This book discusses various renewable energy resources and technologies. Topics covered include recent advances in photobioreactor design; microalgal biomass harvesting, drying, and processing; and technological advances and optimised production systems as prerequisites for achieving a positive energy balance.  It highlights alternative resources that can be used to replace fossil fuels, such as algal biofuels, biodiesel, bioethanol, and biohydrogen. Further, it reviews microbial technologies, discusses an immobilization method, and highlights the efficiency of enzymes as a key factor in biofuel production.  In closing, the book outlines future research directions to increase oil yields in microalgae, which could create new opportunities for lipid-based biofuels, and provides an outlook on the future of global biofuel production.  Given its scope, the book will appeal to all researchers and engineers working in the renewable energy sector.