Development of photo-bioreactors (PBRs) has been accelerated owing to their potential application in the production of algal biofuel. But the application of PBRs should be looked beyond fuel and towards feed items/wastewater treatment solutions it can provide. The PBRs discussed in the review are broadly divided into two major categories, that is, open and closed type. The open PBRs are simple open pond systems while closed ones include vertical, flat plate, tubular, foil and recently developed porous substrate bioreactor. The efficiency of all PBRs depends on the surface-to-volume illumination ratio apart from mixing. The recently developed porous substrate bioreactor is technologically superior to its predecessors in terms of water usage and does not require biomass separation. The authors emphasize on the development of PBRs with the hope that their success would match as that of solar energy panels for power generation which have come a long way from the laboratory to real-world applications.