By 2017, the streets of New York will be bathed in a clear, white semiconductor glow, Mayor Mike Bloomberg recently announced. The city plans to replace 250,000 high-pressure sodium streetlights with LEDs. Bloomberg called the move a “no-brainer.”

New York’s streetlights currently produce a baleful orange glow by electrocuting vaporized sodium atoms. Sodium bulbs have been around since the 1930s and are commonly used in cities. But LEDs last longer (20 years) than sodium bulbs (6 years), tend to be more efficient, and give off cleaner, more illuminating light.

New York has already gone to LEDs on select streets in Manhattan, Brooklyn, and in Central Park. The $76.5 million project will replace streetlights in waves of 80,000 and, and if projections bear out, save $14 million in maintenance and energy annually.

New York’s transportation commissioner, Janette Sadik-Khan, said in a press conference, “These 250,000 new lights will redefine our roadways and neighborhoods, bringing in clearer, whiter and more attractive lights to our 6,000 miles of streets and 12,000 miles of sidewalks.”

Bloomberg and company say New York City’s LED project is the world’s biggest—but it’s hardly the first.Los Angeles, for example, recently finished replacing just over 141,000 streetlights with LEDs. The city says savings have so far outstripped projections (63% cost reduction compared to the forecast 40%), and light pollution is much reduced because LEDs can be better directed, preventing unintended light leakage.

Sources:

1. Singularityhub:
   New York's LED upgrade.