Transparent solar coating turns windows into energy generators

Chinese scientists say they have created a transparent solar coating that turns ordinary windows into energy generators without affecting clarity, according to a Science Daily report. 

The coating, composed of cholesteric liquid crystal layers, redirects polarized sunlight to the window edges where solar cells collect it. Full-sized windows could boost efficiency 50-fold while reducing the need for costly photovoltaic cells.

Unlike conventional luminescent or scattering-based concentrators, the new approach achieves broadband polarization-selective diffraction and waveguiding without compromising clarity. Modeling suggests a typical 2-meter-wide cholesteric liquid crystal window concentrating sunlight by 50 times can significantly reduce the number of photovoltaic cells required by up to 75%. 

The system supports integration with high-performance PV cells such as gallium arsenide for enhanced power conversion.