New Technology Uses Plants to Generate Electric Power

There's no question the sun generates a lot of heat, but capturing that energy is another story. Up until now, humankind has only been able to use a relatively small percentage of the sunlight that makes its way to Earth every day.

Enter researchers at the University of Georgia who say they've taken their queues from nature and are now working on new technology in which plants generate usable electricity.

Their work is explained in a recent paper published in the Journal of Energy and Environmental Science.

"Clean energy is the need of the century," said Ramaraja Ramasamy, an assistant engineering professor at the university and the corresponding author of the research paper, as reported by Phys.org. "This approach may one day transform our ability to generate cleaner power from sunlight using plant-based systems."

The researchers said that after billions of years of evolution, most plants operate at nearly 100 percent quantum efficiency, which means for every photon of sunlight a plant captures, it produces an equal number of electrons.

Converting even a fraction of the solar energy plants process and then turning it into electricity would significantly improve on the typical 12-to-17 percent efficiency of solar panels.

During photosynthesis, plants use sunlight to split water atoms into hydrogen and oxygen, which produces electrons. These newly freed electrons are utilized in creating sugars plants use as nourishment to support their growth and reproduction.

"We have developed a way to interrupt photosynthesis so that we can capture the electrons before the plant uses them to make these sugars," said Ramasamy, who is also a member of the school's Nanoscale Science and Engineering Center.

Ramasamy said his team's technology involves separating out thylakoids, the specific structures in the plant cell tasked with capturing and storing sunlight energy. Then they manipulate the proteins contained in the thylakoids in a way that interrupts the flow of electrons.

The modified thylakoids are then placed upon a backing of carbon nanotubes, cylindrical structures that are nearly 50,000 times finer than a human hair and which  act as an electrical conductor, intercepting electrons from the plant material and sending them along a wire.

Ramasamy said he and his collaborators are working on techniques to improve the stability and output of their device, but much more experimentation needs to be done before the new process is introduced commercially,

"In the near term, this technology might best be used for remote sensors or other portable electronic equipment that requires less power to run," he said. "If we are able to leverage technologies like genetic engineering to enhance stability of the plant photosynthetic machineries, I'm very hopeful that this technology will be competitive to traditional solar panels in the future."

Ramasamy said he and his team "have discovered something very promising here, and it is certainly worth exploring further...The electrical output we see now is modest, but only about 30 years ago, hydrogen fuel cells were in their infancy and now they can power cars, buses and even buildings."