Douglas Council says it's fitted more than half the town's lampposts with energy-efficient LED bulbs.
The local authority says it's now installed 2,500 of the units across the capital - in total it'll replace 4,400 lamps.
The £1.5 million investment is expected to save ratepayers around £2.7 million over 15 years.
The council says the lamps will also improve visibility for pedestrians and road users.
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