The production of biofuels from microalgae, especially biodiesel, has become a topic of great interest in recent years. All the steps in the process must also be very low cost. However, many of the published papers do not consider the question of scale up and the feasibility of the various processes to be operated at the very large scale required if algal biofuels are to make a meaningful contribution to renewable fuels. Recently, technological advancements have made microalgae biodiesel closer to being economically feasible through increased efficiency of the cultivation, harvesting, pre- treatment, lipid extraction, and transesterification subsystems. The metabolism of microalgae can be favourably manipulated to increase lipid productivity through environmental stressors, and ''green'' techniques such as using flue gas as a carbon source and wastewater as a media replacement. This paper discusses the unit processes required for algal biofuels production (i.e., growing the algae, and their techno-economic feasibility.