Gas street lights converted to LED
A German company has developed an energy-saving retrofit for gas street lights. It claimed it can convert them to LED without altering either the antique look or the light quality.
The solid-state replacement for gas mantles was designed by Berlin-based Braun Schaltgeräte & Service, Europe's largest manufacturer of gas streetlights, with assistance from LED solutions provider Future Lighting Solutions. The first eight LED models were recently installed on Berlin's Alexanderplatz public square, cutting power consumption by more than 90 per cent.
The drop-in modules replicate the golden glow of gas lighting with 48 warm-white LEDs, delivering 2000 lumens, said company president André Braun.
"Gas lighting has a colour temperature of less than 2900K. This produces a distinctive glow that is so tied into the character of cities like Berlin that the public won't accept anything else, and that glow cannot be reproduced with cooler light sources like mercury vapour and sodium vapour," he added. "The only way to achieve a comparable colour tone in a street lamp is with warm-white LEDs."
The replacement lamps use LEDs from Philips Lumileds and should last more than 50,000 hours, compared to 4,000 for gas and an average 16,000 for standard electrical lighting. They will also improve colour rendering, giving better visibility of street signs and other objects, Future Lighting said.
According to Braun, Europe still has more than 100,000 gas lamps, including historic street lighting in cities such as Berlin, Prague and Warsaw. As well as using optical modelling to copy the colour of gas light, the replacement modules were designed to use the same base mounting as the gas mantles.
"From an energy point of view, gas lamps have too many negatives. They produce more heat than light - just 2 lumens per watt compared to 50 lumens per watt for LEDs. It is just a matter of time before they will be converted to a more efficient light source," Braun said.