**2.1 Energy mix in Africa**

Africa has low energy consumption per person when compared to other countries, falling below the global average of 2 toe. For example, in 2018, with except

South Africa, the consumption was below 0.8 toe, with sub-Sahara Africa having lower than 0.4 toe [1]. Energy is derived from a variety of sources, including coal, oil, gas, nuclear power, biomass, and other renewables. **Figure 1** depicts the energy mix by energy source. Biomass is still the main source of primary energy mostly used in cooking. Except north Africa, biomass contributes around 60% by which no any part of the global depends [1]. In Sub-Saharan Africa, for example, biomass consumption is currently above 80% [4]. Oil is the next energy source in Africa after biomass. In 2018, oil consumption was over 4 million barrels per day, with 60% of that consumed in transportation and diesel used as a generator backup. **Figure 2** depicts energy consumption in Sub-Saharan Africa by sector in 2017. Household is the main consumer of energy of about 64% and mostly depend on biomass.

Africa continues to rely on fossil fuels for electrical generation (92%); oil (42%), natural gas (28%), coal (22%), hydropower (6%), nuclear (1%), and other renewable energy (1%). **Figure 3** shows electricity production sources through thermal heat technology. The resources are limited, and the deposits will be depleted as quickly as possible as the population grows. Since fossil sources do not rejuvenate, the sustainability of them is in compromise. To solve dependency of fossil fuel, Africa should focus on other resources. Apart from biomass, she still has other potentials such as; 10 TW of solar, 350 GW of hydro, 110 GW of wind, and 15 GW of geothermal energy. Due to high investment costs and distribution of other renewable resources, biomass is and will continue to be a significant source of energy due to wide distribution, modular and simple conversion technologies, and appropriate production land. The population growth leads to large production of biowastes. Due to high increase in energy demand, there comes a need to develop the utilization process of wastes for energy generation. Therefore, in future,

**Figure 1.** *% share of energy sources 2017 [7].*

**Figure 2.** *Energy source consumption by sector in sub-Sahara Africa 2018 [1].*

*Biowastes as a Potential Energy Source in Africa DOI: http://dx.doi.org/10.5772/intechopen.99992*

**Figure 3.**

*Contribution of energy sources in electricity production [7].*

biowastes are expected to contribute highly to the energy mix and hence lead to energy and environmental sustainability.

### **2.2 Challenges of energy sources and stability**

As reported earlier, Africa energy consumption per capital is the lowest in the world. But also it was stated that the population and development in the future will lead to high energy demand. From earlier analysis, still Africa relies on fossil fuel in electricity generation and biomass in other uses. Transport sector has been identified to consume 64% of total energy consumed. Unfortunately, the production of transportation energy is still low with large importation of oil. The utilization of electricity and natural gas in the transportation sector is still low. This implies that much of transportation energy source is dependent on global oil stability. Lack of local and alternative sources puts uncertainty of both energy production and supply. Unluckily, available renewable sources are not well utilized due to obstacles such as investments. These entire situations put a big challenge of energy stability.

It has been also identified that biomass is the main source of energy. Biomass sources such as forest have challenges on utilization when it comes to deforestation. The study report in 2018 has shown that East and West Africa deforestation since 1900 was 93 and 83%, respectively [11]. Thus, the sustainability of biomass as the source of energy is hindered by deforestation. Furthermore, the competition of land and food crops still hinder the sustainability of biomass. In case of biowaste utilization, high investment, knowledge, and technology make them unfavorable resources. Also the poor governmental policy on sourcing local sources are also a challenge. To avoid instability of energy sources from external situation such as environmental movement and global oil market, Africa should find suitable sources. The dependency of virgin biomass and competition of area for food and energy crops, utilization of less used energy resources should be implemented. The policy and investment should be the priority in utilizing sources that lead to sustainable energy and environment.

Thus, to have energy and environmental stability, the use of biowastes is important. To implement biomass challenges such as variation of composition, large distribution, low energy density and poor energy conversion, appropriate technology should be implemented (**Figure 3**).

### **3. Status of biowastes potentials and utilization in Africa**

The global biowastes production is currently estimated to be over 140 Gt per annum [12]. On global scale, more than 2 Gt of garbage is burned inefficiently,


*1 Estimation by FAO for crops Barley, Beans, Maize, Millet, Oats, Potatoes, Rice, Paddy, Rayne, sorghum, Soybeans, Wheat using FAO TIER 1 approximation with factor 0.01.*

*2 Estimation by FAO using FAO TIER 1 approximation with factor 0.015 for manure excreted for Asses, buffaloes, camels, cattle diary, cattle non-diary, chicken broilers, chicken layers, ducks, goats, horses, llamas, mules, sheep, swine breeding, swine market, and turkey.*

### **Table 1.**

*FAO estimation of biowastes in Africa sub-regions compared to globe [13].*

accounting for 18% of total global CO2 emission and significant amount of particulate [12]. Africa produces biowastes, which can be turned into useful energy, from agriculture, forest, and animal residues, as well as MSW. **Table 1** reports the FAO estimate of biowastes. Africa is located in tropical and subtropical region and due to good climate conditions; production rate of biomass is 4-5 times the other regions [14] leading to high agricultural and forest wastes. In 2012, 11.519 Gt was produced and 5.098 Gt was collected and in 2025, 28.155 Gt and 18.232 Gt are expected to be produced and collected every year [4]. In 2025, Africa is anticipated to generate 20.1 TWh of biomass waste and collect 12.5 TWh of garbage, compared to 8.4 TWh of biomass waste generation and 3.5 TWh of rubbish collection in 2012 [4]. This still shows low utilization of these biowastes. These wastes can be a good source of energy if they are successfully transformed. For example, in 2019 Barz et al. reported that if agricultural wastes are properly handled, they can contribute 20-40%ofprimaryenergy [14], demonstrating that all biowastes can contribute significantly. According to estimates, processing crop and agro-processing leftovers might provide 4.2 EJ in 2030, forest Residue 1.1 EJ, and animal residue 1.5 EJ. To reduce competing with food in the production of fuel, boost waste economic value, and safeguard the environment (lower GHG), biowastes should be successfully employed as an energy source [14]. The most difficult challenge is to invest in an efficient method of collecting and converting it. As a result, Africa should invest in an efficient method of collecting and converting these wastes to reduce the use of traditional energy sources. Agricultural wastes have the potential for energy production, but they compete with other uses, such as fodder, fertilizer, fiber, and construction, so an effective balance is required.

### **3.1 Biowastes sources**

In Africa, where the main activity is agriculture and forestry with abundant cultivatable land, the biomass wastes are in abundance. The sources of wastes range from crop, forest, and animal residues, and MSW. There is a huge potential with high organic components. The MSW in Africa has high organic components of

around 70% and thus making them potential for energy conversion. Unfortunately, these wastes are poorly managed and hence become environmental concern. Effective utilization can significantly offset the use of fossil fuel.
