Thorntons has substantially reduced energy consumption and costs at its main chocolate production site in Derbyshire by standardising on Hawker LifeTech high frequency battery chargers from EnerSys across its entire materials handling fleet. The company predicts that it will achieve a two-to-one return on its investment over the lifetime of the contract.
“This is part of a wider programme to reduce our carbon footprint,” says Dan Crow, Facilities Manager at Thorntons. “We wanted to reduce our materials handling energy bills and lift truck downtime and the EnerSys chargers have helped us do this.”
Established by Joseph William Thornton in 1911, Thorntons is now a £200m turnover business with 381 shops and cafés and 261 franchises complemented by its internet, mail order and commercial operations. The company’s main site in Somercotes, Derbyshire, was opened in 1980s and comprises separate but adjoining areas for production, packing and storage. Around 100 lift trucks and other pieces of materials handling equipment are used on the site, including 50 in production and packing areas.
The decision to adopt Hawker LifeTech high frequency chargers from EnerSys was taken during 2007 when Thorntons appointed Linde Material Handling UK Ltd as its new lift truck supplier. The project was overseen by Linde corporate accounts manager Paul Grady. Thorntons wanted to reduce energy costs and improve overall materials handling efficiency by reducing downtime related to battery charging. The first batch of 30 trucks supplied by Linde on contract hire included narrow aisle combination stacker/pickers, low level order pickers, reach trucks, electric counterbalance trucks and powered pallet transporters, all with EnerSys batteries.
“We didn’t specify batteries but took the EnerSys chargers because Linde recommended them,” says Dan Crow. “Battery choice is left to Linde as part of the overall package.”
As part of the contract transition EnerSys and Linde completed a full site survey which included a calculation of the potential energy savings that could be achieved by switching the entire fleet to high frequency charging. This compared the performance of the existing chargers with the new units. The survey concluded that a significant saving would be made in energy consumption and topping up frequency which would be reduced from once a week to once a month. All 100 trucks on site are now using EnerSys chargers although many still have their original batteries.
“We ended up projecting a £14000 saving on a £7000 investment,” says Dan Crow. “For the wider business this is a relatively small figure but it roughly equates to the cost of renting two lift trucks for a year so in the materials handling context it’s significant. The initial cost of the truck is only around 10 per cent of the whole life cost so operational savings are important.”
The Hawker LifeTech high frequency chargers offer outstanding energy efficiency which can be as much as 20 per cent higher than traditional 50 Hz chargers. The charger automatically detects the battery’s level of discharge and will supply only the amount of power needed – and no more – to restore full charge. This means less mains power is required with significant savings in electricity costs. The optimised charging also reduces the amount of electrolyte used which means extended intervals between top ups, with greater truck availability and less downtime.
The increased reliability of the trucks and the shorter charging time has already helped to reduce overall truck downtime which has a direct impact on productivity. Like most businesses there is little spare capacity in the lift truck fleet and any disruption to the materials handling operation can have an immediate and potentially expensive knock-on effect to busy production and packing areas.
“The decrease in charging time is very important but this was a bonus because the main objective was energy savings,” says Dan Crow.
EnerSys and Linde worked closely with Thorntons to manage the transition to the new chargers. On site there are six main charging areas with a few smaller facilities in remote locations. One of the benefits of adopting Hawker LifeTech chargers is their compact size and wall mounting.
“This has saved considerable space across the whole site which can be put to other uses,” says Paul Grady of Linde. “It also helps improve hygiene in food production and storage areas because floors are unobstructed and easier to clean.”
For simplicity Thorntons pairs batteries with each lift truck. The company acknowledges that before the changes batteries were one of the main causes of problems with the trucks. However, a new battery maintenance regime was introduced by the company and then developed in partnership with Linde and EnerSys to improve overall truck reliability and availability.
“As well as saving energy and reducing costs,” says Dan Crow. “the guys on the trucks like them because it makes the job more straightforward.”
The successful reduction in lift truck energy consumption achieved by Dan Crow and the utility team is part of a wider initiative by Thorntons to reduce the environmental impact of its products. During 2009, for example, the company is using a new design for its Easter Egg packs that will reduce the material used by 22 per cent, equivalent to 73 tonnes of packaging.
Enersys Motive Power
Tel: 0161 727 3800