Sainsbury’s, the second largest chain of UK supermarkets, was the first retailer to make a commitment to convert every store across the UK to CO2 refrigeration. In doing so, their carbon footprint will be reduced by a third.
It may sound strange that CO2 is considered an environmentally responsible refrigerant. However, CO2 is a by-product of many industries. Instead of just throwing it out into the atmosphere, supermarkets can contain it in their refrigeration systems.
Trading was Maintained During Installation
Initially, when Sainsbury’s made the commitment to convert their refrigeration, seven pilot stores were chosen. Danfoss has been part of the project since the beginning in 2009.
“We chose Danfoss because of their proven record and the level of technical support they were able to provide us with,” says John Skelton who is Head of Refrigeration at Sainsbury’s. “Four of the seven pilot stores were existing Sainsbury’s stores and it was crucial that trading was maintained in all of these during the retrofit.”
That goal was successfully achieved through a novel approach: a collaboration of 23 suppliers, including Danfoss, who pooled their expertise and installed three different transcritical CO2 refrigeration systems in the pilot stores. All the installations were completed on time and with minimal disruption to trading. Subsequently, a blueprint was created to get it “right first time” in future installations.
Further Savings Through Operating the System
At Sainsbury’s the expectations for the outcome are high. While the carbon footprint reduction has been the primary reason for converting to CO2 refrigeration in all Sainsbury’s stores, the potential operational savings are interesting as well.
“Around 40% of the energy consumption in a supermarket is related to refrigeration so obviously it is important for us to look at ways of reducing that figure,” says John Skelton.
“We know that simply replacing old components with new ones will reduce our consumption – but we do expect that with Danfoss’ dedicated CO2 components we will be able to achieve even further savings.”
Facts about CO2 as Refrigerant:
Today, supermarkets worldwide use synthetic greenhouse gases as refrigerants in refrigeration systems. A 60% reduction in CO2 equivalent emissions can be achieved in the refrigeration systems of food retailers by replacing synthetic refrigerants with natural CO2. Even so, over 99% of grocery stores are yet to make the switch.