Street lighting

Street lighting LED replacement programme

Most street lighting on adopted highway in both the North Northamptonshire Council and West Northamptonshire Council (NNC and WNC) areas is managed and maintained through a PFI (Private Finance Initiative) contract.

This contract is known as Connect Roads and is managed by the infrastructure company Balfour Beatty. This service is hosted on behalf of both unitary councils by WNC.

Through that contract, street lighting was replaced between 2011 and 2016 with ‘white light’ units that reduced the combined annual energy consumption from 29,244,404 kWh down to 8,764,725 kWh in 2022/23.

This was achieved without widespread use of LED lighting. Whilst this is good news in terms of energy used and reduced carbon emissions, we do continually review our ability to limit the carbon we produce and provider better value for the taxpayer. Unfortunately, the lamps used in some of our current older lanterns are becoming obsolete and others will become more difficult to source as manufacturers concentrate on the production of LED lights.

Recent advances in manufacturing mean that LED street light lanterns are now considerably cheaper than they once were but also can provide the same quality of light as more traditional lighting. As such we believe that now is the best time for conversion of our lights to LED.

WNC and NNC have decided to invest in new LED lighting to save money as well as reduce our carbon footprints and have now started a lantern replacement programme, which will likely run through to early 2026.

Saving benefits

The predicted annual savings are:

WNC which has 23,062 units

• 2,680,963 kWh
• £974,000
• 555 tCO2e (tonnes of CO2 equivalent)

NNC which has 22,157 units

• 2,589,668 kWh
• £941,000
• 536 tCO2e

Other benefits of this investment include reduced light pollution, removing the need to routinely change lamps and the ability to be more proactive in identifying outages and other faults by including all new lanterns in the centrally managed system for streetlighting.

Whilst the new lighting will be designed to meet the councils’ current adopted lighting standards, you may notice the following:

• lighting of roads will be to more consistent levels than before when compared to other roads
• the lighting in some areas may appear dimmer than before, where the level previously exceeded the required standard

Frequently asked questions

Are the councils changing lighting level standards when installing the new LED streetlights?
No, the adopted lighting standards have not been changed.

Why do some streets appear brighter or darker than others currently?
Lighting standards are not a precise lighting level, but a range with upper and lower limits. Light levels are affected by distance from the lamp, road layout, junctions, column spacing, column height, vegetation and other obstructions, and percentage output of lamps in terms of maximum brightness.

Why are the current lights not dimmed so that all streets have the same lighting level?
Some of the existing lamps can only be dimmed to a certain level before they either stop working or the output light moves into the blue spectrum (this keeps people awake at night, so we avoid that). Consequently, in some streets with the old lights, the required standard was exceeded because of lamp limitations, but LED’s can be dimmed down to 1% output and consistent standards are much easier to achieve. This means that some streets may appear less bright than before but will still meet our adopted standard.

Why can areas be brighter or darker as you move along a road?
While the optic of the new LED lanterns is much improved, they do not quite match that of the older lanterns, this may be more noticeable as the spacing of columns increases, however the average uniformity level of light along any road will meet the required adopted standard.

In some areas, the old streetlights lit areas other than roads and footways, will the LED lights do this too?
This should be less likely because the LED lanterns provide illumination where the direction is quite controlled, so unlike the old compact fluorescent lamps found in around 25% of our streetlights, private property and non-highway areas should suffer from less nuisance light.

The old lights were too bright and needed a back-shield to be fitted as it shone light into my property, will these be fitted to the new lights too?
Whilst they shouldn’t be necessary, we can do this where light exceeds nuisance levels.

I experience ‘glare’ from the old streetlights, will this happen with the new LED lights?
Many of the old streetlights had a single relatively small lamp and whilst this could cause glare it would not necessarily be classed as nuisance light. Due to the configuration of the lantern and multiple light sources, glare is much less likely from the LED lanterns.

Is there a minimum level to streetlighting should be provided?
No, the provision of streetlighting is discretionary rather than statutory. Local Highway Authorities can determine where it provides light, to what level, when and if they dim and whether they operate on a part-night basis.

Why were LED lights not installed when the lights were changed previously?
Back at the start of the PFI Streetlighting Contract in 2011 this was an emerging technology and longevity of the lanterns was not proven and this did not fit with the council’s requirements. The lanterns were also much less energy efficient and less optically efficient so many more lighting points would have been necessary adding to the project cost.

What is the cost of the project?
The replacement lanterns project will cost £12,632,381 (WNC - £6,492,974; NNC £6,139,407). Comparing this to what the cost might have been had LED lights been originally installed, factoring in electricity, maintenance, installation, lantern efficiency as well as higher numbers of lights, we estimate the additional cost to the contract would have exceeded £30m over its 25-year duration.

Are there any health issues associated with the new LED lanterns?
There is no current evidence to support this. A Public Health England report published a few years ago did raise concerns but this was linked to LEDs with a colour temperature exceeding 4,000 Kelvin. Our lights will be 3,000 Kelvin – classed as Warm White, and so will avoid this concern.

LEDs and white light can be disruptive to wildlife, what are you doing to mitigate this?
Our existing lighting is currently ‘white light’ and the new lanterns will be more controlled in terms of unnecessary light. There is guidance about what lighting is better for wildlife and our selected colour temperature is within that range.

Will the lanterns be used to transmit 5G signals?
The Centrally Managed System uses GPRS (General Packet Radio Service also called 2.5G) so is on the 2G communication network. There are currently no attachments on our streetlights that transmit 5G.

If the lights are creating more dark spots, will crime and accidents increase?
You may recall that in the past, Northamptonshire County Council switched off half of its streetlights, which included removing lighting on some roads where the speed limit exceeded 30mph. 

At that time crime and accident data was kept under scrutiny with both the Police and road safety teams. Accidents rates, severity and speed of vehicles were all found to reduce significantly under lower levels of lighting whilst daytime accident rates and severity remained largely unchanged. There was no hard evidence to support increased crime rates, but close contact was maintained with the Police crime prevention officers and lighting was switched back on in a few locations where better lighting was required for active Police surveillance and enforcement.

We do however recognise that reduced lighting can lead to a fear of crime.

Will the council review and adjust lighting levels if a road is perceived to be too dark?
We will periodically review the new lighting to check that it meets the required standard. It is easily changed if it doesn’t. We will generally only review lighting levels when approached directly by Northamptonshire Police Crime Prevention Officers asking for lighting levels to be adjusted to assist with active crime prevention and surveillance activity.

Last updated 10 October 2023