Turning to coal and other approaches to easing the pressure on fuelwood resources
Gerald Foley and Ariane van Buren
GERALD FOLEY and ARIANE VAN BUREN are with the International Institute for Environment and Development, London. They were engaged by FAO to prepare a report bearing the title of this article for the Technical Panel on Fuelwood and Charcoal for the United Nations Conference on New and Renewable Sources, Nairobi, August 1981. This article is an edited version of their report.
STACKING FUELWOOD IN WEST AFRICA, while there is still wood, seek substitutes
In the coastal cities of Africa, such as Dakar and Nouakchott, in the Cape Verde Islands or Dar es-Salaam, charcoal, and sometimes fuelwood, are the main domestic fuel. In such cases, the surrounding areas are markedly wood deficient and the consumption of fuelwood that is concentrated in the cities has serious consequences for the environment. Alleviating the demand for fuelwood would help in protecting remaining forest resources and would give time for new plantations to grow. On the world energy market refined oil products, such as gas or kerosene, are sold at higher prices than crude oil. But under the evolving market conditions, fossil coal would become cheaper than crude oil. Therefore, if charcoal or fuelwood is to be substituted by an imported energy source, coal could offer a good prospect. Its distribution would take place through existing charcoal systems and its use would not involve major changes. It would, therefore, not necessitate substantial investments. However, it is necessary to use coals whose characteristics are suitable for cooking.
It is difficult to estimate the total fuelwood consumption in Senegal and Tanzania. Accurate statistics are not available for the amount of firewood used in the rural areas; there are also uncertainties about the quantities of charcoal used in the cities. There are further problems with the assessment of the usable wood inventory and the rate of natural regeneration. The latter varies greatly between different climatic zones, and has been heavily affected by the drought conditions of the past decade. Natural regeneration is also influenced by livestock and grazing levels, competition with agriculture and other land uses, and the general management: of land and forest resources.
Analyses of the fuelwood problem are forced to rely upon imprecise data and are based, to a considerable extent, upon subjective impressions. It is thus extremely difficult to arrive at reliable assessments of the pressures of fuelwood scarcity, and of the attractiveness to fuelwood consumers of possible alternatives. The following analysis, nevertheless, attempts to use the available data to bring as much precision as possible to the question of substituting other fuels or improving the efficiency of utilization of fuelwood.
Population distribution. In mid-1980 Senegal was estimated to have a population of 5.7 million growing; at 2.6 percent per year. One third of these people live in the cities and large towns; 65 percent of these, or 20 percent of the entire population, live in one city, Dakar, with roughly one million inhabitants. The next largest towns are only one tenth the size or less. While their average rate of increase of the urban population is 3.3 percent, Dakar is urbanizing far more quickly at around 7 percent per year.
Although Tanzania displays a similar pattern, it is three times as large and still far less urbanized. Its population of 18.6 million appears to be growing at 3.1 percent per year. While it is only about 13 percent urbanized, at present the average rate of increase for all the towns is calculated to be 8.3 percent. Dar es-Salaam contains 50 percent of the country's urban population and, with roughly one million inhabitants, is comparable in size to Dakar. Similarly, it is ten times larger than any other town.
Fuelwood consumption. About 80 percent of Senegal's total fuel consumption and 90 percent of Tanzania's are in the form of wood or charcoal. Estimates of consumption per person vary according to urban or rural use, climatic zones, local availability of wood and the method of collecting statistics. Rural consumption of fuelwood per person is, however, generally reckoned to be higher than urban. This is because of easier access to re sources, greater consumption for cooking and heating, and the use of fires as a means of protection against animals. The 1970 FAO estimate for Tanzania placed annual rural household consumption at 2.2 m³ per person, with an additional non-household consumption, mainly attributable to the tobacco industry, at 0.2 m³ per person. Estimates in mid-1980 were rather lower and the range of 1.5-1.7 m³ per person was preferred. In the Sahelian countries estimates of annual consumption were considerably lower, generally in the range of 1.0-1.5 m³ per person.
More efficient stoves take time to develop and to promote in. actual use in. rural societies. But unless they are developed now and brought to people's attention they will not be available when the need for them arises.
Reliable figures for total charcoal consumption and its impact on wood resources are notoriously hard to Additional difficulties in forming accurate estimates are caused by variations in density between charcoal from different types of wood and by the wide range of efficiencies in the conversion of wood to charcoal. Official records of charcoal entering Dakar in 1978 indicate an annual consumption of 100 kg per person per year. Other estimates place the figure as high as 125 kg/person-based upon an annual consumption of 1 tonne per family of eight. An average figure of 100 kg/person/year has been assumed. Although statistics for annual consumption in Dar es-Salaam are not available it seems reasonable to assume that it is also about 100 kg per person per year. If these assumptions are correct, the total consumption of charcoal in each city is about 100 000 tonnes per year. Estimation of the impact of these consumption figures upon the wood resources in both countries must be highly speculative. Assuming an average conversion efficiency from wood to charcoal of 15 percent by weight and an average wood density of 600 kg/m³, the wood requirement per person per year is about 1.1 m³
Taking these assumptions, the total fuelwood consumption in both countries can be roughly approximated. In Tanzania it is about 30 million m³ per year (assuming 1.6 m³ per person in the rural areas and 1.1 m³ in Dar es-Salaam). In Senegal the total is about 7 million m³ per year (assuming 1.25 m³ per person in the rural areas and 1.1 m³ per person in Dakar).
The charcoal consumption in Dakar accounts for about 15 percent of the total consumption of wood resources in Senegal. In Tanzania, the consumption in Dar es-Salaam is about 5 percent of the total. The most notable characteristic of consumption in both countries, however, is the high proportion unaccounted for in formal statistics in the rural areas. This amounts to at least 95 percent of the estimated total in Tanzania and to 87 percent in ´Senegal (where in 1978 a total production of 932 000 m³ of charcoal and 55 000 m³ of firewood was recorded).
Charcoal supply. The charcoal for Dar es-Salaam is obtained from the woodlands bordering the approach roads to the city. Transport is by lorry, with local maximum haul distances in the vicinity of 100 km. Production of charcoal is almost entirely by individuals operating independently in the natural woodlands. Earth kilns are exclusively used and are, typically, quite small, rarely exceeding more than a few cubic metres. The supply of charcoal to Dar es-Salaam provides an important source of income for the surrounding areas from which it is drawn: but of the total consumption of wood in the country, the capital accounts for only about 5 percent. Checkpoints are situated on the five major roads leading to Dar es-Salaam, where lorry drivers are checked for their possession of a licence for any charcoal delivered to the city. Unlicensed charcoal is confiscated.
In Senegal, the woodlands in the vicinity of Dakar are no longer capable of supplying the city's charcoal needs. Supplies are now drawn from the furthest parts of the country. Transport is mainly by road with large loads sometimes hauled a distance of up to 600 km. Charcoal is produced by licensed operators working usually in cooperative groups under a variety of commercial and contractual arrangements. The earth kilns are generally large, requiring a group of 10 to 15 workers for the heavy tasks, and may use up to 100 m³ of wood. Access to woodland areas. the amount of production and the degree of exploitation of particular areas are subject to controls: in addition to its impact on the wood resources of the country the supply of charcoal has other important economic consequences. The charcoal transport system is part of the trade network for the whole country. since the lorries bringing charcoal to Dakar return to the regions with merchandise. The supply of charcoal to Dakar is thus an economic activity with which much else is linked.
Charcoal prices. Charcoal is largely traded by the bag, a gunny sack which holds roughly 40 kg in Tanzania, depending on the species of wood carbonized. In Senegal, char coal bags are officially assumed to contain 50 kg, but vary in practice. Wholesalers transport the bags in lorries of up to 10-tonne capacity. Retailers sell the charcoal in small amounts, usually by volume rather than by weight; for example, by small heap or by bucket. Charcoal prices were fixed in 1975 at F.CFA 855/bag wholesale, F.CFA 903/bag semi-wholesale, and F.CFA 20/kg retail. The official charcoal price has been held constant for the past five years. In times of seasonal shortage such as the rainy season, the price has, however, been known to double. The price for 1980 was raised to just over F.CFA 1 000/bag wholesale, F.CFA 1 235/ bag semi-wholesale, and F.CFA 1 332/ bag or F.CFA 26.65/kg retail. This is a price rise of just 33 percent for the whole five-year period (F.CFA 200 = $1).
The fact that women are frequently excluded from all cash transactions increases the resistance to domestic change.
In Tanzania the price of charcoal can vary from area to area, ranging from 18 to 90 Tanzanian shillings (T.sh) per bag. Prices are not fixed and depend on varying pressures of supply and demand, population and resource constraints in different areas and the effects of seasonal climatic changes. An average price for Dar es-Salaam can be taken to be T.sh 45/bag which is midway between the new wholesale and semi-wholesale prices in Senegal (T.sh 8 = US$1).
Firewood. In the rural areas firewood is gathered by hand, as a free good, and rarely enters commercial markets. Its collection and use are almost entirely the responsibility of women. It thus remains, even when scarce, outside the realm of economic decisions which are usually made by men. The only purchases, in the rural areas, are made by salary earners, such as teachers who are outside the usual pattern of subsistence living. In towns and on the outskirts of cities, some firewood is also bought for domestic cooking. A certain amount of firewood is also purchased or grown specifically for the fuel requirements of many rural or semi-rural commercial and industrial establishments such as restaurants, brick making and tobacco curing. No precise figures are available for the amount of fuelwood commercialized in these ways, but it is generally estimated to be small. In Senegal, in 1978, the total recorded sales of fuelwood were 91 000 steres (about 55 000 m³ of which 34 000 steres (20 000 m³) were destined for Dakar. If annual consumption in the rural areas is 1.25 m³ per person, the commercialized production is around l percent of the total consumption.
The fact that wood is a free good gathered and used almost entirely outside the cash economy, has considerable consequences. It means that the rural fuelwood sector can be viewed as an almost closed "economy" of its own, within which transactions of various kinds can occur in a completely non-monetized but relatively predictable manner.
Fuelwood exploitation and replenishment policies. An annual inventory of wood resources and their exploitation in Senegal is carried out by the Department of Water and Forests. In addition to roughly one million hectares of classified forest, 190000 ha are organized in 20-year rotational lots, specifically set aside for charcoal and firewood production. These lots are in the forests which lie alongside the railway to Mali and were formerly used to supply it with fuel for its locomotives. However, at present. most of the lots are not being used because there is an abundance of dead wood. from the drought elsewhere.
Ceilings were set recently on char coal and fuelwood production, as well as upon the number of licences :issued to producers., and measures to restrict illegal production have been further reinforced. In addition, controls have been imposed on exploitation in drought-afflicted areas that now contain only dead or dying trees. About 80 percent of the fuelwood producers are reported to have been transferred and concentrated in locations with only dead wood. The managed exploitation in these areas is intended to reduce the fire hazard caused by dead wood, as well as to relieve pressure on other areas and facilitate their natural regeneration. Outside these areas. charcoal production is also permitted in the forest lots alongside the railway to Mali. Yields of 4.5-7.5 tonnes/ha are obtained in these lots when all the trees are used, apart from protected species and those that yield poor charcoal.
Exercises that project fuelwood depletion to total disaster tend. to be counter-productive. They do not take into account the flexibility and. versatility of human response. They may also call for political and economic responses that are not feasible. What they can do is to paralyse instead of galvanize the galvanize the policy makers.
The current Development Plan of the Senegalese Government envisages afforestation targets of 7 500 ha per year for all uses. About a third of this target is met each year. In 1978, programmes specifically intended to supply fuelwood resulted in the provision of 212 ha of forests around cities, 302 ha of village woodlots, and the distribution of 864 318 seedlings through popular reforestation campaigns, or the equivalent of 500 ha: assuming a plantation density of 1700 seedlings/ha.
During the colonial period, forest policy in Tanzania was mainly designed to protect forests so that they could be used for industrial production. Popular use of the official forests was almost totally prohibited. The resultant popular hostility toward the Forestry Service endured for some time after independence in 1961. There was also considerable variation in people's attitudes toward trees and their preservation in different parts of the country. In the Kigoma and Tabora regions which were heavily infested by tsetse fly, people were frequently instructed to cut down trees to prevent them furnishing a habitat for the fly. In the past 15 years substantial efforts have been made to change popular attitudes and to promote the planting and protection of trees. The first popular tree-planting campaigns were launched in the mid-1960s. A more comprehensive campaign is due to begin this year with an emphasis on both popular and professional education. Outside a small number of natural forest and plantation areas, the cutting of trees for firewood and charcoal making is not controlled. In Mbeya Forest, which is organized into a system of authorized rotational wood cutting according to tree size, some encroachment and illegal cutting still occur.
The charcoal supply to Dar es-Salaam is almost entirely informal. Its organization includes an individual licensing system, but this does not extend to the establishment or enforcement of ceilings on production. The Ruvu Forest Project, 60 km from the city, is seen as a possible future source of urban fuelwood supply and had been considered for it during an earlier scheme to clear land in order to make way for pulpwood. However, in the drought of 1973/74, two thirds of the 7 000 ha planted were lost. Efforts since then have concentrated on replacement and selection of drought-resistant species but work has been restricted by a shortage of the foreign funds on which the project depends. Plans for 1980|81 envisage planting 200 ha of eucalyptus for fuel and 200 ha of softwood for timber, but this too will depend on the availability of foreign funding.
Assessment of fuelwood depletion. In neither Senegal nor Tanzania existing tree plantation schemes are able to keep pace with fuelwood consumption. Renewal of supply, at present, depends almost entirely upon natural regeneration in open woodland of which only a limited proportion is subject to any forest management. Where severe drought has occurred, as in the Fleuve region of Senegal, there is now almost no natural regeneration. A generalized estimate for natural forest productivity in the whole of the Sahel is as low as 0.2 m³/ha/year. For the best areas of Senegal, which is better placed than some of the other countries - in the region, 4 m³/ha/year are at the high end of the range of estimates. In Tanzania, the miombo woodland is not believed to 'be capable of producing more than 2 m³/ha/year.
Work is being carried out at FAO to obtain a long-term picture of where present trends in fuelwood use in Africa, Asia and Latin America are leading. Estimates are being made by countries, broken down where necessary, into climatic and ecological zones. The calculations are based on estimated per caput consumption and population densities, then compared with natural regeneration rates and projected forward to the year 2000. The assessments show that a net depletion of natural fuelwood resources is now occurring in Senegal as a whole. This means that in the future increased consumption will have to rely upon a declining resource base. As a result, the rate of depletion will continue to accelerate. In Tanzania the calculations indicate a net depletion over some regions, though the country as a whole is still in balance. Population growth will, however, cause net depletion to occur before the year 2000.
While these figures illustrate the national and regional balances of fuelwood consumption and replenishment, they conceal the particular problems of deforestation in a belt around the towns and cities. There, the production of charcoal for urban consumption is added to rural consumption of firewood and greatly increases the pressures of depletion. The problem is therefore not only one of inadequate resources but also of a mismatch between the distribution of resources and the concentration of population. Insufficiencies in the transport infrastructure exacerbate this problem by rendering areas of the wood resource inaccessible. A future problem of fuelwood supply arising from a localized depletion of the natural wood resources in both Tanzania and Senegal seems clearly in prospect. It is one in which the questions of urban and rural supplies are both deeply intertwined.
Concerning wood, charcoal, coal and peat
There are wide variations in the physical properties of different kinds of wood, charcoal, coal and peat. Units, conversion factors, and conventions for measurement and description of their physical properties vary widely.
For convenience, the following average values have been assumed in this report. In reality, there are large variations around these averages. The selection of these values is thus relatively arbitrary. In particular practical cases the actual values obtained from direct observation and measurement would, of course, take precedence.
|
Wood |
|
|
1 stere = 1 m³ stacked wood = 0.6 m³ equivalent solid. | |
|
Density (air dry) |
= 600 kg/m³. |
|
Calorific value (air dry) |
= 3 500 kcal/kg. |
|
(oven dry) |
= 4 500 kcal/kg. |
|
Charcoal |
|
|
Density = 400 kg/m³ -loosely packed 250 kg/m³. | |
|
Calorific value = 7 000 kcal/kg. |
|
Coal
Methods of analysis of coal vary. The average values given below are for a proximate analysis, that is, an analysis based upon the coal as received and without making allowance for ash and moisture contents (as is done in the ultimate analysis). The proximate analysis of coal is broadly comparable to the analysis of wood on an air-dry basis.
|
Density: Anthracite |
= 1 600 kg/m³. |
|
Bituminous coals |
= 1 200-1 500 kg/m³. |
Lignites are very varied ranging in density downward from the lower range of bituminous coals to a peat-like soft, friable, fibrous material with a moisture content of up to 50 percent.
|
Calorific value: Anthracite |
= 8 500 kcal/kg. |
|
Bituminous coals |
= 5 000-7 500 kcal/kg. |
|
Lignites (air dry) |
= 2 500-3 500 kcal/kg. |
"Standard Coal" to which other coals are related by calorific value to obtain "tonnes of coal equivalent" has a Calorific value of 7 000 kcal/kg.
Peat
When dug, peat has a moisture content of about 95 percent When air dry, the moisture content is about 25 percent.
|
Density (air dry) |
= 400-600 kg/m³. |
|
Calorific value (air dry) |
= 2500 kcal/kg |
Hydrocarbon fuels
|
1 tonne crude oil |
= 7.3 barrels |
|
1 tonne crude oil |
= 1.5 tonnes coal equivalent. |
Calorific values
|
Butane |
= 11 700 kcal/kg. |
|
Kerosene |
= 11 100 kcal/kg. |
In principle there is no insurmountable obstacle to the use of coal for domestic cooking-the history of the industrialized countries is a clear illustration. As their wood resources declined, people switched to the use of coal for most of their heating and cooking, and continued to use it in most of the European countries until after the Second World War. Since then, coal has been almost totally displaced as a cooking fuel by gas, electricity and oil.
In China, at present, coal is widely used as a cooking fuel in urban areas. People frequently mix coal-dust with water and a clay binder to make briquettes which are dried on the pavements or in the courtyards of urban dwellings. The dust is commonly obtained as a waste product from large-scale industrial uses, from coal storage and distribution depots, or from railway yards where coal is handled.
Resources and availability. Coal is an extremely plentiful fuel. World reserves are estimated to be about 12 million tonnes, around 25 times more than the estimated reserves of oil. Moreover, coal is much more widely distributed than oil. The USSR, the United States and China between them possess the bulk of the world's resources, but exporting countries such as Poland, Australia, South Africa and Canada possess reserves sufficient to last for hundreds of years. To date, exploration has revealed significant coal deposits in about 410 countries.
The World Coal Study (Wilson, 1980) anticipates a trebling of world consumption over the next 20 years from the present level of about 2 500 million tonnes of coal equivalent (mtce) to 7 500 mtce. Between 500 to 700 million tonnes of this might be traded internationally. (In these statistics, because coal varies so much in thermal quality, actual tonnages are converted to tonnes of coal equivalent on the basis of their individual heat contents - a standard tonne of coal equivalent has a heat content of 7000 kcal/kg.) Tables 1 and 2 show the World Coal Study projections of steam-coal imports and potential exporters in the year 2000. Metallurgical coal trade might amount to an additional 250300 mtce. Fears are sometimes expressed that a coal producers' cartel similar to OPEC might emerge under such conditions. While the possibility of such a cartel cannot be completely discounted, it is extremely unlikely it would be as powerful or coordinated as OPEC.
At the present delivered price of around $38 per barrel or $277 per tonne, the oil price is about four times that of the delivered price of coal when corrected for thermal value. Table 3 shows some indicative prices for coal delivered to northwest Europe from the present exporting countries. The range is if 31-$49 per tonne with an average of around $40 per tonne. On this basis, imports to Senegal through the port of Dakar, which is well equipped with modern handling equipment, should be no higher than imports to northwest Europe. Allowing for inflation since the World Coal Study figures were calculated, an indicative base price of $60 per tonne can be assumed. In practice, the price would depend upon quality of coal, size of ship, place of origin and conditions of contract.
Fears are sometimes expressed that a coal producers, cartel might emerge. Possibilities of it cannot be discounted but it is unlikely it would be as powerful or as coordinated as OPEC.
Tanzania possesses its own coal resources; there are large deposits in the southern part of the country. Only one small coal-mine is at present in operation at Ilima in the southwest of the country, near the town of Mbeya. There are plans, however, to construct a new mine with an output of 300 000 tonnes per year in the Songwe-Kiwira coal-field, which is close to the existing mine at Ilima and it is hoped this mine can be in operation by the mid-1980s. The output from the Ilima colliery is about 7 000 tonnes per year. The present price of coal at the Ilima colt fiery is T.sh 250 per tonne. The Tazara railway line connects Mbeya with Dar es-Salaam and can be used for the transport of coal from the present colliery and later from the Songwe-Kiwira mine. Transport costs are estimated to be T.sh 150-250 per tonne, giving a delivered wholesale price in Dar es-Salaam of T.sh 400-500 per tonne.
Import and distribution of coal. Although coal is a relatively dirty cargo, its handling causes no especially difficult problems, nor aces it require elaborate handling or storage facilities. In the past, coal was, of course, a widely traded commodity. Exports of British coal to French West and Equatorial Africa were 149 000 tons in 1913 and 68000 tons in 1946.
The port of Dakar is large and well equipped. The total quantity of merchandise handled in 1978 was 6.7 million tonnes. The phosphate quay handled exports of 1.75 million tonnes in 1978. The port infrastructure authorities have stated that with present facilities, handling up to 100 000 tonnes of coal per year would present little problem and, over a period of years, facilities could be developed to handle much larger quantities without requiring large investments. Distribution of coal from the port to wholesale or retail merchants raises no problems in principle. The details would depend upon the quantitie, of coal, the length of time it was stored, the cost of storage, and the amount of mark-up required by wholesalers and retailers. As a first approximation, it can be assumed that handling and other charges from the port to the retailer would add 200 percent (for quantities below 5 kg) to the delivered quayside price. The retail price is thus assumed to be three times the delivered price at the port of Dakar.
PREPARING SACKS OF CHARCOAL IN GHANA; statistic: an African city family of eight burns a year
In Tanzania, coal would be taken from Mbeya to Dar es-Salaam by rail. It would then be distributed to wholesalers and retailers. Again, there are no problems in principle. The. final price would depend upon similar factors to those mentioned above. In the absence of data on which to base a more precise estimate, distribution and mark-up for small quantities can be assumed to double the delivered price at the railhead in Dar es-Salaam.
Coal and peat. Coal is not by any means a homogeneous fuel. It varies from hard black anthracite through the dark bituminous and sub-bituminous coals to soft brown lignites. The bituminous and sub-bituminous coals are those most commonly used for industrial and domestic applications. Although classifications are being applied to coal for industrial and, particularly, metallurgical use, no such widespread grading system exists for coal for domestic use.
One of the most important characteristics for domestic consumption is the proportion of volatiles in the particular coal. This proportion is highest in the lignites and decreases through to anthracite. The volatile component of a coal consists of tars and other complex hydrocarbons. While the volatiles make a coal easier to burn, they tend to produce both smoke and flame. The most common coals are the bituminous and sub-bituminous: their volatile content ranges from around 10 percent up to 30-40 percent and they have calorific values in the range of 5 000-7 000 kcal/kg. Some bituminous coals can contain 5 percent or more of sulphur, which makes their use both unpleasant and hazardous to health. The ash content of coal itself is generally not more than 5-10 percent but coal, as mined, may be interleaved with large quantities of rock or inert material. Cleaning is then required to remove a sufficient amount of this material to render the coal suitable for its final use. Power-station coal, for example, does not need to be as clean as that destined for domestic use.
The coal from Ilima colliery is a medium-quality bituminous coal with 24 percent volatile content, 10 percent ash and 0.6 percent sulphur. Its calorific value is around 7 000 kcal/kg. Coal from the Songwe-Kiwira coal-field has similar characteristics but a somewhat lower calorific value (5 5006 500 kcal/kg). The lignites are by and large unsuitable for domestic use except under special circumstances. They are of low calorific value, in the range 2 500-3 500 kcal/kg.
Peat is the first stage in the formation of coal from vegetable matter. While it can be used as a domestic and power-station fuel, as is done in Ireland, there are many problems associated with mining, processing, and using it. Peat usually occurs in shallow deposits at the land surface or under water. It is usually of low density and may contain up to 95 percent water. It varies greatly in quality from a friable almost moss-like substance through to a material close to lignite in its properties. Given time and the right geological conditions peat, in fact, changes to lignite.
Indications of significant peat deposits have been found in northern and central Senegal. The amount and quality of this peat remain to be determined. While it may prove to be a welcome addition to the country's indigenous industrial fuel resources, no reliance can be placed upon it as a means of relieving the pressure on fuelwood.
Charcoal. Despite the variety of trees from which it is obtained and the different methods of manufacture, charcoal, in contrast with coal, is a relatively homogeneous and predictable fuel. It usually consists of about 80 percent carbon and 20 percent volatiles and has a negligible ash content.
Its solid density is about 400 kg/m³. Its solid density is thus a third to a quarter that of coal. Its calorific value :is about 7000 kcal/kg, roughly the same as that of a good-quality bituminous coal. Once it has been kindled, charcoal burns steadily and smokelessly as long as it is given an adequate supply of oxygen. As a fuel, charcoal is considerably more reactive than coal and continues to burn stead fly even in small quantities. This reactivity is to a large extent related to the fact that its much more porous structure than that of coal permits a ready access of oxygen to the combustion.
Coal and charcoal as domestic cooking fuels. In both Tanzania and Senegal charcoal is almost invariably burned in a traditional metal stove called, in Tanzania, the jiko, and in Senegal, the fourneau malgache. Both are simple devices, made from thin sheets of scrap steel, in which the charcoal is ignited using twigs, paper or other kindling; this is often done out of doors to take advantage of the wind as an aid to lighting the fire. When the charcoal is alight, the cooking pot is usually placed directly on top of it, though some pots have legs which enable them to stand clear of the charcoal. Because of the ease with which it continues to burn after it has been ignited, charcoal can be used in small quantities.
Coal presents considerable problems when an attempt is made to burn it in the same way as charcoal. Although it has roughly the same calorific value as charcoal, it is considerably less reactive and is thus much harder to ignite than charcoal. Anthracite and processed "smokeless" coal are close in composition to charcoal but are less reactive and hence even harder to light than the bituminous coals; the same is true of coke. Another result of the lower reactivity of coal is that it requires a relatively greater quantity of material in the fire if it is to stay alight. Coal will not stay alight in the small quantities to which a charcoal fire can be reduced without stopping combustion.
The fact that the density of coal is three or four times that of charcoal, although the calorific values are roughly the same, also has important consequences. It means that for the same volume, a coal fire will produce three times the heat of a charcoal fire. The natural tendency of people to use the same volume of coal as charcoal., plus the need to maintain the minimum volume of coal for combustion, result in coal fires which are considerably hotter than their apparent equivalents in charcoal. This can cause considerable overheating and burning problems in cooking. The volatile components in coal tend to cause it to burn with a smoky flame. This can be unpleasant and may, with prolonged exposure, be dangerous to health. These effects are increased if the coal contains a substantial amount of sulphur. In general, it can be assumed that coal is not suitable for indoor burning without a chimney.
In Senegal' the woodlands in the vicinity of Dakar are no longer capable of supplying the city's needs. Wood for Dakar's charcoal makers comes from the country's most distant forests' 600 km away.
Coal-dust is almost: impossible to use on its own because of the difficulty of ensuring an adequate supply of oxygen for combustion. This difficulty can be overcome by blending the coal-dust with sufficient clay so that it can be pressed into briquettes which can then be used in the same way as lumps of coal. Because of their clay content these briquettes will be harder to ignite and keep alight than coal. Given a suitable stove they can, however, be used quite satisfactorily, as is done :in China. The burning of coal can be dangerous unless it is done in a suitable appliance. Circumstances can occur in which there is a sufficient supply of oxygen to maintain combustion but insufficient to ensure complete combustion and the result could be the production of carbon monoxide. The disadvantages of coal in comparison with charcoal add up to a formidable case against its introduction. They must, however, be set against the fact that coal c an be used satisfactorily as a domestic fuel. The problems arise when an attempt is made to substitute coal directly in present appliances as though it: were a fuel with the same properties as charcoal.
The introduction of coal as a replacement for charcoal requires both research and development. The coal-burning appliances of the industrial countries were to a considerable extent based on the use of cast iron. What is required for Senegal and Tanzania is a small light stove like the fourneau malgache or the jiko which has been adapted to burn coal. In practice such a coal-burning stove would have to evolve from present stoves by experiment. It would probably need to have a more compact combustion area for the coal, a wire grate through which ash from the fire could fall and be removed and a wire grill on which the cooking pot could stand. In principle, a coal-burning stove of this kind could be made at a cost not greatly in excess of that of the stoves now us-d for charcoal. If coal is to be usable as a substitute for charcoal in the future the design and demonstration of such a stove are essential. Work should be carried out in both Senegal and Tanzania to ensure that suitable coal-burning stoves are developed and that the problems of adapting cooking habits to the use of coal are understood and solved.
Introducing coal to domestic use. At present the domestic market for coal in both Dakar and Dar es-Salaam is zero. The flavour charcoal gives to certain dishes basic to the local diet is considered to be very important. The switch to coal would require changes in equipment and cooking methods and would impose both financial and social costs. Under such conditions a substantial price difference between charcoal and coal in favour of coal would be required to make people adopt an even partial use of coal. No measurement of what such a difference would have to be has been made, but it is evident that there is considerable resistance to change in cooking habits. In Dakar, it was reported that in the early 1970s some coal which, several decades earlier, had been imported for electric power generation was simply thrown away. It was offered free to anyone who wished to take it but no one could be found to do so. In Tanzania in 1978, some investigations were made into the possibility of marketing charcoal made from pine obtained as a waste material from a sawmill. The charcoal obtained was less dense than that usually purchased for domestic use and burned more rapidly. It evoked little consumer interest even at 50 percent the price of normal charcoal. In Tanzania, under the price assumptions made, coal could be made available at about T.sh.1 per kg in Dar es-Salaam. This is about the same price as charcoal. In Dakar coal imported at $60 per tonne might reach the consumer at around $180 per tonne or F.CFA 3 600/kg). The range of charcoal prices is F.CFA 20-40/kg. The only conditions under which a voluntary shift to coal from charcoal would occur are if charcoal prices were rising at a rate which was truly indicative of a scarcity considerably more severe than exists today or seems likely to occur within the next five years. Such rising prices, because they reflected a real decline in the availability of char coal, would force people to switch to alternatives and would begin to place charcoal beyond the means of the poorest sections of the community. In short, attempts to introduce coal for domestic use into Dakar and Dar es-Salaam, at this stage, are unlikely to prevent the use of charcoal increasing with rising population (and possibly income). If, however, charcoal does become scarce, coal could well provide for at least a portion of basic cooking needs. Ensuring the availability of coal to meet such an eventuality is a strong additional reason for considering its use in large-scale applications.
Coal in large-scale uses. For uses such as electric power-stations, cement works, and large-scale industrial applications coal is now extremely competitive with oil, even when the costs of plan conversion are taken into account. Typically, coal can be obtained at one third to one quarter the price of oil. Industrialized countries are already engaged in shifting to coal for such uses and securing long-term supply contracts with the producer nations. Countries such as Senegal and Tanzania should relieve some of the pressure caused by oil imports on their balance of payments by switching at least some of their major oil uses to coal. This will also have the effect of reducing the internal costs of production of such essentials as electricity and cement and thus help prevent further erosion of the competitive position of these countries in international trade.
One of the main obstacles to any dissemination of coal into small-scale or domestic uses is, as we have seen, the non-existence of any actual market for coal. If, however, a market based upon one or more large-scale users had been established, such difficulties would not exist. The use of coal could be extended gradually into small-scale industries such as bakeries, forges, factories, brick making, tobacco curing, and institutional cooking and water heating. If coal were available it would also become realistic to envisage legislative controls on the use of wood and charcoal in such applications, even going as far as prohibiting their use where coal could be used as an alternative.
Table 1. World steam-coal imports by country and region (mtce)
|
|
Year | |
|
Country/region |
1977 |
2000 |
|
Denmark |
4.8 |
9.4- 20.9 |
|
Finland |
4.1 |
7.7- 12.4 |
|
France |
14.0 |
26.0-100.0 |
|
Federal Republic of Germany |
3.0 |
20.0- 40.0 |
|
Italy |
2.0 |
16.5- 45.5 |
|
Netherlands |
15 |
19.9- 43.2 |
|
Sweden |
0.3 |
14.3- 23.1 |
|
United Kingdom |
1.0 |
- 15.0 |
|
Other western Europe |
7.0 |
32.0- 42.0 |
|
OECD Europe |
37.0 |
146.0-333.0 |
|
Canada |
6.0 |
8.0- 4.0 |
|
Japan |
2.0 |
53.0-121.0 |
|
Total OECD¹ |
45.0 |
210.0-460.0 |
|
East and other Asia |
- |
60.0-179.0 |
|
Africa and Latin America |
1.0 |
6 0- 10.0 |
|
Centrally planned economies |
17.0 |
30.0- 30.0 |
|
Total world ¹ |
60.0 |
300.0-680.0 |
¹ Totals are rounded.
Source: Wilson, Carroll L., 1980.
Table 2. Estimated coal export potentials for principal exporters (mtce/yr)
|
Country/region |
1977 |
Current expectations year 2000 |
|
United States |
49 |
125-200 |
|
Australia |
38 |
160 |
|
Republic of South Africa |
12 |
55- 75 |
|
Canada |
12 |
27- 47 |
|
Poland |
39 |
50 |
|
USSR |
25 |
50 |
|
People's Republic of China |
3 |
30 |
|
Federal Republic of Germany |
14 |
23- 25 |
|
India and Indonesia |
1 |
5 |
|
Latin America, Africa, others |
7 |
25- 50 |
|
Total world |
200 |
550-700 |
Source: Wilson, Carroll L., 1980.
The availability of coal in large quantities would also provide a base from which domestic use could begin to spread as charcoal prices rise. At least two routes for such dissemination can be envisaged. Coal-dust, which is essentially a waste product, could be made available al very low or zero prices. This would enable low-income people to make briquettes and use them to meet at least part of their fuel needs. On the other hand, domestic coal could be selected, washed and, hence, upgraded from the industrial-quality coal as delivered. This selected domestic coal could begin to appear attractive as the price of charcoal rose.
Improved wood stoves in rural areas. In the rural areas wood is used mainly in the traditional three-stone fire. While this method appears extremely inefficient it is well adapted to the needs of the rural people. It is versatile in its acceptance of different kinds and sizes of fuel. Long pieces of wood need not be cut (an important consideration when tools are poor and scarce) but can be gradually pushed into the fire or withdrawn when cooking is finished. Dung, twigs, or agricultural wastes can be easily used as substitutes or supplements for wood. The three-stone fire is thus effective, familiar and convenient. From the viewpoint of the person using it, it is a highly satisfactory method of cooking, although at any particular moment an analysis of its thermodynamic performance may show it to be relatively inefficient at transferring the heat of combustion of wood to the contents of the cooking pot.
The main work on improved stoves in Senegal is going into the development of the ban ak souf or sand-and-clay stove. This is based on the Lorena stove developed in Central America and is being adapted for construction and use in Senegal by the Centre d'études et de recherches sur les énergies renouvelables (CERER). The stove is made by hand out of locally dug sand and clay, it thus incurs a labour cost but requires no capital investment. Combustion is insulated inside the solid stove structure as are the partially inserted cooking vessels. Up to 50 percent savings in the consumption of wood have been reported. Some technical problems such as durability, particularly when the stove is built outdoors and exposed to rain, remain to be solved. Nevertheless, seventeen organizations are contributing to a major effort now being launched by the Secretariat d'Etat a La promotion humaine to popularize these stoves. While the programme is receiving considerable support and publicity, it is too early yet to draw any conclusions from this project.
A change from the three-stone fire to the ban ak souf stove, while it does not require a cash investment, doer, demand a construction job usually performed by men and then a change in cooking habits. As long as fire wood is readily available people may not wish to make such a change. The probability is that for the most pare the dissemination of improved wood stoves will only be widespread in areas where fuelwood scarcities already exist and are felt to be onerous by the rural people themselves.
The same remarks would apply to any other innovations aiming to alleviate the pressure of rural firewood consumption. The fact that firewood remains outside the monetary circuit means that increasing scarcity will not, in general, favour the introduction of any substitutes requiring a cost investment. People will economize in the use of firewood, will walk further to get it, or will increase their use of free substitutes such as dung and agricultural wastes. Even when cash :is available and hardship is severe, investment in different fuels or improved stoves will only take place if no other expenditure has a higher priority. The fact that women are frequently excluded from all cash transactions increases the resistance to investment in domestic change.
This is not to discourage the promotion of more efficient stoves in rural areas. They can readily be envisaged playing an important role in a future of reduced availability of wood, as in other parts of the world. Unless they are developed now and brought to people's knowledge, they will not be available when the need for them arises.
Rural energy technologies. Numerous energy technologies are being promoted for rural use. They include rural electrification by extensions of central grids; small-scale hydro; wind power for mechanical work or electricity generation; solar energy for water heating, cooking, and electricity production; biogas for cooking and use in internal combustion engines; and gasification by partial combustion of organic materials to provide fuel for diesel engines. Apart from solar cookers and biogas, it will be noted that none of these provides energy for cooking. Promotion of these technologies, while it may result in additional energy supplies in impoverished rural areas, does nothing to ease the pressure on fuelwood. However, work: is being carried out in Tanzania on gasification by partial combustion using maize cobs as fuel.
Solar cookers have not been a success on a large scale anywhere in the world. There does not appear to be any realistic possibility of their being adopted to any significant extent by the rural people in Senegal and Tanzania. While they may be suited to specialized applications in isolated areas such as rural dispensaries, their potential for easing the pressure on wood resources is, as far as can be seen at the present, negligible.
Considerable success, on the other hand, has been achieved with the use of biogas in Sichuan Province in China where 8 million units have been installed. Outside this area, even in China, the use of biogas has been much less extensively adopted. In other countries the use of biogas has, so far, been extremely limited, with only India reporting a significantly extensive adoption of the technology. While experiments have been conducted in Tanzania and Senegal and some promising results have been obtained, the technology is at a very preliminary stage in both countries. The widespread use of biogas, as an alternative to firewood, must be a matter for the long-term future, if, indeed, it ever occurs.
FUELWOOD GATHERERS IN MALT, a journey through increasingly desolate landscapes
Alternatives to charcoal in urban use. Bottled butane gas, kerosene, and electricity can all be used as alternatives to charcoal for cooking. All are considerably dearer than charcoal and none has been popularly used on a large scale in Tanzania or Senegal. The Senegalese Government made vigorous efforts during the 1970S to promote the use of butane as a means of reducing the consumption of charcoal. Early steps in the campaign began in 1972 when a strategy for publicizing and promoting the use of butane was drawn up. Subsidies or tax relief were given for the purchase of stoves, rechargeable bottles and the butane itself. The major promotional efforts began in 1974 with the establishment of the Commission rationale de butanisation. Expectations from the campaign were high but may, to some extent, have been based upon a misapprehension. Some documents describe butane as having a calorific value ten times that of charcoal. In fact, the calorific value of butane is 11 700 kcal/kg, about 1.5 times that of charcoal, so that 10 000 tonnes of butane would only replace 15 000 tonnes of charcoal. On a calorific basis the butane is about three times as dear as charcoal. The butanization campaign has had little impact. Surveys have apparently revealed that the main use of butane has been for making tea and for re-heating previously cooked foods. It has not displaced charcoal to any significant degree as the fuel for cooking the main household meals. Rather than cutting into the use of charcoal, the butanization campaign seems to have provided additional amenities to the portion of the population able to afford the investments in stoves and refillable bottles. Kerosene has approximately the same calorific value as butane, tends to cost about the same and is slightly easier to handle than butane, since it does not require pressurized containers. But it is a petroleum product, subject to the same constraints of cost in foreign exchange and availability. Kerosene, like butane, will continue to be used for lighting and to a certain extent for cooking. Neither suggests itself as a realistic or prudent large-scale substitute for charcoal in either Senegal or Tanzania.
In Senegal, electricity is generated almost entirely with oil. Using electricity for cooking, bearing in mind the 75 percent loss of energy at the power-station, is an extremely wasteful way of consuming energy and adding to the country's dependence on imported oil. In Tanzania, a high proportion of the country's electricity is generated by hydro power and much untapped capacity remains. In the long term, therefore, a case might be made for extending the use of electricity into domestic cooking. In the short to medium term, this would probably lead to an increased use of oil for generation and is thus not advisable. The present price of electricity of T. sh 0.4/kWh is about three times the price of charcoal (at T. sh 1.0/kg) and, in fact, makes any large increase in its domestic use unlikely. The cost of the necessary appliances such as cookers and kettles puts electricity further out of the reach of the majority of people.
Improved charcoal stoves. The traditional charcoal stoves - the jiko and the fourneau malgache-for all their technical deficiencies, are cheap and familiar. The materials and skills for their manufacture are also readily available locally. Numerous experiments have been conducted with stoves of improved efficiency but no large-scale dissemination appears yet to have taken place in Tanzania or Senegal. As with improved wood stoves, the fact that their introduction would occur as a response to scarcity and not as a preventive measure does not mean that research and development of' these stoves should not be carried out. The threat of severe charcoal shortages in the future is so real that the functional improvement remains as important and urgent a task as ever.
Improved methods of charcoal production. Charcoal making has achieved considerable notoriety as a result of its apparent inefficiencies. The yield of charcoal from a small earth kiln corresponds to about 10 percent of the weight of the original wood; in the larger, more efficient kiln commonly used in Senegal the yield may be around 20 percent. However, the calorific value of charcoal is roughly twice that of wood so that the thermal efficiency of charcoal production ranges from 20 to 40 percent, that is, about twice the efficiency when measured by weight; exactly as for the thermal efficiency of electricity generation. Furthermore, wood cannot replace charcoal for every use because of its bulk:, and because it burns more erratically and smokily. Driving off the volatile components of wood is not just an energy waste; it is an essential part of turning a relatively poor-quality fuel, such as wood, into a fuel able to meet the demanding requirements of urban domestic use.
Improvements in the efficiency of charcoal manufacture are nevertheless possible-though the scope for them may be less than commonly realized On an air dry basis the maximum theoretical recovery of charcoal, by weight, is around 40 percent and, :in. practice, is not likely to exceed 30 per. cent. Metal kilns offer an undoubted improvement in efficiency over earth kilns because they allow better control of the air flows and hence of the car. bonization process, and also better recovery of the charcoal produced. Properly used they can reduce the amount of over-burning and under-burning which tend to occur in different parts of an earth kiln. They can also be adapted to recover some of the tars and combustible gases evolved during charcoal making, which under some conditions may be found valuable either as chemical feed-stocks or as a gaseous fuel similar to that produced in the gasification by partial combustion process.
Metal kilns, however, do not fit easily into the traditional methods of charcoal making in Tanzania and Senegal. In particular, they require substantial financial investments. A price of $1 000 has been reported for kilns tried in Senegal in the early 1970s. It is thus unlikely that the improvement in efficiency which they offer will encourage their wide-scale adoption for the time being. Improved efficiency can also be obtained by increasing the size of small earth kilos, which reduces the proportion of charcoal lost in the earth surrounding the kiln and increases the possibility of controlling the burning operation.
In Senegal adaptations have been made to the traditional earth kiln. based on experimentation at the Eeaux et forêts and FAO project in Casamance. These include a slightly raised base of logs to allow better air and gas circulation, a different method of stacking the wood, and a chimney made from discarded oil barrels. The Casamance kiln gives a greatly increased rate of production, more controlled carbonization, and a reputed efficiency of up to 40 percent (on an oven-dry basis). One of the dangers associated with improved methods of charcoal production is that they may achieve the opposite of what was intended. There is no guarantee that the introduction of a kiln with greater speed of production and higher yields will result in charcoal production being held constant so that less wood is used. Unless the market is controlled or saturated it is more likely that the amount of charcoal produced will crease. The result of a faster production cycle could also be to increase both the total quantity of charcoal produced and the amount of wood used to make it. This is why improved kilns must be associated with measures for the effective control of both the cutting of wood and the amount of charcoal reaching the market. In Tanzania this would lead toward a concentration and formalization of charcoal production, either around village production centres or in forestry plantations. In Senegal it would require an intensification of the present methods of control and tighter restrictions on the areas of forest land released to charcoal burners.
Table 3. Indicative steam-coal costs and prices ($ US per metric ton, 1 979)
|
|
Price f.o.b. mine |
Mine to Port |
Price f.o.b port |
Port loading |
Ocean freight |
Port unloading |
Delivered price range |
Avg. |
|
To: NW Europe |
|
|
|
|
|
|
|
|
|
From: United States |
|
|
|
|
|
|
|
|
|
East - Underground |
25-35 |
10-15 |
30-45 |
1- 2 |
6-10 |
2 |
39-59 |
49 |
|
West - Surface |
8-18 |
10-20 |
20-:35 |
1-22 |
8-11 |
2 |
31-50 |
41 |
|
Canada |
|
|
|
|
|
|
|
|
|
West - Surface |
15-20 |
10-20 |
25-35 |
1 |
8-12 |
2 |
36-50 |
42 |
|
Australia |
|
|
|
|
|
|
|
|
|
Underground |
15-25 |
5-10 |
20-25 |
2 |
10-14 |
2 |
34-43 |
39 |
|
Surface |
12-20 |
5-10 |
18-25 |
2 |
10-14 |
2 |
32-43 |
38 |
|
South Africa |
|
|
|
|
|
|
|
|
|
Underground |
10-15 |
5- 7 |
15-22 |
1 |
8-10 |
2 |
26-35 |
31 |
|
Poland |
|
|
|
|
|
|
|
|
|
Underground |
|
|
23-31 |
1 |
5 |
2 |
31-39 |
35 |
Source: Wilson, Carroll L., 1980.
It is possible to project present trends in fuelwood depletion and find they lead rapidly to total disaster. Such exercises tend, however, to be counter-productive. They do not take into account the flexibility and versatility of human response. More important, they call for large-scale remedial measures which are far beyond the boundaries of political and economic feasibility. In proposing impossible responses to what may appear to be exaggerated projections of future needs such analyses may succeed in paralysing rather than galvanizing policy makers.
Effective policy making depends upon matching practically achievable actions to needs and priorities as they are actually experienced. This does not mean that the seriousness of the outlook for fuelwood supplies should be ignored but that action should be concentrated where it is most likely to be productive and effective.
One of the main findings of this study is that concentrating policy upon substitute fuels and technical improvements in stoves and charcoal making is unlikely to be effective in preventing the continued depletion of fuelwood resources. Such measures will generally be unattractive to consumers in the rural areas as long as free-good firewood remains available. In the cities, the relatively small price increases for charcoal in Dakar, the fact that people are uninterested in inferior qualities of charcoal and that charcoal dust is being thrown away are clear indicators that charcoal scarcities are not yet being experienced, whatever the future may hold. Until charcoal is felt to be scarce and dear, there will be little pressure to make changes in the way it is used.
Work is being carried out at FAO to obtain a long-term picture of where present trends in fuelwood use in Africa, Asia and Latin America are leading. Estimates are being made by countries, broken down, where necessary' into climatic and ecological zones.
The policy perspective is thus one of a long-term worsening of supplies and a short-term ineffectiveness in technical responses. Policy measures must, therefore, have the dual objectives of slowing the progression toward widespread energy scarcity and ensuring that fuel supplies and efficient methods of using them are available when the present pattern of free-good resources in the rural areas and cheap charcoal in the cities no longer applies.
Rural energy supplies. Wood and free-good substitutes such as dung and agricultural wastes are the only fuel sources which can realistically be envisaged in most of the rural areas over the next three or four decades. Dung and vegetable wastes are generally inferior fuels to wood; moreover, their use as fuel prevents them from fertilizing the soil through the nutrients they contain. While it may prove possible to meet minimum future fuel needs from these sources, sole reliance upon them would be severely detrimental to agricultural productivity and living conditions in the rural areas. Any acceptable view of the future must, therefore, include a large-scale provision of wood in the rural areas.
It is unrealistic to expect government forestry services to be able to take responsibility for the whole future supply of wood in the rural areas. The provision of woodlots, if it is to occur, will thus have to be achieved by local initiatives. Village tree-planting campaigns, with some exceptions, have not been conspicuously successful. While this has been attributed, at times, to a lack of awareness on the part of rural people of the need to secure their future energy supply, it is unlikely to be the full reason for their reluctance to plant and care for trees. Before tree planting can be effectively promoted, an understanding of the priorities of rural people, from their own viewpoint, is essential. Only thus will it be possible to persuade people to provide for their own energy future.
Areas where villagers themselves recognize an existing or impending fuel shortage need to be identified as the priority areas for action. In such areas, studies can then be carried out to ascertain how people would assume, or delegate, responsibility among themselves for providing their own future firewood supplies. Such a willingness to engage in locally generated activity would furnish a starting point for the provision of assistance and advice on species selection, the planting and c are of trees. The supply of suitable seedllings would be undertaken by forestry services. Demonstration could begin at local schools and dispensaries. The lessons, both successes and failures, of such efforts are essential to future progress. The experiences should be described in detail and reports should be made widely available. In commissioning detailed reports, at a village [eve], and in distributing the results, FAO could play a valuable role.
In areas where there is no realistic possibility of villages being able to provide for their own future wood supplies, forestry plantations may have to be considered. Plantations of this kind should be regarded as last-resort suppliers. They should be sited in locations from which wood could, if necessary, be mechanically transported to those likely to need it. Their size should be calculated on a basis of meeting minimum firewood requirements so that planting targets are within the manpower and financial capabilities of the forestry services.
Urban energy supplies. If present trends in urban growth continue, charcoal consumption in Dakar and Dar es-Salaam will double in the next 10-15 years, reaching a level of 200 000 tonnes. This would still be a relatively small proportion of total fuelwood consumption in Tanzania, it could, however, be as much as 30 percent of the total in Senegal. The establishment of village plantations would also have some beneficial side-effect: they would naturally become supply sources for urban charcoal. This would have the further advantage of putting a cash value upon trees, encouraging economy in wood use, and adding to village incomes. Charcoal production centred upon. controlled village woodlots would create suitable conditions for the introduction of large-scale and more efficient kilns. It would also increase the likelihood that the responsibility for replenishment of wood resources could be made to rest primarily upon the villagers themselves. Formal arrangements between villages and city authorities or charcoal wholesalers for the supply of guaranteed amounts against guaranteed prices would add strength to the case for village control of charcoal making.
In Senegal there exists already a system of control and regulation of charcoal production on lands controlled by the forestry service. This provides much of the organizational planning required for this kind of initiative. The main task is of integrating it with the provision of rural wood supplies at a village level and ensuring that responsibility for replenishment rests with those who use the wood rather than upon the forestry service.
In Tanzania, the rural administrative structure lends itself to concentrating charcoal production within certain selected villages. Responsibility for the pattern of activities within the villages rests with village councils which are responsible to the villagers and to the regional and central government. They are thus in a position to formalize agreements with city authorities for supply and payment and to integrate tree planting and charcoal production with other village activities.
Village charcoal-making centres and associated woodlots might provide a focus for special technical assistance and advice by forestry services-and possibly by foreign aid agencies. If a substantial proportion of the production of charcoal for urban use can be allocated to villages in this manner, the future task of the forestry services in both Senegal and Tanzania becomes more manageable. They would not be burdened with the task of providing enormous plantations for the supply of charcoal to the cities. Instead, their role would be to create those strategic reserves of woodland from which supplies could be drawn in times of scarcity, in order to supplement the charcoal reaching the market and to aid in controlling the price.
Coal-an emergency alternative. Forest policies are both difficult and slow to implement on a substantial scale. Even when they are put into effect, from seven to ten years are required before trees have reached a harvestable size. Moreover, even plantations cannot escape the effects of a climate which hats borne harshly upon both Senegal and Tanzania in the past decade. It is for these reasons that preparations should be made to ensure that if forest policies fail to produce results there will be an alternative fuel available for, at least, the cities. Coal is far from an immediate substitute for charcoal. Considerable work needs to be done on the details of stoves and cooking methods to enable it to be used safely in Dakar and Dar es-Salaam. Such work needs to be carried out whether coal is adopted as a large-scale industrial fuel or not. For all its disadvantages, coal remains the only alternative fuel likely to be able to take over from charcoal on a significant scale, should the need to do so arise.
Charcoal imports. Some of the countries of West Africa such as Guinea-Bissau and the Ivory Coast have large forest areas capable of supplying far more than their own needs of wood and charcoal. Imports of charcoal from these countries to Senegal could, therefore, be a satisfactory alternative to domestically produced charcoal or coal imports. Such charcoal imports should take place provided they are economically competitive, with a reasonable assurance of supply, and do not impose too great a burden upon the national balance of payments. But it should be remembered that though imported domestic fuels might slow the growth of internal charcoal production, they would not actually prevent the depletion of the country's free-good wood resources. Neither would they remove, or even substantially alter, the task of securing the wood supplies of the rural areas.
WILSON, CARROLL L. 1980 Coal- bridge to the future. World Coal Study Report. Ballinger, Cambridge, Mass.
