We've done this to support efforts to tackle climate change, meet CO2 reduction targets and enable budget cuts within street lighting to be maintained.
There are several benefits of LED street lights:
- LED lights are expected to last for 100,000 hours or 20 to 25 years allowing for 10% failures - this is much longer that the 15,000 to 20,000 hours - or 3 to 4 years - of other street lights, so we'll benefit from lower maintenance costs
- there are big energy savings of around 60% in comparison with traditional street lights
- they make colours look more natural, and LED street lights provide better facial recognition for security and CCTV cameras
- unlike traditional lights in Derbyshire, LEDs can be dimmed when light is not needed, resulting in additional energy savings
- LEDs don't contain the harmful chemicals found in traditional lights such as mercury and sodium. They don't emit any ultraviolet or infrared light and will be 100% recyclable
- there are fewer lamp changes than with traditional lights which means less waste, reduced fuel used to service the lights and reduced congestion through fewer roadworks
- LEDs emit light in a specific direction, which is aimed at providing uniform lighting, meaning there is less wasted light
We've also identified some potential concerns:
- some research has suggested that blue light can disrupt sleep through suppression of the hormone melatonin. LED street lights do contain more blue light than traditional street lights, but are classed as 'risk group one' which means that no specific precautions need to be taken. The use of televisions, phones, tablets and computers are likely to have a much greater impact on melatonin levels in the body
- both natural and artificial light has the potential to damage the eye - it's best to avoid looking at any light source directly for any length of time
- flicker is present in some light sources, including LED. This could potentially cause distortion of the visual field. We've discussed this with Public Health England who has given guidance to ensure that flicker frequencies likely to cause concern are avoided
The amount we've paid in electricity for street lights has gone up on average by 11% per year in recent years due to increases in fuel prices. LEDs use less electricity and it's envisaged that the capital investment could be paid back in just over 8 years.
We also intend to dim lights in most locations unless a reduced level of lighting wouldn't be appropriate, for example in areas with an above average record of crime or safety concerns. Dimming will be to a maximum of 50% of their total output from midnight to 5am.
This is a unique opportunity for us to improve much of the street lighting that we're responsible for and will redefine the way we operate and manage street lighting in Derbyshire for many years.
The list of parishes and when we plan to start work on replacement of all lights on residential streets with an LED lighting source is attached to this page.
So far we've installed over 71,000 LED street lights (October 2019 figures).