Monday, March 27, 2017

Unnecessary light on a field

My colleague Andrej Mohar recently shared this image with me:

This work by Andrej Mohar is licensed under a
Creative Commons Attribution-NonCommercial 4.0 International License.

The photo shows the light spread from single 20W 4000K LED that was recently installed. The lamp itself is designed to have no direct upward emissions (which is good), but much of the light is shining into an area which doesn't need to be illuminated (which is very bad), and even the area that is intended to be illuminated happens to be a region of very low traffic. It is so out of character for the region it is installed in, that at least two people in the nearby village have already officially complained about it.

In these sorts of cases, it doesn't matter how efficiently the lamp converts electricity into visible light. The light itself is unnecessary, so it is an inefficient use of electrical resources.

Thursday, March 23, 2017

Milky Way and Skyglow from the Fürstein

Martin Würzer recently sent me this amazing panorama showing the skyglow over Switzerland:

Fürstein 360 Panorama v2 by Martin Würzer is available
under a CC BY-NC-SA license

He took the photo on New Year's Day 2017 around 8 pm, from the peak of the Fürstein. The light from Milan is visible at the far left. It's an amazing photo, and you can see it in full resolution by clicking on the name of the photo in the caption above.

Martin also sent me this image, which shows where at least some of that waste light is coming from:

Illuminated facade by Martin Würzer is available under a
Creative Commons Attribution 4.0 International License..

That photo was taken shortly before 3 am! There is some good news associated with this photo, however. By having a polite discussion with the architect and the firm that owns the building, Martin convinced them to remove the light that illuminates the facade, and to also improve the other lamps so that they produce less skyglow. Great job Martin!

For Swiss and other German speaking readers, Martin provided two useful references:

Friday, March 17, 2017

Spotlight on air

My colleague Martin Morgan-Taylor sent me this photo of a newly installed floodlight that doesn't actually seem to be pointed at a building facade, or really anything in particular at all.

Misdirected floodlamp by Martin Morgan-Taylor is licensed
under a Creative Commons Attribution 4.0 International License.

There are some flower beds nearby, but if they are meant to illuminate the flowers they are pointed in the wrong direction! (Incidentally, surely only someone who hates fireflies, glowworms, and other nocturnal insects would do such a thing, no?)

The design is such that the lamps will produce a lot of glare, making vision in the area worse. At the same time, about half of the light emitted is going to go up into the sky, producing skyglow.

One final, but really important point: It does not matter how "efficient" this lamp is in lumens/Watt. Almost none of the light produced by this lamp will assist humans with a visual task, so the true efficiency in the commonsense meaning of the word is near zero.

Wednesday, March 8, 2017

Tweetstorm about light pollution and citizen science