17 transcritical CO2 stores already installed in South Africa

With the use or R22 now banned in South Africa, and the country committed to reducing carbon emissions by 34% by 2020 and by 42% by 2030, national retailers are investing in new, climate friendly refrigerant technology. One South African contractor has already installed transcritical CO₂ systems across 17 Woolworths and Makro stores.

Whilst many supermarket refrigeration systems in South Africa still use high global warming potential (GWP) refrigerants, the food-retailing sector is switching over to natural refrigerant systems such as NH₃/CO₂ and CO₂ transcritical systems.

Energy savings of 45% at Woolworths South Africa thanks to CO₂ transcritical

Back in 2010, the Woolworths at the Palmyra Junction shopping centre in Claremont, Cape Town, was only the second store to install a CO₂ refrigeration system. Today Woolworths has at least 8 transcritical CO₂ installations.

The installed refrigeration technology features Danfoss controls and uses a common liquid line to the chillers and freezers with individual suctions lines back to each section on the multiplex system i.e. freezer rack and chiller rack. Thanks to the electronic expansion valves, pack controllers, heat exchangers and plate heat exchangers a reduction in power consumption of up to 45% has been measured.

According to Commercial Refrigeration Services, each Woolworths store has a refrigeration capacity of about 300kW. They also say that because of the size of some of their CO₂ plants, compared to an R404 system the R744 installations cost about 12% more.

In addition to investing in CO₂ refrigeration in store, Woolworths is trailing the use of liquid nitrogen refrigeration in its trucks, which it is hoped will allow the retailer to run an environmentally friendly supply chain from farm, through distribution centre, to ‘green’ store.

All new Makro stores feature CO2 transcritical refrigeration

Makro’s stores built after 2009 incorporate a series of ‘green’ technologies, which include energy efficient CO₂ refrigeration. Each Makro store has a total refrigeration capacity of approximately 600kW, made up of:

2 x 300kW systems
1 x 200kW chiller
100kW freezer

One of the newest CO₂ installations to be built this year will be in the Amanzimtotu Makro store. This store will also feature heat reclaim from the refrigeration system, which will be used to produce hot water to control the temperature on the trading floor.

South African Standards Offer Program – an incentive for investing in natural refrigerants?

The Standards Offer Program offers financial incentives for businesses that can achieve a reduction in energy consumption of between 1kW and 250kW at a single facility. The Programme has been designed to pay large users, who consume electricity for at least 16 hours a day between 6am and 10pm. Retailers can submit applications with required equipment changes either themselves or appoint an energy services company or project developer to do so on their behalf.

Submissions are assessed according to a list of approved technologies and verified energy savings. Once approved, and installations have been completed, the retailer can receive 70% of the total price incentive, with three subsequent payments of 10% based on the system’s actual performance.

Background

According to the submission of the Government of South Africa UNIDO for HCFC phase-out management plan (HPMP) funding, natural refrigerants such as hydrocarbons, CO₂, and ammonia are relatively well known in South Africa. However, stakeholder perceptions about safety considerations, power usage, required skills and the cost of capital equipment continue to constitute the main barriers for their use. The project proposal therefore recommends that each of these barriers needs to be addressed by awareness campaigns.