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On the occassion of the International Ozone Day, we have updated our article about one very successful project, where natural refrigerants replaced ozone depleting substances: Two South African HCFC-22 supermarket refrigeration systems with high leakage rates are currently being replaced with R717/R744 cascade systems. 2,000 tonnes CO₂e per year of direct emissions will be eliminated, in addition to improved energy efficiency. The project will also provide technicians with training. UPDATE: The Deutsche Welle has visited the supermarket after project completion and taken a closer look at the installed systems. The video is now online. 

Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH in conjunction with the South African Department of Environmental Affairs and Tourism, the National Ozone Office, the Designated National Authority, and South African supermarket chain Pick'n Pay are in the final stages of a project under which the refrigeration systems in two supermarket stores in South Africa are being converted from HCFC-22 to cascade systems with ammonia as the primary refrigerant. The project, funded by the German Environment Ministry and approved in October 2008, uses a budget of €1.6 million until December 2009.

Two stores with high leakage rates selected for the conversion

Two supermarket stores located in zones of South Africa with different climate condition, namely in Johannesburg and in Cape Town, were selected for the conversion. The systems that these stores featured, suffered from high refrigerant leakage rates:

• 30% leakage rate per year in the Johannesburg store: The refrigeration system at this store with a refrigerant charge of 1,200 kg has a 30% leakage rate per year, which equals a release of 360 kg HCFC-22 and approximately 600 tonnes CO₂e annually.

• 80% leakage rate per year in the Cape Town store: The refrigeration system at the store in Cape Town with a refrigerant charge of 1,000 kg has an 80% leakage rate per year, which equals to a release of 800 kg HCFC-22 and approximately 1,400 tonnes CO₂e annually.

Due to these high rates of leakage, the systems had to be refilled regularly with expensive fluorinated refrigerants to avoid operation at reduced efficiency. Through the conversion of the HCFC-22 system to natural refrigerants, direct emissions of 2,000 tonnes CO2e per year will be eliminated, while about 0.06 ODP tonnes HCFC-22 will also be avoided. In addition, significant energy savings will be realised through the installation of more energy-efficient natural refrigerant-based equipment.

Technology & Training to work together

The technology: The new technology is a cascade system, with ammonia as the primary system located in a machine room outside the sales area and a glycol-water solution for distribution inside the store. The CO₂-cascade, as the secondary system, provides the cooling for the low temperature applications. Although manufactured in Europe, the technology is supplied through local refrigeration companies, to ensure wider deployment in the future.

Training of technicians: Training the supermarket’s service technicians in the maintenance and servicing of the new equipment constitutes integral part of the project, as it will ensure optimal performance and safe handling of the equipment.

Generating Clean Development Mechanism credits: The project also develops a financing model including tradable carbon credits for emissions reductions via the Clean Development Mechanism (CDM).

South Africa - naturally cooling supermarkets

Have a look at the video (German) showing the installed R717/R744 cascade systems and interviews with the supermarket manager and involved companies. 

Source: Deutsche Welle