2. The Current African Energy System
The structure of the African energy system is illustrated in Figure 1. The most remarkable feature is the fact that the continent exports 40% of the energy it produces. This is largely oil and gas that is exported from the North and West African countries. As such, energy scarcity is not an issue for Africa as a whole. The problem is the uneven distribution of the resource and the fact that the indigenous population is too poor to afford commercial fossil energy.
In the centre of Figure 1 is the energy transformation sector. Energy use for power generation is small compared to other regions. Yet this is where most of the discussion on energy access takes place. Latent demand is very high. With electricity demand having a tendency to grow at the same rate or even faster than GDP, a rapid rise is likely. Therefore, the main issue is not how to deal with existing plant, but making the right choices for new plant.
Charcoal production from solid biomass is also a key energy consuming activity, which is often ignored. Ef-ficiency tends to be low while proven higher efficiency charcoal production processes exist. Charcoal is the fuel of choice for city dwellers in large parts of Africa.
The right hand side of Figure 1 shows the end use sectors. The use of natural gas is rather low - lack of distribution infrastructure being one of the reasons. In addition, low demand for heating and the absence of a large industry are not there to sustain a distribution network in most parts of the continent.
Direct use of traditional solid biomass is very large and accounts for over half of final energy use, the highest share of any region in the world. While biomass is renewable, traditional biomass use is considered problematic for a number of reasons. The question in many countries is what can be done to overcome this problem. Many projects have failed. This is in stark contrast with India where the use of traditional biomass for cooking has declined from 72.3% in 2001 to 55% in 2009/10 (Khan, 2011).
FIGURE 1*: AFRICAN ENERGY SYSTEM, 2008 (MILLION TONS OF OIL EQUIVALENT, MTON)
*Difference between inputs and outputs are accounted for by losses.
It should be noted that five countries alone account for nearly 60% of African primary energy use (see Figure 2). Development in these countries will, to a large extent, determine energy trends for Africa as a whole. As such, they are given special attention. In the other countries, energy poverty and energy access are most urgent issues to address.
African power generation is dominated by fossil fuels (see Figure 3). Hydropower accounted for 15% and other renewables accounted for 1% of total power generation in 2008.
Africa has 129 GW of power generation capacity (Platts, 2009) as shown in Figure 4. This includes 24.3 GW of renewable energy capacity, with hydropower making up 95% of this figure. A total of 1,260 hydropower plants have been identified (operational, under construction or in the planning stage), with an average capacity of 46 MW. About 579 plants have a 10 MW capacity or more (large hydro), and 681 plants are less than 10 MW (small hydro). Other renewables include 63 wind farms with an average capacity of 27 MW. Bagasse dominates biomass power generation (159 plants with an average 7 MW capacity, 94% of biomass-based power generation). Finally, 19 geothermal plants have an average capacity of 19 MW.
A pertinent, very costly issue for Africa was the decision to build oil-based power plants in the 1990s when oil was cheap. Longer-term, realistic price forecasts would have shown that this was a very risky decision to take. Along the same lines, recent decisions to build new coal-fired power plants face the uncertainty of future CO2 emissions regimes.
TRADITIONAL AND MODERN BIOMASS
Biomass accounts for half of primary energy use in Africa. Throughout sub-Saharan Africa biomass use dominates for cooking. Data for Eastern Africa suggests that wood dominates in rural areas, charcoal dominates in cities. Approximately 3% of households in sub-Saharan Africa use non-woody biomass such as crop residues or dung (Bailis et al., 2005). Analysis for Nigeria in West Africa suggests that poorer geopolitical regions tend to use more wood fuel to meet their domestic requirements (Onuche, 2010).
FIGURE 2: AFRICAN PRIMARY ENERGY USE BY COUNTRY, 2008 (IEA DATA)
FIGURE 3: AFRICAN POWER GENERATION BY FUEL, 2008 (IEA DATA)
FIGURE 4: AFRICA POWER PLANT CAPACITY SHARES (PLATTS, 2009)
Nigeria has the highest population in Africa (about 17% of total). In 2007, the types of fuel used for cooking in Nigeria included: wood (74%), electricity (0.7%), gas (0.7%), kerosene (24%), and coal (1.6%). Between 1996 and 2007, the amount of kerosene consumed in the country decreased steadily while the use of wood increased. This can be attributed to the rising cost of fossil fuels.
Significant efforts have aimed to introduce more effi-cient woodstoves. These could double efficiency and halve biomass use. However, uptake has been slow. Uptake in Kenya, Tanzania and Uganda stood at 4%, 4% and 9%, respectively, in 2010 (Muchunku, 2010). One of the challenges is that stove designs vary widely and are culture-specific. Stoves need to be developed with full consideration of cooking needs, such as pot sizes, food types, cooking position, portability. The GTZ efficient wood stove projects in Uganda and Kenya is a semi-commercial approach based on building capacity of local stove builders.
Charcoal is a more efficient cooking fuel. However, charcoal consumption is an issue because of the low efficiency of charcoal production and the unsustainable levels of production (Mwampamba, 2007). About 20 Mt of charcoal is produced every year (about 13 Mtoe, 5% of all final bioenergy use or 15-20% in primary bioenergy terms). Nearly all charcoal in sub-Saharan Africa is currently produced in traditional kilns, which have sub-optimal conversion efficiency and no emission controls (Bailis et al., 2005). Conversion effi-ciency rates would double if modern kilns were used.
Use of traditional biomass is a major cause of health problems. In 2000, an estimated 51% of child lower respiratory infection deaths (350,000 deaths) and 63% of adult female chronic obstructive pulmonary disease (COPD) deaths (34,000 deaths) in sub-Saharan Africa were caused by household use of wood and charcoal (Bailis et al., 2005). In arid and semi-arid areas, the need for fuel wood is a major cause of the reduction in tree cover and the primary cause of forest loss. Charcoal use reduces health damaging emissions in homes as it produces lower concentrations of pollutants like particu-late matter (PM). Concentrations of PM in households using charcoal were found to be 88% lower than households using open wood fires (Bailis et al., 2005).
Apart from higher net carbon emissions due to deforestation, combustion of biomass is a major source of methane and N2O emissions. In 2000, the net GHG emissions from residential energy use in sub-Saharan Africa were 320 million tons of CO2 equivalents (61% from wood, 35% from charcoal, 3% from kerosene, and 1% from LPG) (Bai-lis et al., 2005). Moreover, combustion of biomass emits non-methane hydrocarbons and particulates.
While traditional wood fires have the highest emissions in terms of health impact, those related to charcoal use are higher from a GHG perspective. Each meal cooked with charcoal has 2-10 times the global warming effect of cooking the same meal with firewood and 5-16 times the effect of cooking the same meal with kerosene or LPG depending on the gases that are included in the analysis and the degree to which wood is allowed to regenerate (Bailis et al., 2005).