Around £500,000 a year will be saved by Barnsley Council after residential street lighting is replaced.
Cabinet members approved the plans in March which will see a large proportion of street lights in the town changed from energy inefficient fluorescent bulbs to efficient LED alternatives.
Around 20,000 lights are due to be replaced starting in September, following more than £4 million of borrowing, which will be paid back through future savings on energy costs.
Coun Roy Miller said: “These new street lights will help maintain a safe environment by keeping lit those areas that are vulnerable to pedestrians and will also help to drive down the council’s carbon footprint.”
Benefits are energy savings and lower maintenance and carbon emissions.