Brit smart streetlight bods Telensa named 'global market leader' British IoT streetlight firm Telensa has been named as a global market leader in, er, LED streetlights with networked cameras on them. Telensa is one of the few IoT-focused firms that has made serious inroads into the smart cities market, with a million IoT streetlights deployed around the world. Its PLANet streetlight system …
"Your correspondent's experience of LED streetlights is that the lamps are a straight swap for sodium lamps on existing lighting poles, while the blue light they generate is finely tuned so as to cast inky black shadows over anything you actually want to look at while destroying your night vision."
This. 'kin idjits, the lot of them. I miss stars.
The future is bright because the future is no longer orange. :/
This. 'kin idjits, the lot of them. I miss stars.
Actually, LED units are a lot better for sky watchers. You wouldn't try and stargaze next to any streetlamp, but the LED luminaire design is at least much better at stopping upward light spill. The traditional nasty dark orange 30W low pressure sodium units use designs unevolved from putting a candle in a pie dish, with the result that a third of the light goes upwards. That's a big part of the orange cloud glow above towns, rather than ground reflection.
In terms of simple efficiency, LED streetlights don't offer much better luminous efficiency than a good gas discharge lamp, the reason you'd install them is much longer life, better controllability, and modest energy savings of about 8W on a single column on a residential road, and most of that saving is from the fact that you don't have the upward and sideways spill.
It is a personal choice, but I think that the split spectrum light from an LED luminaire is much better than the horrible single wavelength from a crude LP sodium lamp. YMMV.
@Ledswinger
"Actually, LED units are a lot better for sky watchers."
Is that an off the cuff remark based on your own opinion or is this a result of investigation and evidence?
The broadband wavelengths that most LED lights output directly affects nightvision. At least with the sodium lights, or at least those narrower wavelengths, you had a hope of filtering those out as it was quite narrow, plus it didn't affect your vision as much as the LED ones do.
I get the effiency angle. What I was really referring to was the lack of 'joined up thinking' regarding the entire usage and implementation.
This post has been deleted by its author
Is that an off the cuff remark based on your own opinion or is this a result of investigation and evidence?
That based on working for a company that designs streetlighting installations, erects and manages these things (not to mention the day to day experience because our large HQ and surrounding estate has had LED streetlighting for a decade now). But you stay up there on your high horse.
Since you think there should be more "joined up thinking", what exactly would you like joined up?
LEDs in smart lamp heads cannot have a bank of narrow wavelength emitters mimicking the old sodium lamps?
Interestingly one published survey where old sodium lights were replaced with new, 6000°K, LED lights gave the following result:
40% reported that the new lights were better, 44% reported that the new lights were neither better nor worse, and 16% reported that the new lights were worse.
Our local council cited the report in defence of spending £m with one of the councillor's cousin's company, stating that more than twice as many people found LED lighting to be an improvement than those who had a problem with it, and therefore majority rule, it was a good investment even without considering the long length of time the electricity savings would take to repay the outlay.
A neighbouring council cited exactly the same report when asked why they hadn't take the initiative that our council had, claiming that the majority of people found LED lights made no difference to them, and that therefore they couldn't justify the capital expense required currently for the energy saving offered which was cost neutral at around the 20 year mark, but that they would reconsider if costs fell or if other factors arose which required wide scale lighting renewal outside of the normal cycle.
Another neighbouring council, again in response to a question about not taking the initiative to update lighting, used the same report to say that 60% of people found that LED lights made either no difference or were worse than the existing lighting, and therefore it would never be an initiative they would take unless forced by legislation, as well as the council being suspicious over the actual savings estimated.
TL;DR version, opinion is divided on the matter.
"That based on working for a company that designs streetlighting installations, erects and manages these things (not to mention the day to day experience because our large HQ and surrounding estate has had LED streetlighting for a decade now). But you stay up there on your high horse.
Since you think there should be more "joined up thinking", what exactly would you like joined up?"
Ok - not a high horse. It was a geniune question - you made a definitive statement which I wanted qualified. Surely this is a reasonable thing to do?
So take the first one:
"That based on working for a company that designs streetlighting installations"
Right - which are the very things that certain groups of people, myself included, are not happy with. Taking aside the astronomy aspect for a moment as I think you will struggle to find much agreement with astronomers who have the sodium replaced with broadband lighting, all the installs that have been both my own address and my parents address, two different County areas btw, result in considerable increased light pollution within the home. Wheras before the sodium wavelengths were soft, this is now harsh and, to my mind, irritating on a nightly basis.
With this in mind - what were the design goals of the lights you design?
To state that X is the case, that must mean you have evidence of X in order for it to be true.
"Since you think there should be more "joined up thinking", what exactly would you like joined up?"
From my persepective, the use of these lights - what is their primary purpose? To provide light for, as someone said, seeing more detail of your assailant/suspect? Or or to provide a safety feature to allow enough light to see by without the aid of a torch. Maybe shrouding so it doesn't send needless light into the upper bedrooms of nearby housing. Maybe altering the wavelength so it doesn't destroy night vision. This was just off the cuff, admittedly.
From my persepective, the use of these lights - what is their primary purpose?
From the point of view of the installer, the purpose is to light the highways to the relevant British Standards and other relevant regulations. For the commissioning body (usually a local authority) the fundamental purpose is public safety. That's why, for example, main road junctions have much better lighting than straight bits of road or lower traffic routes.
There have been many attempts to turn off, remove or turn down streetlighting, but the vast majority of these have met with public objection - if you can turn them off when nobody is around, nobody complains, but if it is YOUR daughter trying to walk home at 02:00 in absolute pitch black because some eco-twat has turned the lights off, you might be unhappy. In some instances turning the lights off to save energy has been reported as a major contributor to fatal road accidents.
There are relevant standards published by the Institute of Lighting Engineers (available on the web via quick search) for ensuring that stray light doesn't cause a nuisance ("Light trespass"), and there are measures that can be taken, but you'd have to ask the local authority since they are the people who commission the services (or provide them themselves). Since the recommendations for light trespass are in lux, you may need to buy a £10 light meter to be sure of your case.
"There have been many attempts to turn off, remove or turn down streetlighting, but the vast majority of these have met with public objection - if you can turn them off when nobody is around, nobody complains, but if it is YOUR daughter trying to walk home at 02:00 in absolute pitch black because some eco-twat has turned the lights off, you might be unhappy."
What would be the feasibility of control by PIR? LEDs don't take time to come to full brightness like sodium lights. There could actually be a use for smart features - if a pedestrian is heading towards the next light in the sequence it could be turned on remotely to light the area ahead of them. The downside would be the distraction caused to residents by lights flicking on and off but if the light spill is controlled this would be minimised - unlike the average security light.
I have a feeling that I have read about this being implemented somewhere but it caused issues with people going in different directions causing disco light shows up and down the street.
Not sure though. I might be making it up.
One this that is touched on earlier up the thread is about spill. If you drive the A40 at night between Greenford and Denham you will notice that the lighting around Northolt Airfield is significantly better to drive through than on any other stretch (in my opinion anyway). The lumiers are on much shorter poles and and are 'barn-doored' somehow to prevent sideways and upward spillage to avoid interfering with pilots who are landing at the field.
I often wondered why all street lights weren't like that.
FWIW, we had LED lamps replacing the Sodium lamps in our street about a year ago. The street is much brighter and spillage into our bedrooms is much reduced as a consequence. (Light spillage!)
Quite right. As a visual physiologist, I am somewhat interested in this issue of street lighting. I personally find the new LED lamps to be a very poor replacement for sodium-vapour lamp night-time lighting.
1) The multiple sources create peculiar multi-edged shadows which trigger the high-spatial frequency motion pathways into firing erroneously, thus creating a feeling of uneasiness.
2) The high content of short wavelength light bleaches the rods, which can take between 4 minutes and 4 hours to recover. It is this effect which causes the shadows to look deeper than they are.
I've taken my measuring gear out on the main road near us. Under the old lighting, you could see many metres into the dark parkland to the side of the road, with the new lighting, it's under 2 metres. Shocking.
Is it not posible to design these heads so that they operate in a meso-scopic range, where you can have both colour renditioning AND low-level sensitivity?
"I've taken my measuring gear out on the main road near us. Under the old lighting, you could see many metres into the dark parkland to the side of the road, with the new lighting, it's under 2 metres. Shocking."
That is no test at all
That is likely to simply down to the fact the lighting is more directional and have bugger all to do with the light colour? Otherwise your LED headlights would be utterly useless if the effective range is 2m
Sorry? A >£15,000 Spectrascan PR650 spectroradiometer with an integrating cosine receiver dome is NOT a test at all?
I'm afraid I got interrupted whilst I was typing that earlier reply. I have done several things.
One was to take spectral and illumination readings using the PR650, which showed there was a sufficiently high level of light around the 450nm mark to bleach rods completely. This compares to the ~590nm of the low-pressure sodium lights that were previously fitted, though I didn't cart over £15k worth of equipment 20 miles on the train to make readings of street lamps at the time the LPS lamps were still operating - it didn't seem worth it. At 590nm, the absorption of photons by human rhodopsin is practically nil.
I brought the expensive gear out after I made a first set of measurements where I got someone to walk into the park outside the flat holding the end of a groundsman's measuring tape until I could no longer make out their outline against the grass whilst viewing them from the path on the far side of the road. I then did the same in a different park about a mile away where the streetlights were still the low pressure sodium type. Under the LED light, it was two metres, under LPS lighting, it was forty metres. Not a controlled experiment, I know, but what the heck.
I've taken my measuring gear out on the main road near us. Under the old lighting, you could see many metres into the dark parkland to the side of the road, with the new lighting, it's under 2 metres. Shocking.
I can't speak for what's gone in and what came out, but as a rule the replaced lights will have been sodium vapour lights, and most of these had appalling "spill" in all directions. Which was great if you wanted to illuminate the dark parkland, but as a rule most highways lighting is intended (yeah!) to light the highway and the pavement with the minimum of spill. So only lighting a couple of metres behind the column is probably absolutely intentional. In situations where you need all round illumination you'd use a larger luminaire and/or different design.
As for whether you could design better lighting, yes, within limits - you know what LEDs are like for light output and light quality. It can be pretty good, done well, but for streetlighting the key demand is long life and reliability (like a design standard of 100,000 hours MTBF/80% rated light output), so there's things you can do with shorter life room lighting that represents a more costly challenge with streetlights. Realistically LED streetlighting quality will improve, but as a generational thing.
Round my neck of the woods (but not a job by my company) the county council have re-lit all the A road junctions with high power LEDs on tall columns, and the improvement in visibility over sodium vapour is unbelievable. Having said that, the latest SON gas discharge lamps give LED a run for its money - buy the right bulbs and the life is up to 80,000 hours (claimed), the efficiency is comparable, and you have a much less harsh quality of light than LED. But they don't have the "eco feel good" appeal of LED for councillors, and they still require a new luminaire and new electronic control gear compared to an old sodium lamp.
Ah, you see we are approaching this from different directions. It's a bit like the ITIL thing on another thread... you're focussed on what light reflects off what bits of the environment and where about those bits of environment are relative to the lamp. I'm focussed on (an I believe the article's author is also referring to) the HUMAN aspect of lighting. I'm not saying that I couldn't see my friend standing 3 metres inside the park because the new LED lamp wasn't shining on her, I'm saying that I couldn't see my friend standing 3 metres inside the park because all the blue light between myself and her had screwed up my scotopic vision and buggered the dynamic range of my eyes so that the tiny amounts of light scattering and bouncing around the environment and reflecting back off her are pretty much wasted when they get into my retina.
The practical upshot of all of this is that it's all well and good saying "Well, for these 4km of M-class road between points A and B we meet x, y and z standard of illumination", when Joe Bloggs is driving along in his car from A to B but then leaves the M road and proceeds along another road from point B to point C which meets some other version of lighting standard x, some 300m later, where he turns off into an unlit unclassified road (which doesn't meet any illumination standard) heading towards point D and his bed and flattens Jane Doe because he didn't see her under the half-moonlight because his vision hadn't yet adapted back to a scotopic or mesopic range. The answer is not to then light all roads to standard x, y and z, but to go back and revisit what the effect is of standard x, y and z when humans move from one condition to another. If there's a fault, it lies in the standards and those who apply them unswervingly forgetting that there may be confounding factors at work.
Firstly - please be aware that I am not trying to provoke an argument for arguments sake (you should see my posts on Apple articles for that :) )- this is something that has bothered me for a long time and actually - this is the first time I have ever been in realtively direct contact with someone who deals with this for a living.
My point is that the joined up approach was more to do with how the 'consumer' of that lighting source is really brought into play, simply over the use of broadband over narrowband lighting. But I also am aware the the criteria for a lot of these standards is set from a specific measure - which you have confirmed. Arguably, they could have used a narrowband lighting source, in a similar area of the spectrum, and gotten the same results regarding spill etc, but with the better ability for this area of the spectrum to both travel and not affect night vision.
I have to say, that if my daughter was walking home at 02:00 in the morning, I would be effing furious with said daughter for walking home at said time on her own. But there is an interesting point to be made here: Does lighting actually stop an opportunist if he saw her at that time by herself, street lighting or not? That is a hard thing to prove. Same to be said for fatal accidents - if there is an accident at that time - there are arguably other factors at play - which will affect statistics, if it is indeed those that are being used to make these cases.
But I can appreciate where you are coming from, I just don't agree with the standards that continue to use broadband lighting and my own experience means that I hates it. Is my opinion any less valid because I am a 'consumer' and not a manufacturer? Not to me. But obviously, that isn't what makes the lighting companies money when the client is a governmental body.
"There are relevant standards published by the Institute of Lighting Engineers (available on the web via quick search) for ensuring that stray light doesn't cause a nuisance ("Light trespass"), and there are measures that can be taken, but you'd have to ask the local authority since they are the people who commission the services (or provide them themselves). Since the recommendations for light trespass are in lux, you may need to buy a £10 light meter to be sure of your case."
THis is really useful to know, and I appreciate that information. I will be using that!
Light reflected off person in sodum-light-illuminated area; minimal.
Light-reflected-off-person in LED illuminated area = much more.
A personal observation of course...but I have noted that road workers at night are MUCH easier to see in the LED illuminated areas, the Hi-Viz is much more visible. Translate that to kids walking along a road.
The lighting is being adapted in my town (Bedford) as a rapid-rollout..on the same lighting poles as the Sodium lights they are replacing.
a) Street lights with light sensors on top automatically come on in the middle of the day, generally obviating need for remote control. Remote control is only required for councils more concerned with saving money at 3am than safety of pedestrians.
b) Remote control over the mains is ancient and replaced time switches very long ago. Signalling rate is very low, so reliable.
How long till these are hacked?
There are huge number of daft luminare [sp?] designs out there being used by councils, including uplighters with ineffective reflector hats. Some go more for style than function.
Many are too bright on the pole to look at, whatever the lumens sprayed on the ground are, thus worse for night vision. Bad design of luminare.
Pretty much every install I've seen involves a pole swap as well.
May be just coincidence that the poles are nearing end of life anyway and are being upgraded as they role out.
Also our are pretty white and mean when you are trying to describe, say a car looking dodgy, you can say "It's a dark metallic green one" instead of "it's dark coloured".
As for not seeing the stars, it's only when you go to a dark skies area, such as the Elan Valley, you realise how rubbish your view is, regardless of orange or white.
"May be just coincidence that the poles are nearing end of life anyway and are being upgraded as they role out."
That seems to be generally the case in the 4 or so local authorities in my immediate area. The costs of replacing just the top stem now and still having to replace the pole in 5-10 years is not as economic as installing the LED lamps by default as part of the normal pole replacement/upgrading process as they EOL
Also, for other comments on seeing the sky. Since we got the new lamps down our street, I can actually skywatch from the attic window now, being above the height of the street lamps and very little upwards glow compared to the orange sodium lamps. Still not as good as going out to the sticks, or the dark skies parts of Northumberland, but far, far better than previously.
Around our way not only did the new LED lights involve a pole swap, but they also removed one in every 4 poles too, so there are now great sections of what now looks like absolute darkness compared to the new bright lights.
Ironically 3 out of the 4 remaining lights shine in to our back garden, making it impossible to see the stars, unless you hide behind the shed one the one spot they don't reach, and then you can only see directly above you.
Ours seem to be particularly badly designed to spill so much light away from the road. At my parents the new LED ones there are so tightly targeted that while the road is well illuminated the front of the houses are now in darkness, you can hardly see them on the other side of the road. Of course my parents are now worried this will allow criminals free reign to creep around.
So a bloody bad idea all round.
Any 'ticket' issued using data from these 'cameras' will be IMHO invalid because the cameras are not properly calibrated and such calibration is needed at regular periods.
The cameras are also not in an approved housing with a Yellow colour and this not readily visible by the road user. Also because the housing is not approved the cameras could be tampered with by the locals which would be sure to happen once tickets were being issued.
Lots of farmers in Suffolk have lots of machinery easily capable of getting someone up close and personal to the camera so that it could be 'adjusted'(cough cough)
Then the local council would want to charge PLOD for the data.
Then the data network is not secure so data protection issues would be another problem.
I'm sure that PLOD would love to get their hands on all this lovely data and issue tickets galore
@AC " i don't understand why people are so pissed off about the law being enforced ?"
I suspect some people think they should just be allowed to drive at whatever speed they want "because they're good drivers" - or 'dickheads' as they're also known.
But others object to the black-and-white nature of speed limits. Yes, a 20 limit past a village school on a narrow road at 8.45 on a Tuesday morning in January seems sensible, and few would dispute it. But if that same 20 limit is applied 24/7 it's silly - the kids are the reason for the limit, and there's no need for that same limit at 10pm on a Sunday in August.
Similarly fixed limits do not take any account of road conditions. They simply say there are no possible circumstances when doing more than 30/40/50/60/70 is safe. 30 through a built-up area when there are a lot of pedestrians around and it's dusk and raining is actually probably a very bad idea, and a 'good' driver will have slowed down to well below 30. But if they're doing 40 through the same area on a clear dry Sunday evening when visibility is good and there are no pedestrians etc then they're likely to meet a bored speed camera van looking to up their statistics.
Trying to do a legal 70 (OK, it's probably 'dangerous driving') on the M6 past Bristol at 5pm on a Friday is probably a short cut to the graveyard, for you and several other people. Doing 90 on the M6 past Shap on a quiet dry summer evening with cars about a mile apart is probably not appreciably increasing the risk of an accident.
Really, by now we should be able to have a network of speed limit signs that can dynamically alter (up and down) to reflect weather, traffic volume, road conditions, time of day etc. Sadly even if the technology could be developed the legislative system couldn't handle it, as it likes simple rules, even if they're unreasonable. And of course only enforcing speed limits based on actual danger would reduce the plods income quite a lot.
You'd just reach an argument where a variable limit is then based on some person's opinion of the maximum speed for the conditions prevailing, programmed into a smart road system, and Jeremy Clarkson would be complainanaining that "the brakes on his Ferrari Testosteronezo R7 are far superior to those on an Austin Allegro and that, therefore, his 85mph is perfectly acceptable on that road". And that's just the start of it.
But that's just it, the speed you can go on a particular bit of road is already variable. The posted limit, which used to be set at the 95th percentile of best case, is the _maximum_.
If it is rainy, or foggy, or kicking out time at the school, you probably should not be at say the 50 limit that stretch of road otherwise warrants. Unfortunately there are many retards and unobservant drivers around who can't or won't drive to the conditions. This leads to situations where we have limits being artificially reduced on broad swathes of road, just to cope with one slightly tight bend near one end, and ultimately to generally slower and slower limits being imposed.
This in turn leads to devaluing the lower limits, driver resentment of said low speed limits, and then more 'speeding' because people drive to the perceived risk of the bit of road they are on.
The better action is to engineer that bit of road so that the speed the majority of people would drive below is safe rather than attempt to force lower limits. If you want engage drivers in slowing themselves down, you need to have road engineers redesign the road so drivers believe it to be riskier. For instance, planting trees down the edge of the road leads to a significant decrease in driver speeds, as do things like pedestrian refuges in the centre of the road.
"i don't understand why people are so pissed off about the law being enforced ?"
A driver has a lot of sources of information which should receive his attention. Most of them are outside the vehicle. Forcing him, by draconian enforcement, to concentrate on one particular one inside the vehicle does not seem to me the best way to improve road safety.
That seems quite likely to me given just how much bandwidth would be required if every street light had a live video feed.
I would also imagine cameras are pointing downwards to detect cars passing on the section of road they illuminate, average speed being calculated from the length time it takes for a vehicle to pass underneath; it doesn't have to be that accurate.
The idea that Suffolk Police will be tapping in to the lights to add speeding ticket printers seems fanciful to me. That appears to me to be more scaremongering than credible fear. Had there been more of a technical review of the hardware used and its capabilities we could all have perhaps been better placed to assess it.
That seems quite likely to me given just how much bandwidth would be required if every street light had a live video feed.
I would also imagine cameras are pointing downwards to detect cars passing on the section of road they illuminate, average speed being calculated from the length time it takes for a vehicle to pass underneath; it doesn't have to be that accurate.
My thinking too.
You can do machine-vision with a Raspberry Pi (to a point). It would not be difficult for a small embedded board to count cars and ping back numbers, obviating the need for the high-speed networking necessary to carry multiple video feeds.
I want the lights to come on while I walk dark streets, I also want them to do some random stuff or play with me so I know when the IOT has gained sentience.
"He walked the usual route but knew something was wrong, the lights they came on but just a perfect fraction late as if they cultured and valued his annoyance, even his Jack Russell would look up and to the distance as if something was coming, and the flickering lights foretold."
I have a hall light that is coupled to a microwave motion detector. However what it doesn't have is the handy feature where a quick off/on of the light switch will make it stay on permanently. It also has insufficient "darkness" control range - even set for maximum darkness it still switches on in reasonable daylight.
Another example of well established features being left out of "improved" products.
Or oncoming drivers with high intensity lights going over a bump and going off like a camera flash, or cresting the brow of a hill and dazzling you, or just at the wrong angle on a bend/slope on the opposite carriageway of the motorway. All properly dipped, of course.
According to the highway code, lights should not be used in such a way as to dazzle other road users. But these HID lights seem to to that by design. Does that mean the drivers or the manufactures should be getting tickets?
There seems to have been little mention of human sensitivity to blue light and the way it affects circadian rhythm. See, e.g.:
https://www.scientificamerican.com/article/q-a-why-is-blue-light-before-bedtime-bad-for-sleep/
Is this because the new lighting doesn't cause any significant effects or because these have been ignored?
The Register 
Biting the hand that feeds IT
Copyright. All rights reserved © 1998–2024
