Streetlight dimming trial set to cut carbon and costs

12 month trial approved by Devon councillors

A 12-month countywide trial to amend the dimming of streetlighting in Devon has been approved by councillors.

Devon County Council first introduced part-night streetlighting in residential areas in 2009 and its current policy has been in place since 2019.

As well as part-night lighting of residential streetlights, the roll-out of LED lighting and dimming of streetlights on main roads has successfully reduced energy use, carbon emissions and costs, while keeping the public safe.

Devon's streetlights used around 12million kWh of electricity in 2023/24, compared to around 31million kWh in 2015/16, which equates to an annual £6million saving.

Earlier this year, a small-scale pilot of 550 streetlights in Abbotskerswell, Holcombe Rogus, Kingskerswell and Sidmouth, trialled earlier switch-off times and additional dimming, using the upgraded technology of the Council’s Central Management System which currently allows adjustments to be made remotely to around 50% of Devon’s 80,000 streetlights.

Following feedback from residents in these trial areas, as well as recommendations from the Council's Corporate Infrastructure and Regulatory Services Scrutiny Committee, a three-tiered system was today put before Cabinet for an extended 12 month trial. The proposals took into account the separate needs of city, market towns and rural communities, as well as recognising the importance of dark skies, and the benefits to wildlife and the environment.

Councillors agreed that an extended countywide 12-month trial will start early in the next financial year but will not change the current policy on streetlighting on main roads. For residential streetlights, the trial will apply the following:

- In Exeter, residential streetlights will be dimmed to 40% output from 9:30pm - 12:30am, before being switched off from 12:30am until 5:30am, and returning to 40% output from 5:30am-6:30am.

- In market towns, they will be dimmed to 40% output from 8:30pm-midnight, then switched off from midnight to 5:30am, with 40% output from 5:30am-6:30am.

- Rural areas will see residential streetlights dimmed to 40% from 7pm to midnight, switched off from midnight to 5:30am, with 40% output again from 5:30am-6:30am.

Councillor Stuart Hughes, Devon County Council Cabinet Member for Highway Management, said: “Over the last decade, our streetlighting team has focused on reducing energy usage while keeping the public safe. I'd like to thank them for their efforts in this area. They've done a sterling job but there's an opportunity to do more, for further carbon reductions and cost savings.

“The installation of our central management system will enable us to make adjustments to light dimming and timings during this extended trial. It’s quite interesting that in Sidmouth, which was one of those areas chosen for the six-week trial earlier this year, I only received two responses which speaks volumes.”

The County Council has worked closely with Devon and Cornwall Police throughout the small-scale trial earlier this year, and in developing the proposed 12-month trial. If Police raise any safety concerns over the lighting levels during the trial, they can be reviewed and they have the potential to be altered via the Council’s Central Management System.

The findings of the trial will be reviewed in 2026 for further consideration by Cabinet.