1766 First oil-powered street lamps installed in Paris.
1807 Gas lamps introduced to London.
1932 Introduction of low pressure sodium (SOX) lamp characterized by its dull, monochromatic yellow light. Although highly efficient, delivering 160 lm/W, the arc tube is very long.
1933 Introduction of high-pressure, mercury-vapor (MBF/U) lamps – the first high-intensity discharge (HID) luminaires. The discharge mainly produces UV with a small amount of pale blue visible light. Very inefficient by modern standards, producing around 34-45 lm/W.
1965 Introduction of the metal halide (MH) lamp – a derivation of the MBF/U lamp. It has a crisp white light with excellent color rendering, but has poor lumen depreciation.
1968 First UK installation of high-pressure sodium (SON) lamps in Huddersfield. There were retrofitted into hundreds of thousands of the MBF/U lamp holders.
2011 UK´s first light-emitting diode (LED) street lights introduced in Somerset.
The information was published at the CIBSE Journal September 2014, www.cibse.org.