Two of the Australian chain’s 39 transcritical stores are retrofits, as it tackles refrigerant emissions.
Australian food giant Woolworths, which operates 1,050 supermarkets nationwide, has so far installed transcritical CO2 (R744) refrigeration systems in 39 stores, including two existing outlets where a retrofit took place.
The transition of legacy stores to natural refrigerants is being undertaken through the company's "renewal and refurbishment program," explained Dario Ferlin, Woolworths’ National Sustainable Engineering Manager.
Ferlin shared Woolworths’ refrigeration strategy during an online end-user panel discussion at the ATMO Virtual Trade Show (VTS) on natural refrigerant technologies, held globally on March 30-31. ATMO VTS was organized by shecco, publisher of R744.com.
Woolworths’s two legacy stores were converted to transcritical CO2 without interruption to the store's business hours, Ferlin said.
"That's really where we need to focus our attention because it's the biggest fruit on the tree and it's how we start to bridge that gap,” he said. “It is also the most challenging aspect of our transition."
In addition, wherever feasible, all new stores will be built with transcritical CO2 refrigeration systems, he added.
Woolworths is also striving to install, where possible, transcritical CO2 refrigeration systems that use heat reclaim and incorporate air conditioning. said Ferlin.
Of its 39 transcritical stores opened to date, 19 have integrated space heating. "What that means is we no longer have to rely on natural gas-fired hot water boilers for the production of space-heating hot water," said Ferlin
In addition, 11 of those 19, he said, also incorporate space cooling.
Woolworths began installing transcritical CO2 systems in 2017 at a store in Western Sydney. In addition to the 39 transcritical stores, it also operates more than 350 that use an R134a/CO2 cascade system.
Targeting 60% emissions cut by 2030
Ferlin also discussed the company's recently released 2019 Sustainability Report, where it announced its commitment to reduce carbon emissions by 60% below 2015 levels by 2030. "That aligns with the objective of limiting global warming to 1.5°C above pre-industrial levels," said Ferlin.
Ferlin explained that while around three quarters of Woolworths total emissions are indirect and attributable to off-site fossil fuel energy generation, one quarter are direct emissions.
"The lion's share of direct emissions consists of fugitive refrigerants or specifically fugitive high-GWP synthetic refrigerants," said Ferlin.
To reduce indirect emissions, Ferlin said the company is using rooftop solar as well as renewable energy purchase power agreements (PPAs). Woolworths has committed to purchasing 100% of its energy through renewable PPAs by 2025.
Regarding the remaining quarter of direct emissions, Ferlin said, "Whilst we've made some significant inroads with the adoption of lower-GWP synthetics, i.e., R134a and CO2 cascade, we also have decades of legacy stores that need to be converted."