When it comes to delivering on environmental promises, Groupe Auchan has an enviable record, having been rated among the greenest supermarket chains – and openly publishing its ambitious annual carbon reduction targets.
Part of this eco-commitment involves finding greener ways of operating its stores – and this includes refrigeration – so when the company heard about the benefits of a new Honeywell HFO blend – Solstice N13 (R-450A) – they were keen to test its credentials. Solstice N13, recently awarded official ASHRAE R-450A, is an alternative to R-134a, offering similar performance but with a superior GWP of ~600, and is suitable for chillers – and MT refrigeration (distributed, CO2 cascade), offering the best nonflammable replacement for R-134a.
Approval was given to design a combined Solstice N13/CO2 refrigeration system for a new large hypermarket opening in Epinaysur-Seine (Paris), with measurement criteria focused on energy efficiency, equivalent CO2 emissions reduction and refrigeration performance.
The test utilised a new design of low energy refrigeration unit, and involved a team from Auchan, the company’s refrigeration partners Axima Refrigeration and Honeywell. The test focused on assessing the merits of a system that incorporated an N13 liquefaction unit alongside a CO2 refrigerated distribution circuit.
The system was then compared with Auchan’s current standard setup that used R-134a and glycol water with CO2.
The results to date have been encouraging, and include:
- Easy commissioning, with similar energy efficiency as R-134a
- A global saving of 90 tonsCO2eq / year compared with a secondary
Glycol / R-134a /CO2 system and savings of 960 tons CO2 eq / year compared to using a standard R-404A DX system.
“Our aim was to successfully trial the new HFO blend N13 in a flagship store and to prove its operational and energy saving credentials. The results speak for themselves,” said Jean-Michel Deroo of Groupe Auchan.
Supporting environmental goals
Groupe Auchan is at the leading edge of mitigating the ecological footprint generated by its different activities, and constantly strives to innovate in order to lower energy consumption, contribute to the fight against global warming and promote biodiversity.
All of the group’s businesses control their energy consumption by setting ambitious annual reduction targets. The installation of smart meters helps chains identify waste and optimise consumption.
To help meet the European Union’s objective of 20% of all energy usage coming from renewable energy by 2020, Auchan has invested in solar and geothermal energy over the recent years. All new buildings include autonomous energy production systems and, as a result, more than 55% of energy consumed by Auchan comes from renewable sources.
The refrigeration pilot project at Epinay-sur-Seine is, therefore, entirely in keeping with the context of building a greener operating environment.
From this start point, the company participated in a wider partnership, involving the end user plus Honeywell (and its Solstice ze technology), L’Ecole des Mines de Paris and Total – Ademe, to build a second prototype machine. The aim was to develop a machine that was not only capable of delivering hot water at 97OC, but could also immediately cool the product down to 2OC using chilled water. This second machine would be assessed against key criteria, including environmental performance, process effectiveness and pay-back linked to energy efficiency.
Field test and implementation
Groupe Auchan worked alongside its refrigeration partner Axima Refrigeration to develop a system for the Epinaysur-Seine store that combined the low GWP and energy efficiency benefits of a new refrigeration HFO blend named Solstice N13 (R-450A) – and the proven performance of pumped CO2.
The system uses Solstice N13 in a liquefaction unit to convert gaseous CO2 into a liquid that is then pumped to deep freeze containers, cold rooms and display cabinets. The CO2 returns in a gaseous form to the Solstice N13 liquefaction unit ready for converting again to liquid.
“Groupe Auchan places environmental responsibility at the top of its business agenda, and we are very supportive of innovations such as this new approach to refrigeration _ that delivers benefits to us as a business, to the customers we serve and to the wider community,” said Deroo.
“We are continuously looking to apply more sustainable and lower GWP solutions into supermarkets such as Auchan. With the experience and results of this Solstice N13 trial, we are now confident that we can deliver even greater environmental benefits to the industry. The choice of refrigerant is a fundamental element in our strategy for the reduction of CO2 equivalent emissions and for maintaining or improving energy efficiency,” said Cédric Leroy, Axima Refrigeration.
Rolling out the benefits
The field test with Groupe Auchan confirms the energy efficiency benefits of using Solstice N13 (R-450A) alongside CO2 in a cascade system, with additional advantages in terms of CO2 equivalent emissions reduction and much lower GWP (-58%) over traditional refrigerants such as R-134a.