Solar is one of the most common forms of green energy, with the U.S. getting 43 times more electricity from solar in 2016 than it did in 2007. But what if solar panels were even greener?
I mean, they’re literally going green.
Researchers in the Netherlands have developed a process for making conventional bluish-black solar panels bright green. It involves imprinting existing solar panels with silicon nanopatterns that give solar panels a green appearance from most angles.
Why is this important? Some people have apparently not installed solar panels because of aesthetic concerns. After all, those traditional blue-black solar panels can be a bit of an eyesore for people who want their roofs to be all one color, for example. This process might make it possible to create panels in other colors—and even white.
“The black appearance of the [conventional] solar panels is not attractive for many people and a reason to not put solar panels on their rooftop,” Verena Neder, lead author of the research paper describing the new technology, told NBC News. “Making solar cells colored makes it possible to integrate them in an architectural design of houses and full cities, but also to merge them in the landscape.”
What about efficiency? It seems that the green solar panels only show about a 10 percent power reduction and a 2 percent efficiency decrease due to the loss of absorbed green light.
“Some people say, ‘why would you make solar cells less efficient?’ But we can make solar cells beautiful without losing too much efficiency, Neder said. “The new method to change the color of the panels is not only east to apply but also attractive as an architectural design element and has the potential to widen their use.”
Previous attempts to create color solar panels have resulted in an efficiency loss of about 45 percent compared to conventional panels because they reflect much of the sunlight that falls on them due to the dye and reflective coatings that give them their color.
The prototype for this colored solar cell is about the size of a postage stamp, but “in principle, this technique is easily scalable for fabrication technology,” said Albert Polman, senior author of the paper. “ You can use a rubber stamp the size of a solar panel that in one step can print the whole panel full of these little, exactly defined nanoparticles.”
The researchers are currently designing imprints to create red and blue solar cells, too. Once they master these three colors—the primary colors of light—they can create any color by combining different nanoparticles. “If they get very close to each other, they can interact and that will affect the color,” Polman said.