In a stroke of brilliant biomimicry, scientists have found a way to build a solar cell that renews itself -- just like a plant.
Photovoltaic cells are the most popular way to harness the sun's energy to create electricity. But as the sunlight fades, so does the energy, in most cases.
For years, scientists have looked for a way to duplicate photosynthesis, turning sunlight into power as efficiently as plants do. And now, thanks to a hodge-podge of chemical solutions and water, they might be on the right track.
At the Massachusetts Institute of Technology, scientists have found a way to generate solar energy with chemicals similar to those plants use. In addition, it works for long periods of time, with the chemicals used able to reassemble themselves (IB Times).
Using a chemical called a phospholipid in a solution of water with carbon nanotubes and molecules called reaction centers, Michael Strano, an associate professor of chemical engineering has been able to imitate, if only in a small way, the reaction that occurs in plants exposed to sunlight.
"It's not at all like static photovoltaic cells," Strano told IB Times. "I'm just fascinated by it."
How It Works:
When sunlight hits the reaction center is generates a tiny current. Millions of them together generate more. The amount is measured in billionths of an ampere, Strano says.
Ordinarily that would be the end of the story. But as the solution generates power, it loses efficiency, because each time the photons hit the reaction center it changes the molecule.
In order to solve this problem, Strano mixed the solution with a surfactant called sodium cholate, which breaks up proteins. It is, Strano said, similar to soap. "You could wash your hands with it, even." he said. Similar chemicals are used to break up oil spills.
This new type of cell converts energy with 40% efficiency, which is far better than the traditional photovoltaic cell. But right now, it's unable to produce a substantial amount of energy because only a small amount of sunlight hits the molecules because the solution is clear. Strano said concentrating the mixture into a gel might work better.
One of the coolest advantages over regular batteries is that the proteins harvesting the light in this new type of solar cell can come from plants. This means that in the future yard waste could be used to help heat your home.
Image Credit: MIT