What exactly is the point of leaving the lights on for an entire city or country for that matter over night?

If it’s not being used turn it off!

It certainly used to be the case that it took more energy to switch on a street lamp than it did to keep it on for several hours.

1) street lights take about 20 minutes to come on properly. You’d have to be walkign pretty slowly to see the benefit.

2) muggers would learn to stand very still and then go ‘Booo’ when the light went on as you walked up to it.

Costs loads in the short term to upgrade them all….yes there probable be savings in the long run, but in case you’ve not notice we haven’t got any money right now!

I heard on the news recently that one area had experimented with turning lights off during the small hours or selectively turning off every other light.

Seemed like a reasonable idea to me – but the residents complained, so they all had to changed back (at huge cost).

A lot of the street lamps near me still have a horizontal bar sticking out near the top where the bloke with a ladder used to lean it so he could climb up and light the wick on the gas lamp. I’m not sure they’d cope with motion detectors.

Can’t see it being popular, people feel safer with street lights.

What size of moving object would trigger them (ref RLJ & traffic light sensors) skateboarder, cyclist, car, cat, child, ??

Also it would look pretty amazing from the ISS, like a global Blackpool illuminations.

free head torches for all.

As has been pointed out, sodium lamps take a while to “heat up” so would be impractical newer LED technologies would be more suited but then as was also mentioned it would require a significant upgrade to have motion sensors. There have been experiments in europe on small scale switch off where residents can remotely switch on lights if they are out and about but i’m not aware of what the results were. I was also under the impression that it helps with the national grid in keeping stations “ticking over” until the morning demand starts.

If it’s not being used turn it off!

They are turning many off. Particularly the ones on motorway junctions.

Remember they are only something like 20W each, the normal orange ones, so the power consumption is probably less than the houses outside which they stand.

Also, we are so used to street lights in towns and cities that it’s easy to forget how frigging dark it can be when they’re not on.

Just out of curiosity what kind of bulbs do they use and how efficient are they?

Who exactly do we pay for the energy that powers the lights and how much does it cost us each year to run them?

They should have a coin meter on each lampost. 5p.

15p per lamp per night for leccy, maint etc.

according to: http://news.bbc.co.uk/1/hi/magazine/7764911.stm

See above – the really orange ones are low pressure sodium vapour lamps which are the most efficient of all lighting forms at 100-200 lumens per watt, as opposed to 50-100 for LEDs, 50-75 for a CFL and a shocking 15 for a traditional light bulb.

That’s why we put up with the horrible orange colour.

kaesae – this may sound like a stupid question, but do you ever do any research of your own on these odd questions or do you just ask random things as they come into your head.

Just out of curiosity what kind of bulbs do they use and how efficient are they?

traditionally – the yellowy orange ones are sodium lamps, If forget what the white ones are. They have an electronic doo-hickey that brings them up to full brightness slowly, as much to preserves the bulb (which cost a lot in labour to replace) as much as anything. But if you switch them off you need to bring them up to brightness slowly again.

Once they are bright they are using about 1/4 of the power used when they are warming up.

Loads being switched off permanently round here, I think there are big savings in maintenance costs rather than just electricity. No plans to take the redundant lamposts down though, that would cost more than the savings.

Can I propose one Trout Light per town and an elaborate system on mirrors?

We haven’t been able to make anything more efficient in 90+ years 😯

quite a few councils now switch random lights off at night, Powys council even put stickers on theirs to tell you theyre going to be switched off at certain times,

All motorway lights should be switched off after midnight except those at junctions then half could be off.

They need to warm up to vapourise the sodium. To allow current to flow and get it warm in the first place, they are full of neon. Which is why they start off pink 🙂

To me it seems dumb to have these old out of date lights running all the time throughout the world!

Read up, they are old but they are still the most efficient.

http://en.wikipedia.org/wiki/Luminous_efficacy

kaesae – this may sound like a stupid question, but do you ever do any research of your own on these odd questions or do you just ask random things as they come into your head.

😀

Can they not use lamps that harvest the astral energy from the Milky Way to power them…? 😉

As mentioned previously the reason they are there is for safety.

In terms of street lights in residential areas they help the public feel safer walking about at night.

On the motorways they are generally there to improve visibility at night time, particularly around junctions where accidents are more likely to occur.
In the North West we have been experimenting with midnight – 5am switch off on the quiter bits of the network (eg M6 J27 – 31), and in some cases, where schemes are being carried out, a number of lighting columns now deemed to be not required are being removed.
However on busier sections and complex junctions lights are likely to stay on safety grounds.

Many of the existing columns on the motorway network are being upgraded to new, more energy efficient ones, however only a small amount are done a year due to the cost involved.

From a purely selfish viewpoint, I would find it really annoying trying to sleep with the lights constantly turning on and off as people walked/drove past my house. (I know this could probably be solved with better curtains).

When I lived in the Isle of Man, they used to turn the lights off for the small hours each night in the village.

It used to make drunken walks home on a Saturday night very interesting.

Apart from RTC and crime hotspots, the local council turn the street lighting off round here from midnight to 5am. Saves money and carbon, and I get to ride home in proper dark – everyone is happy.

Won’t we need them more than ever if the volcanic dust clouds continue and the sun dies?

Won’t we need them more than ever if the volcanic dust clouds continue and the sun dies?

I think the glowing rivers of lava will help a bit.

we are currently undertaking a programme of altering the vast majority of our street lights to either part night lighting, dimming them or switching them off altogether. so far the evidence shows no noticable increase in crime or collisions in these areas.
as others have said, they take so long to switch on that a motion sensor just wouldnt work. columns in urban areas with a 30 mph speed limit have to be retained (but not necessarily lit) so that the 30mph limit remains enforcable.

Remember they are only something like 20W each

More like 200W.

If the motion sensor turns the lamp on…
…how does the motion sensor sense the motion?

We haven’t been able to make anything more efficient in 90+ years

To think were still using the wheel. What a joke. Surely someone can come up with a better device for moving mass in a horizontal direction. I saw a documentary once with a flying car; why haven’t we made that yet. Pathetic.

If the motion sensor turns the lamp on…
…how does the motion sensor sense the motion?

Some sort of infra-red I guess… maybe a lazer! 😯

Read up, they are old but they are still the most efficient.

Not so. The latest metal halide lights are of comparable (or even slightly better) efficiency. And because they have much better colour rendering than the yellow sodium lamps, they can be run at a lower wattage and still appear to give out the same amount of light. Savings of 30-40% are possible.

Savings of 30-40% are possible.

Great, but you’d need to find the dosh for millions of them.

LEDS are poor on paper compared to sodium becuase the mesures are the lumens emitted by the bulb rather than lumens reflected from illuminated objects. Sodium lights are monochromatic yellow; most of the light is absorbed rather than reflected by any thing other than yellow objects. LED light is white light which contains all the colours of the spectrum and nicely lights up any colour. If you want to be seen on a bike under sodium lights it is essentail to wear white or yellow.

So 20W LED lights with movements detectors on 2/3 of the lights would save lots of energy and provide better illumination as recorded by human eyes.

Some good info!

So we can use leds or halogen, are we swapping the existing light/bulbs for others when they burn out?

In Birmingham the council have been replacing the old street lights with new LED arrays. It involves digging up and replacing the whole column, not just the light fitting.

We’ve just had a load of new LED lamps fitted around our perimeter fence at work, they seem to be on day and night at the moment but that could be due to testing.

This sort of thing

A few years ago (15) our shift changed all the streetlights on our site (approx 200) from 400w mercury vapour to 250w SON-T I would have thought they’ve just about paid for themselves by now.