Dec 21 2008
Researchers at Imperial College London claim that they have set a new record for concentrating the Sun’s light on to a solar cell with the aid of a transparent polymer plate.
They think that their solar concentrator sheets may help develop a technology that can result in vastly improved solar power capabilities at much cheaper cost. Luminescent solar concentrators (LSCs) are plates of plastic or glass that have solar cells mounted along their edges.
They are coated with light-absorbing dye molecules. When the molecules re-emit the light, it bounces through the plate by total internal reflection until it hits the solar cell. Amanda Chatten, from Imperial College London, says that the novel LSC has a power conversion efficiency of 7.1 per cent, which is about 0.4 per cent higher than the previous official record-holder. The researcher admits that that efficiency is still not very high. “But it could find application where space is not an issue,” Nature magazine quoted Chatten as saying.
“I think the result is very encouraging for the field, and the efficiency is competitive with other technologies,” says Marc Baldo of the Massachusetts Institute of Technology, Cambridge, who unveiled glass-based solar concentrators of his own earlier this year. Chatten recently presented the results through her former graduate student Lenneke Slooff at the Materials Research Society meeting in Boston, Massachusetts. The researchers revealed that one drawback of their system was that to operate at its highest efficiency, it must be teamed with expensive gallium arsenide cells, rather than conventional silicon.
They hoped that they would be able to move away from using dyes that degrade over time, and replace them with quantum dots, that is, tiny nanoparticles of semiconductor materials that are longer-lived. Chatten believed that within a decade, windows that could act as solar concentrators will be integrated into buildings. The efficiency of the novel LSC has been verified by the European Telecommunications Standards Institute in Sophia Antipolis, France. (ANI)