Scientists from King Abdullah University of Science and Technology (KAUST) and King Abdulaziz City of Science and Technology (KACST) in Saudi Arabia have collaborated to develop an innovative nano-coating technology that promises to significantly improve the energy efficiency of LED streetlights and reduce carbon emissions. The study, published in the journal *Light: Science & Applications*, indicates that its application in the United States alone could potentially reduce carbon dioxide emissions by more than 1.3 million metric tons annually.
Lighting is a major source of energy consumption, accounting for approximately 20% of global electricity consumption and contributing nearly 6% to greenhouse gas emissions. Street lighting alone accounts for 1-3% of global electricity demand, placing a burden on municipalities. While LEDs are highly efficient light sources, about 75% of their energy is lost as heat during operation. High temperatures not only reduce luminous efficiency but also shorten the lifespan of luminaires. Therefore, effective thermal management is crucial for improving LED performance.
The key material developed by the research team is a nanomaterial called nanoPE (nanoporous polyethylene). This material is made from common polyethylene, and through a special process, it produces pores only 30 nanometers in size (about one-thousandth the thickness of a human hair). Its unique feature is that it allows infrared light (the main source of heat radiation) to pass through efficiently (more than 80%), while reflecting visible light efficiently (more than 95%).
To maximize the benefits of nanoPE, researchers proposed installing LED streetlights coated with this material "upside down." In this way, the heat energy (infrared light) generated by the lamp can easily penetrate the nanoPE and radiate upwards to dissipate into the sky, while the visible light required for downward illumination is effectively reflected to the ground. This is completely different from the traditional LED design that traps heat energy inside and has the lamp head facing downwards.
Experimental results confirmed that applying the nanoPE coating reduced LED temperature by 7.8°C in the laboratory environment and by 4.4°C in outdoor measurements, resulting in efficiency improvements of approximately 5% and 4%, respectively. Professor Qiaoqiang Gan, the research leader, emphasized that even small efficiency improvements can have a significant impact on sustainable development in large-scale applications. Co-author Dr. Hussam Qasem also believes that this design significantly improves heat dissipation and maintains high lighting efficiency, making it a potential solution for sustainable lighting.
