Harry Potter fans, does the cloak of invisibility ring a bell? You know, the one that bends the light’s path around the user to hide anything under them? Well, our solar panels are about to get one too! But not for the same usage.
Researchers from the Karlsruhe Institute of Technology in Germany have made a mini solar panel on which its metallic contact fingers was covered with an invisibility cloak.
Metallic contact fingers are very important as these gather the generated current, however, they were also found to reduce the light each panel can absorb by 10 percent.
So, the researchers utilized a single solar cell in the lab of which they added such contact fingers, covering six percent of its surface area. They then covered these contact fingers with an etched-groove polymer coating. And with that, the mini panel's efficiency rose by nine percent! This is because the light the solar cell wasn't able to absorb was stored in the cloak.
“In the end, solar cell energy has to compete with all the fossil-fuel energy and it’s essential to increase the efficiency as much as possible in order to decrease the costs,” says Martin Schumann at the Karlsruhe Institute of Technology.
However, according to engineer Gerhard Peharz from the Joanneum Research in Austria, the cloak will also have its own set of problems. The grooves in the cloak would introduce dust and particles where they can gather and block sunlight, and the UV rays in sunlight will damage the cloak over time consequently reducing its effectiveness.
“This is good work and shows what can be done, but there is a big gap in the application,” he says. “It needs to be shown that there is a polymeric material that you can pattern in order to achieve this effect and is reliable for 20 years outdoors in the desert of Arizona.”
Schumann also recognizes this problem. Hence, he plans to experiment further and enclose the whole panel in a glass case, protecting the cloak from the environment. “We have done this in a lab scale, so it’s not really a solar module that we’re looking at,” he says.
So it turns out the invisibility cloak isn't only for hiding but also to boost renewable energy. Avada Kedavra, climate change!
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