Researchers from the Institute of Microbiology of the Chinese Academy of Science have discovered a new type of a BPV (Bio-Photovoltaics) system which can operate stably for periods that go beyond 40 days.
This is an important step in the development of new BPV systems, a field that is relatively new, and which has drawn the attention of scientists due to the multiple benefits that underpin it. While the new BPV system may not see commercialization as it stands right now, it certainly opens the door to more targeted experimentation that will result in further improvements.
BPVs employ biological photosynthetic microorganisms that have the capacity to convert solar energy into electricity. The problem with these “living” materials is their stability and longevity, while their power density isn’t exactly impressive either. Their advantages, on the other side, all stem from their environmental friendliness. For example, the fact that they aren’t toxic means that they don’t require special manufacturing methods and disposal practices. BPV panels are easy to recycle, cheap to make, and won’t introduce any form of damaging agents to the environment.
The Chinese researchers managed to deal with the problem of the longevity, by using the photosynthetic cyanobacteria and the exoelectrogenic Shewanella bacteria. The energy carrier that helps direct the transfer of the energy chunks between the two types of bacteria is D-lactate.
The D-lactate is actually produced by the cyanobacteria and available CO2 when the sunlight hits the panel, while the Shewanella oxidizes the D-lactate to produce electricity. Through this mechanism, the scientists managed to achieve power densities of 150 mW*m-2, which is a magnitude greater than what the best of BPV systems have demonstrated so far.
Image Credit: LI Yin’s group, Institute of Microbiology, Chinese Academy of Sciences