Researchers at Nanjing University have developed a groundbreaking transparent solar coating that turns windows into electricity-generating surfaces without affecting clarity. Using cholesteric liquid crystals (CLCs), this coating acts as a diffractive solar concentrator, guiding sunlight to the edges of the window where photovoltaic cells convert it into energy.
Unlike traditional solar panels, which block light, the CLC coating allows an average of 64% visible light transmission, maintaining bright, naturally lit interiors. It also preserves 91% color accuracy, ensuring that indoor spaces appear natural. Early prototype tests successfully powered a small 10mW fan, demonstrating the technology’s practical energy-harvesting potential.
Lab tests show optical efficiency of 38% with monochromatic light and around 18% under full sunlight. Scaled to commercial window sizes, this technology could capture up to 50 times more energy than current semi-transparent photovoltaic systems, offering significant energy savings for urban buildings.
This innovation marks a major step forward for building-integrated photovoltaics (BIPV), seamlessly combining energy generation with modern architectural design. Researchers are now exploring durability and large-scale integration, bringing the concept closer to real-world applications. 
Source: livescience.com with additional information added by Glass Balkan
