What is biological photovoltaics?
Biological photovoltaics (BPV) is a clean energy-generating technology that uses biological photosynthetic material to capture solar energy and directly produce electrical power. BPV systems are sometimes also described as living solar panels. Take a look at the video for an introduction here.
There is a biological photovoltaics Wikipedia page where more information about this technology can be found.
How does BPV technology work?
BPVs are biological electrochemical systems, similar to microbial fuel cells. In a BPV system, photosynthetic material is employed in the anodic half-cell where it oxidises water using light energy. Some of the electrons generated by water photolysis are transferred to an electrode (anode). At the cathode, a reaction with a relatively high potential consumes electrons and creates a potential difference between the two electrodes, driving electrical current through an external circuit.
BPV systems can employ whole algal or cyanobacterial cells as the light harvesting material, or purified photosynthetic sub-cellular fractions such as thylakoid membranes or isolated photosystems. Sub-cellular photosynthetic material is able to transfer electrons to the anode more effectively, but cannot repair itself. In contrast, we have demonstrated that BPV systems using whole organisms can generate power for months at a time. This ability to self-repair and self-assemble will hopefully make BPV systems a cost-effective alternative to conventional solar panels.
Research on BPV technology in the Howe lab
We are mostly concerned with the biological element of BPV systems, as electron export from the biological material is the main limit on electrical power production by this technology. Research so far has demonstrated electrical current production from various types of BPV system, probed the intracellular electron transfer pathways that contribute to current production, and shown that increases in current production are possible using genetic engineering approaches. The majority of our work uses cyanobacteria as the light-harvesting material, as these organisms have a relatively simple membrane structure and therefore fewer barriers to electron export, and can be easily genetically modified. BPV publications from the Howe lab are listed below.
Terminal oxidase mutants of the cyanobacterium Synechocystis sp. PCC 6803 show increased electrogenic activity in biological photo-voltaic systems. Bradley RW, Bombelli P, Lea-Smith DJ, Howe CJ. (2013) Phys. Chem. Chem. Phys. 15, 13611-13618
Hydrogen production through oxygenic photosynthesis using the cyanobacterium Synechocystis sp. PCC 6803 in a bio-photoelectrolysis cell (BPE) system. McCormick AJ, Bombelli P, Lea-Smith DJ, Bradley RW, Scott AM, Fisher AC, Smith AG, Howe CJ. (2013) Energy Environ. Sci. 6, 2682-2690
Biological photovoltaics: intra- and extra-cellular electron transport by cyanobacteria. Bradley RW, Bombelli P, Rowden SJ, Howe CJ. (2012) Biochem. Soc. Trans. 40 (6), 1302-1307
Surface morphology and surface energy of anode materials influence power outputs in a multi-channel mediatorless bio-photovoltaic (BPV) system. Bombelli P, Zarrouati M, Thorne RJ, Schneider K, Rowden SJL, Ali A, Yunus K, Cameron PJ, Fisher AC, Wilson DI, Howe CJ, McCormick AJ. (2012) Phys. Chem. Chem. Phys. 14, 12221-12229
Comparison of power output by rice (Oryza sativa) and an associated weed (Echinochloa glabrescens) in vascular plant biophotovoltaic (VP-BPV) systems. Bombelli P, Iyer DMR, Covshoff S, McCormick AJ, Yunus K, Hibberd JM, Fisher AC, Howe CJ. (2012)App. Microbiol. Biotechnol. 97, 429-438
Quantitative analysis of the factors limiting solar power transduction by Synechocystis sp. PCC 6803 in biological photovoltaic devices. Bombelli P & Bradley RW, Scott AM, Philips AJ, McCormick AJ, Cruz SM, Anderson A, Yunus K, Bendall DS, Cameron PJ, Davies JM, Smith AG, Howe CJ, Fisher AC. (2011) Energy Environ. Sci. 4, 4690-4698
Photosynthetic biofilms in pure culture harness solar energy in a mediatorless bio-photovoltaic (BPV) cell system. McCormick AJ, Bombelli P, Scott AM, Philips A, Smith AG, Fisher AC, Howe CJ. (2011) Energy Environ. Sci. 4, 4699-4709
Porous ceramic anode materials for photo-microbial fuel cells. Thorne RJ, Hu H, Schneider K, Bombelli P, Fisher AC, Peter LM, Dent A, Cameron PJ. (2011) J. Mater. Chem. 21, 18055-18060