Part night lighting
Why have we introduced part-night lighting?
Part-night lighting was introduced to enable us to meet our obligations under the government's Carbon Reduction Commitment (CRC) Policy. This policy requires that all qualifying organisations must reduce their consumption of electricity, with the incentive of a £12 levy on every tonne of CO2 produced, and if a qualifying organisations does not comply they may face penalties. Such non-compliance penalties levied in May 2014 varied between £2,500 and £179,952. Find out more about this on the gov.uk website.
You can also find out more about the CRC scheme on gov.uk.
The government has a stated objective to reduce the levels of UK carbon emissions by 80% by the year 2050. Some analysts have projected that the current levy of £12 per tonne will increase to £30 per tonne by 2020 and £70 per tonne by 2030.
Our 18,980 street lights consume 23% of the electricity we use, and consequently must play a large part in reducing energy consumption.
We're looking at further changes in the way that we operate street lighting across the county to ensure that we continue to be able to operate our lighting in as economical a way as possible, while at the same time maintaining the benefits to as many people as possible at any one time.
What savings have been made due to the scheme?
Street lighting produced 4,514.65 tonnes of CO2 between 1 November 2013 and 31 October 2014. This would have attracted a levy of £54,175, which has to be passed on in council taxes to householders.
However, by introducing part-night lighting to 12,200 (64%) of our street lights we will save about 830 tonnes of CO2 annually, together with a reduction in energy consumption of around 20% or 1.59 million kilo-watts per hour, saving in the region of £179,000 annually.
What is a tonne of CO2?
Carbon dioxide (CO2) emissions, and greenhouse gas equivalents such as methane, are calculated by measuring the quantity of CO2 produced from the burning of fuel. The amount of CO2 produced depends on the type of molecules included in the fuel, their concentrations and the conditions in which they are burnt.
So, to get an idea of what one tonne of CO2 is, here's some context to help picture it:
- it weighs as much as ten baby elephants
- it would fill a swimming pool 10m wide, 25m long and 2m deep
- it would be produced by a medium-sized petrol-fuelled car travelling 3,104 miles
So based on the car example, our saving of 830 tonnes would allow you to travel 2,490,830 miles, or 100 times around the world!
(data based on the UK conversion factor carbon smart website)
Why can't every other street light be switched off rather than part-night lighting?
One of the intentions of part night lighting is to develop a safe and sustainable method of mitigating against the long term risks of energy price increases and financial penalties from carbon consumption, and to reduce light pollution. In order to meet this goal, the number of lights included in the schemes needs to be maximised. Switching every other light off would not achieve this aim. It would also result in a lot of variations in the level of street lighting, which is not considered appropriate.
Our policy is that where new street lighting is installed and operating it should meet the current standards for lighting of the highway, ie British Standard BS EN 5489 (Code of Practice for the Design of Road Lighting) (2013).
Part 1 of BS 5489 Para 4.4.2 'Measures to minimize electrical use', says that:
"Good lighting can contribute to electrical energy and carbon reduction strategies, and should be at the forefront of any electrical energy and carbon reduction strategy developments."
With regard to part-night lighting it further says that:
"Longitudinal uniformity should be maintained during switch off and switch on that occur during the hours of darkness."
Therefore, to switch off alternative lights would be contrary to that standard.
It's understandable that this may be seen as desirable to maintain at least some light in a street. However, as identified by our independent road safety auditor, there's a concern for both drivers and pedestrians that their vision would be unable to adapt quickly enough to the rapid “on/off” difference in light levels, leading to the potential for reduced night-time visibility and a potential increase in accidents.
Had we opted for a scenario where every other light had been left on we could have been seen to be implementing a distracting and disturbing flashing strobe effect for car drivers, which could lead to many more road traffic incidents.
What are the criteria for turning street lights off after midnight until 5.30am?
All street lights will be individually assessed as to whether part-night lighting is appropriate to that area. Exemption criteria have been established through workshop working with key partners to determine which street lights should be included, and these criteria will be applied to each street light. By using these criteria it's estimated that some 62%, or 12,200, of our street lighting will be eligible to become part-night lit. The exemptions are:
- on a major junction or roundabout
- situated in a town centre where there's either CCTV and/or lots of people at night, for example near night clubs and train stations
- in an alleyway where one end is linked to a street that is lit all night
- on or near traffic islands, pedestrian crossings, footbridges and subways
- on or near level crossings, traffic calmed areas (speed humps, build-outs etc) or traffic signals
- in an area experiencing higher than normal crime levels after midnight
- in an area experiencing higher than normal accident rates after midnight
- where a water feature is present
It should be noted that as LED lighting replaces the less efficient conventional lighting, part-night lighting will still apply to these new lanterns for consistency countywide. Savings and CO2 reductions are still to be made on LED lanterns and changing the policy due to the fact a new lantern has been installed on one road and not another may bring up equality issues.
What happens if there is an increase in crime / accident levels where part-night lighting is in operation?
West Mercia Police, through one of the three Bronze Level Tasking Groups (BLTG) covering the north, south and central areas of the county, can request that lights be turned back on if they demonstrate that there has been a significant increase in crime due to the introduction of part-night lighting.
Individual/public requests are recorded and passed to the BLTG to review where concerns of crime have been raised in particular areas. Where areas of concern have been acknowledged, the street lights at the request of the BLTG will be converted back to dusk to dawn operation. Crime is not expected to increase due to the scheme. Crime statistics recorded during the trial and through the first two years of conversions have shown no significant change due to the installation of part-night lighting. Since the pilot schemes began there has also been no demonstrable increase in road collisions.
Where an individual person identifies an anti-social activity, this should be reported to the Authorities Public Protection Team via the firstname.lastname@example.org email address, or by telephone on 0345 678 9020, where they will automatically be included in the BLTG deliberations on a particular area.
With respect to the levels of crime being reported to the police, Superintendent James Tozer, West Mercia Police, stated: “Since the start of the introduction of part-night lighting in 2012, there has been a decrease in levels of crime recorded”.
Chris Edwards, area commissioner for south Shropshire has said: “Accident records indicate that those collisions which occurred between midnight and 05:30 in the last five years did not happen as a result of the implementation of part-night lighting, as they all occurred in areas that remain lit now or areas that were lit at the time of the collision”.
Have you considered alternative technology for street lights?
We're currently installing LED lanterns as part of our maintenance replacement programme, with 8% of the total stock of 18,900 street lights converted countywide.
The LED market is constantly changing and improving, but at the moment the cost to use this type of light has only just become a realistic option given previous payback periods to initially purchase the lanterns.
For the cost of an LED lantern a couple of years ago, you could buy two of the conventional type.
With regards to the use of motion sensors to switch the lights on/off, in principal it does sound like a sensible alternative to reduce CO2 and energy consumption but it does have its drawbacks.
To operate this way, all the current conventional lights will have to be removed and new LED lights (and associated network hardware/connections) replaced.
A conventional street light when first switched on initially takes a large electrical current, and takes between one and three minutes to fully light up to an acceptable lighting level. This wear and tear on the equipment from lighting up and switching off continually will reduce the lamp and ballasts efficiency, and increase the power consumption every time it ignites, which would make this idea less cost effective.
Other points of concern have been raised over the use of motion sensors, including the method of billing for the energy consumed, potential of uneven lighting for drivers and the disturbance for residents with lights being switched on and off during the night.
An alternative to the use of photo-electric cells to part-night light could be through a central management system (CMS). This allows LED lanterns to have switch on/off times changed remotely, together with dimming lighting levels through certain hours of the night if required. This could maximise savings in terms of energy consumption, with the flexibility in the way CMS operates. This could also improve the street lighting service, with instant fault reporting negating the need for a night patrol. The first trial in Shropshire was undertaken in January 2015 along Longden Road in Shrewsbury.
We're constantly watching for innovations as they come on the market. Likewise, the cost of solar-powered lighting is currently a very expensive option, and life spans limited. Added to this is the risk of theft, not only of the batteries but the solar panels. This has already happened on other highway equipment. Solar or wind-powered lights would be most appropriate in areas where part-night lighting applies, as there would be reduced battery drain. A wind turbine would help keep the batteries topped up but the additional cost of this is significant. There would also be the additional cost of replacement batteries every few years.
I'm likely to be out after midnight, what am I meant to do?
Anyone using these roads when the lights are switched off needs to make their own assessment of the possible risks, taking their own appropriate actions to mitigate those risks down to a level acceptable to them.
How will you monitor the effects of part-night lighting?
It's important to note that the safety of residents is an important concern to us. All of the lights in the scheme will have been rigorously selected according to specific exemption criteria which were agreed with the police, traffic management team, and workshops involving several town councils.
The police and traffic management teams will carefully monitor the safety of the roads throughout the installation period and year on year after that.
If I become the victim of crime or have an accident can I claim against the council?
There is no statutory duty for local authorities in the UK to provide public lighting, and you're unlikely to be able to claim as a result of this service reduction.