**1. Introduction**

Energy has been a critical issue in most African countries where most of their populations are deprived of it. With the current population growth, the situation is alarming and needs serious intervention to rescue. It is predicted that one-in-two people added to the global population between 2019 and 2040 will be African. In 2025, Africa's population is predicted to exceed that of both India and China [1]. This increase in the population, combined with an increase in purchasing power, will put additional strain on the existing energy supply, resulting in a significant

increase in energy demand. With the current trend of industrialization and population growth, the energy demand is expected to rise and put high pressure on the current fossil fuel resources. In 2018, Africa's energy demand was estimated at 700 TWh of which 70% was consumed by south and northern countries. This energy consumption is forecasted to reach 1600-2300 TWh by 2040 [1]. Such a huge increase in energy demand requires African countries to be prepared for a sustainable solution. The globe's energy resources have mainly been dominated by fossil fuels, which cover around 81% of the total energy supply in 2018 [2]. High dependency on fossil fuels not only brings uncertainty but also leads to global warming and environmental pollution. Therefore, the appropriate use of fossil fuels and the introduction of renewable energy technologies are required for sustainable energy and the environment.

The use of some renewables may be associated with high cost and occurrence, but bioenergy sources are expected to be the most promising option for meeting future energy demands [3]. Its conversion cost is expected to be lowered due to the availability of biomass, low cost, and high energy demand. Due to the global goal to departing from fossil fuels, the incorporation of bioenergy in energy generation has gained attention, mostly in developed countries. Although Africa is blessed with biomass, its use in electricity generation is still low, but expectations in the future are high [1]. The biomass potential is expected to continue to increase due to available cultivatable and fertile land, unutilized wastes, and cheap and simple conversion methods. Also, the utilization of biomass will continue to grow due to initiatives of African countries to intensify energy security. The African Union has the 2063 agenda that aims to have modern, efficient, reliable, and cost-effective renewable energy for all households, businesses, industries, and institutions [4]. This agenda has gained support with investments, among them being the African Development bank since 2016 [4]. High investment of USD \$43-55 billion per year compared to USD \$ 8-9.2 billion that is currently invested, will continue to stimulate incorporation of renewable energy, among them being biomass. To achieve this goal, understanding the type, quality, quantity, and distribution is necessary.

Although utilization of fresh biomass for energy has a great potential in unlocking energy demand challenges in Africa, it tends to bring competition for land with food crop cultivation. Furthermore, it leads to high utilization of fertilizers and high investment costs. To reduce the dependency of fresh biomass, alternative biomass sources should be considered. The possible sources that have gained attention not only for energy generation, but also for environmental concerns, are; crops and forest residue, non-edible biomass, animal wastes, and Municipal Solid Wastes (MSW). The application of biowaste for energy generation will not only solve the forecasted energy demand but also improve waste management in Africa. Africa is faced with ever-increasing waste management and utilization challenges. Among the challenges that hinder biowastes utilization are poor management, weak legislation, lack of enforcement, low public awareness, corruption, conflict and political instability. While the amount of waste produced in Africa is minimal in comparison to developed nations, waste mismanagement in Africa is already having an impact on human and environmental health [5]. It is estimated that an additional USD\$8 billion could be injected into the African economy each year by just diverting waste away from dumpsites or landfills for reuse, recycling, and recovery [5].

Converting biomass waste to energy necessitates a thorough understanding of the potential type and availability of waste feedstock, as well as the potential application of the chosen technology. The knowledge of energy potential and possible appropriate conversion technology affects investors and policymakers. Therefore, there is a need to expose the huge potential of biowaste as an energy

source for Africa to shift the alignment from fossil fuels to biowaste energy for sustainable energy and the environment. This chapter mainly focused on biowastes as a potential energy source in Africa. It describes the potential biowaste sources, such as crop and forest residue, MSW, and animal waste, and the potential energy present. Different technologies available for converting have also been discussed. Finally, this chapter proposes a way forward towards sustainable biowaste energy generation for Africa.
