A construction site in Dublin has embraced a new approach to reduce electricity use and minimize reliance on fossil fuels. By installing batteries to charge generators, the site has made significant strides in saving energy.
Construction sites typically require a substantial amount of electricity for equipment such as cranes, drying rooms, worker offices, and lighting. This high demand often exceeds the capacity of the local electricity supply, prompting many sites to generate their own power, typically through diesel generators.
However, this method can be inefficient. Generators are often sized to meet peak demand, such as when a crane motor lifts a heavy load. Once the demand drops, most of the power generated is not needed, leading to unnecessary fuel consumption.
Tom O’Malley, sustainability lead at Clancy Construction, has been working at a construction site in Stillorgan, where a social housing project and library are being built for Dún Laoghaire/Rathdown County Council. He explained that the site typically operates three generators for ten hours each day, even when not all of the power is required.
“These generators run continuously, burning fuel even when not all the site equipment is using power,” O’Malley said. “It’s like running a car engine just to charge a mobile phone.”
Recognizing the inefficiencies in their energy setup, Clancy Construction partnered with JTM Energy, a Wicklow-based company, to implement a new solution. The setup involves one generator charging a 160kVA battery, which stores 240kWh of energy. This battery now powers the entire site.
The generator now operates for just five hours a day to charge the battery, a significant reduction compared to running three generators for ten hours daily.
Frank Daly from JTM Energy pointed out that this is the first construction site known to operate entirely on battery power, both in Ireland and the UK. “The whole site runs off the battery, and the generator simply tops it up when needed,” Daly explained.
The key advantage of this system is that it eliminates the inefficiencies of traditional generator setups. “Generators work most efficiently when they are fully loaded,” Daly said. “A generator running without a proper load is like a car stuck in traffic—it’s not operating at its best. By using the generator to charge the battery, it stays loaded and runs efficiently, turning off once the battery is full.”
While the battery and control system required a significant investment from Clancy Construction, the company expects it will pay off in a few years. O’Malley estimates that the system will have a return on investment in about three and a half years. “We’ll use this system on future sites as well,” he said, noting that the battery is robust and suitable for long-term use across the business.
Dún Laoghaire/Rathdown County Council also supported the project. County Architect Andrée Dargan explained that the council is committed to climate action, making it a priority to explore innovative solutions. “We looked at this from our energy support budget, and the council is eager to support sustainable initiatives.”
Daly added that battery systems like this can be used in various settings beyond construction sites, including homes and businesses. “Batteries offer grid resilience in case of power outages, like the recent storm. They can also help businesses take advantage of cheaper electricity at night or during low demand periods,” he said. “They’re also useful for enhancing renewable energy systems, such as solar panels.”
Dargan also highlighted the broader benefits of battery use, such as reducing noise and air pollution. “This project is not just about emissions reduction. It’s also about improving working conditions and benefiting the surrounding community,” she said. “The site is quieter, which is better for both the workers and local residents.”
This initiative marks a positive step forward in making construction more sustainable and less reliant on traditional, polluting energy sources.
