Friday, February 10, 2017

Excellent LED streetlamps

This December I visited my family in the town of Wetaskiwin, Alberta, Canada. The first evening that I drove into town I immediately noticed that the city had switched from Sodium lamps to LED, and I was very pleasantly surprised to see that the LEDs they chose shine the light very carefully. To see what I mean, take a look at the photo below:

Good streetlamps are invisible by Christopher Kyba is licensed
under a Creative Commons Attribution 4.0 International License.


You almost can't see the streetlights at all, because they shine light on the street, rather than into your eyes. On most lit streets around the world, you can see the lamps from kilometers away, because they shine a portion of their light directly into drivers eyes. These photos from Wetaskiwin show how unnecessary that glare is.

That being said, the lamps aren't entirely glare free, particularly for pedestrians (see below). However, in terms of (white) LED streetlamps deployed in an urban setting, these are the best I have yet seen.

Close-up glare by Christopher Kyba is licensed under
a Creative Commons Attribution 4.0 International License.

When you have a good light distribution, then you can light the streets and sidewalks, and avoid shining light into peoples bedroom or living room windows. Take a look at the photo below. One house is lit with Christmas lights, but did you notice the one to the left? The street and sidewalk for that house are lit, but the facade of the house is not.

Orion over LEDs by Christopher Kyba is licensed under a Creative Commons Attribution 4.0 International License.


Camera photos don't accurately represent what our eyes really see (which is why I often show photos using two different exposures). I didn't do that (or HDR) in this case, because I hadn't planned on taking photos and wasn't dressed for the cold. But you can take my word on it: as a pedestrian, you have no problem to see the house on the left, the camera doesn't show it because the exposure was set to highlight the lit snow.

Thanks to Rod Mc Connell and Noel Smith, I was able to get some information about the lamps themselves. They are the "RoadFocus" series manufactured by Philips lighting.

The only negative side with the current lamps is that they are 4000 Kelvin, which produces considerably more skyglow than a lamp with a lower color temperature (warmer, less blue light). But I hear the city is planning on switching to 3000K in the future, and is also thinking about reducing the wattage so that the lights don't shine overly brightly.

So hats off to the city of Wetaskiwin for choosing driver friendly low-glare lights!

Here is a copy of the original photo, in case you'd prefer it without the text.


Good streetlamps are invisible by Christopher Kyba is licensed
under a Creative Commons Attribution 4.0 International License.

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