Algae and photosynthetic bacteria could also be exploited to generate electricity, besides jellyfish. University of Cambridge researchers let by Adrian Fisher and Paolo Bombelli study how they could use the two fore-mentioned to actually generate usable energy.
A transparent conductive electrode facing a carbon cathode, seeded with platinum nanoparticles holds a thin film of photosynthetic cells, that if exposed to sunlight begin to perform an electrolysis and produce oxygen, electrons and protons (and hydrogen).
The process is part of the algae’s natural habit of converting CO2 into organic compounds, to feed itself. The device produced by the scientists produces electricity instead and siphons the organics off. “The algal cells produce electrons very generously,” says Fisher.
The solar cell created this way is only 0.1 percent efficient, but the scientists will study different kinds of algae to figure out which of them is more effective in producing electricity. However, the algal solar cells could be used at sea, where space isn’t that important – there’s plenty of it. “We might end up with less efficiency than [conventional] photovoltaics, but we think we can win on cost, and we don’t require space where people want to live,” says Bombelli.
As a demonstration that their device works, they powered a clock with the electricity obtained from the algae.