The Project

As part of the UK’s leading community food retailer’s ongoing drive to reduce energy consumption at its stores, Resource Data Management (RDM) have worked closely with the company and its suppliers to trial and provide a new approach at its Lees store in Manchester. The project has resulted in savings of 42% in the energy used to power refrigeration plant, and a 28% reduction in energy use overall at the petrol forecourt and related food store.

The Challenge

With energy costs rising and the necessity to reduce carbon emissions to protect the environment, the UK’s leading community food retailer has set itself the target to significantly reduce energy consumption at its outlets. The aim is to reduce power consumption by at least a third.

The company had already implemented a number of energy-saving measures as part of this strategy. Existing energy-saving technologies included: use of high-efficiency LED lighting in cold rooms; use of EC fans on cases and condensers; optimisation of trim heaters on frozen food cases; use of Passive Infrared Sensors (PIR) to back of house lighting; use of air-bloc air curtain in place of conventional over-door heaters; and Variable Speed Drive (VSD) control for lead compressors.

This latest initiative was intended to further improve energy performance, and provide quantitative evidence of the effectiveness of new energy-saving measures in a working store – that, if successful, could be rolled out across other stores in the future.

The Solution

A control strategy based on the latest RDM control and monitoring systems was at the heart of the fresh approach.

This provided both precise local control to individual items of plant, and an overarching high-level intelligent system – providing detailed feedback on the performance of the total system, including refrigeration and all major energy-using plant.

RDM worked closely with the Co-op and key suppliers George Barkers and installer RSR to implement a solution based on RDM's new control and monitoring system front-end DMTouch and PLC software TDB.

The key elements of the approach included the following:

  • Replacement of existing case controllers with new RDM Mercury case controllers;
  • Replacement of pack controllers with new RDM controllers;
  • Introduction of floating head pressure;
  • Case lighting switched off outside trading hours via GP timer on RDM's DMTouch;
  • Control to ensure optimum condenser temperature difference;
  • Night blind monitoring to ensure maximum savings.

VSD was also used to control supply and extract fans with the air handling unit, and capacity control was added to secondary compressors.

Energy consumption was monitored at the level of individual plant and at the total store level, to enable the effectiveness of the approach to be monitored and compared with previous performance.

The Benefits

Energy consumption monitoring data for the store shows that, as a result of the new approach to control and other energy savings, power consumption by refrigeration equipment fell by 42%. Energy consumption for the store and forecourt as a whole fell by 28%. This equates to a reduction in power consumption per hour of 28.3kW, saving a predicted 247,908kW/ hrs per annum. At a cost of 11p per kilowatt hour, this will result in a saving of £27,270 a year for the store.