Despite the worthy concept of transforming sunlight into electricity, solar photovoltaics are problematic. For one, their manufacture and disposal causes lots of long-term issues with toxic byproducts, and they also don't perform very well yet in northern regions or places that don't get a lot of sun. But that could change if voltaics were plant-based, as designer Elena Mitrofanova is proposing for her thesis, done for the Institute for Advanced Architecture of Catalonia. Using digitally fabricated, modular clay "bricks" that would be connected as a conventional circuit, Mitrofanova's concept would use moss as the medium to generate electricity. Check out the video explaining this novel idea:
Due to the presence of symbiotic bacteria in a soil-less medium, the moss in the voltaic "cell" is able to generate electricity as it undergoes photosynthesis, delivering organic compounds into this soil-less substrate made of water-absorbent hydrogels and conductive carbon fibers, which essentially acts as the anode of this power-generating system. The bacteria in the substrate is nourished by these compounds, producing free electrons as a byproduct, which is harnessed by the system as electricity.
The system could be organized in either a parallel or series circuit, and could be installed on the facades of buildings. One of Mitrofanova's aims was to design the moss voltaics as a scalable system, potentially suited for urban areas. The bricks themselves form a protective shell for the moss, shading them from sunlight while allowing a favourable, moist microclimate to flourish within. To do this, Mitrofanova left most of the clay's surfaces unglazed, except for the interior's bottom, where pooling water would pose a problem. Moss itself was chosen because it is low-maintenance, requires little water, and grows well in northern climates.
So far, Mitrofanova's system is capable of producing only 3 watts with a 16-module setup, but she believes that with future technology potentially having lower energy requirements and higher efficiency, moss voltaics could be a viable option someday. The graphic below shows the estimated surface area that would be needed to power things like laptops, cellphones and more.
She also notes that other plants like algae could be used instead, and that in the long run, biological photovoltaics would be less expensive to produce, self-repairing and self-replicating and even biodegradable. More over at ArchDaily and Elena Mitrofanova.