Recently, the ALDI SÜD group has equipped its 300th store with refrigeration systems for cooling racks that are run with the carbon neutral refrigerant CO2. Yet, this is only a portion of the provisions with which the grocery retailer increases sustainability in its stores. In this interview, Agnes Schmitter, Director of Cooling Technology at ALDI SÜD, talks about comprehensive energy management in food retailing and the use of intelligent cooling control systems.
Ms. Schmitter, ALDI SÜD has already being focusing on sustainable environmental management in cooling technology in its stores for many years. Could you briefly explain the different aspects of environmental management?
Environmental management of the cooling technology at ALDI SÜD takes a holistic approach. It starts with investment and ends with the disassembly of the cooling units. Overall, our cooling technology integrates solutions for energy-saving refrigeration equipment, carbon neutral refrigerants as well as permanent quality control with current cooling systems. Obviously, short-term activism is not enough in this case. Progress in sustainable cooling technology for us means continuous improvement.
I would like to give you some examples of this. During the past few years, we were able to reduce energy consumption by up to 50 percent compared to conventional analog control systems by investing in modern and environmentally friendly freezers. Our new plug-in freezers use the natural refrigerant propane (R290). Propane does not contribute to the greenhouse effect and does not exhibit any ozone-depleting effect. We are pleased that we are able to run four out of five freezers at ALDI SÜD with propane today. Our goal is to replace the remaining F-gas freezers with propane-powered units by the end of 2015.
Starting in 2015, the European Union prohibits the use of conventional HCFC refrigerants in existing cooling and air conditioning systems due to their ozone-depleting effect. We at ALDI SÜD however, have already decided in 1996 to completely dispose of ozone-depleting refrigerants in new systems. What’s more, in 2008, we have replaced all of the existing HCFC cooling equipment with climate-friendly refrigerants such as R134a (tetrafluorethane) or R744 (CO2).
Since 2010, we have also been outfitting all multi-compressor refrigeration systems (NT/LT) in our new stores with the natural refrigerant CO2 (R744). In more than 300 of our stores, we run transcritical CO2 refrigeration systems. In the same way, we continuously replace old cooling systems with GWP refrigerants such as R404A with this sustainable and efficient technology, so that we also expect significantly reduced greenhouse gas emissions from F-gas losses and reduced energy consumption this year.
What other measures does ALDI SÜD take to achieve an improved energy balance?
Thanks to the comprehensive integration of modern fluorescent lighting with electronic ballasts in freezer cases, we were able to already achieve significant energy savings; in fact up to 35 percent compared to conventional lighting systems. Since the lighting we use has a considerably longer lifespan, higher light output and energy efficiency, we also save important resources and are able to reduce our electronic waste immensely. Since 2012, all of our new freezers and cooling shelves are equipped with LED lighting. Particularly in a cold environment, the very high efficiency of this LED technology can be optimally utilized.
However, we are also pursuing many other measures, addressing –among others – topics such as optimized night covers, Frigotakt PLUS Control (the Frigotakt Plus Control process continuously calculates the ideal operating point of the unit), speed-regulated compressors, energy-saving fans, waste heat recovery, optimized defrost management systems, Bitzer ECOLINE compressors, additional condenser unit cleaning throughout the year or a full maintenance contract with predetermined service intervals.
We also conduct quarterly conferences with our suppliers to discuss energy consumption and refrigerant losses. Every new unit also receives a technical inspection by an external service provider.
What role does the use of intelligent control systems as well as other technical improvements in cooling units play during daily operations at an ALDI SÜD store?
Intelligent control systems have many advantages for daily operations. On the one hand, by using our intelligent control systems we guarantee an optimal temperature level in our cooling shelves and freezers. It is our requirement that our customers receive our products at anytime and anywhere on the cooling shelf or in the freezer at the required temperature level. Our intelligent cooling control systems make it possible to optimize the evaporation temperature at the individual cooling positions and the multi-compressor refrigeration system.
In addition, we have introduced energy monitoring via remote data transmission and also control the settings by remote transmission. Run-time control for the compressors and load management result in continuous energy improvement. What’s more, they allow us to act proactively in terms of the units – instead of just reacting to problems like before.
Particularly with regard to the F-gas regulation that becomes effective on January 1, 2015, the technical development of Mobilec is a big advantage in daily operations at ALDI SÜD. Mobilec, short for “mobile leakage monitoring system“, is an innovative quality assurance system for tracking all refrigerant activities and services such as maintenance operations and leak testing. Mobilec utilizes communication options between the mobile phone of the service employee on site and the benefits of central data management and evaluation. Today, Mobilec already tracks all refrigerant activities and automatically informs the responsible regional subsidiary about an increased leakage rate of a unit. Thanks to Mobilec, today we already meet the “record-keeping and reporting requirements” of the upcoming F-gas regulation.
Many supermarket operators use systems with integrated waste heat recovery to further increase sustainability. Does ALDI SÜD also use these kinds of solutions?
Yes, we do. In our system concepts at ALDI SÜD, we differentiate between waste heat recovery from ventilation systems and waste heat recovery from cooling processes.
Interview by Daniel Stöter, iXtenso.com
