E.coli: Solar panels which have amazing promise
Solar panels have amazing promise, but serious limitations. They are expensive to produce, and as it is in the name – you need the sun to power them. What if there is a way to make solar panels cheaper and functional even in places of limited sunlight? And what if the key to this is a bacterium? Of course, this is surprising because this whole discovery makes use of photosynthesis and E.coli.
Traditionally, a solar panel is made up of subunits, called photovoltaic(PV) cells that have to generate an electric current, and hence each end of the cell is formed of either the negative or the positively charged material, consists of silicon mixed with either phosphorous or boron. This creates the pre-existing electric field, and when this field gets exposed to photons through sunlight – it knocks some electrons loose from the silicon. Being a semiconductor, silicon is used in all kinds of electrical applications. Then those free-floating electrons, turn into an electric current by the other components of the solar cell that can either be stored or used.
Now that with another research showing up by the team at the University of British Columbia, who came with an economical solution from a totally different angle –Solar powered by E.coli! They have genetically engineered bacteria to produce large amounts of a pigment called lycopene. This is a light-harvesting dye that gives tomatoes their red-orange colour and is photoactive, meaning that, in its native state inside a plant, it’s extremely effective at converting light into energy. In this case, the lycopene is what is being excited by light to release an electron, instead of a synthetic material like silicon. But the bacteria aren’t a semiconducting material and for the energy generation the E.coli have absorbed to be transferable, so the team coated the bacteria in Titanium dioxide nanoparticles which make these light absorbing, mineral-coated bacterial cells semiconductors. They are then attached to a glass surface doped with oppositely-charged materials, and between the lycopene, nanoparticles, and doped glass, you have got an electric current induced by light.
This bio-hybrid PV technology shows a big leap here. Unlike the other technologies that used light-harvesting bio-based dyes in solar cells, the dye extracted from the bacteria is though expensive and not easy too. The new technology is quite cheaper and easier as the pigment remains inside the bacterial cells, and using a new technique that coats the bacteria in the nanoparticles suit. This new experiment yielded almost twice the electric output of previous bio-based PV experiments. This, definitely, gives a whole new meaning to the term Green Energy, which will be in use in the coming years.
E.coli is actually a super common bacteria used in research all the time. There are lots of different strains, most of which can be found in the intestines of humans and other animals, and only some of them or dangerous – most are really useful that we couldn’t live without them in our systems. E.coli can be used in the laboratory as it is easy and inexpensive to grow. These new bacteria-powered, or biogenic solar cells seems promiscuous not only because of the gains being made in how much electric current they produce but also these PV cells, unlike the silicon, can produce just as much energy in dim light as in bright light, and because the lycopene is so effective at harvesting energy from the sun.
Still, there are a few details that need to be straightened out before these ‘live’ solar cells get ready for market. For one reason, the bacteria die during the process, so it needs to figure out a way to keep them alive, reproducing, and producing lycopene through the lifetime of the solar cell to avoid replacing the bacteria every time. In addition, this prototype currently produces about 25 times less power than a traditional solar cell, so the design of the device needs to be significantly improved before it’s a feasible option. Regardless, this is an exciting way of reimagining solar panels that work in areas that don’t get a lot of suns. Both the Plant Power along with the Bacteria Power definitely makes the favourite combo in the whole world.