The nights are drawing in and the public lighting on our streets and roads is taking over earlier and earlier every day. We’ve put together an overview of good practices.
The more light there is at night, the safer the environment. This widely held belief has, however, been undermined by various studies. “Night-time lighting gained momentum during the first industrial revolution for the purposes of improving workers’ performance at night without measuring its impact on human health”, explains Daniel Gliedner, lighting advisor to the Our Natural Park. “You have to light what you need, when you need it and where you need it”, he continues.
At a time when EU countries are calling on their populations to achieve at least 15% energy savings this winter, the need for public lighting is an issue everyone is talking about. “Where are we going to find these 15% savings— by turning off the heating in schools or by cutting back on public lighting? The answer seems obvious to me”, says our expert.
An tailored solution
Most public lighting systems these days are turned on and off according to sunset and sunrise times while at the same time producing the same level of light intensity throughout the night. However, not all places require the same level of illumination, depending on the space and the time. A road doesn’t need to be lit on full power when no-one is using it, for example. Smart lighting allows the light intensity to be adjusted based on need, but more importantly it allows the light to be activated only when the space it is lighting is occupied.
“We have run a trial in a rural environment by installing on-demand lighting that is activated only when a pedestrian, cyclist or vehicle is passing by, and the result speaks for itself, with lighting usage plummeting from 4,200 hours to 365 hours per year. This means that the lighting was only actually needed for an average of one hour per night”, Daniel Gliedner concludes.

Caption: The street lighting in Nachtmanderscheid, near Vianden, has been entirely overhauled by replacing the bulbs.
Did you know?
- Illumination is expressed in lux and measures the amount of light that actually reaches a lit surface (e.g. a floor or work surface), regardless of how much light the light theoretically emits.
- The standard level of illumination in a residential area with a 30km/h speed limit in Luxembourg is 5 lux. This might even be reduced to 2 lux in the middle of the night, in order not only to make savings but also to reduce light pollution.
- The iris of the human eye is capable of adapting to almost any situation and can see between 0.03 lux (under the light of a new moon) and 120,000 lux (on a bright sunny day).
AC is there to advise you and help you take care of yourself. Do not hesitate to contact us if you have any questions at acl@acl.lu or on +352 450045-1.