Peak Shaving: powering heavy luffing cranes on small mains supplies - Dumarey

Dumarey’s partnership with London Tower Cranes & JRL Group

Dumarey supplied London Tower Cranes a revolution battery to run a tower crane. The battery removed the requirement for a diesel generator which cut costs and emissions.

Cliente:

London Tower Cranes & JRL Group
Royal Mint Construction Project

Industries:

Construction

Applications:

Tower Cranes

Customer’s benefits

The Revolution Battery replaced a diesel generator saved over 2400 litres of diesel per week, preventing the emission of 6.4 tonnes for CO2 per week. It also cut costs, reduced noise and improved air quality.

Customer’s need

The London construction boom continues to drive the use of heavy luffing cranes to support high rise buildings on small plots. The Sáez Cranes SL 730 is typical of such heavy cranes, with a 36 tonnes maximum lift capacity. Heavy cranes require large power systems, and with a 123 kW hoist and a 110 kW luffing motor, 315 kVA of mains or a 500 kVA diesel generator would be needed to power the system.

This site had four challenges.

The Royal Mint site was highly compressed with electrified rail lines alongside and underneath. The site had no space for a diesel generator and fuel tank.
The availability of mains was very limited, and adding another 315 kVA to the supply was not possible.
The site is in the Ultra-Low Emissions Zone (ULEZ) mandating the use of a Stage V generator. With a 500 kVA this would require the use of a loadbank to increase engine loading, and this in turn would significantly increase fuel usage.
Fuel deliveries to central London are very challenging with time and size restrictions

To address these challenges, Dumarey Green Power and London Tower Cranes deployed the Revolution Battery energy storage system. The Revolution is a high-power battery, capable of 300 kW of power. It uses a small battery pack to save on costs and space.

Results

The introduction of the Revolution Battery delivered impressive savings in just the first month:

Energy use for the crane averaged 1100 kWh per week, with a cost of just £290
Fuel Savings: Over 2,400 litres of diesel saved each week
Emissions Reduction: More than 6.4 tonnes of CO₂ avoided each week (plus significant NOx and SOx reductions)
Cost Savings: The site avoided rental costs on a 500 kVA Stage V generator, loadbank, fuel and delivery. Savings were far greater than the cost of the battery.
Zero noise, no fuel deliveries, small system footprint

The load cycle of tower cranes is not well suited to Stage V generators. The high peak power demand combined with long periods at idle normally require large generators running at low average loads. These low loadings can result in reliability issues and downtime.

The Revolution Battery, with its small high-power battery pack is ideal for crane applications. 32A of infeed seems very low, but even the most aggressive duty cycle allows for significant charging time as crane loads are connected and disconnected. The small size of the battery system makes it a great choice for a compressed construction site.

Eliminating the use of diesel generators on cranes, and from construction sites in general, has wide ranging benefits. Most obviously cost savings on generator rental and fuel, but also social benefits from CO2 reduction, improved air quality, reduced noise and less deliveries to site.

Dumarey solutions

On-site in London, the Sáez SL 730 installed by London Tower Cranes for customer JRL. The Dumarey Revolution Battery was installed and connected to a 32A 3-phase supply for charging. The output of the battery was connected to the crane isolator. The battery was energised and remained running 24 hours per day.

Compared to a 500 kVA generator, loadbank and fuel tank, the footprint of the battery reduced the space requirement by 70%. As a result of removing the requirement, the site avoided the use of diesel generators completely.