New bacteria-powered solar cells could have vast applications, researchers say
Vancouver’s typically grey cloudy skies are one of the many hurdles for large scale adoption of solar power in the city, but a research team may have figured out a cost effective solution.
University of British Columbia scientists say they’ve found a cheap, sustainable way to build a solar cell using E. coli bacteria that convert light to energy.
The genetically engineered bacteria can be used to generate an electrical current when they absorb light, says lead researcher and UBC professor Vikramaditya Yadav.
“This really comes from two ingenious and stubborn students I had in the lab,” said Yadav.
All thanks to lycopene
Initially, the students’ goal was to produce natural dye pigment using E. coli. However, every time the research team created the dye — in this case lycopene — and stored it in sunlight, the dye would begin to degrade.
Yadav challenged his students to stop the degradation of the lycopene.
“The next thing you know, these guys have come up with the most ingenious solution to design the next generation of solar cells,” said Yadav, laughing.
The new solar cell design uses the photoactive lycopene, explained Yadav. When light falls on the lycopene, it releases electrons.
E. coli bacteria can be genetically modified to produce huge amounts of lycopene and are essentially turned into miniature dye factories, said Yadav.
Next, the team coated the E. coli in a layer of titanium nano particles so they could act as a semiconductor. The bacteria was then applied to a glass surface.
Light falls on the bacteria, the lycopene generates electrons and the electrons are propagated because of the titanium.
0.686 milliamps
With the coated glass acting as an anode at one end of the cell, the research team generated a current of 0.686 milliamps per square centimetre — an improvement on the 0.362 milliamps achieved by others in the field.
Yadav said that in theory, any device that uses electricity to function can use the bacterial solar cells. While the milliamps currently produced by the cells are comparably small, the cells are easy and cheap to create, said Yadav.
They also work under low light conditions, he added. Because the bacteria works in dim light, the cells could be used in cloudy areas and even in mines.
“Instead of looking at it as a competitor to conventional solar cells, you could view it as a complement,” he said.
