Forecasting woodfuels demand of the household sector in Ghana - the process model approach

In Ghana, wood fuels (fuel wood and charcoal) accounted for about 74% of the country’s total annual energy consumption in 2000, with imported petroleum and electricity making up the balance of 19% and 7%, respectively. Notwithstanding the significance of wood fuels in the energy sector of Ghana, information on the levels and patterns of wood fuels demand of households, which constitute the highest consumer of wood fuels, is rather inadequate as it ignores significant dynamic factors including household income and location. Reliable estimates of the future demand of wood fuels are necessary for the planning of interventions which will ensure the sustainability of the resource. The objective of this study is to investigate the factors that influence the quantity and patterns of use of wood fuels by households in Ghana, and thereby develop a model for forecasting wood fuels demand of the household sector. A nationwide survey covering a sample of 440 rural households and 480 urban households was conducted in 1994 to determine wood fuels consumption patterns of households in rural and urban areas, in the different income groups, and in the three major ecological zones of Ghana. The Basic Energy Demand (BED) for cooking by the various categories of households was estimated and statistically analysed to identify the parameters and their influences on the BED. The Basic Energy Demand for cooking is a key parameter for forecasting the demand of wood fuels by rural and urban households for cooking, and it is defined as the energy (in mega joules) required for cooking, assuming the cook stove is 100% efficient. The estimation of the Basic Energy Demand for cooking is a major result of the study. The BED per capita for cooking is 1314 ± 302 MJ/year, 1540 ± 354 MJ/year, and 1369 ± 315 MJ/year for rural, Accra and all other urban households, respectively. This BED per capita is expected to remain constant in the short to medium term, unless the type of meals cooked and household sizes changes considerably. Thus, the application of the BED should facilitate the forecasting of wood fuels demand of households without the need for frequent and expensive national surveys. The observations from the study indicated that, at a confidence interval of 95 per cent, the differences in the Basic Energy Demand per capita for cooking of rural households in Ghana were not significant, regardless of the ecological zone in which they were located. It was also observed that the differences in the Basic Energy Demand per capita for cooking of all urban households in the different ecological zones and income groups were not significant. Finally, it was confirmed that the differences in the Basic Energy Demand per capita for cooking of rural and urban households were significant. A model for forecasting the demand of wood fuels by the household sector of Ghana was then developed based on the analysis of the wood fuels conversion and end-use processes (Process Model), with the Basic Energy Demand for cooking as the key characteristic of households. The model, which is presented as a spreadsheet was used to make projections for wood fuels demand for cooking by Ghana’s household sector in 2000- 2010. The forecast model is based on the general observation that households tend to shift from fuel wood to charcoal, and from charcoal to LPG end electricity as their income improves. The spreadsheet is presented on a compact disk enclosed in the back cover of this thesis. The main variables of the forecast model are: i) end-use device efficiencies; ii) calorific value of wood fuels; iii) growth rate of household income; iv) conversion efficiency of charcoal production; and v) population growth rate. By varying these parameters, various scenarios can be developed and used to study the impact of policy interventions, such as the promotion of efficient cook stoves and substitution of LPG to wood fuels. This enhances the use of the model for policy analysis on wood fuels in Ghana.

Source: KNUST