Light-emitting diode all the potential mechanisms that can induce failures in LEDs. The most common symptom of LED (and diode laser) failure is the gradual lowering of light output and loss of efficiency. Sudden failures, although rare, can also occur. Early red LEDs were notable for their short service life. With the development of high-power LEDs, the devices are subjected to higher junction temperatures and higher current densities than traditional devices. This causes stress on the material and may cause early light-output degradation. To quantify useful lifetime in a standardized manner, some suggest using L70 or L50, which are runtimes (typically in
LED street light 10 largest metropolitan areas in the U.S. could reduce annual carbon dioxide emissions by 1.2 million metric tons, the equivalent of taking 212,000 vehicles off the road, and save at least $90 million annually in electricity costs. As LED lighting fixtures normally produce less illumination it is important to use a well-distributed illumination pattern in order to produce the same illumination as higher-lumen conventional fixtures. For example, different LEDs in one fixture can target different points on the street. LED street light An LED street light or road light is an integrated light-emitting diode (LED) light fixture that is used