There had been a big change in traffic flows, energy costs, and grid demands over the 17 years of Dublin Port Tunnel’s existence – and it was no different for the lighting.
Seventeen years back, all 1,800 lights in the tunnel had been lit with HPS (high-pressure sodium, 150W/250W/400W) lighting, a perfect solution at that time to provide the tunnel with the level of lighting it required.
HPS lights have been found to be energy-inefficient and emit heat that adds to carbon emissions, making them unsustainable. They also did not have a long lifespan, which added to maintenance costs, tunnel closures, lamp replacement costs, cleaning regimes when compared to the LED alternatives that are now available, meaning the time was ripe to upgrade to a more modern lighting solution.
We all know LED offers an extremely long lifespan relative to every other lighting technology and is more energy efficient relative to every other commercially available lighting technology. On maintenance, too, transitioning to LED made complete sense.
While the tunnel still needs to be regularly cleaned because of the emissions from heavy goods vehicles, the light units now simply need to be wiped clean on the glass exterior to allow for maintained light source.
This has reduced staffing costs and the carbon footprint of movement of staff to conduct works on site. All in all, it has been a very positive move in the right direction.
The Irish government has committed to reducing the country’s emissions by 51% by 2030 and achieving net zero by 2050. This has highlighted the imperative of doing better on reducing emissions in Ireland. To that end, Egis Road & Tunnel Operation Ireland (ERTO), which manages the operation and maintenance of the tunnel, along with the client Transport Infrastructure Ireland (TII), believed that reducing energy consumed in the tunnel would an important step in the right direction.
This could be made true in both performance and in energy savings with a switch to LED. While we work to build a long-term energy infrastructure that’s less dependent on fossil fuels, it is only right that we should also be exploring every avenue simply to use less.
Ultimately, lighting is just one piece of the energy efficiency puzzle, but it is a relatively ‘easy win’. In the case of Dublin Port Tunnel, replacing the old HPS lamps with LED could cut the tunnel’s electricity consumption – and the costs and emissions that come with it – by up to 60%.
When Signify was approached by tunnel maintenance operator ERTO to upgrade the lighting, the R&D team set out to a find a solution that could help go beyond even this energy saving, for example by creating better visibility in the tunnel’s uniform lighting.
The team went a step further in evaluating how the already installed lights could be reused to save TII cost in infrastructure, so the project could contribute to a circular economy.
The team was hopeful that a solution could be found that would bring all the benefits of modern LED road lighting while giving a new lease of life to the fittings, cabling and infrastructure that was already in place.
