ALDI US, a small-format discount grocery chain with more than 2,400 stores across 38 states and growing, has now deployed transcritical CO2 (R744) refrigeration systems in 745 outlets – considered the most installations of this technology for any U.S. food retailer.
The installations include 188 remodeled stores, with the rest new buildings. The chain implements natural refrigerant-based systems in about 70 to 100 stores annually, including both new and remodeled stores, as it heads toward a chain-wide rollout by 2035.
This update was provided by Amber Hardy, Director, Systems & Sustainability, for ALDI US’s National Real Estate division, based in Dublin, Ohio. (The chain’s corporate headquarters is in Batavia, Illinois.) On November 12, Time magazine announced that Hardy was part of its TIME100 Climate list of the 100 most influential climate leaders in business for 2024.
In Southern U.S. states, where ambient temperatures are higher than the U.S. average, ALDI US typically uses adiabatic gas coolers to improve the efficiency of the transcritical CO2 systems. “We also have several trials using other [efficiency-enhancing] technology,” such as parallel compression and ejectors, said Hardy, adding that ALDI US is also looking at other options.
ALDI US’s primary transcritical CO2 system is the Advansor Flex from Hillphoenix, though the chain has installed systems from other OEMs as well, said Hardy.
“Natural refrigerants are the one of the biggest opportunities for us. We’ve been aware of that and have strategically positioned ourselves to make the full commitment for years.”
Amber Hardy, Director, Systems & Sustainability, for ALDI US’s National Real Estate division
ALDI US has also fully equipped almost 30 new stores with propane (R290)-based display cases and walk-ins for medium- and low-temperature refrigeration, including nine “hybrid” stores with R290 cases and R448A walk-ins, said Hardy. Most of these stores are in Florida, with some in California, and one in upstate New York. All use a glycol loop system to remove condensation heat except for the New York store, which employs air-cooled cases.
In addition to the R290-based stores, ALDI US has installed between eight and 10 self-contained R290 spot merchandisers and chest freezers in the rest of its outlets. The chain’s R290 case providers include Hussmann and AHT Cooling Systems USA, said Hardy.
In the Southern U.S. ALDI US is deploying both transcritical CO2 and store-wide R290 cases “to ensure, with our rapid expansion, that we have plenty of options, especially in more challenging climate zones,” said Hardy. The chain is conducting a cost/benefit analysis of each system type.
At its 26 distribution centers, ALDI US has ammonia (R717)-based cold-storage systems.
Hardy did not comment on the refrigeration systems used by independently operated Winn-Dixie and Harveys stores, both of which ALDI US acquired this year.
SBTi emissions targets
Like all U.S. retailers ALDI US has been impacted by HFC regulations at the state and federal level in formulating its refrigeration strategy. But the biggest driver of ALDI US’s leadership in natural refrigerant installations is the overall commitment by its parent company, Salzburg, Austria-based ALDI SOUTH Group, to carbon emissions reduction, explained Hardy. This includes one of the most aggressive Scope 1 and Scope 2 targets for 2035 under the Science Based Targets initiative (SBTi) – a 90% reduction from the 2021 base year – leading to net-zero emissions by 2050 across the value chain. The company is one of the first international grocery retailers with net-zero emissions targets validated by the SBTi.
In the effort to reduce greenhouse gas emissions, “natural refrigerants are the one of the biggest opportunities for us,” Hardy said. “We’ve been aware of that and have strategically positioned ourselves to make the full commitment for years.”
Using natural refrigerants, which have an ultra-low GWP, has helped ALDI US save 60% of potential carbon emissions annually, she said. Regarding their effect on energy efficiency, “we do [find energy savings] but it’s climate-specific.”
Being part of ALDI SOUTH Group, which has adopted natural refrigerant technology widely in Europe, has directly helped ALDI US’s rollout. “Working with our peers internationally and seeing the trends has supported our strategy and decision-making,” Hardy said.
ALDI US’s plan for natural refrigerants will stay on course, regardless of whether U.S. federal regulations change under the second Trump administration. “Our strategy is independent and based on global goals and initiatives,” said Hardy.
In September, ALDI US’s natural refrigerant stores enabled it to receive, for the sixth year in a row, the Store Certification Excellence award from the U.S. Environmental Protection Agency (EPA)’s GreenChill program. The award goes to the food retailer with the most stores meeting the GreenChill certification criteria for emissions reduction. ALDI US certified 611 stores, all using natural refrigerants, between July 1, 2023 and June 30, 2024, at the platinum (highest) level. ALDI US secured more EPA certifications at the platinum level than all participating U.S. grocery retailers for the third year in a row.
The EPA also awarded 164 ALDI stores in 23 states with GreenChill Store Re-Certification Excellence, recognizing these locations for five consecutive years of platinum level certifications. One of those stores is located in Decatur, Georgia, where a transcritical CO2 system is used in a warm climate. In addition, ATMOsphere, publisher of NaturalRefrigerants.com, recognized ALDI US in 2023 with its ATMO Best-in-Sector/Retail award for its leadership in natural refrigerant installations.
Doors and other energy savers
Natural refrigeration is not ALDI US’s only store-based initiative. It recently announced that it has piloted the installation of multi-deck unit doors on deli sections in more than 100 stores, which has reduced energy usage by up to 25% in these stores. “We are continuing to study the impacts,” said Hardy.
The chain has also implemented technology from Flō Energy Solutions to recover waste heat from transcritical CO2 units and reuse the heat for space heating at most CO2 stores, with the rest slated to get this capability. It has also installed digital temperature monitoring system from IMS Evolve in about half of its stores on the way to a full rollout.
According to ALDI US’s 2023 Sustainability Report issued last month, 185 ALDI stores and 14 distribution centers are powered in part by solar or wind energy.
