Identify existing street lighting which was high maintenance and improve it by making the lights retrofitted to LED.
Donegal County Council has identified existing street lighting which was high maintenance and a large energy user, and has now retrofitted to LED street lighting.

The now fitted LED fittings are controlled via a photocell which brings on the LED lighting at a slightly darker time of the day, due to the instant light from the LED fittings vs the Old SON fittings that take time to warm up before they reach max light output.

The Natural White light gives off a different light source vs the SON Orange lighting and this adds to the energy saving as the LED does not need to be as intense as the SON fittings. S/P ratio (the scotopic lumens to photonic lumens ratio) gives the human eye a different perception on light. Natural white light from an LED gives a better colour rendering light source, thus adding value to installing an LED Lantern.

Resources needed

It is needed a significant input from lighting maintenance contractor to complete accurate inventory. It is also requested to set up a street lighting division within Roads Directory and assign a Senior Executive Engineer to division.

Evidence of success

A complete inventory of lighting in County Donegal has now been completed. The total number of street lights is 16,605. The average annual wattage per lamp has reduced from 465 kWh to 440 kWh. This will continue to reduce as more retrofit projects are completed.

Difficulties encountered

Completing an accurate inventory, lighting design, pole spacing and pole heights.

Potential for learning or transfer

Street Lighting has been identified in Donegal County Council’s energy management system as its biggest Significant Energy User. This is most likely the case for many local authorities or municipalities. There is therefore a need to renew street lighting systems in order to reduce energy consumption. With ongoing developments and changes in LED technology the costs of upgrading existing SON/SOX lanterns has become more affordable. It is therefore sensible to attempt to upgrade in a phased planned way, particularly when maintaining or updating existing lighting system to take advantage of continuously improving new technology.
Main institution
Donegal County Council
Border, Midland and Western, Ireland (Éire)
Start Date
June 2016
End Date


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