As part of the OPW’s commitment to reducing energy consumption and waste, The National Shared Services Office underwent a large-scale lighting upgrade.


The 2023 Climate Action Plan reaffirmed several targets for public bodies that had been originally introduced in previous iterations of the plan.  These include a requirement that all public bodies must reduce their GHG emissions from burning fossil fuels by 51% by 2030, compared to a 2016-18 baseline.  They must also reduce their electricity emissions in line with anticipated supply-side reductions.  SEAI’s pathfinder programme has been working collaboratively with public sector organisations to develop scalable solutions to meet these targets, for benefit across the public sector and the wider non-domestic sector. 

The Office of Public Works (OPW) has one of the largest and most diverse property portfolios in Ireland, including Government offices, Garda stations and historic buildings such as Dublin Castle and the Customs House.

  • Electricity savings

    190,270 kWh/y (2022 emission factors)
  • C02 savings

    63 tonnes/y
  • Abatement cost

    €3,460/tonne C02 (single year's C02 savings)


The National Shared Services Office (NSSO) is an Irish Shared Services provider for Human Resources, pensions, payroll and finance administration for Government Departments and Public Service Bodies. The service is in Belfield Office Park in Dublin; the development was finished in 1999. 

Project Description

Most light fittings that were replaced during this lighting upgrade project were fluorescent tubes and bulbs.  LED DALIs were chosen as the lighting option to replace the in-place fluorescent lights due to their high efficiency rating.  LEDs convert most of their energy into light with minimal heat loss which allows for efficiencies up to 80% higher than conventional fluorescent lighting.  Of the nearly 1000 LED DALI’s installed, over 70% of the lights selected were dimmable models. 

In addition, 173 Control sensors were installed to allow for better control of energy usage.  These controls were designed to detect both daylight and presence.  Where applicable, exit lights were refitted with LED equivalents. 



Electrical usage data was gathered from OPW’s energy logging system to assess the electricity savings achieved by the project.  The baseline year selected for data comparison was 2019 as the project was carried out from August to December 2020.  The weekly electricity use for the baseline year and post-works year (2022) is illustrated below in Figure 2.  2022 was deemed to be more suitable for post-works assessment to avoid conflating the effect of lockdowns and work from home advice during the Covid pandemic. 

As can be seen from the graph, significant electricity savings were achieved after the lightings upgrade, in the order to 54% of electricity usage.  Metered data reveals that 190,270 kWh of electricity was saved over the course of a year compared to the annual usage of 354,560 kWh used in 2019. 



This project demonstrates the very significant savings that can be achieved throguh lighting upgrade projects to convert fluorescent light fittings to LEDs. With short payback periods achievable in the majority of projects, the measure should be considered for inclusion in any planned retrofit project.

Learn more about the Pathfinder Programme