Microalgae have been discussed to be a potential biomass source for the production of biodiesel. This article investigates the renewability of microalgal-sourced biodiesel by analyzing the fossil energy requirements for the microalgal biomass production and fuel conversion process. The results of the analysis carried out in this article indicates that with the present day scenario, the fossil fuel inputs into microalgae biodiesel production outweighs the energy outputs obtained. However, it is further shown that with the integration of renewable electricity generation systems and non-conventional nutrient sources, microalgal-derived biodiesel can be truly considered to be a renewable fuel.