A peer-reviewed paper published by authors, Nina Vaidya and Olav Solgaard, about their findings on a light-gathering device called AGILE, an acronym for Axially Graded Index Lens. The device looks like an upside-down pyramid with the point lopped off. It creates a brighter spot at the output by light entering the square, tile-able top from any number of angles, and is channeled down.
Micropyramid lenses help solar panels capture more light even on a cloudy day
Solar panels work best when they are in direct sunlight. Current solar system arrays actively rotate them towards the sunlight to capture as much energy as possible. This system makes the panels more efficient, but also more expensive and complex to build and maintain than a stationary system. It seems that these challenges were a motivation source for the researchers at Standford University to come up with an alternative. In their prototypes which were fabricated at Standford, the researchers were able to retain over 90% of the light’s power by concentrating it on a much smaller area. Nina Vaidya, who is now an assistant professor at the University of Southampton, UK said;
« We wanted to create something that takes in light and concentrates it at the same position, even as the source changes direction. We don’t want to have to keep moving our detector or solar cell or moving the system to face the source. »
Glass pyramid fabrication steps are shown below;
a. Thin glass slabs of different refractive indices bonded together and the pyramid shape machined in the stack. Seen in the corners is the ‘checkerboard’ pattern, which is an optical illusion due to graded index layers
b. Aluminum deposited on the sidewalls
c. Pyramid in optical contact with solar cells absorbs and concentrates most of the incident light and appears dark.
Although there is no confirmation of any plans that the device can be commercialized in near future, according to a Stanford press release, the researchers hope that AGILE designs will be able to be put to use in the solar industry and other areas as well. While AGILE is still far from “enough” to deliver the power needed by data centers with green energy, it is a big step for capturing the light from all angles without a need for a complicated, motorized system. We still need a technological leap that will help with light-capturing cells’ efficiency.