Presently, researchers and industry stakeholders are interested in the search of alternative and renewable energy sources, driven by rising energy demands and concerns over escalating levels of greenhouse gases and pollution. Bioenergy is a sustainable energy source derived from biodegradable biowaste. Agricultural, industrial, and residential sectors generated diverse types of biowaste and by-products. Biowaste can be transformed into one or more forms of energy including heat, electricity, biofuel, biochemical, or other bioproducts through various unique conversion techniques i.e. thermochemical conversion and biochemical conversion processes. In this chapter, conversion technologies especially, biochemical conversion processes such as anaerobic digestion, alcoholic fermentation and photobiological hydrogen production are discussed. Furthermore, the discussion also encompasses transestrification, which is a straightforward and economically feasible method for producing biodiesel on a pilot scale. The growing need for renewable energy has been a driving force behind the recent progress in waste and biomass-to-energy technologies. Continued research, innovations, and investment are essential to further improve the efficiency, scalability, and environmental performance of these technologies for widespread deployment and adoption.