An Insight into Biological Photovoltaic Cell Based Electrochemical System

Biological photovoltaic cells can be called as living solar cells. They use oxygenic photoautotrophs such as cyanobacteria and algae, instead of silicon, to capture light energy for photolysis. The organisms such as cyanobacteria and algae capture light energy during the process of photosynthesis and perform charge separation of water molecules (photolysis), producing protons, electrons, and oxygen molecules. The electrons thus produced are transferred to the anode and through external circuit they move to cathode to get reduced to water, producing electric current. Biophotovoltaic (BPV) are different from traditional silicon based solar photovoltaics (SPV) cells in a number of ways. Unlike SPV, the presence of water is imperative in BPV for the algae/cyanobacteria to perform photolysis. The BPV are self-renewing in nature and do not require any external carbon source for growth. The technology of BPV can be incorporated in bioelectrochemical systems (BES) to generate green energy. BPV based electrochemical technology can be used as solar bio-battery or bio-solar panel. It can also be utilized in low powered devices such as alarm clocks. Despite the multiple advantages of BPV, still they are in the threshold of its development due to its energy conversion efficiency. The chapter would comprehensively explain the principle, working, and application of biological photovoltaic systems.