System to Make Plants Generate Usable Electricity Developed at University of Georgia

Great progress in solar energy technology over the years has made the process more efficient and affordable, but still only a fraction of the solar radiation on Earth is converted to useful energy. In an attempt to close the gap, University of Georgia scientists in search of a novel solution have turned to nature's most efficient consumer of solar energy: plants.

The UGA team is developing a new technology that will make it possible to use plants to generate electricity.

Ramaraja Ramasamy, assistant professor in the UGA College of Engineering and study co-author says that clean energy is the "need of the century." And he believes plants are the key to ignite the clean energy revolution the world needs.

Current limitations on commercial solar panel capabilities limit their energy efficiency levels to no more than 25 percent, according to the Massachusetts Institute of Technology.

But plants operate with near perfect quantum efficiency, meaning that for every photon of sunlight a plant captures it produces an equal number of electrons. Plants produce energy during photosynthesis, where the plant splits water atoms into hydrogen and oxygen, which produces electrons.  The electrons then go on to help create the vital sugars a plants needs to grow and reproduce.

"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 in a statement. 

The technique involves separating part of the plant called thylakoids, cells responsible for capturing and storing energy from sunlight. Researchers manipulate the proteins contained in the thylakoids, interrupting the pathway along which electrons flow. Using nanotechnology, the electrons are captured from the plant with an ultra-fine tube that acts as a conductor.

In small-scale experiments, this approach resulted in electrical current levels that are two orders of magnitude larger than those previously reported in similar systems.

But Ramasamy cautions that the technique is still in experimental stages and  more work needs to be done. Still, he did offer some suggestions for potential ways to use the technology on a small scale.

"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."

As the technique becomes more refined, Ramasamy  sees promise for the technology in the future.

"We have discovered something very promising here, and it is certainly worth exploring further," he said. "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."

The research was published in the journal Energy and Environmental Science