Tesco, Multiple Depots Nationwide

Regional Distribution Centre project delivery by Eco Instruments greatly reduces Tesco energy bills.

Subject: RDC Energy savings delivery

Tesco is the largest food retailer in the UK with approximately 4000 stores in total, of which around 1400 of are Extra superstores and the remainder are the Express convenience store brand. To support this Tesco runs a 24/7/365 Distribution activity with several major UK RDC hubs

Challenge

Tesco has worked for over 10 years to reduce the energy consumption per m2 by over 50% across their entire property portfolio and took a leading role in legislation around Climate Change Levy, Carbon Reduction Commitment and more recently new ESOS legislation (Energy Savings Opportunity Scheme). These warehouse units operate 24/7 and contain a combination of refrigeration areas for product storage, ambient temperature racking and lighting and heating for staff comfort and safety.

Eco Instruments was asked to come up with new initiatives for energy savings in the majority of their sites, the Regional Distribution Centres that are located throughout the UK to support the retail networks. Many of the complexities in energy reduction are due to constant door opening/closing throughout the 24 hour period and ensure both correct storage temperature for all products as well as staff comfort.

Solution

Eco Instruments was given access to historical data and daily profiles for sites for all utilities to initially assess how working patterns and shipments impacted energy consumption at the sites. After careful on site audit work they identified key areas for improvement that would allow for effective on-going operations without changing working conditions for staff – and most importantly focusing on energy efficiencies and the resulting cost and carbon footprint reductions.

After initial site analysis and audits, the key areas of wastage were identified as:

• Inadequate control of space heating systems
• Lack of insulation of heating system distribution network
• Air Handling Unit management was not synchronised with heating demands
• VSDs not installed on large motors.

Eco Instruments initially implemented a mechanical solution to reconfigure the return AHU – it had previously been pulling fresh unheated air from outside, whatever the external temperature, and using high amounts of energy to heat the cooler air to target temperature. By taking already heated air from within the RDC ceiling area and only heating this volume they achieved a significant reduction in gas consumption.

In addition by installing an array of temperature sensors in appropriate locations within the RDC the newly configured  control system was able to respond to local demand in a more efficient manner, creating an intelligent feedback loop. As a result of not “overheating” the air then a more even and comfortable temperature was achieved throughout the warehouse.

Results

• Overall reduction of 4,200,000kwh 
• Split 55% gas, 45% electricity
• Payback well under 4 years