Streetlights
Published: 23 February 2025
Dear Councillor Charlie Marks
Subject: Environmental Information Regulations response – ref EIR-202501004282
Cambridgeshire County Council (CCC) has now considered your request under the Environmental Information Regulations.
We can confirm that we do hold the information requested by you. Please find our response as set out below.
Request
I am a Fenland District Councillor for Manea, in the last few days CCC contractors Balfour Beatty have replaced a number of street lights in Scholars Close, Hutchinson Way,Teachers Close and Orchard Way, Manea.
A number of residence have contacted me regarding the new lights fitted as they have a number of concerns, the new lights seem to be up giving off upto 50% less illumination than the ones they replaced, the actual light splays which again seems to now be inadequate and only lights up the area around the street light itself meaning there are a number of unlit spots between post which could lead to pedestrians tripping and also giving the possibility of intruders breaking into properties under the cover of darkness as the previous light splay gave greater security by the area they covered.
Also raised is a number of these lights have either previously been installed when the new development were built or have been replaced over the last 3 to 5 years, so my questions I would like responses to via a “freedom of information” are as follows:
1) What difference of illumination is there between the new lights and the ones replaced?
2) As it is obvious the lights now fitted illumination is less than the ones replaced why was this decision taken and by whom?
3) What trials were held and consultation before the go ahead was given to buy and fit the new lights by CCC?
4) What is the cost to buy each new unit?
5) What is CCC being charged per unit by the contractor to fit them.
6) Is any other work required to replace old for new?
7) If rework is required to fit the new unit, what cost is this and would any full lamp posts require replacing to?
8) was a health and safety risk assessment undertaken regarding the reduced splay the new lights illuminate?
9) As reduced illumination is given off were the police consulted due to security issues?
10) How many lights are CCC looking to replace with these new lights in Fenland?
11) What electrical yearly cost per unit saving do these new lights give?
12) What is the expected life span given for these new lights by the manufacturer?
13) What has happened to the working lights removed?
Our response
1) What trials were held and consultation before the go ahead was given to buy and fit the new lights by CCC?
Our standard streetlight for residential roads has previously been a 36W fluorescent type, known as PL-L. During the planning of this project, the Council worked with lighting manufacturers to seek to as closely as possible replicate the lighting output of this light with LED lanterns. It should be emphasised, however, that the Highways Authority is concerned with the illumination of the highway (road surface and adjacent footpaths), not the overall ‘spread’ of the 36W PL-L, which is much wider and less controlled than is required to accurately light the highway. Whilst it is never possible to 100% replicate any light source with another, our manufacturer demonstrated a product which very robustly met with our requirements. The overall consumption of this product is 6W, representing a very significant energy and carbon saving to the authority.
This product was tested carefully using software until we were satisfied with the performance. Prototypes were then installed at a trial location, where various representatives and stakeholders met to review the appearance of the lights, and the lighting levels. Everyone was satisfied with the appearance and the recorded lighting levels on the ground.
2) As it is obvious the lights now fitted illumination is less than the ones replaced why was this decision taken and by whom?
The decision to approved street lighting LED lantern replacement project was made by the County Council's Highways and Transport Committee meeting held on 3rd October 2023. The report to the committee upon which this decision was made can be viewed at: County Council’s Highways and Transport Committee.
3) What difference of illumination is there between the new lights and the ones replaced?
‘Luminance’ is the term used to describe the amount of light hitting the eye at a given point. When looking at a street illuminated by 36W PL-L lights, the luminance impact on the eye will be rather high, as you can generally see the lamps themselves, and there is a lot of sideways light. This gives the impression of brightness, and as this brightness increases it can become glare, which is uncomfortable for our eyes. With the new LED lanterns, the luminance is reduced, as now the light sources are much more hidden, and there is very little sideways light. Therefore, to the observer, the brightness of the scene is reduced.
For residential roads, we are concerned with the amount of light hitting the highway (illuminance, or light measured on a surface), between the backs of footpaths. Our findings have been that the illuminance on the highway itself is very similar under our new LED lights as it was with the 36W PL-Ls. In some spots the levels are higher, in some spots lower, but the overall average is directly comparable. It may seem counter-intuitive, but the luminance (overall sense of brightness to an observer from a given position) can be reduced while the illuminance (light reaching the ground) remains the same or even increases.
Additionally, to provide some explanation as to how a 6W LED can be equated to a 36W lamp: firstly, LEDs are more than twice as efficacious as PL-L lamps, meaning that the amount of light emitted per watt is more than doubled. Our 5W LEDs emit just over 1,000 lumens (200 lumens per watt), and the 36W PL-Ls emit 2,900 lumens (81 lumens per watt). Lumens is a measure of the amount of light emitted from a source. With LEDs, all this light is projected downwards towards the road in the intended direction, so in that sense they are 100% efficient. All 1,000 lumens are lighting the ground.
A 36W PL-L lamp emits light in 360 degrees; roughly 40-50% of this light is ‘lost’ as it is emitted upwards and reflected into itself or above the horizontal plane. Therefore, only approximately 1,500 lumens are directed down towards the ground. Of these, at least 30-40% are above the ‘useful’ plane (i.e. they are not lighting the highway, sending wasted light in front, behind, and sideways but above the road surface). Therefore, only around 1,000 lumens are utilised in actually lighting the highway, which is roughly the same as the output of the LED lights.
4) What is the cost to buy each new unit?
The average cost for this project is £275.81 per lantern, which includes installation costs.
5) What is CCC being charged per unit by the contractor to fit them.
Please see response to Question 4.
6) Is any other work required to replace old for new?
No additional works are required.
7) If rework is required to fit the new unit, what cost is this and would any full lamp posts require replacing to?
Not applicable.
8) was a health and safety risk assessment undertaken regarding the reduced splay the new lights illuminate?
A streetlighting design assessment was completed in line with the County Council’s policies for the new street lighting lanterns.
In addition, for designated traffic routes, there are British Standards for lighting which must be met, which is achieved by carrying out a specific lighting design for each road.
9) As reduced illumination is given off were the police consulted due to security issues?
Police consultation was not required because streetlights were not being removed in any location.
10) How many lights are CCC looking to replace with these new lights in Fenland?
Our street lighting inventory mapping system corresponding to Fenland locations details that 7,811 streetlights will be included in the LED programme.
11) What electrical yearly cost per unit saving do these new lights give?
This varies depending on the previous lantern wattage versus the new lantern wattage, and the current energy rate. At 30p per kwh, the range is generally between £30 - £100 per year.
12) What is the expected life span given for these new lights by the manufacturer?
The new lanterns will last 20 years, which is covered by the manufacturer’s warranty.
13) What has happened to the working lights removed?
The redundant street lighting lanterns are being recycled.
Complaints
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