Multilayer Coatings to Improve the Efficiency and Life of High Intensity Discharge Lamps

High Intensity Discharge (HID) lamps ¿ which are used extensively for large area lighting, such as parking lots, streets, and warehouses ¿ increasingly are being used for general lighting in stores and homes. HID lighting currently accounts for 26 percent of the lighting energy used in the United States, and this number is increasing. Based on this large usage, small efficiency improvements to existing technologies have the potential to yield significant national energy savings. This project will develop an economically viable, robust, multilayered coating that will improve the efficacy of HID lamps by 20%, increase their life by 20%, increase the color rendering index, and produce a more desirable correlated color temperature. The multilayer coating will be designed to reflect ultraviolet and infrared radiation back into the HID lamp while passing visible wavelengths. In Phase I, Finite Element Analysis (FEA) computer simulations will be used to design the lamp and optimize its performance, based on experimental measurements of coated HID lamps. The coatings will be applied using a robust inexpensive process that produces excellent adhesion and coating properties. Commercial Applications and other Benefits as described by the awardee: HID lighting accounts for about 200 TWh out of approximately 765 TWh per year of the energy consumed by lighting in the U.S. A 20% increase in the efficacy of HID lamps will result in a savings of 40 TWh per year, which would help reduce U.S. dependence on foreign energy sources.