Annual savings of more than £1m a year are expected as Wiltshire Council agrees to invest in low-energy street lighting.
The council is responsible for almost 45,000 lights on its highways. But with energy costs rising sharply it is investing more than £12m to replace older lamps with Light Emitting Diode (LED) lighting.
Unlike older lights, LED can be dimmed to save energy.
The intention is to dim the lights from 8pm to 6am. That will cut energy consumption by 69% while keeping roads as safe as possible.
Subject to the proposals being approved by Full Council, procurement will get underway, with the two-year installation planned for 2019/20.
The council has also agreed to consider converting non-highway lighting to LED, including public open spaces, car parks and housing estates, subject to suitability and cost.
Wiltshire Council cabinet member for highways, Bridget Wayman, said: “Now is the right time to convert our ageing streetlights to modern, flexible LED technology.
“It’s a significant investment but in the long term it will make vital savings and give us a much more reliable system.
“As well as the financial benefits it will also significantly reduce our carbon footprint.”
The decision was agreed at Wiltshire Council’s cabinet meeting on 11 December.