As part of our #PlanetSeries, we turn the spotlight on the everyday actions of our people who are innovating, pioneering, and embracing solutions that will leave the planet in a better place for future generations.
For Leroy Walker, sustainability is a personal and professional passion. The Project Manager has spent the last six years optimising both his home and his sites, looking for incremental gains in sustainability and efficiency.
Leroy joined Kirby as an Electrical Apprentice in 2006, and has progressed through the ranks, from Site Supervisor to Site Manager and now Project Manager.
Hailing from Ballinasloe, Galway, Leroy built a bungalow on the family farm in 2014. Now home to him, his wife, and their two children, he has spent the last six years optimising the home’s energy performance, while also turning his pursuit of performance to his role as Project Manager on a confidential data centre project in Dublin.
Can you tell us a bit about your project to improve the efficiency of your home?
We installed solar panels in 2020 and chose a 7kW, 20-panel system, as we wanted to future proof the system.
Since 2020, the system has generated about 52MW, which is approximately 7,000kW per year. With a 5kW battery system, we know we have enough energy to run the house when the panels aren’t generating energy and also sell any excess back to the grid.
Our bills now come in at around €380 a year, which includes standing charges.
What else have you done to improve the home?
When building, we invested in six-inch, pumped cavity wall insulation. The bungalow is constructed using block, with sand and cement walls instead of skim, so we made huge gains by doing this. We aren’t quite passive, but the house happily sits at about 19°C degrees during the day and night.
We have vented windows, which keeps air flowing through the home, and that is important for buildings that are as well insulated as ours. Houses need to breathe!
We don’t use oil, and our current heating is solid fuel via a back boiler, however we are looking at the next heating upgrade, which will either be a heat pump or pellet stove.
What type of energy tips would you give to people reading this article?
For us, programming high-use appliances during solar-generating hours or overnight to make use of off-peak prices was hugely beneficial. You’re making use of energy generated and it can be cheaper if you select the right tariff.
Personally, I also monitor energy use across every circuit. I like technology and have systems in place to monitor the performance of the house, constantly optimising it for incremental performance gains.
I’d also recommend people upgrade their immersion heaters if they are looking at a solar system. We have an electric immersion with a circulating pump bypass system and a solar divertor, which is a good way to store energy as hot water when your panels are performing well. The bypass system ensures that water is circulating through your hot water tank, ensuring the whole tank is hot instead of just the top half, this is timed for when the solar is generating and hits a set temperature.
Solar diverters are highly efficient, cost-effective devices that maximise self-consumption of solar energy by directing surplus power to heat hot water instead of exporting it to the grid.
Tell us about how you’re using your passion to improve sustainably on site?
We have centrally controlled electric radiators on site. With 30 container offices and 50 employees, a few small changes have had a huge impact on performance.
We’ve created a system to monitor the usage, with controls to set the temperature – setting it to 20°C during the day and reducing the temperature to 16°C from 6pm. We have halved our energy use in the site cabins thanks to that small change.
We can see our usage on an hour-by-hour basis. The next step is to have modular portable roof-mounted solar panels on our projects, that can be lifted in and out as our projects change, giving various kW sizes.
Our teleporters and site vehicles are also fuelled by HVO. By changing the filters on the vehicles, we have significantly reduced our impact.
Hydrotreated Vegetable Oil (HVO) is a sustainable, paraffinic diesel fuel produced from waste fats and vegetable oils through hydrogenation. As a direct “drop-in” alternative to fossil diesel, it requires no engine modifications, offers up to 90% CO2 reduction, improves cold-weather performance, and is cleaner burning.
