Ordinary glass will be able to generate “green” energy: what is known about the new technology

Scientists consider the luminescent solar concentrator a promising alternative to conventional panels, but there are some problems.

As the world's need for clean renewable energy grows, scientists are developing advanced technologies for obtaining solar energy, one of which is the luminescent solar concentrator. The Advanced Science News portal writes about this.

A luminescent solar concentrator is a device for converting solar energy that is considered a promising alternative to traditional solar panels. The technology can be integrated into existing infrastructure, such as windows and building facades.

According to Wilfried van Sark, a professor at the Copernicus Institute for Sustainable Development at Utrecht University, these devices typically consist of a thin, transparent material known as a waveguide, into which phosphors are embedded – special molecules or nanoparticles. These molecules absorb sunlight and re-emit it at longer wavelengths.

“This wavelength shift allows the re-emitted light to remain confined inside the waveguide through a process called total internal reflection. The light then travels to the edges, where solar cells convert it into electricity,” the professor explained.

The paper says that to function as transparent “solar windows,” phosphors must strike a delicate balance: minimizing absorption of visible light and efficiently capturing ultraviolet and infrared wavelengths. This will preserve the transparency of the devices, making them well-suited for integration into glass structures such as skyscrapers.

To find molecules that best absorb energy and can act as phosphors, Wilfried van Sark and his colleague Thomas de Bruyn used modern modeling techniques to study how light interacts inside the waveguide — how it is absorbed, re-emitted, and directed to tiny solar panels at the edges.

The researchers tested different concentrations of 92 known phosphors in combination with a transparent waveguide material commonly used in solar concentrators, called polymethyl methacrylate, to find the most efficient setup for capturing and converting sunlight into electricity. The researchers also studied different combinations of multilayer waveguides with different phosphors to see if such designs could lead to improved overall efficiency.

“With the current choice of phosphors, given their absorption spectra and quantum efficiency, and given the limitations of high transparency, a maximum solar energy conversion efficiency of about 1% is possible, compared with more than 20% in conventional solar cells,” — said Wilfried van Sark.

Despite the relatively low efficiency of luminescent solar concentrators compared to traditional solar panels, they are still considered a promising technology for commercial application. Scientists also believe that in the future the efficiency of the technology could increase to around 10%.

“Although the efficiency may be lower than that of standard solar panels, the huge area available in such high-rise buildings justifies their use, also in line with the upcoming (EU) requirements for the development of energy-efficient buildings,” — Wilfried van Sark concluded.