April 26 - Researchers at Georgia Tech University have developed an organic solar cell made of wood. The biodegradable, transparent films are designed to replace the layers of glass or plastic found in conventional solar cells, heralding the possible development of solar panels that are 100 percent recyclable. Ben Gruber reports.
The future of solar power could be taking shape in a lab at Georgia Tech. It's a solar cell made of wood, created by scientists led by Bernard Kippelen. The cell is organic and therefore, 100 percent recyclable. Kippelen says it solves a problem created by conventional solar cells whose main components are made of plastic, glass, or silicon. If solar power is to be truly eco-friendly, Kippelen says its generation should not be dependent on materials that can't be recycled. (SOUNDBITE) (English) BERNARD KIPPELEN, PROFESSOR OF COMPUTER AND ELECTRICAL ENGINEERING, GEORGIA TECH UNIVERSITY, SAYING: "We have to worry on how we are going to recycle some of these materials and that recycling and full life cycle thinking really motivated our research. We asked the question that if we are going to deploy plastic solar cells on plastic substrates are we going to solve an environmental problem by creating another one? To answer that question, Kippelen began to look for materials that would make solar technology not only renewable, but sustainable as well, and it didn't take long before he discovered that the chemical components of wood from trees and other plants can do the same job as man-made materials. The researchers processed wood samples to create a thin transparent film of cellulose nano-crystals. This biodegradable film allows light to reach organic semi conductors that convert sun light into electricity in the cell. Kippelen says the organic cells work just as well as conventional cells, although he has since discovered that a biodegradable solar cell can be both a blessing… and a curse. (SOUNDBITE) (English) BERNARD KIPPELEN, PROFESSOR OF COMPUTER AND ELECTRICAL ENGINEERING, GEORGIA TECH UNIVERSITY, SAYING: "These materials we have shown are easily recyclable by just immersing them in water that means that if you deploy them like this and they are in the rain they would basically disappear." So, in order to overcome the "disappearing cell" problem, Kippelen and his colleagues are developing an organic barrier layer that will protect them on rainy days. Kippelen says he's convinced that workable, eco-friendly solar technology is within reach. He says it will benefit not only the environment, but the sustainable timber industry as well, turning wood into power for the 21st century.