In this work, we provide a cost comparison of micro-photosynthetic power cells (μPSC) with the well-established photovoltaic (PV) cells for ultra-low power and low power applications. We also suggest avenues for the performance improvement of μPSC. To perform cost comparison, we considered two case studies, which are development of energy systems for: (i) A typical mobile-phone battery charging (low power application) and (ii) powering a humidity sensor (ultra-low power application). For both the cases, we have elucidated the steps in designing energy systems based on PV and μPSC technologies. Based on the design, we have considered the components needed and their costs to obtain total cost for developing energy systems using both PV and μPSC technologies. Currently, μPSCs based energy systems are costlier compared to their PV counterparts. We have provided the avenues for improving μPSC performance, niche application areas, and aspects in which μPSCs are comparable to PV cells. With a huge potential to develop low-cost and high performing technologies, this emerging technology can share the demand on PV technologies for ultra-low power applications. © 2019 by the authors.