Algal are currently being considered as a versatile feedstock for biofuels production because of their fast growth rate and high biomass productivity. Algal could simultaneously act as a carbon sink and water purifier if its cultivation were coupled with flue gas and wastewater treatment, respectively. Hence, an understanding of the overall supply chains for algal biofuels production is exceptionally important to determine whether it is worthwhile to scale-up and commercialize algal cultivation for biofuels production. In this chapter, various aspects and constraints associated with the commercialization of algal biofuels will be discussed in detail, especially from the perspective of life cycle energy balance. Apart from that, discussions on the economic assessments of algal biofuels are also included in this chapter to provide an overview of the current state of algal biofuels in the fuel market. Potential algal biofuels conversion technologies, such as transesterification, starch hydrolysis and fermentation, pyrolysis, and hydrothermal liquefaction, are also presented. © 2019 Elsevier B.V. All rights reserved.