Microalgae, such as algae and cyanobacteria, which are cultivated for their biomass and are rich in lipids, proteins, and carbohydrates, can be used as a renewable energy source. Seeking to mitigate climate change and ensuring energy security, this approach provides several advantages, including being carbon neutral, requiring low water usage, and having high oil content. However, challenges persist, including scalability, cost-effectiveness, biomass harvesting, conversion efficiency, water management, and land use competition with food crops. This book describes the development of a production method of bioenergy from microalgal biomass, and examines the entire process development, from strain improvement and cultivation optimization, through the conversion process, and systems integration. The book delves into related technologies, including catalytic conversion, separation and purification techniques. The potential of microalgal bioenergy as a sustainable energy source is assessed by considering scalability, cost-effectiveness, and environmental impact.