Researchers have imprinted solar panels with silicon nanopatterns that scatter green light back at you.
Solar panels are mainstays of renewable energy and for good reason. By converting the sun’s rays into energy, they can serve as a clean and green source of inexhaustible power. There’s a bit of a problem, though, and that problem is aesthetics. Solar panels tend to be unsightly, to be precise. They hardly blend into their natural surrounds and so many people continue to shun them.
But what if we could turn them green? Literally so.
A team of researchers in the Netherlands have done just that. They have devised a method for imprinting solar panels with silicon nanopatterns that scatter green light back at you from almost any angle you look at them. The method is known as soft-imprint lithography, “which works somewhat like an optical rubber stamp to imprint a dense array of silicon nanocylinders onto the cell surfaces,” the researchers explain.
“Each nanocylinder is about 100 nanometers wide and exhibits an electromagnetic resonance that scatters a particular wavelength of light,” they add. “The geometry of the nanocylinder determines which wavelength it scatters and can be fine-tuned to change the color of the solar cell. The imprint reduces the solar panel’s efficiency by about 2 percent.”
There’s a downside, however. While they may look prettier in color, these modified panels are slightly less efficient at absorbing sunrays. Whereas unmodified solar panels already boast a more than 20% efficiency of turning sunshine into useable energy, dyes and reflective coatings reduce that efficiency.
“Some people say ‘why would you make solar cells less efficient?’ But we can make solar cells beautiful without losing too much efficiency,” said Verena Neder, the lead author of a new study on the process published in Applied Physics Letters. “The new method to change the color of the panels is not only easy to apply but also attractive as an architectural design element and has the potential to widen their use.”
Even if some efficiency is lost, improved aesthetics may well be seen as a plus by many companies and homeowners.
Nor are these panels the only ones that have been designed in a way to make them more appealing to homeowners. New solar-powered roofs designed by Tesla come with fancy new tiles that obviate the need for traditional solar panels. They are connected to what his U.S.-based clean energy company calls the Powerwall, a neat battery that can power a two-bedroom house for an entire day.
Better yet: Tesla’s new-generation solar panels boast built-in features that make them both efficient and more visually pleasing than traditional tiles. Made of glass, the newly design titles are aesthetically appealing, unlike the rather bulky banks of solar panels currently in use. To make them even more attractive to homeowners in towns and suburbs, the tiles will come in four designs – textured glass, slate glass, Tuscan glass and smooth glass.
The company says that its new solar tiles could last for at least a half century and are at least 98% as efficient as their traditional, photovoltaic counterparts when it comes to harvesting sun rays. They can also defrost themselves in chilly weather, albeit that feature might not matter much in Malaysia, where temperatures always remains safely in warm-to-hot territory … and where those temperatures are set to rise further still as a result of climate change.