Philippe Girard is head of the Biomass Energy Environment Unit, Forestry Department, International Cooperation Centre of Agricultural Research for Development (CIRAD-Forêt), Montpellier, France.
With mounting urbanization, African populations are increasingly shifting from fuelwood to charcoal for domestic cooking and heating.
Urbanization and economic devel-opment are bringing about changes in consumption patterns and increases in household income in developing countries, which in turn are leading to major changes in the household energy sector. A pronounced shift from fuelwood to charcoal, especially in Africa, has raised concerns among environmentalists and those responsible for forest development and management.
This article describes the trend towards increased use of charcoal in Africa, identifies the resource issues and highlights some of the requirements for the sustainable development of this sector.
In general, energy consumption in rural areas of Africa is still low and is limited almost exclusively to fuelwood. However, energy consumption and the type of fuel used by households evolve as countries develop. A survey carried out for World Bank’s Energy Sector Management Assistance Programme (ESMAP) in 45 cities in 12 countries between 1984 and 1993 (Waddams Price, 2000) showed that a decrease in the use of woodfuel and a shift to petroleum products is clearly related to improvement in incomes, as well as to new policies and programmes established by governments.
Energy consumption and fuel types are also influenced by high migration flows and the high growth rate of urban populations. Although migrants to cities keep their rural habits and traditions for several generations, the pressures of urban life (modernization of housing, lack of time, etc.) are rapidly swinging many towns from fuelwood to other fuels such as liquefied petroleum gas (LPG) or kerosene. Urban women interviewed during household energy surveys in Ethiopia, Chad, Madagascar, Mali, the Niger and Senegal did not like to cook with wood because they found it difficult to kindle, awkward, dangerous for children, smoky and messy (Madon, 2000). Charcoal is perceived to lack most of these negative effects, and it is priced more competitively than LPG and kerosene, which are still too expensive for many people (Foster, 2000). A study in Dar-es-Salaam, United Republic of Tanzania, for example, clearly showed charcoal used in energy-efficient stoves to be the cheapest fuel per unit of energy (Foster, 2000). It is therefore often used prior to the adoption of other more expensive modern fuels.
The urban shift from fuelwood to charcoal is illustrated by the case of Bamako, Mali, where in 1990 over 85 percent of families used wood as their everyday household fuel. The figure is under 50 percent today, and in 1997 charcoal (which had previously been kept for such special uses as tea-making and barbecuing) replaced wood as the primary fuel in Bamako (see Figure). The low level of household income is probably the only factor holding back the shift to fossil fuels, LPG and petroleum.
Most striking is the increasing use of charcoal in average-sized towns, and sometimes even in rural areas. For example, a recent survey of household consumption in all towns in the northern region of Mahajanga, Madagascar, showed that charcoal was the main domestic fuel used (CIRAD, 1999). The figures reveal a trend of increasing charcoal consumption when compared with a 1992 survey realized for the World Bank by the Household Energy Planning Unit of the Ministry of Energy and Mines (CIRAD, 1992).
With urbanization, the charcoal sector has acquired considerable economic weight. Work carried out under ESMAP in the Niger and Mali since the late 1980s has shown that this mainly informal sector accounts for an annual turnover of several million dollars for a number of African countries. In terms of employment, if not in financial terms, its importance is comparable to that of cash crops (Matly, 2000).
Globally, the use of woodfuels has been growing in line with population growth, so that the annual growth in demand is between 3 and 4 percent depending on the country (Amous, 2000). During the past two decades, a better understanding of wood energy systems has led to the recognition that supply sources are more diversified than was once assumed, including not only forest areas but also trees outside forests. Thus the alarmist predictions of the 1970s of a “fuelwood crisis” in which supply sources would not be capable of meeting the demand have proved unfounded.
Nevertheless, in places where high fuelwood and charcoal consumption and weak supply sources put strong pressure on existing trees resources (because of high population density, low income and/or severe climate conditions), deforestation and devegetation problems are still of great concern.
The shift from fuelwood to charcoal, even if it lasts only a few decades, could have major ecological consequences if it is not kept under control. However, since charcoal stoves are more efficient than wood stoves, the ratio of primary energy to usable energy is almost the same as with fuelwood. Thus with adequate supervision, management and support, the shift does not need to disrupt present levels of resource use.
One great concern, however, is that charcoal, unlike fuelwood, is most often produced from forest resources. Thus the use of forest biomass for charcoal making could still represent a threat to the future of the resources in local terms, especially in certain situations with high demand (for instance the periphery of large urban zones with low resources) and lack of proper forest management practices and regulations.
With adequate forest management, supervision and control practices, however, the growth of charcoal use does not have to have a serious impact on forested areas that supply consumption centres. Work carried out in the Niger and Mali, for example, indicated that control of the resource by the people living in the charcoal production areas can lead to proper management of the resource while improving local people’s incomes (CIRAD, unpublished documents, 2001).
Despite some successful examples like these, many African governments, concerned about the potential threat of charcoal to forest resources, have launched programmes in the past two decades to encourage substitution of charcoal with other fuels (particularly LPG and kerosene) through subsidies and provision of equipment to households. Despite the effective distribution of equipment (in Dakar, Senegal, over 60 percent of families were equipped to use LPG), these programmes have not succeeded, in part because African cities do not always readily take on urban habits (Matly, 2000).
However, substitution programmes have also had the negative effect of creating unemployment in forest areas when charcoal production was discouraged. The lack of employment led to increased migration towards urban and peri-urban areas and accentuated the demand for fuelwood and even more charcoal, as these are the main source of affordable energy for poor people.
Banning the production and/or marketing of charcoal, as has sometimes been done (for example in Mauritania and Kenya), has proved counterproductive: bans do not in fact reduce production, but simply drive producers underground, thereby precluding proper control of production procedures (FAO, 1993).
The sustainable production and use of charcoal through proper management and planning of supply sources, together with rational trade and marketing infrastructures and efficient use, can also have a significant positive impact by helping to conserve resources, reducing migration from rural or forested areas and improving people’s incomes. However, the necessary interventions for long-term solutions are not easy to implement, especially for poor tropical countries that lack the necessary financial resources, institutional capacity and skilled personnel.
Use of wood versus charcoal as fuel in Bamako, Mali
Source: World Bank, 2000.
Charcoal is often traditionally made from species that yield a dense, slow-burning charcoal. These species are slow growing and are therefore particularly vulnerable to overexploitation. There is thus a need to encourage diversification and the use of plantation species or species producing less dense charcoal. While less dense charcoal may have different physical properties, there is no difference in energy terms, as shown in the Table. Since charcoal is marketed by volume (piles, sacks, etc.), a heavier product gives consumers the impression of buying more. Although dense charcoal does indeed hold more energy by volume, this is not the case by weight.
Where the use of alternative species for charcoal making is promoted, it is necessary to re-evaluate the processes involved in the charcoal production and utilization chain. One necessary adaptation is the design of energy-efficient charcoal stoves, as most of the stoves currently used are not really suitable for charcoal from lightweight species, burning it too quickly and vigorously for consumers’ needs.
When charcoal comes to be used as cooking fuel in a given country, the speedy introduction of procedures encouraging the use of light charcoal (sale by weight, quality-based prices, control over the species used, etc.) could limit overexploitation and encourage production from plantation species, to the considerable benefit of the environment and consumers. Professional training and supervisory measures could also help reduce the current pressure on species that yield dense charcoal.
In industrialized countries a large number of more efficient and rational technical solutions are being developed to enable carbonization processes to conform to environmental and energy norms and to improve carbonization yields because of increased wood prices. The basic goal is to produce more charcoal using less wood.
The solutions are many. These include batch-type retorts where wood is carbonized by an external source of heat; metal kilns equipped with vapour incinerators; and Lambiotte-type continuous retorts where wood is introduced at the top of the kiln and the charcoal is extracted from the bottom, with the vapours burned to meet the heat requirements of the process. All of these require a large investment and are usually unaffordable for small-scale charcoal makers in tropical countries.
Most traditional or improved traditional charcoal production techniques give good yields, with relatively low capital investment, if they are efficiently used. However, they are labour intensive.
Many charcoal projects have not achieved the hoped-for results because they have considered only the energy aspects of the technical process and ignored the social and economic aspects. However, considerable economies could be achieved in the sector, as shown in the Box.
Many sawmills produce great amounts of waste, which is often simply burned for disposal or very roughly carbonized. Semi-industrial charcoal making processes with incineration of pyrolysis gases and heat recovery could provide a satisfactory way of optimizing sawmill by-products, since such mills have the necessary technical and human resources (FAO, 1985). There are some examples of this kind in the humid tropical zone (e.g. Côte d’Ivoire, Brazil).
The choice of technology must always be governed by analysis of the socio-economic context. A set formula should never be applied, even if it has had excellent results in another context.
Although globally charcoal consumption could be expected to decrease in the near future, locally or in specific countries (developing and developed) it may still increase as a result of new industrial “green energy” market opportunities under development. Therefore forest services and energy agencies should give particular attention to charcoal and its sustainable production and use. Effective actions might include, among others:
If charcoal making is regarded as a source of supplementary income or as women’s work, investment in training will be less likely, and less labour-intensive methods – which are also the least productive – will be preferred, limiting possible improvements. The education and training of forest planners, extensionists and charcoal makers, and the implementation of more sustainable charcoal making technologies, may be determining factors in improving working conditions in the sector, as well as environmental impacts and energy effectiveness.
Charcoal is part of a range of fuels for domestic use that needs to be incorporated into any programme to rationalize energy resource use in tropical countries. Rather than seeing it as the forester’s public enemy, planners need to understand the problems and to implement suitable solutions to make the best possible use of charcoal.
Traditional charcoal mound in West Africa (Guinea)
FAO Forestry Department/CFU000334/R. Faidutti
A semi-permanent low-cost “Subri-fosse” type metal kiln in Madagascar was designed to carbonize offcuts from sawmilling
Metal kilns equipped with vapour incinerators (shown here in France) can help reduce environmental pressure by increasing charcoal yields, but they tend to be unaffordable in developing countries
Some figures regarding economic and environmental issues
Mass yields from a Casamance kiln and a well-managed traditional mound kiln are about 25 percent. In other words, 1 tonne of wood will give 250 kg of charcoal. With poorer techniques, however, yields often do not exceed 15 to 20 percent, in other words about 150 to 200 kg from 1 tonne of wood. Many charcoal makers, for example, use green wood, and the energy needed to dry it is provided by part of the load, reducing yields to 15 percent.
The carbon content of wood and charcoal is 50 and 90 percent respectively, giving the following carbon equivalents:
When a tonne of wood is carbonized, 365 kg are released into the atmosphere with a poorly managed technique and 275 kg with improved methods. Improved technique thus prevents the emission of 90 kg of carbon per tonne of carbonized wood, equivalent to 300 kg of carbon or 1.1 tonnes of CO2 per tonne of charcoal consumed.
For the city of, Abidjan, Côte d’Ivoire, which consumes about 300 000 tonnes of charcoal per year, the annual savings amount to:
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