Aluminum is already one of the greenest metals around, from its high recycling efficiency to its manufacturing usage as a means of increasing car MPG. Here’s another feather in aluminum’s environmentally friendly cap: now it’s a groundbreaking way for solar panels to become more efficient and consumer friendly — and it all comes down to nanometers of aluminum cylinders. From Scientific American:
A problem with solar panels is that most of the light energy that hits a solar panel is not absorbed.
But by trapping light in a solar panel, researchers found they can increase the overall efficiency of a panel by up to 22%. These results are published in the October issue of Scientific Reports by researchers from Imperial College of London, Belgium, China, and Japan.
Dr. Hylton and his colleagues attached rows of aluminum cylinders just 100 nanometers across to the top of the solar panel – giving them a Lego®-like appearance – where they interact with passing light, causing individual light rays to change course. More energy is extracted from the light as the rays become trapped inside the solar panel and travel for longer distances through its absorbing layer.
Looks like aluminum’s won this race — but who were its competitors?
Previous attempts have used silver and gold studs because those materials have strong interactions with light, but researchers found that they interact too well with light by absorbing the light before it enters the solar panel.
“The key to understanding these new results is in the way the internal structures of these metals interact with light. Gold and silver both have a strong effect on passing light rays, which can penetrate into the tiny studs and be absorbed, whereas aluminum has a different interaction and merely bends and scatters light as it travels past them into the solar cells.”
Gold and silver may be prettier to the eye, but in this case, aluminum’s the smarter material choice. At this rate, could aluminum jewelry be far behind?