The decision to switch follows a  trial of 10 battery storage units on the contractor’s sites.

Kier has established a monthly saving per unit of seven tonnes of carbon, an overall reduction in generator run time of 59%, and a cost saving of over £2,000, after BSU hire costs are accounted for.

Hirer Sunbelt Rentals will supply the battery storage units to Kier sites.

Generators and BSU work in tandem as the main source of electricity to site operations.  When the battery is running low, the generator automatically starts and recharges it, turning off once fully charged.

This means generators can be downsized, leading to significant fuel savings, reducing both costs and carbon.

Chris Lilley, Kier Group health, safety, wellbeing and sustainability director, said: “This is a positive step forward for us to achieve the commitments laid out in our Building for a Sustainable World framework.

“It will help us to reduce our greenhouse gas emissions in line with our pathway to net zero, outlined in our carbon reduction plan. Not only that, but it will allow us to significantly lower our fuel costs.”

Mark Bown, national account manager at Sunbelt Rentals said: “This BSU agreement between Sunbelt Rentals and Kier dovetails with our on-going strategic capital investment in clean energy solutions. It also allows us the scalability to be able to provide cost-savings for our customers while lowering noise and carbon emissions.”