Transcript of the Aylesbury Mains presentation: 14 November 2016
** are comments made. - is AM response
INTRO: Willie from Aylesbury Mains; thanks for attendiing. As as we said on Agenda item 16 An informative presentation on the different types of street lights. As a committee, as a council we agreed that we are going to go LED is what we have said. LED is good, LED is wonderful LED is beautiful. We have communicated to the village that that is the way we are going to go with a systematic changing of lights so we need to kick off and get on with it. The floor is yours to give us an update of your bag of tricks.
LED IS BAD, I will start with that.
** Why? That’s nice!
- The problem you have is that it is an older village and you have sparseley positioned street lighting columns or lanterns. So, whilst I agree LED is good in some situations and locations it is not the answer in alland the reason for thatis that what Pitsford currently has is a lantern like acandle in a jam jar. It radiates quite indescriminately. Therefore you get a bit of a glow from one to the next lamp. If you adopt an LED option you will get a wonderful pool of lightand nothing between it.
I will liken it to a car headlight if I may. A car headlight is designed to light the road directly ahead of you and very little each side of it, like a footpath, but there it stops because that is what we want it to do. An LED street light is designed to light the road. That is probably not what you want. And you have probably not thought about this. If I ask the majority of parishoiners, and I travel around quite a lot and ask the question, what is the purpose first of all of your lighting in the parish?
** Keep yourself safe. See where you are walking
- So, security and the ability to be able to see where we are walking.
** Plus, cost effective.
- Security is one of the biggest things, If we put a luminaire up that lights the road, it is kind of defeating the object because as a cardriver we don’t need to be able to see where the road is we have headlights on our cars. As a pedestrian, as residents we need to look at more from our street light, we need to be able to see what is ahead in front of you. If you put these LED lanterns in which light a pool in the road and nothing else you are not going to get that, in fact you are going to get glare
Because you are trying to look ahead of you and you will get glare. As I can demonstrate shortly.
- So, on the face of it,LED is great, why is LED good?
** Low power, life expectancy, more env friendly, no dangerous gasses in it to get rid of at the end of the day. No mercury to get rid of. Less light pollution because the light is pointed where you want it to be pointed and not all over the place as you describe. Not reflecting off everything and going off up into the air and so forth. Need I go on?
- Yes, carry on, I am noting these points and we will take them one by one .
- In reverse order Light pollution:
Absolutely right, light pollution is a great factor of LED lighting. As I have just explained it cuts off, it stops dead, gives you a box light and that is it. If you are creating a new design, or a new development
** But surely the light is going to reflect off anything anyway. I mean it reflects off the road, the stones, puddles in the road, off lamp posts, and so forth and it spreads out
- In fact we cannot see light, it is invisible to us all. All we see from light is what it reflects off. Light is invisible, it is a good job that it is, otherwise, if you take for example a foggy day and you are trying to drive that reflection, if we can see light that is what we get, this…. That is what we would see. So, light only ever reflects. Light has to spread, it has to go. You could go to B&Q and hang one of these wonderful new LED torches and hang from your ceiling and it would give you a pool of light. It would not be much to live with though.
** Do you know of a village nearby that has made what you consider to be a mistake.
- Silverstone village, for instance,
People are sold LED because it is environmentally friendly. We don’t actually know that for sure because the spectrum of LED light is very blue. We are not sure about the health reasons.
** You can get warm LED lights.
- It does not make any difference to the spectrum.
** Yes it does. Absolutely it does. In America they are using nothing but red LED lights.
- We go from 3000 Kelvin here to 5000 Kelvin. The minute we go to 3000 Kelvin they become less effective, it is only the very cold light that gives the high efficiencies.
** when you get to 3000, 8000 or 30,000 kelvin you have lost me. Can we keep it simplistic. Because as I say Steve has come up with a 8 answers to the question, why LED? I am sort of LED from a domestic use because I replaced all my bulbs to LED bulbs and my bills have dropped dramatically. So can we keep it to simplistic terms because we are all simple people and we have got to sell it to the parish as well.
** Basically they rate the light as a 1,000, 2,000, 3000 and that gives a colour basically. 4000, 5000.
- Those cold blue white are the bluer colours.
** but you can get warmer LED lights that give out more in the red rather than the blue or green which is where most of your cold light comes from. So you can actually get the red spectrum as well.
- You will find nothing in 3,000 LED’s not here in the UK anyway.
** You have caught me cold and I am sure you have caught other people cold because every piece of literature, propaganda if you want to call it that, has said LED is the way to go.
- Why do you think Northampton as a CC has not.
** I thought they had. So did I, so did I.
- No it is not LED, it is a ceramic discharge lamp (Ceramic Metal Halide or CMH)
** Is there an option 3
- I am trying to explain to you that LED in the right design criteria does the job, but it doesn’t when you have spacings of 60, 70, 80, 90 metres between them. You will have a pool of light under an LED and that isas far as it will go. That is not what you currently have and it is certainly not what you have with SOX.
** Can you not direct the pool?
- You can spread to a certain degree. If you are talking about efficiencies, you have a lot of 80w MBF/U’s currently. Mercury vapour. They are the ones that go on for ever and a day and reduce in output as they get older. They need changing every 3 years to get the real efficiency put of them but they are in a jam jar and just radiate out in all directions. We get a bit of light pollution from that but you also get a lot of light everywhere. It costs you for an 80W MBF/U probably somewhere in the region of 120w . So for the 80w in your lamp you waste another 40. Because it is old technology.
Disposing of them is not particularly difficult because they go to a recycling plant where gasses and metals are extracted environmentally so they are taken away before going to recycle.
So, you are faced with a situation whereby yes you could put LED up, you could put LED up at probably 16w and you would say, fantastic look at all the energy we are saving. But In my view you are wasting it because all you have now is a little pool of light underneath and that is as far as it goes. You could pretty much do without it quite honestly because that’s how much use it is.
** but the thing is with that, I can’t picture it, I’d have to see it because what you have said about the LED has caught me cold.
- There are other options than LED and it is all about what you want from an LED. I am going to switch one on so that you can get the feel of what an LED does The one I have brought is a very good quality LED we use it a lot for things like cycleways and narrow paths so we have got exactly what you say where you want this spread of light that is the one that if I was going to put, or recommend, an LED for a Parish that would be the one that I would use. Urbis Axia.
- If you are looking up the road to something that is about 5m above the ground you will have this very harsh luminaire looking at you. This one is 24w, runs at about 26w. If I turn it up the other way you can see the distribution on both ends of the wall. You can see how it cuts off in the other direction. We have got an array in here that goes left and right, goes forward a little bit and back a little bit but the majority of the output is longitudinal. The beauty about LED is that we can do that, we can change the direction of how we distribute on the many little lenses that surround the diode. Each one of those bulbs is a lens that directs the pattern. It is a bit like holding a bunch of torches, each one slightly in a different direction. That how we get the distribution.
Fitted, something like that is going to cost you in the region of £350 each.
** that fits to any of the standard poles because we have a mix of poles.
- Yes and no. That weighs about 15kg some of your wooden pole mounted MBFU’s would struggle with something of that weight. Theyhave probably been up there about 50 years. So we would have to be careful mounting something of that weight on relatively old, decaying bits of tube.
** can you get smaller ones?
- Can get smaller but if you are putting smaller ones on you are going to put a smaller wattage up as well. If you put a smaller wattage up as well we are back to that scenario where you might as well hang a torch off the end. You can’t get blood out of a stone. You may get someone saying we can get a 6w, 10w, 16w lantern to put up there that is all you need. Poppycock.
** Is that one of the colder ones?
- That is a 4000.
** Is that colder or warmer? Higher numbers are colder?
- It is mid-range.
Lighter lanterns 254w, is the same does not produce the lumen output that the 24w LED will put out but it is a much more user friendly lantern in all respects because we are back to a less controlled distribution which is what we want but it is not as harsh. I will put it on and it will take a couple of minutes to warm up..
** Whereas the LED comes on instantly. It is an old fashoined strip light.
- It is a new generation compact flourescent.
** What is the gas in it?
- It is completely non-toxic there is absolutely nothing in there. They have taken all of the nasties out of it. It is completely inert.
** what did you call it?
- A compact flourescent PLL.
What we have now is something you can actually look at. It does not give us thisstartling light but gives us a distribution that is a lot kinder.
** what do you mean by kinder?
- Less harsh, a much broader distribution, it has actually got louvres in it as well which we can take out. If you see it upside down, lot less weight so it is more likely to fit on more of your existing fittings. It is a lamp that will last 6 years between changes.
** How long will the other one last?
- The driver is a problem with the other one, not so much the LED’s. Most of the manufacturers are looking at around 6-10 years for a driver. The other issue with LED is the failure rate of an LED lantern is a subject for discussion. When does it actually fail because that one has got 24 LED’s if one fails the whole light does not fail, 2 fail it has not failed, You can get several that fail at what point do you say it has failed. It does not matter so much for an environment like a parish because if it is on, it is on. If we do lighting designs where we have to achieve a certain level of lighting distribution when they start failing the design starts to fail as well. Lighting design is a science that is very important to us when we are building new installations. It is not as important when we are doing a retro fit like in a parish.
** and that one still has some minimal lighting pollution.
- It is pretty good on that score.
** How much does that weigh and how much does it cost?
- £250 fitted. Weighs 3.5 – 4kg. It is a heavier version it has an alluminum body and something like 95% recyclable.
** The annual running costs of one above the other?
- The running costs on those two are very very similar as both run 26w.
** Per year?
- I can give you the calculations because not many parishes understand how your tarrifs actually work.
It is on an unmetered supply,a non-sup supply and what happens is with all lanterns when they are manufactured if the manuf wants to put it into the public domain they have to send it to an organisation called Elexon. Elexon take 5 samples and put them in a laboratory and run it for x hours. They then compare the running wattages of each of them, draw an average and say that lantern uses x amount of energy then all we do is take approximately 4130 burning hours, which would depend upon which type of photocell you may have. 4130 for this area if you had say 35 lux photocell controlling it that would be your approximate burning hours. So Elexon say there is a code for that lantern, there is a code for that control unit, multiply that by 4130 (26w x 4130/1000) you are probably paying something like 12p or something per kw. That will give you your kw burn per year and your costs for year. It is a huge saving over an 80w MBF/U. 24w as opposed to 120w.
** is it in the red or yellow?
- In terms of colour? We have the same colour options as we have with LED. We can go to a cold white, to a 5000 kelvin, 4000, 3000 or a lot lower actually with a PLL
** for instance most of the yellow ones are in the green or blue spectrum.
- It depends upon what you want. The colder the white generally the better the colour rendering.
** visible light or some of the other spectrums? On the astronomical side. For LED’s a lot of them tend to give out – Blue or green (UV colours) rather than red unless you get what is called warm LED’s. Those as far as astronomy is concerned can be filtered out and the whole basis of light is that it is more important to have a cut off and have the light shining down where you want it rather having it going in all directions. To me anyway. I am no expert.
- You have the other end of spectrum here with the orange lights that you have, the 35w SOX are still one of the most efficient light sources that we have and in its day it was a revolution. The downside of it is the colour rendering, the ability to see colours under artificial light. So if you go to one of the orange lights and look down and expect to see green grass you won’t see green grass. Likewise if you had somebody dressed in a red dress you would not be able to identify that it was a red or yellow jumper because those colours become inditinguishable to our eyes. Which only becomes an issue if there is a crime and you need to identify what colour, a car, what was he wearing? Probability is that you will give the wrong colour. So from a security perspective Sox is not fantastic but it has a wonderful glow to it, and you won’t like it for pollution because it does go everywhere – but then a lot of people love that, they like to be able to see their keyhole to put the key in.
The point I am trying to make is. It is not about lighting the road it is about lighting to be able to see what you are doing and where you are going.
** So, you have LED at Silverstone, any other ones?
- Another area they did was Wing (leighton Buzzard). They are awful and I have actually spoken to residents of Wing. We fit whatever the client wants.
** So Wing is LED what about these other lights, compact flourescent?
- PLL: Cambridge have done a PFI and all the residential areas have been lit with PLL. Oxfordshire; we are doing conversion programmes in Oxfordshire, and we offer that here as well where you have 35w
SOX we can change the gear tray within the 35w SOX lantern and put a PLL into it using all the same old lantern giving a white as opposed to the orange light, saves about 50% in energy. 35w runs at about 55w. That is another option with exactly same lamp as the second lamp.
- Oxfordshire are rolling out a fairly big programme. We have already done some in Whitney, replaced those. The technology is a good option, reducing the light levels that you would get from a 35w by half.
But the quality of the light is much better so, because we have a good colour rendering index for the white light, the same as you have in herewhere we can see all of these colours you would have that same colour out in the street and our eyes perceive it therefore as being brighter because we can distinguish things much easier. Fooling us that there is not as much white being put out.
** So colour rendering is the ability to see true colour?