What if on a sunny day, your bedroom window could power your cell phone? Or better yet, your computer? Sounds a little science fiction, but in reality it doesn’t seem like it is that far off.
Michigan State University researchers have created a transparent solar concentrator which means that any window or pane of glass can become a photovoltaic solar cell. As you can tell by the photo, it is truly transparent, which puts it shades ahead of previous transparent cells that were more opaque than clear.
Technically, a transparent photovoltaic panel would be impossible because it produces energy by absorbing sunlight. A transparent material allows light to pass through itself, thus there is no absorption and why the previous attempts had not been truly transparent.
Researchers at Michigan State used a different approach and instead of creating a transparent photovoltaic cell, they created a transparent luminescent solar concentrator. The concentrator uses organic salts to absorb specific wavelengths of infrared and ultraviolet light, which are not visible to the naked eye. These salts then emit a glow on yet another infrared light frequency and guides the light towards the edge where traditional photovoltaic solar cells (black strips) convert it to electricity.
The research team leader, Richard Lunt, is confident that these transparent panels could be efficiently deployed throughout a wide array of applications including tall buildings or even the glass cover of your cell phone.
Current efficiency is around 1%, but this is only the beginning.
Source: Zhao, Y., Meek, G. A., Levine, B. G. and Lunt, R. R. (2014), Near-Infrared Harvesting Transparent Luminescent Solar Concentrators. Advanced Optical Materials, 2: 606–611. doi:10.1002/adom.201400103