Residential areas across Cardiff are set to benefit from the rollout of 23,750 new LED street lights which will save the council almost half a million pounds in energy costs each year and reduce the authority's carbon dioxide (Co2) emissions by 836 tonnes annually.

The rollout follows a successful pilot in a residential part of Radyr and the conversion of more than 13,000 lanterns on the main highway network.

Cllr Caro Wild, Cabinet Member for Strategic Planning and Transport, said"This is good news for the city and will play a major part in helping develop our ‘Smart City' agenda. These lights can be individually dimmed and lit up as required. The lighting column use ‘smart' technology to send messages back to head office about any failures, so we all know when a light malfunctions and will be able to carry our repairs without having to wait for residents to call about an issue.

"I want residents to know we have carried out a lot of consultation and work with interest groups and campaigners to ensure that the proposed colour and brightness of the light for our scheme is appropriate and safe. The lights will be dimmed from midnight until 6am to ensure residents' sleep isn't disturbed, but we do have the ability to increase the brightness if required - say if an accident occurred and the emergency services needed more light to help them carry out their work.

"The council has announced a climate emergency, so we need to take every step we can to cut the carbon we produce."

The specification of 3000 kelvins (brightness of lights) was set after a significant review of relevant literature and learning from other local authorities in the UK. The Cardiff specification has been endorsed by a number of organisations including the International Dark-Sky Association and Cardiff's Astronomical  Society.

The conversion of t lighting in residential areas to LED is expected to cost around £6.5m. The project will be paid for by the reduction in energy costs of £423,800 per year.

LED lighting systems have a longer lifespan and use less energy than traditional lighting systems which will also help the Council deliver savings.

Cllr Wild continued: "Research has also shown that the use of LED technology in street lighting does have positive benefits, such as a reduction in street crime and the fear of street crime. An analysis of eight different studies has found that improved street lighting can reduce crime by an average of 7%."

The council's Cabinet will consider the proposal at its meeting on Thursday, May 16^th, and if approved, the project will be advertised as an OJEU Notice (tender) in the European Journal and to the market at the beginning of August. The contract start date is set for the end of October, 2019.

Questions & Answers - Fact and fiction about LED street lights

Why is Cardiff using LED lights for street lights?

There are significant benefits to using LED Lights. They are more efficient at converting energy to light. So you get the same quality of light at a reduced cost. There is also a significant reduction in carbon emissions from LED lights.

What are the benefits? Is it proven that street crime reduces with these new LED lights?

The new lights have a better visual presence on our streets, revealing obstacles for pedestrians and cyclists more clearly, reducing street crime and develop safer routes to our schools.

In terms of the reduction of crime, eight different studies have taken place and have found that improved street lighting can reduce crime by an average of 7%.

In England there have been a number of complaints that the new LED lights are too bright and cause glare to drivers. What will be different in Cardiff?

We are using a different specification, so a warmer white light and not a blue-rich light. This is measured in what is called Kelvins (K). The specification of LED lights can range from 2200K to 5500K. Although the brighter LED light (Blue-rich light) are more efficient, Cardiff is committed to striking the correct balance between residents wants and needs and the potential for savings in cost and carbon emissions. Given this we have chosen LED lights that are 3000K.

To ensure drivers are not affected by glare from street lights it's important lanterns are installed correctly to the lighting column. The Council will be responsible for ensuring this happens. Also the warm white light that we will be using in Cardiff will reduce glare and is well within the current British standard - (BS EN 13201-2:2003)

Has there been consultation and tests of different types of LED lights in Cardiff?

Yes - extensive consultation with interested parties and campaigners took place in November 2015. The Council carried out a number of tests in the area behind City Hall by testing eight different lantern types from manufacturers, at no cost to the council, at an identical classification of 3000 Kelvins. The most suitable and cost effective LED product was then chosen for Cardiff's street lights.

Concerns from health campaigners claim that LED lights can have an impact on human sleeping patterns. Is this true?

The most efficient blue-rich light (above 4500 Kelvin) can affect sleep patterns but Cardiff isn't using this specification. The Council is using a warm white light (3000 kelvins) and this specification has been endorsed by a number of campaigners including the International Dark-Sky Association and Cardiff's Astrological Society.

Environmentalists claim that the brighter white light can have an impact on birds and other wildlife. Is this true?

Any light during the night has an impact on birds and other wildlife and this is more of an issue in cities, due to the amount of light used. However, Cardiff is using a warm white light (3000 Kelvins) which is significantly less of an issue than Blue-rich light (5000 Kelvins and above)

Will the lights be dimmed during the night?

The existing residential street lights are currently dimmed between 12 midnight and 6 am. The new LED lights will be controlled remotely, therefore, the Central Monitoring System will allow us to raise and lower the brightness of the new lights if required through digital technology.

Will the maintenance of the street lights be easier to manage with the new LED light system?

Yes - the proposed new LED lights are far more advanced and will allow us to have far more control over street lighting. If, say an accident occurred, we could turn up the lighting to help the emergency services. The lights can also self-report any faults or issues they are having to a central computer. This will enable the Council to be far more efficient at fixing faults. The LED units have a longer life than the existing units reducing the number of outages and associated maintenance.