A lot of places are not able to use solar panels efficiently due to weather conditions. More precisely, places where overcast skies are common. For example, British Columbia and parts of northern Europe.
However, University of British Columbia researchers have found an effective and a cheap solution to this problem. They built a solar cell using bacteria that can convert light to electricity. There were similar solutions that allowed generating a current in dim light. However, the new solar cell generates a current stronger than any previously recorded current from similar devices. It works efficiently in both dim and bright lights.
This project will be a step towards using solar power even in areas similar to those mentioned before. With further development, these “biogenic” solar cells can become widely used in solar panels.
Previous prototypes of such devices used an extracted natural dye that bacteria use for photosynthesis. However, this is a very expensive and difficult process that uses toxic solvents and causes the dye to degrade.
The UBC researchers’ solution was to leave the dye in the bacteria and to use the whole bacteria in the cell. They genetically engineered E. coli to produce a large amount of lycopene (very effective at harvesting light dye that also gives the red-orange color to tomatoes). The bacteria were coated with a mineral (it would act as a semiconductor) and applied the mixture to a glass surface.
The coated glass has a function of an anode at one end of the cell. The cell was able to generate a current density of 0.686 milliamps per cm². The other prototypes could achieve a maximum density of only 0.362 milliamps per cm².
According to Vikramaditya Yadav, a professor at UBC’s department of chemical and biological engineering who led the project, these cells can be manufactured economically and sustainably, and, optimized, could compete with conventional solar cells.
The cost savings are almost impossible to be estimated by now, but, for sure, it reduces the cost of dye production to one-tenth of the previous solutions’ (extracting the dye from bacteria) cost. The ultimate goal by now is to find a process that doesn’t kill bacteria, so they can produce dye indefinitely.