Waitrose supermarkets gain up to 9% energy savings
07 November 2016
Waitrose, a British supermarket chain with over 336 shops ranging from large supermarkets to service station forecourts, was looking for a way to dramatically decrease its carbon footprint.
In 2010, Waitrose published its Carbon Plan which clearly documented the business’ approach to reducing emissions. The indirect and direct emissions from the refrigeration systems in its shops are a very significant contributor, making this area a prime target for improvement.
In addition to Waitrose’s internal plans, on 1 January 2015 the European F-Gas regulation (EU 517/2014) came into force, which from 2020 will ban the use of refrigerants with a GWP (Global Warming Potential) of 2500 or more, e.g. R-404A and R-507A, in all new equipment and for service in systems with a charge >40T CO2e (>10.2kg of R-404A).
The Chemours Company is supporting Waitrose in its transition from R-404A refrigeration systems to low GWP Opteon XP40 refrigerant. By retrofitting the refrigeration systems in one of its stores in Devon from R-404A to Opteon XP40, Waitrose gained up to 9 percent energy savings, providing the business with a significant opportunity to lower its CO2e emissions and help achieve the targets set out in its Carbon Plan.
Opteon XP40 refrigerant
Opteon XP40 (R449A) was introduced as an ideal replacement for R404A. Opteon XP40 is a HFO based blend with a GWP of just 1397 which is well below the GWP threshold stated in the F-Gas regulation. The performance of Opteon XP40 is very similar to R404A with a significant reduction in power consumption under a wide range of operating conditions, making it an ideal candidate for retrofitting existing R404A systems.
Refrigeration system and conversion to Opteon XP40 (R-449A)
The decision was taken to retrofit a typical Waitrose store in Holsworthy, Devon from R404A to Opteon XP40. The refrigeration system consisted of two high temperature packs and one low temperature pack all of which were manufactured by Space Cooling Systems in 2004 and all packs use Copeland Scroll compressors. The low temperature pack was connected to six in-store cabinets and one cold store. The high temperature packs were connected to a total of 18 cabinets and three refrigerated counters in the store and three cold rooms for storage.
Operation and energy performance
The energy consumption of the refrigeration systems was measured for two weeks before the retrofit and then for three weeks after the retrofit had been completed. ColdService (part of the EPTA Group) was chosen to perform the retrofit and the first retrofit took place overnight on the 12 July 2015 and the other two packs retrofitted on consecutive nights, without causing any disruption to the trading floor during the store’s opening hours. The Opteon XP40 retrofit guidelines were followed and no components or oil changes were required, making the retrofit very fast and straightforward.
Analysis of the energy consumption data was performed by Emerson Climate Technologies, Retail Solutions, which revealed that at equivalent ambient temperatures during the monitoring period, the high temperature systems energy consumption was reduced by 8.7 percent. For the low temperature system, the energy consumption was reduced by 3.0 percent. For the total refrigeration system, this equates to a reduction in energy consumption of 6.6 percent.
Paul Blanch, Senior Manager, Emerson Climate Technologies, Retail Solutions said that no component changes, no oil changes and similar system operating parameters made the retrofit very straightforward and fast once the R-404A had been recovered. The good cooling performance and lower energy consumption makes Opteon XP40 an ideal retrofit option for R-404A systems.
The reduction in energy consumption and the 64 percent reduction in the GWP of Opteon XP40 compared to R-404A offer a significant opportunity for Waitrose to lower its CO2e emissions and help to achieve the target set out in its Carbon Plan.
Danny Ryan, Refrigeration Manager, Waitrose, who is leading the overall project commented said that reducing the CO2e emissions is a key target and so retrofitting existing R-404A systems with a lower GWP refrigerant is a key part of the strategy. Opteon XP40 has helped achieve this by not only reducing the direct emissions of the refrigerant, but also by reducing the energy consumption of the systems.
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