Kostuk Uses Rainbows to Boost Solar Power
Researchers at the University of Arizona have created a holographic system designed to reduce some of the lost efficiency in solar panels due to the blank spots between solar cells. A holographic light collector is inserted into the solar panel just over the dead space. Then, the sunlight passes through this collector and splits into its ROYGBIV colors (because only certain wavelengths of light are of most use to a solar cell -- in this particular case, those producing yellow to red light). The useful colors are then bounced back up and off the glass covering the panel, and down into the solar cell itself.
This bit of extra light, scientists say, could make a big difference in the solar industry.
“If you [ask] solar cell engineers and physicists, if they get a tenth of a percent or two-tenths of a percent increase in performance, they go wild,” said ECE and optical sciences professor Raymond Kostuk.
By adding in the hologram, Kostuk and his fellow scientists were able to improve a panel’s performance by almost 5%, at its best. A hypothetical solar power system that normally generates 100 kilowatt-hours of electricity per year could expect an additional 4.5 kilowatt-hours thanks to the rainbows.
“Extracting more electrical energy out of the system by optical methods, I think, has a really potentially very high payoff for a lot of these systems,” Kostuk said.
Kostuk, along with PhD students Jianbo Zhao and Benjamin Chrysler, published these results in the Journal of Photonics for Energy. The efficiency improvements with the holographic system can depend on several factors, most importantly the actual amount of dead space on a given solar panel. This can vary depending on the specifics of the panels’ design and manufacturing process, Kostuk said, but at times it can be as high as 10%. For the new study, the researchers modeled their work on a panel with just over 8% wasted space.
Read more about Kostuk's work at SPIE.org.
This article appears in full at: The Daily Beast