Transparent solar windows generate power 24/7 at any weather

Researchers in South Korea have developed an innovative transparent solar window capable of generating electricity continuously by harnessing sunlight during the day and indoor lighting at night. Led by Professor Jun Yong-seok of Korea University, in collaboration with Korea Aerospace University and the Korea Institute of Science and Technology, this hybrid solar window maintains high transparency and color accuracy while delivering stable power output regardless of time or weather conditions. Unlike conventional transparent photovoltaics that often compromise efficiency or distort visible light, this technology preserves clarity and color rendering with a visible transmittance of 75.6% and a color rendering index of 93.8%. The technology employs a structure combining a distributed Bragg reflector (DBR) with bifacial silicon solar cells. The DBR selectively redirects invisible near-infrared light toward the solar cells while allowing most visible light to pass through, enabling energy conversion from wavelengths typically wasted in other systems. This design addresses the key challenge of balancing efficiency and usability in building-integrated photovoltaics (BIPV).