This lighting upgrade project demonstrates the significant electricity and carbon savings that can be achieved by installing energy efficient light fittings.


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.  This lighting upgrade project, undertaken under the Pathfinder Programme, demonstrates the significant electricity and carbon savings that can be achieved by installing energy efficient light fittings. 

  • Electricity savings

    80,300 kWh/y
  • C02 savings

    27 tonnes/y
  • Abatement cost

    €9,300 / tonne C02


The building is a three-storey office building, with a total floor area of c. 3,900m2.  The project scope was based on a full survey of existing lighting, with fluorescent fittings throughout the building being replaced. 

This lighting upgrade project follows a previous project undertaken under the pathfinder programme during the summer of 2019, when the existing boilers were replaced with high efficiency LPG units with variable speed pumps.

Project Description

Most lighting that was installed prior to the project was T8 fluorescent tubes.  Installed units were a combination of both modular and surface mounted units, totalling more than 670 light fittings (primarily 3 x 36 W and 4 x 14 W modular units).  Units were replaced throughout the building with high efficiency LED units. 


Electrical usage data from OPW’s energy logging system has been used to assess the electricity savings achieved by the project.  Building electricity usage post-installation compared to the baseline is shown in Figure 2.  The baseline year selected for data comparison was April 2019 to March 2020, so as toto exclude the impact of Covid lockdowns on energy consumption, while also capturing energy usage with the new boiler system (with associated variable speed pumps) in situ within the baseline.  Works were undertaken from October 2020 to January 2021; savings have been evaluated against 2022 usage, again to exclude any potential impact of the Covid pandemic on energy usage. 

The results demonstrate that significant electricity savings have been achieved, primarily attributed to the lighting upgrade project, with a reduction in annual building electricity consumption of 22%, equating to annual savings of c. 80,300kWh, and carbon savings of 27 tonnes CO2 based on 2022 grid carbon conversion factors. 


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

Learn more about the Pathfinder Programme