Lights Out!

[Kieran]

http://www.dailymail.co.uk/news/article ... bills.html

[Initiation]

Well considering that both of the 2 councils mentioned saved £200k+ a year i don't think you can complain much, the people complaining are probably those who immediately moan when there council tax bill goes up because of energy costs. OK if they were cut all the time then yes that could hardly be justified however from midnight to 5:30 is a time when there are almost no people around other than in a few cars which have headlights anyway!

[OrraLoon]

Well considering that both of the 2 councils mentioned saved £200k+ a year i don't think you can complain much, the people complaining are probably those who immediately moan when there council tax bill goes up because of energy costs. OK if they were cut all the time then yes that could hardly be justified however from midnight to 5:30 is a time when there are almost no people around other than in a few cars which have headlights anyway!

And just to add my own fragment of the jigsaw, my own mittelschottisch council is dimming lights by 30% at night in a couple of localities. I also see that there's a programme of installing new street lights in my own area, so maybe it will follow.

[maryb]

I'm not against this in principle but midnight seems too early especially on Friday and Saturday when young people are coming home after a night out. If it puts girls at greater risk it's bad news.

Anyway isn't it mainly base load electricity generation at that time? Maybe they should just get an economy 7 meter!!

[adam2]

I am in favour of the idea, the energy saving is substantial, and also the saving in replacement lamps. Although the lamps are relativly cheap, the labour cost is substantial.

Dimming street lights after midnight is also worthwhile when possible, though most designs cant be dimmed.

Street lights are not normally metered (via economy 7 or otherwise), the current used is charged for by counting the number of streetlamps, determining the lamp wattage and the average hours of operation.
The same prcedure is used for other small nonmetered loads such as CCTV equipment, traffic lights, warning signs etc.

In some districts though turning the lights off after midnight would be a logistical challenge.
Some streetlights are switched on/off by "ripple control" by which coded signals are sent from a central location via the mains, to the street lights telling them when to go on/off. With such a system the times may be easily altered by human intervention at one or two central locations.

The most common method of control though is to fit each street lamp with a photocell for automatic control. Some photocells have a facility to turn the lights on at dusk, off at midnight, and then on again at 05.30 (if still dark). If such photocells are installed, then an engineer must visit each street light to make the alteration. The "off at midnight" is not normally adjustable since the photocell does not incorporate any clock or time of day setting, it simply determines midnight as being half way between sunrise and sunset.
If older type photocells are installed they will have to be replaced for "off at midnight" control.

In a few cases, streetlights have a dedicted electrical circuit with switching by a central timeswitch or manually, this of course is easily altered to whatever time is required. Such installations are now rare since they require that street mains be of non-standard five core cable.

[RenewableCandy]

Street lights are not normally metered (via economy 7 or otherwise), the current used is charged for by counting the number of streetlamps, determining the lamp wattage and the average hours of operation..

Interesting...so the council could just say it's turned all the lamps off... and who's going to rat on them?

...it simply determines midnight as being half way between sunrise and sunset.

For at least 1/2 the year, this happens at 1 am (BST) so you can still stagger home from the pub well-illuminated!

[adam2]

Street lights are not normally metered (via economy 7 or otherwise), the current used is charged for by counting the number of streetlamps, determining the lamp wattage and the average hours of operation..

Interesting...so the council could just say it's turned all the lamps off... and who's going to rat on them?
!

I think that they might notice!, and more to the point in many areas the council sub-contract the street lighting maintenance, often to the electricity company.

[adam2]

[quote="RenewableCandy

...it simply determines midnight as being half way between sunrise and sunset.

For at least 1/2 the year, this happens at 1 am (BST) so you can still stagger home from the pub well-illuminated![/quote]

True, when dusk to midnight switching is employed, this is a source of complaint by people who expect it to be midnight by the clock, and not local midnight.
The time varies a bit depending on how far east or west of Greenwich one is.

The advantage of photocell swtiching is that the lights out will be spread over a few minutes, rather than all lamps going out together which might upset those unused to it.

[maryb]

OK the economy 7 comment was being flippant but seriously, looking at the bigger picture, not just from the councils' perspectives, I would like to know what difference it will actually make to overall energy consumption given that there is a base load requirement for electricity generation - power stations which can't easily be brought on line in a hurry (unlike, say First Hydro) but have to be kept generating 24/7. If we do commission a new generation of nuclear power stations that would be yet more base load forming part of the mix

[Bandidoz]

I've been reliably informed by my contact in NGT that the idea of "keeping street lights on to maintain minimum demand to suit nuclear output" is "bollocks".

[MacG]

I've been reliably informed by my contact in NGT that the idea of "keeping street lights on to maintain minimum demand to suit nuclear output" is "bollocks".

AFAIK this is correct. The excess from a nucular plant could just as well be vented off in the cooling cycle. Streetlights are just a nice bonus alternative to venting.

[maryb]

so there doesn't seem to be any reason why we shouldn't have the "bonus" of adequate street lights other than the fact that councils would be charged at a rate which does not reflect the real marginal cost .

I have to walk home along a station approach road where the lamps are widely spaced. Probably equivalent to turning off every other street light in a normal street. You can't get adjusted to the darker parts because there are still some lights but at the same time you can't see properly in the lit parts. Leaving aside the fact that you feel nervous, it's horrible in the winter, because you can't see where you are treading in the piles of slippery leaves that just get left all winter to form a greasy mulch. I don't feel good lighting is just a 'nice to have'

Allocating costs with joined up objectives in mind would probably result in a lot of different choices being made by authorities. That station car park is often half empty because it costs so much to park there on top of the cost of a rail ticket. And the car park ticket machine doesn't give change. If they wanted to make it easy for people to use public transport the car park charges would be half what they are now - but they have outsourced the management of the car parks to private companies who have to generate maximum profit, resulting in more people driving all the way into London

[Cycloloco]

No one so far has mentioned movement sensors. What is wrong with having the lights out from midnight onward except that they come on for one minute after movement is sensed nearby below? That way we get the safety but less energy consumption. I don't know if the usual high pressure sodium lamps can come on fast enough to be useful with a movement sensor. If not then other types of lamp can be used. At the least we could have alternating full-time lamps and intermittent lamps.

[contadino]

All the street lamps outside the main part of my local town are solar. I read a newspaper article that it was cheaper and quicker to install them than to wait for a cable to be run along the roadside.

[adam2]

No one so far has mentioned movement sensors. What is wrong with having the lights out from midnight onward except that they come on for one minute after movement is sensed nearby below? That way we get the safety but less energy consumption. I don't know if the usual high pressure sodium lamps can come on fast enough to be useful with a movement sensor. If not then other types of lamp can be used. At the least we could have alternating full-time lamps and intermittent lamps.

The lamps commonly used in street lights take several minutes to warm up, and once warmed up, if extinguised, can not be re lit for a few minutes. This of course renders them unsuitable for movement sensor control.
It has been proposed to use incandescent lamps on movement sensors for street lighting, unfortunatly such lamps use roughly six times as much electricity as sodium lamps, therefore unless one could be certain that the lamps would be out at least five sixths of the time, energy use would increase.
LEDs however light instantly, and are becoming viable for street lighting, and I suspect that we may soon see LED street lights controlled by movement sensors.
I suspect that the people will hate them ! "the lights keep going on and off and frightening my baby" "I cant bear to walk down the road because the light the other end is out and I dont know that it will come on" "the light did not come on and my friend was frightened" etc. etc.

Slightly O/T but many new or refurbished offices have lighting controlled by movement sensors, the occupants absolutly hate it! they cant leave lights on all day in empty rooms, if they go to sleep at the desk the lights go out, and everyone knows someone who was nearly killed by the lights going out, and women especialy feel threatened if the whole building is not lit.