Green streetlights after brief lighting faul

13.10.2025

Yesterday (12 October) evening at around 7 pm, a few of the streetlights on some of the streets in Berlin-Mitte suddenly started glowing green. Prior to that, the street lighting in several neighbourhoods had been out for around 20 minutes.

The reason for the lighting failure was an error in a lighting control database, which Stromnetz Berlin was able to rectify at short notice by switching over. There was no power outage in the affected neighbourhoods. The traffic lights were also supplied with power at all times. There were no further disruptions to the street lighting.

The green light was not a surprise contribution to the "Festival of Lights", but a completely normal phenomenon due to the type of street lighting. Some streetlights operate with what are called metal halide high-pressure discharge lamps. These light sources require a higher operating temperature in order to develop their full luminosity. During the "run-up phase" of around two minutes, the light sources emit a different colour spectrum, resulting in a bluish or greenish light. This effect is normally hardly noticed, as the "ramp-up phase" starts at dusk. However, this effect was observed as the result of the delayed switch-on last night.

Stromnetz Berlin operates the public lighting in the capital on behalf of the state of Berlin, which owns the lighting systems.