CityCyclingEdinburgh Forum » Debate!
Now something else to worry about…
(11 posts)-
Posted 2 years ago #
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I believe there's still some scientific dispute over the "blue light can suppress sleep hormones" in people angle, but the impact on insects and some other critters seems robust enough, and honestly even if there wasn't a negative impact biologically speaking...I miss the sodium yellow-orange colour at night.
Switching to LEDs is a good thing for energy consumption, but I don't understand why they also had to increase the colour temperature, the entire city has the feel of a motorway service station forecourt now.
Posted 2 years ago # -
but I don't understand why they also had to increase the colour temperature
Cost. Cool blue lights produce more lumens per watt than warmer ones and at middling outputs cool white is cheaper than warm white.
Assuming the council have a spec to deliver a certain lux on the ground upfront costs of the cool white is lower per unit to deliver that and ongoing running costs are lower.
Posted 2 years ago # -
I'm generally sceptical of the "media want us scared line" but I'd like to compare the research paper that article is based on and really see how much of a scare story has been drummed up from the story vs how negative the actual paper is.
Posted 2 years ago # -
Cost.
Yes. We make white LEDs by using a yellow phosphorus filter on a blue LED. The more filter, the whiter the light, but the more filter, the more powerful the base LED needs to be.
Just as I have found with my IKEA multicoloured selectable LED strip in my kitchen, some hues give quite incredibly poor/odd/intruiging colour rendition, in which pink looks purple, or red looks brown, we could have put yellow LEDs in our street lights, but they might've been even worse than sodium, given the natural assumption that whiter is better. No light at all is better if we ever cared about living things that aren't humans.
Posted 2 years ago # -
The warm white LED strips in my shed are terrible in photographs but quite nice on the eye but they were just a cheap experiment and are starting to wear out now, should probably replace them with good CRI rated ones.
Posted 2 years ago # -
I feel a bit sad when I see a robin singing under a streetlight at midnight and wonder what wider effect it has.
Street lighting is an extremely emotive topic pulling in arguments about personal and road safety. Can be hard not to fall into the 'natural cycle paths' trap where paving a 2m wide path (or felling some trees for one...) in a 'natural area' can generate infinitely more anger than a brand new four lane road nearby - ie. screw the safety of the vulnerable to satisfy some potentially illusory nature benefit while ignoring the impact of eg. all the headlights on the Bypass.
Perhaps the most positive way of responding to LED lighting would be asking what innovations we could get out of them? Presumably they don't suffer too much from 'cold start', are more adjustable and more amendable to central control? So could we think about dimming them or turning them off in some areas in the quietest hours etc? Would it be absurd to consider motion sensors for some?
Presumably they're more flexible in terms of how and where they can be positioned too - would eg. lower, dimmer but more frequent lights be better in some specific areas? (Don't look at the Union Canal for tips!)
Posted 2 years ago # -
I do sometimes wonder about sensors for street lights in side streets or paths with little foot or car traffic.
Upsides are clear- even lower power consumption, less light pollution, benefits to wildlife.
Downsides, cost - unit, installation maintenance. Personal Safety? Would you walk down a dark street and trust it would light up for you? Is a street light coming on outside you bedroom through the night more annoying that just being on? Dunno.
Posted 2 years ago # -
I think if the lights were in view of residences they'd have to come on very gradually so as not to be an annoyance, which would probably mean you'd need to detect a user very far away, which would mean it would only be suitable, really, for very quiet streets. And cynically, all the sensors would break after a year anyway and leave the lights stuck on or off. But interesting to think about.
Posted 2 years ago # -
The new lights are more directional (so bright pools of light and deep shadows). There's very little light bleed from the one outside my flat into my flat via the window whereas there was from the sodium light it replaced.
It would be interesting to see if this makes a difference to the effects on insects.
Posted 2 years ago # -
“
Prof Gen Matsuzaki, an industrial design researcher at the Chiba Institute of Technology in Japan whose insights on the “rotary control of columnar knobs” won the engineering prize, said he had been recognised for “focusing on a problem that no one cares about”.
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Posted 2 years ago #
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