Reviewed by Lexie CornerMar 20 2025
Recent research, conducted in collaboration between KAUST and King Abdulaziz City for Science and Technology (KACST), demonstrates how nanomaterials can reduce carbon emissions from LED streetlights. The research team estimates that adopting this technology could reduce carbon dioxide emissions in the United States by over one million metric tons.
Image Credit: King Abdullah University of Science and Technology
The nanomaterial, known as nanoPE, enhances thermal radiation emission from the LED surface, effectively lowering its temperature. LEDs generate heat, which raises their temperature and poses a risk of damaging the electronics, ultimately shortening their lifespan. Notably, around 75 % of the input energy in LEDs is lost as heat.
LEDs are preferred light sources because of their superior efficiency and lifespan. But small enhancements can improve them even more, and that can make a big difference on sustainability because even small improvements have a big effect when used everywhere.
Qiaoqiang Gan, Study Leader and Professor, King Abdullah University of Science and Technology
He noted that lighting accounts for approximately 20 % of the world's annual electricity consumption and contributes to nearly 6 % of global greenhouse gas emissions.
Our design significantly improves LED cooling while maintaining high illumination efficiency, making it a promising solution for sustainable lighting in Saudi Arabia.
Dr. Hussam Qasem, General Manager, Future Energy Technologies Institute, King Abdulaziz City for Science and Technology
Traditional LED streetlights are designed to direct light toward the object being illuminated, typically pointing downward. However, they also trap thermal radiation within the LED, which increases heat buildup. In contrast, streetlights coated with nanoPE are positioned upside down, directing thermal radiation toward the sky while still effectively illuminating their target.
The inversion is necessary because nanoPE is engineered to allow infrared light—the primary contributor to thermal radiation—to pass through while reflecting visible light. The study found that over 80 % of the infrared light emitted by LED streetlights coated with nanoPE passes through and escapes toward the sky, while more than 95 % of the visible light is reflected back to the ground, effectively illuminating the area below.
NanoPE is derived from polyethylene, the world’s most widely produced plastic. To develop a nanoplastic that reflects short-wavelength visible light while allowing long-wavelength infrared light to pass through, scientists engineered pores as small as 30 nm—approximately 1,000 times thinner than a human hair—into the plastic. They also stretched and transformed it into a thinner sheet.
Contributors to this research include KAUST Professors Osman Bakr and Boon Ooi, Postdoctoral Researcher Saichao Dang, Master’s Student Hasan H. Almahfoudh, and KACST Assistant Professor Abdulrahman M. Alajlan.
Journal Reference:
Dang, S., et al. (2025). Sky cooling for LED streetlights. Light Science & Applications. doi.org/10.1038/s41377-024-01724-7.