What is Streetlight?
[[File:Na-light.jpg|thumb|Streetlight]] [[File:Lyktstolpar - Gatubelysning - Ystad-2021.jpg|thumb|Streetlights in [[Ystad]] 2021.]] A '''streetlight''' is a [[light bulb]] on a pole used for lighting streets. Streets can be lit for safety or visibility reasons, so people can see where they are going at night. There are five main types of streetlight: * An [[LED lamp|LED]] streetlight gives a white light, and the lantern is usually short and thin because each LED is small. * A [[mercury-vapor lamp|mercury vapor]] streetlight gives a green-white light, and the lantern is usually short. * A [[metal-halide lamp|metal halide]] streetlight gives a white light, and the lantern is usually short. * A [[sodium vapor lamp|low pressure sodium]] streetlight gives a yellow light. The lantern is usually long, because low-pressure sodium lamps are shaped like a tube. * A [[sodium vapor lamp|high pressure sodium]] streetlight gives an orange-white light, and the lantern is usually short. Many countries are replacing, mercury vapor, metal halide and sodium vapor streetlights with LED streetlights, because LED streetlights are cheaper to run. However, some models integrate the LED panel in a way that the whole lantern must be replaced, if the panel burns out or becomes faulty. ==Related pages== *[[Incandescent bulb]], rarely used in streetlights *[[Fluorescent bulb]] {{science-stub}} [[Category:Light sources]]