Energy-input analysis of the life-cycle of microalgal cultivation systems and best scenario for oil-rich biomass production

•Aim: To realize the energy inputs of the LCA to produce oil-rich algal biomass for biodiesel.•We considered recent technologies and main bottlenecks in algal biomass production.•We calculated and compared the energy requirements of the algal cultivation systems.•Lowest energy input for a complete harvesting process requires ∼4MJperm−3 algal suspension.•We propose the best scenario to grow microalgae for biodiesel.