Solar
energy that doesn't block the view
A team of researchers at Michigan State University has developed
a new type of solar concentrator that when placed over a window creates solar
energy while allowing people to actually see through the window.
It is called a transparent luminescent solar concentrator and
can be used on buildings, cell phones and any other device that has a clear
surface.
And, according to Richard Lunt of MSU's College of Engineering,
the key word is "transparent."
"No one wants to sit behind colored glass," said Lunt,
an assistant professor of chemical engineering and materials science. "It
makes for a very colorful environment, like working in a disco. We take an
approach where we actually make the luminescent active layer itself
transparent."
The solar harvesting system uses small organic molecules
developed by Lunt and his team to absorb specific nonvisible wavelengths of
sunlight.
"We can tune these materials to pick up just the
ultraviolet and the near infrared wavelengths that then 'glow' at another
wavelength in the infrared," he said.
The "glowing" infrared light is guided to the edge of
the plastic where it is converted to electricity by thin strips of photovoltaic
solar cells.
"Because the materials do not absorb or emit light in the
visible spectrum, they look exceptionally transparent to the human eye,"
Lunt said.
One of the benefits of this new development is its flexibility.
While the technology is at an early stage, it has the potential to be scaled to
commercial or industrial applications with an affordable cost.
"It opens a lot of area to deploy solar energy in a non-intrusive way," Lunt said. "It can be used on tall buildings with lots of windows or any kind of mobile device that demands high aesthetic quality like a phone or e-reader. Ultimately we want to make solar harvesting surfaces that you do not even know are there."
Lunt said more work is needed in order to improve its
energy-producing efficiency. Currently it is able to produce a solar conversion
efficiency close to 1 percent, but noted they aim to reach efficiencies beyond
5 percent when fully optimized. The best colored LSC has an efficiency of
around 7 percent.
The research was featured on the cover of a recent issue of the
journal Advanced Optical
Materials.
Other members of the research team include Yimu Zhao, an MSU
doctoral student in chemical engineering and materials science; Benjamin
Levine, assistant professor of chemistry; and Garrett Meek, doctoral student in
chemistry.
Story
Source:
The above story is based on materials provided by Michigan State University. Note: Materials may be edited for
content and length.
Journal
Reference:
Yimu Zhao, Garrett A. Meek, Benjamin G. Levine, Richard R. Lunt. Light Harvesting:
Near-Infrared Harvesting Transparent Luminescent Solar Concentrators (Advanced
Optical Materials 7/2014). Advanced
Optical Materials, 2014; 2 (7): 599 DOI: 10.1002/adom.201470040
Cite
This Page:
Michigan State University. "Solar energy that doesn't block
the view." Science Daily,
19 August 2014. <www.sciencedaily.com/releases/2014/08/140819200219.htm>.
