Low operating cost approach in Spirulina platensis bio-photovoltaic cell

Abstract

Bio-photovoltaic (BPV) cells are receiving more attention due to their clean electricity generation, utilisation of renewable energy, self-sustainability, and their ability to reduce carbon footprint by imitating the microorganism metabolism in the natural environment. This paper studied the performance of BPV using Spirulina platensis (S. platensis) as a biocatalyst in the anode compartment, under intermittent and continuous illumination with a light supply of 1500 lux. Zarrouk medium (ZM), and fertiliser medium (FM) became the anolyte, with graphite brush as electrodes. S.platensis cultured in FM showed a growth rate of 0.02285 ± 0.004 Abs/day, which was 15% less than growth in the ZM (0.02713 ± 0.006 Abs/day). The average current density normalised by the projected surface area of electrode produced by BPV with ZM under intermittent illumination at the end of the test period (≈1.654 A/m2) was higher than that of continuous illumination (≈0.391 A/m2). Meanwhile, the average current density by BPV with FM under intermittent illumination at the end of the test period (≈2.027 A/m2) was higher than that of the continuous illumination (≈0.839 A/m2). By comparison of the polarisation curve and the current density of ZM sets and FM sets, it can be deduced that the FM can be used to replace ZM in BPV operations.