For decades, scientists have looked for an efficient and affordable method of harvesting, storing, and discharging solar energy. The most common method of producing energy in today’s era is from silicon solar cells which are heavy and bulky in general, and can occupy entire rooms. Recent models, made from softer materials, are more flexible, reasonable, and adaptable, but are much less efficient in comparison to their expensive counterparts.
Now, Susanna Thon, an assistant professor in the electrical and computer engineering department of the Johns Hopkins University, is working on a new model of solar cells that is both efficient and cheaper to produce. “If you want to install solar cells in cities (which requires them the most), you’ll do so and always prefer the highly-efficient technologies because of their compact nature and the ability to work at large-scale. However, they are way too expensive. And you can’t switch to the cheaper alternatives since they come with their own drawbacks and are much less efficient,” Thon says.
A couple of years prior, Thon came up with an approach to develop versatile, flexible, and cost-effective solar concentrators especially for these newer models of solar cells. In the past, solar concentrators used huge mirrors and lenses to capture light and focus them down to a smaller area. Thon and her team redesigned the entire structure where they reduced the size of the concentrators to a sleek one-inch square and replaced the bulky mirrors with a light silicon-containing plastic. “With the microconcentrator, solar cells can capture more light and increase the power-generating capacity by up to 20 times or more–pertaining to the specific application,” Thon says.
The team of researchers then 3D printed molds for the lens arrays of the microconcentrator and then created lenses out of a ductile silicone polymer. The outcome is a slim, transparent sheet of bumps similar to the shape of an upturned egg container that can be attached over solar cells. Thon said that these microconcentrators are cheap and can be effectively scaled to conceal a large area, increasing their potential and paving the way for commercial use.
The team filed a patent for their underlying design, and now they’re attempting to improve the technology to better capture both direct and indirect sunlight. “There’s a lot of sunlight that gets scattered off of clouds or concrete structures, or you might want to install a solar cell on the side of a building, where it won’t be in the direct contact of sunlight at all times,” Thon added.