Bowmer & Kirkland is using an AMPD Enertainer ‘smart battery’, hired from Select Plant, to power two tower cranes on its £60m Goods Yard development in Stoke-on-Trent.

The contractor says that the savings have been remarkable and surpassed expectation.

The Enertainer, made by Hong Kong-based AMPD Energy, provides power when mains electric supply is restricted. It is an energy storage device that is recharged by plugging in to the mains. When off grid, it can be charged by using a smaller diesel generator but by storing energy, it cuts fuels consumption compared to using a traditional diesel generator alone. Select, the plant division of Laing O'Rourke, is AMPD's first UK customer. [See our previous report here.]

Bowmer & Kirkland group crane manager Dave Shooter has calculated that the carbon consumption of the tower cranes at Stoke Goods Yard has been reduced from 7,205 kg of carbon per week to just 106kg – a 98.5% reduction.

The cranes’ specified generator is a 500kVa unit on each, together burning 2,750 litres per week. The battery pack, by contrast, is consuming 550 kwh per week on mains charge.

Dave Shooter says that other benefits over a diesel generator include silent operation, more space on site (because one unit powers multiple cranes) and easier logistics because it needs no fuel monitoring or deliveries.

“We are also looking to connect the construction hoist when the site requires it,” he said. “This eliminates a further generator.”

Bowmer & Kirkland was open to trying the Enertainer because the mains power supply on the Stoke site is not sufficient to power all the heavy plant. The company has previously hired a Punch Flybrid flywheel system with its tower cranes from Select to save on fuel, money and carbon.

Capital&Centric’s Stoke Goods Yard should be completed in 2025.

Sustainability manager Daniel Birkinshaw said: “The team at B+K are very passionate about exploring the use of new innovative low carbon technology to help us to eliminate diesel generated power supporting our net zero carbon by 2040 ambitions. Our data suggests that 80% of our carbon emissions are generated from the use of fossil fuels for site-generated power, where temporary grid electricity is not available.

"Clearly employing battery technology such as the Enertainer plays a large part in reducing our sites carbon emissions for our clients for selected project sites where we have a mains grid power connection installed. The main purpose in us trialling equipment on our cranes is to ensure it works practically and is stable and reliable and to really test the ability and further benefits of this technology, giving our site teams more confidence to role this technology out to further projects.

"As group sustainability manager, I am very pleased with the power and crane teams that they continue to allow us be at the forefront of low carbon technology and continue to look at innovative ways to reduce our carbon emissions.”

The Goods Yard project is turning an industrial site next to Stoke-on-Trent railway station into a new urban neighbourhood, with 174 flats for rent, shops and bars. The developer is Capital&Centric. Completion is expected in 2025.