Devon could become England’s darkest county if plans to turn off street lights to save energy are approved.

Thousands of lights could be dimmed, or removed, to help to combat global warming.

Devon’s highways department says that street lighting is responsible for nearly 40 per cent of the county council’s carbon footprint.

A light-dimming trial is under way in one street in Exeter and the council also plans to remove non-essential lights and signs, install dimmable bulbs and turn off lights at night. It will also switch about 2,800 of 3,800 250watt bulbs to 150watt bulbs to save nearly 500 tonnes of carbon dioxide a year. The council said that the £6,750,000 cost of the project would be offset over 12 to 19 years by energy savings.

Lester Willmington, the head of highways management, said that the council had been working with the police over road safety and assessing areas with low levels of crime at night. Maurice Spurway, of Friends of the Earth in Exeter, said: “There is clearly a lot of scope for energy reductions.”

Martyn Rogers, of Age Concern Exeter, said: “There are issues for older people on being safe on the streets and going out after dark.”

Ronald Higgs, who has lived for 38 years in the Exeter street where the trial is going on, said: “I would be in favour of anything that diminishes lights that aren’t necessary.”