See 'Transparent solar panel represents new wave of solar technology' for an update on this signal of change.
Imagine solar cells that are fully transparent, and could cover the windows of your building or the screen of your smart phone. Such a technology is one step closer thanks to the development of a fully transparent solar concentrator by a team at Michigan State University, which could act as the basis for a clear photovoltaic solar cell.
Conventional solar cells are necessarily opaque, as they must absorb sunlight (photons) to convert them into electricity in the shape of electrons. Instead, the Michigan State University team uses a transparent luminescent solar concentrator (TLSC) that absorbs non-visible wavelengths of sunlight. These are then emitted as infrared light to the edge of the transparent area, where a conventional photovoltaic solar cell converts it into electricity.
Image credit: sj_sanders / flickr
Fully transparent solar cells could be used in places where conventional cells would not be suitable. For instance they could be used to cover the windows on a building, without the need for an array of unsightly an intrusive panels. They could also be used as a power source on devices with clear screens, from smart phones to e-readers.
This technology is still at an early stage. The researchers say the TLSC is currently one percent efficient, but they may be able to reach five percent efficiency (non-transparent luminescent concentrators have a current maximum of seven percent efficiency). Despite these relatively low figures, they could be a useful back-up source of power for small devices, and - if they can be reproduced affordably at scale - the possibility of covering all the windows on a building with TLSCs potentially means a large increase in the places solar energy can be harvested.
Original paper - 'Near-infrared harvesting transparent luminescent solar concentrators' (Yimu Zhao, Garrett A Meek, Benjamin G Levine, Richard R Lunt) - http://onlinelibrary.wiley.com/doi/10.1002/adom.201400103/epdf
Offgridquest.com - 'A fully transparent solar cell that could make every window and screen a power source' - http://www.offgridquest.com/extra/a-fully-transparent-solar-cell-that-coul