Essex Highways said 800 old street lamps were being replaced across Essex each week
All 128,000 street lights in Essex will be LED-based by 2024, a council leader has said.
Essex County Council leader Kevin Bentley said the scheme would save 6,500 tonnes of carbon per year and result in a saving of £39m to the council over 25 years.
The Conservative-run authority said it was investing £26.8m in the programme.
Mr Bentley said addressing climate change was the “biggest global challenge we face”.
The Conservative councillor said his pledge, made during his leader’s speech at the full council meeting, was a “signal of our intentions” to build “climate resilience”.
“We lead by example and we said we would encourage and provide better alternatives for people to travel and live more sustainably, and this we are starting to do,” he said.