:1 wheat W 1.75:1 barley B 1.75:1 millet M 2.00:1 rye Ry 1.75:1 oats 0 1.75:1 jute J 2.00:1 The energy content of agricultural residues was taken to be 13 GJ per metric ton. Jute sticks were included only for Bangladesh. In all other countries, jute production is less than 2 percent of total cereal production. Cereal residues are only a fraction of total agricultural residues produced. In most parts of the Third World, roots and tubers, vegetable, fruit, nut, pulse, cotton production is very significant. However, the extensive residues from these crops are not included in this table. For projecting cereal crop residues, several sources were used. If availal-ie from Price Prospects for Major Primary Commodities (Report No. 814/78, June 1978), country specific growth rates for wheat, rice or coarse grains were applied to the 1977 FAQ based production figures. These growth rates were only available for certain crops for twelve developing countries. For the majority of countries, cereals production were projected to grow at the rate implied by the International Food Policy Research Institute report, Food Needs of Developing Countries: Projections of Production and Consumption to 1990 (Volume 3, pages 129-136; December 1977). For the remaining countries, approximately 15, not covnrnd by these sources, FiAO bo:5sic proJ2ct%O8;) growth rates for cereals for differest geogrzprz-ical reg-tons fro.. ''AO Comno6 Ity Projections 1985, Cereals: Sygk Demand and 'frade ?roJection_ 985 (Juy y978) were used. For all of the countries except those for whlich som. 3trnk project:ons were available, it was implicitly assumed that the miA of diffeen.c cerea.- crops produced, residue-product ratios and energy contents remained constanat. 7. The baseline figures are based on 1977 FAO Production Yearbook; th-e 1990 f:igt.-zs are based on projected growth rates from World Bank, The ratio of bagasse to sugarcane harvested at field moisture (sbout 50 percent) uned Wc So5 with a corresponding energy content of 9.5 CJ per metic ton, Bagasse availability was forecasted for only those major sugarcane producers for which the Bank makes country specific projections of sugar production growth rates. The document used was Market Prospects for Sugar (June 1978) by Ezriel Brook of the Economic Analysis and Projections Department. 8. In the 1976 Yearbook of Forest Products, the data for fuelwood, charcoal and non-fuelwood use for Lesotho and Nam-lbia are included under those for South Africa. Therefore the per capita results for the3e tWo categories (fuelwood and charcoal and non-fuelwood use) for South Africa are based on the total populLtion of the three countries. The population figures presented for South Africa are for that country only. 9. The potential availability of agricultural residues for the Republic of China (Taiwan) are based on 1976 agricultural oroduction levels from the U.S. Depar:ment of Agriculture, Indices of Agricultural Production for Asia and Oceania, StatistiLcal Bulletin No. 606 (June 1978), lOo The 1977 population figure for Puerto Rico is an estimate from the New York City office of the Commonwealth of Puerto Rico (telephone call), 11. In both the 1977 FAQ Production Yearbook and the 1976 Yearbook o' Forest Products, the data for China include both China PR (m.ainland and the provioce of Taiwan (the Republic of China). As a result the per capita igures for woo6 use, forest yield and agricultural and livestock residiues are based on the total populatlon of China PR and Taiwan. The population figures presented for Chiina PR are only for that country, -101- TABLE I-5 Fuelwood and Charcoal Use -- 1976-19901 AFRICA, SOUTH OF SAHARA (million GJ) FAO Projections based on FAO historical data Country 1976 1980 1985 1990 Regional Group 1 Benin 25.77 27.42 30.63 33.83 Burundi 9.59 10.52 11.40 12.25 Central African Empire 19.58 (22.78). (24.16) (25.55) Chad 37.63 38.78 42.14 45.48 Ethiopia 250.24 271.22 288.84 306.34 The Gambia 2.63 2.94 3.39 3.85 Guinea 28.81 31.35 34.18 36.97 Kenya 125.08 133.22 143.47 153.68 Lesotho n.a. n.a. n.a. n.a. Madagascar 52.90 60.08 68.18 76.23 Malawi 33.05 (28.20) (24.16) (20.15) Mali 30.34 33.24 36.38 39.54 Niger 25.26 28.02 30.55 33.11 Rwanda 42.11 47.18 51.32 55.48 Sierra Leone 27.20 26.93 26.61 26.30 Somalia 34.52 37.42 40.87 44.33 Tanzania 398.69 427.49 475.02 522.55 Uganda 147.87 163.73 176.70 189.70 Upper Volta 42.64 46.82 50.31 53.80 Zaire 128.36 (142.66) (149.28) (155.94) Regional Group 1 Totals 1462.27 1580.00 1707.59 1835.08 102 - >ŽB3L2 I-5 (continued) 2zFRXCA, SO`15 Of.? SAIR.-\ FAQ ),.).ojecJ- ons bpased on FAQ histori cal data Country 1976 . .980 1985 1990 Regional Group 2 Angola 73..90 7'/53 04-1.2 9G071 k3otswana 7.,51 0O;.17 0,,85 9 55 tIu.eroon 76.55 820,,65 89029 95,o96 Congo 19.32 22oK .0 2,5,20 28.69 Ghana 114,59 131 026 15138 17Lo53 Gmin.ea-Bissau 4068 4.90 5012 5.34 XV0ory Coast 5 3 ..I 25225) (51,,41) (5006;) Liberia 14,84 1$5o87 17,43 l9o00 kituxitania 5 .72 6018 6.66 7.o1 P£auitius .24 02; . 1) t 10 Mozambique 89.59 9 7 L 65 04. o 88 a 1252.3 Mamibia n.a. n, a. n.a. nXa. P- k\!igeria 699.24 762 097 848882 935o22 Rhodesia 58,69 5'f.97 70.20 75.44 Seneceal 25,,96 28321. 30.79 33.35 Sudan 227059 (226096) (232,62) 238019 Swaziland 4,o89 53 59 6,25 7 00 Togo 10,33 10 ,54 11.23 11,95 Zambia 40.56 (47,70) (49,35) (51.18) X9gional Group 2 Yota2s 1525.31 :64i5,36 1793,77 19430.1 Regional Group 3 Gabon 11.96 O3,ll9 0 (12.00) (12.08) R°unJ. on °34 I'5 °09 °05 South Africa 1099 12_39 !3.55 J.4 81 Regional Group 3 Totals 23.29 2444 25064 26094 AFRICAk, SOUTH CF SAHARA- TOTALS 30i0o87 3249.80 3527000 3805013 -103- TABLE I-5 : Fuelwood and Charcoal Use -- 1976-1990 1 NORTH AFRICA AND MIDDLE EAST (million GJ) FAO Projections based on FAO historical data Country 1976 1980 1985 1990 Regional Group 4 Algeria 14.08 15.75 17.70 19.65 Egypt 1.22 1.35 1.50 1.62 Jordan .03 .02 .01 .005 Morocco 29.63 32.45 36.01 39.56 Syria .54 .54 .54 .54 Tunisia 18.76 20.68 22.71 24.73 Yemen A.R. n.a. n.a. n.a. n.a. Yemen PDR n.a. n.a. n.a. n.a. Regional Group 4 Totals 64.26 70.79 78.47 86.11 Regional Group 5a Iran 21.83 19.94 -1.89 23.87 Iraq .16 .12 .09 .06 Lebanon .65 .86 1.01 1.16 Regional Group 5a Totals 22.64 20.92 22.99 25.09 Regional Group 5b Kuwait n.a. n.a. n.a. n.a. Libya 4.36 (4.43) (4.64) (4.86) Oman n.a. n.a. n.a. n.a. Saudi Arabia n.a. n.a. n.a. n.a. UAE n.a. n.a. n.a. n.a. Regional Group 5b Totals 4.36 4.43 4.64 4.86 NORTH AFRICA AND MIDDLE EAST TOTALS: 91.26 96.14 106.10 116.06 -:104- TABLE I-5 z Fuelwood azid CbercoF2 Use* 1976 3cX) Asx), AND AX5C (mi,.ilion CJ) FAO Pzojections based on FAC 7- .stoxicat. c u. Country 1976 3.980 3.S85 9 2t .egiona1 Group 6a Cambodia 44.10 A84.8 53 3 2?9 . Laos 32.33 35.44 38,6' a,, Vietnam 177.26 194.73 208.70 22206S Regional Group 6a Totals 253.69 2,78.63 300,o3 322~51 Regional Group 6o Afghanistan 62.91 67020 73.23 -i >2f Bhutan nOa. n O a. n.a, o 2 I Nepal 94o61 101.47 107Jo0 1>2o7,. Pakistan 92.09 103.48 14 o61 i 2?,) o 7x' Regional Group 6b Totals 249.61 272015 294, 94 31 7 dg3 Regional Group 6c India 1285.19 1359,27 14A2J10 L606Os. 3 Sri Lanka 45o95 410S 50 52,28 5.., Regional Group 6c Totals 1331014 j./08,37 :t p334,f 1661958 Regional7 Group 6d Bangladesh 152038 I90,89 231o03 2ViS Burma 206.62 2:i7.69 304,8:3 3632.,3 Regional Group 6d Totals 359.00 4i48,58 533,86 6 3, 4 43 -105- TABLE I-5 (continued) ASIA AND PACIFIC FAO Projections based on FAO historical data Country 1976 1980 1985 1990 Regional Group 6e Indonesia 1207.12 1344.04 1484.76 1625.49 Regional Group 6e Totals 1207.12 1344.04 1484.76 1625.49 Regional Group 7a Republic of China (Taiwan) n.a. n.a. n.a. n.a. Fiji .12 .07 .05 .03 Republic of Korea 79.93 81.00 76.88 72.74 Malaysia 61.04 64.53 69.32 74.08 Papua-New Guinea 51.69 56.73 62.00 67.26 Philippines 249.69 274.42 307.46 340.50 Thailand 174.99 186.35 201.00 215.63 Regional Group 7a Totals 617.46 663.10 716.71 770.24 Regional Group 7b Hong Kong n.a. n.a. n.a. n.a. Singapore n.a. n.a. n.a. n.a. Regional Group 7b Totals 0.0 0.0 0.0 0.0 ASIA AND PACIFIC TOTALS 4018.02 4414.89 4867.88 5332.10 -106- BBLE I-5 . Fuelwood and Chnarcoal Use -- 1975-1990 XATXN AMERXCA AND CARIBBEAN (million GJ) FAO Projections based on FAO h:.storical data Country 1976 198C 1985 1990 3g9xona1 Group 8 Bo1livia 38.61 36016 32055 28094 Caile 32063 32032 32019 32005 Colombia 217.50 211007 200,24 189,40 Costa Rica 23.85 27.24 3Co33 33.42 Cuba 16.31 14.2S 12269 11.09 Dominican Republic 18089 (20010) (20.36) (20.63) Ecuador 21010 (22o70) (26o02) (29.34) El Salvador 34.58 %31,C5) (33021) (35.37) Guatemala 55o68 61o29 69o06 76o81 Guyana o17 o08 .04 0 C2 Haiti 40/78 44.,44 1 47.46 50.48 Honduras 32.62 35.00 35.90 36S82 Jamaica .01 .1 00101 oOl Nicaragua 23022 23033 24.29 25.27 Paraguay 32,62 35,84 39.82 43.79 Peru 62,50 69o12 76013 83013 Regional Group 8 '.Iotals 651.07 664,04 680,30 696,56 Regional Group 9a Mexico 88,85 87.26 82.53 77,81 Regional Group 9a Totals 88085 87.26 82.52 77,81 -107- TABLE I-5 (continued) LATIN AIERICA AND CARIBBEAN FAO Projections based on FAO historical data Country 1976 1980 1985 1990 Regional Group sb Brazil 1522.50 1635.32 1720.85 1806.39 Regional Group 9b Totals 1522.50 1635.32 1720.85 1806.39 Regional Group 9c Argentina 87.00 82.00 75.86 69.74 pana a 15.22 (15.73) (16.42) (17.11) Puerto Rico n.a. n.a. n.a. n.a. Trinidad and Tobago .11 (.10) (.07) (.04) Uruguay 10.33 10.90 12.20 13.50 Venezuela 79.69 88.56 97.85 107.16 Regional Group 9c Totals 192.35 197.29 202.40 207.55 LATIN AMERICA AND CARIBBEAN TOTALS 2454.77 2583.91 2686.08 2788.31 --1O8- TBLE I-5 Fuelwood and Charcoal Use 197' 199O- SOUTHERN EUROPE, WESTERN EUROPE, NORTH AMERICA & OCJIANIA (million GJ) FAO Pxojections based on FAO historical dat' Country 1976 1980 1985 3990 SOUTIHERN EUROPE Regional Group lOa eizkey ll1l9 D(i38.86) (4 7,44s ( l56,56 Regional Group lOb Cyprus, Portugal Yugoslavia 49.35 30o80 19.84 Regional Group lOc Greece, Israel, Spain 42,87 33vS4 21L27 13.34 SOUTHERN EUROPE TOTALS 206.41 203060 18O8855 18205'! WESTERN EUROPE Regional Group 11 Austria, Belgium- Luxembourg, Denmark, Finland, France, Germany FR, Ireland, Italy, Netherlands, Worway, Sweden, Switzerland, United Kingdom WESTERN EUROPE TOTALS 212077 157.57 118.32 88085 WORTH AMERICA & Regional Group 12 OCEANIA Australia, Canada, Japan, New Zealand, United States WORTH AMERICA & OCEANIA TOTALS 225.01 132.44 85059 55030 -108a- TABLE I-5.: Fuelwood and Charcoal Use -- 1976-19901 CENTRALLY PLANNED ECONOMIES (million GJ) FAO Projections based on FAO historical data Country 1976 1980 1985 1990 Regional Group 13a China PR 1544.25 1663.11 1793.61 1924.00 Korea DPR 50.46 55.75 61.06 66.38 Mongolia 14.68 18.16 20.92 23.69 Regional Group 13a Totals 1609.39 1737.02 1875.59 2014.07 Regional Group 13b Albania, Bulgaria, Romania Regional Group 13b Totals 82.01 72.83 64.08 56.38 Regional Group 13c Czechoslovakia Germany DR, Hungary, Poland, USSR Regional Group 13c Totals 952.37 868.17 793.08 724.49 CENTRALLY PLANNED ECONOMIES T\OTALS 2643.77 2678.02 2732.75 2794.94 -109, Notes for Table T-5 n.a. not available. 1. This table is based on pages 17 and 18 of the 1976 Yearbooke of Forest Products. The 1983, 1985 and 1990 figures are trend projections based on regressing historical data from >She 1976 Yearbook. Projected figures in parentheses are the result of regressions which explain less than one half of the variance (r2 < 0.5). These per capita use estimates were based on FAO fuelwood and charcoal production estimates. As a result there is some distortion because imports and exports were not tciken i.nto account; however, this error is small since international trade of fuelwood and charcoal involves less than one half of one percent of total production. Furthermore, the FAO figures pose a problem in that imports and exports do not balance: total world imports are 80 percent larger than world ecnorts. -110- -ANNEX II NON-CONVENTIONAL ENERGY TECHNOLOGIES CONTENTS Page (Biomass Conversion) A. IMPROVED STOVES ..., , ,,. 111 B. BIOGAS .. 114 C. PYROLYSIS AND RELATED PROCESSES . .............. 117 D. ALCOHOLS ... .119 (Direct Solar). E. PHOTOVOLTAIC CELLS .........................-.-.-.--.-.120 F. SOLAR COOK ERS.121 G. SOLAR DRIERS .. ............... . . 125 H. SOLAR STILLS ........................................... 126 I. FLAT PLATE SOLAR WATER HEATERS .. 127 J. CONCENTRATING SOLAR WATER HEATERS................ 128 (Wind and Water Power) K. WINDMILLS. 129 L. MICRO-HYDRO............................................ 130 A. IMPROVED STOVES 1 Most people who cook with wood use "stoves" that accomplish little more than holding the pan, pot or other cooking vessel at an apprcoriate height above an essentially open fire. Many improvements are possible in this system. Generally, they involve enclosing the fire, regulating t'le flow of air into the stove, and adding a chimney. These measures can increase efficiency by a factor of 4 to 5 in laboratory tests; a halving of fuel requiirements for household use has been claimed for a variety of designs. In some designs, the stove is given a large thermal mass, so that much of the heat which is lost for cooking purposes is released over an extended period after a meal is cooked and is thus useful for space heating. 2. The primary purpose of the chimney is to improve the stove's draft. In effect, this allows for a greater exi:raction of heat from the combustion gases by increasing the efficiency with which their buoyancy is used to pull air through the stove. The chimney can also be used to conduct the exhaust gases out of the home, which helps improve eye and respiratory system health. in some areas, however, smoke in the home is considered beneficial because it cr>ves away insects that attack not only people but also roofing materials, 3. Two general types of improved stoves have been developec0 The type illustrated in Figures II -l and II-2 'is sometimes referred to as r, "mud" stove, but is in fact made from a mixture of sand and clay wi-th enough sand to prevent excessive cracking and enough clay to hold the stove together0 The clay should fire, producing a hard surface in the firebox and flues0 Similar stoves have also -112- FIGURE II-1 IMPROVED STOVE (GUATEMALA) K' H t:~ ~ - !- -113- CL) I FIGURE 11-2 IMPROVED STOVE (INDONESIA) *1 (Section) Wood Storage (Complete Stove) -114- been built with mixtures of clay and ashes, and fibrous material such as straw may be added for strength. The chimney may be made from metal stovepipe, bamboo, lengths of ceramic pipe, or built up with bricks of stove material. 4. The second type of improved stove is made with a metal shell, usually a used can of 5-gallon or larger capacity. An inner liner of ceramic or other material may be used to separate the fire from the shell, reducing heat losses and prolonging the shell's life. The cooking vessel and food may be placed on top of the shell for frying or inside it for stewing and higher efficiency. Some stoves of this type are designed to be packed with sawdust, rice hulls, or other loose fuels rather than for use with wood. B. BIOGAS 5. A mixture of gases containing 55-65% methane is obtained from the anaerobic decomposition of organic materials. It occurs in nature (e.g. swamp gas) and has been produced in controlled environemtns for many years, as a by-product of certain types of sewage treatment plants. When produced for use as a fuel, it is often referred to as biogas. 6, There is currently considerable interest in many countries in the potential use of family or village scale biogas plants to provide fuel, improve sanitation, and increase the fertilizer and soil-conditioning value of animal dung and other organic wastes. The theoretical advantages of biogas production are especially great in areas in which firewood is unavailable and animal dung is used as a household fuel because it allows the use of a given quantity of dung as both fuel and fertilizer. It does this by separating the fuel-valuable carbon from the nitrogen in the dung. Most pathogenic organisms can be destroyed in a biogas digester, so the technology can be used for the treatment of human wastes as well. -115- 7. Biogas can be produced in controlled environments, but the process involved is a biological one involving several types of bacteria and is not fully understood. The process is sensitive to temperature, acidity-alkalinity, and to the type of feedstock used. Most digesters are operated at 30-35°C, although the process can be maintained at temperatures down to about 10°C. At temperatures well above the normal range, a different type of bacterial culture dominates ("thermophilic" as opposed to "mesophilic") and the process of methane production is greatly accelerated. However, a thermophilic digester must be kept at 50-600C and the cost of maintaining these temperatures is generally considered to exceed the cost of using the larger digester required to obtain the same production from a mesophilic system. 8. A biogas digester consists basically of a sealed container filled with water and the material to be digested. Gas produced rises to the top of the container and is extracted through a tube or pipe. In most designs, an upper portion of the container is reserved for gas storage. Raw materials are generally added through an inlet at one end of the digester and the digested "sludge" withdrawn via an outlet at the opposite end. At least three families of designs are under development. They are distinguished by the means used to cope with variations in the quantity of gas in storage. The "Indian" design approach is to construct the digester in two telescoping parts with a system of guides and counterweights to adjust the volume. The "early Chinese" solution is to let accumulating gas push the liquid contents of the digester up the outlet (which is covered but not pressure-sealed) and to minimize fluctuations in water level by providing a large surface area between collected gas and liquid. "Bag" digesters are made from a flexible material and easily adjust to changes in the volume of their contents by changing shape. "Recent Chinese" biogas units are built to withstand pressures of up to about 100 cm of water, and so accomodate fluctuations in gas quantity by allowing pressure to build up within a fixed volume. -116- 9. Biogas is usually produced under low pressures (5 to 10 cm water) and often contains small amounts of hydrogen sulfide, which may cause corrosion problems in any exposed metal parts with which the gas comes in contact. However, with suitable adjustments to the burners, most appliances made for natural gas or LPG can be adapted for use with biogas. Biogas can also be used to run internal combustion engines, but to use it in vehicles would require compressors and pressurized tanks. 10. India and China have both launched large-scale biogas programs at various times. The Indian program involved technical assistance and subsidies on construction costs and reportedly resulted in the construction of some 37,000 plants. The program was criticized and cut back on income-distribution grounds: benefits went to the relatively wealthy who had the cattle, land, and credit needed to build and use a biogas plant and, apparently, introduction of the plants induced an increase in the value of dung, so that the program had a negative impact on the real income of the poorest groups, who cook with dung obtained from others. 11. Biogas was one of the technologies promoted in the Chinese "Great Leap Forward" program of 1958-60, but was reportedly not used on a widespread basis until the 1970s. According to some reports, there were "well over" four million biogas digesters in China by 1977. Many of these are apparently family-sized units. 12. Most Asian developing countries appear to have between ten and a few hundred biogas plants in operation. They appear to be most successful in the Republics of China and Korea (where they are not operated during the winter). In both of these countries, as in PR China, the primary feedstock is pig manure, which has technical advantages over cow dung. 117 C. PYROY.LSS ABD RE LAT:TD PTR J1I S IS !3Aher tiood is neated su"ff ici ) S'n 2n oXygen I-ree env.i.:'onment, a di!:tSJltI`or- process occurs AWOiS-:u0'e -'Vd >ola.i-le -e-e-a½ In the woo& are eva9,o.-ated, les v:-9 zcrbon and. ci. meritlS :n the fo:-m c5 churcoa). Ar ambieni. tempera.ure ancl pressare conditions, soiae o' the volp ; X > a e o e e >a e z 40 c3 40 40 40 41 41 U _ O 'C J C 0 0 <..i C 0_0 C0 b 0 D 0 a u 1- I.. IN CO X Cl 0 0 C u X I .0 > I 4 14 ¢~ 41 Q CJ- >Ut1C C C -0 4 . .' 0- 01441.0.o~~~~~ IN 0 '.4 410 41 ~~to0 0 411. 1.I. 4., . IN _0 .0 C 41 014 . b 214 e o14 o 0 U e 14 -4 0 IN 1 1.*.. a c1 a1 O w 0 la 4 4.4 4 0 4 4 C O O aa 0 0 .-4 ~~~~~~~~~~~~~~~~~~41M 41~~~~~~~~0' cg 0 CO Z ° e 4° > z > o 4 U 0 ,. 4 . , _I~~~~~~~~~~~~~~~~~~~~~ Q 1 N 0 0 l...v0 U 4 0 CN Q40 41 0 . 14. .40 0 41 41.-1410>,o '. I * 0 M ~~~~~~~~~~~0 U*I-. 14 .0 .0 14 ~~~~~~~0 41 U 403- CZ U o > 4o. 0' 0 0 0 4 0 0 0 0 ..e 0X 1 . 0u 0L 0 41 ' -'* 0 1 0 0 0 - 0 0 4 0 14 0 11. !50 0 1 6 N c0 4- 0s co Z ) cn X Oc 0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~4 4 0 C. 0 014 41 0 3 0 cn44 1 C 0 NO 1 4e < = e 0 0 4.4 0 144 0 4 o ,% 0 4) 0 40 a c> 0 Z1 ca :: co 00 4) ¢^ 4c 49 cc c 0 a p o 41 .41 0~~~~~~~~~~~~ 40 - *ow 41n 40 4 A.0 414Ca 1410 41 4 ,4 10 C: -0~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ .0 .41~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 40 0. U x c c o 0 - GJw 4 0 w u ~ U i 2 ^ _ X U >> + c a 8 ~ . - 0 waw IN~~~~C C u 0 z 40 u~~~~~~~~. 0 04 Z .000 00.-.0 11 00 0 In r, v 4c~~~~~~~~~~~~~. 4.-4 . 4 0 4 0 4 4 C .0 '.1 ~ 0 41 41~~~~~~~~~~~~~~~~~~~~~~ '.4 .00 41'..' 0 410 * 40 lC)0u 0 4.0 U404j410 0~~ .> 0 4 4 >4 I 0 a--' ae .J v144110 I Ci 0- 0 0 41 U41 UU 4~~~~~~~~~~~~~~~-4 C 0m .04W1 d 410 410 0. 410 '~~~ '~~ a W 4 .0 410 . 1 4 0. W 0 :, ~ ~ 1 ~~4 0 0 4 1.4 '0 . . . .0 4 1 0 .0 14 > W W * 4.I 040 0 144. ~ 4'1 14 14 l~ Q1 14 0 ,U0 0 .4 1. 4 114 G. SOIAR DR3iRS 39 Experience over some twenty years in S~ furkey, Canada, Australia Brazil, India, and Trinidad demonstratcŽs the potenk:ial for using s:7-plI solar equipmen'> for drying or curing meats, fzuit, vegetables, grains, tobacco, and timber ei'tier directly in the colleci.o z or xtith dry air heated in flat plate collectors and transported 'o a sepa-fa' 6nry."3'lg chamber0 The collsctors toemselves are generally either shallow boxes of gfood (painted bKck on the inside) withn sloping clear glass or plastic covers aimed at the su-Ln0 40. With advances in technology and the rising costs of fuel, it may be feasible to 'narness solar energy for controlled food dehydration instead of depending on the traditional sun dryliig. 41. Under favorable climatic conditions, simple sun drying 1,c) feasible at low cost and without complicated equipment5 L;ut sun drying has the following disadvantages: a. The traditional process is ur,contn.rllable, as it is at the mercy of the elements. b. Good quality of the product cannot be guaranteed. c. A large area is requirea for -,:"e drying purposes. Irn sun drying of fruits, approximately one h,ectare of drying sa-r:ce is required per 20 hectares of crop land with an average yield0 d. Sanitary conditions caPnot be controlLed, as the food can often be contaminated by dust, insects, birds, and rodents. The quality of the product is often reduced by beetle iiifestation dv.ring 6rying, s0 Sun drying is time consumhng, 1/ Adapted from "Utilization of Solar Energy in Food Preservation"' by ToW. i4aembe in Workshop on Solar Energy for the Villages of Africa, an NAS/Tanzania National ScientIfic Research Council publicet'on, 19/8). -126- 42. To avoid these problems, wood is often used for smoking and drying of fish and high value crops. However, traditional fish smoking by using wood is reported to produce a product of low quality, and in the Philippines, for example, the cost of fuel for curing tobacco has doubled over the last three years for all major sources -- oil, firewood, and LPG. Plans are under way to test solar equipment to supplement or replace conventional fuels in the tobacco curing process. Timber drying in Australia using flat plate collectors has proven to be only slightly more expensive than conventional drying with fossil fuels. 43* Solar driers could be used by either individual families or by coops or entrepreneurs at the village level. If costs can be kept low enough, the benefits from solar driers could be significant in light of the potential for overall increased availability of food, reduced costs for curing tobacco and similar products if substitution for fuelwood can be accomplished, and possibly improved income to farmers and fishermen as a result of better quality products available to consumers. H. SOLAR STILLS 44. A solar still was used to produce water for the mules that provided mechanical power at a mining operation in northern Chile for about 20 years after it was built in about 1870. Solar distillation has been used more recently in the U.S., USSR, Australia, and various Caribbean and Mediterranean islands to provide drinking water, water for livestock, distilled water for automotive batteries and other uses. 45. Though there are numerous designs, a so12a S.' ," .o' :> of a black bottomed tray filled with brackish water and coved-fe £y £ repfg roof of glass or plastic sheet. Sunlight evaporates t"e- D condenses on the underside of the transparent cover and _rickcler cc\J into a trough running along the bottom edge of the covez Suv,c, a.- ca& yield five liters of fresh water per square mzter of collectoT ^ach Gacyc Lifetimes of stills have exceeded 20--30 yeazs with maintenance and oieras-tng costs that are generally very low, dependlng upon t',.e design a'1d materials used. Potential problems involve removing the de'hydrated resiu.e of tle Feed water, the durability of the clear cover, corrosion and siltiLng. 46. Solar distillation units can reportediy 1bn bouilta fo-r between $15 and $30 per square meter, which with a capital recovery ratze of 10 to 20 percent annually implies capital costs of $1 to $4 pser cubic me*.c (thousand liters) of water distilled. I. Flat Plate Solar Water 1-1eaters 47. The prototypical flat plate collector solar water Ii_ter consists of a glass covered box through which water moves iLn tubes from tne bottom of the collector up the face and on to a storage tank0 Hovemeit -_.y be by convection or a pump may be used. 48. Solar water heaters are widely used :n J7?, f aoe r