How Coles has reduced its refrigeration costs and environmental impact
How Coles Katoomba has reduced its costs and environmental impact by implementing a new refrigeration system is revealed by BRENT HOARE of the Australian Refrigeration Association.
Until recently, conventional supermarket refrigeration systems have relied on a fluorocarbon refrigerant known as HFC 404a. These systems have had an average leakage rate of around 15 percent of the charge, which is typically around 500 to 1000 kilograms for a suburban supermarket. Although safe for the ozone layer, every kilogram of HFC 404a has the same climate impact of just less than four tonnes of carbon dioxide.
Even before the substantial increase in refrigerant prices introduced by the Clean Energy Future program, the cost burden of leaking HFC refrigeration systems was of concern to supermarket operators. Rapidly rising increases in atmospheric HFC concentrations are a relatively easy source of emissions to control.
As far back as 2005 the impending introduction of a price on carbon led to the construction by Coles of the first supermarkets with carbon dioxide refrigeration systems in Australia in Gisborne, Victoria and Winmalee, New South Wales. Many design advances have been made since then.
TRIALS AND MONITORING
Coles’ head engineer, Calum Shaw notes that Coles has invested heavily and spent a lot of time and money on designing, testing and trialling environmentally safe carbon dioxide refrigeration systems to deliver the most cost and energy efficient solutions.
“We have worked hard to research best practices all over the world. We know retailers and system designers across Europe well and talk with them regularly to keep across the latest developments in this rapidly moving field. Applying this knowledge to Australian conditions with our contractors has enabled us to develop new supermarkets that are among the best in the world.
“There are many improvements we’ve made to cut costs and electricity use, things like efficient LED lighting, installing night blinds on display cabinets and integrating the air-conditioning system with the refrigeration in the one central plant. But, using carbon dioxide refrigerant throughout all the fixed cabinets in-store is an efficient and future proof approach,” Shaw states.
He adds that Coles now has 44 stores that use carbon dioxide refrigerant among the over 700 it owns and that, as new stores are developed and existing ones retrofitted, this number will grow rapidly. “Refrigeration is a major source of energy costs for our stores – typically over 50 percent. This new refrigeration system will reduce our energy bill by approximately 5 percent in new stores.”
He adds that in its existing stores Coles is seeking to reduce emissions immediately by substituting HFC 404a with an interim substitute called HFC 407f, which has around half the direct global warming impact and is considered only an interim solution.
“More importantly, Coles, in partnership with City Facilities Management, has made huge improvements in system monitoring, so we know where and when any leakage is taking place, and have paid a lot of attention to implementing a tightly controlled program of preventative maintenance to ensure leaks are minimised to the fullest extent,” Shaw states.
7 PERCENT LESS ENERGY
Coles Katoomba uses a cascade carbon dioxide refrigeration system with a 1.2-tonne charge of carbon dioxide on the ‘low side’ servicing the cabinets, and a 400-kilogram charge of R134a on the ‘high side’ that is contained in the plant room. Using this system to run both refrigeration and air-conditioning cooling demands is estimated to deliver around a seven percent reduction in energy consumption compared to conventional stores.
On 29 January 2013, at Coles Katoomba, the results of changes it has implemented – which have reduced both its costs and environmental impacts – were proudly presented by Shaw to Senator Doug Cameron, who was accompanied by ALP candidate for Macquarie, Susan Templeman and Ward 1 councillor, Don McGregor.
Initiated by the Australian Refrigeration Association, the site visit made in order to highlight the outstanding achievements being made by Coles at its new stores. Cameron stated that he was “extremely impressed” by how far Coles has moved in the last few years in reducing both its environmental impacts and costs.
“Last year, the Gillard Government introduced a levy on the synthetic hydrofluorocarbon (HFC) refrigerants, as a complementary measure to the price on carbon. These gases have an impact on global warming that is sometimes thousands of times more potent than carbon dioxide. End users such as Coles have been planning for this for many years, and the state-of-the-art carbon dioxide cascade refrigeration system at the Katoomba store is the result.
“Coles deserves great credit for reducing the direct emissions of fluorocarbon refrigerants, and has been rewarded by substantial cost savings. I’m very pleased to see this kind of innovation being used to reduce energy consumption and eliminate the cost of using synthetic refrigerants,” Cameron noted at the event.
Australian Refrigeration Association president, Tim Edwards complimented Coles on the innovation in evidence at the new Katoomba store. “Due to the financial incentive now imposed by the government for industry to avoid the use of environmentally harmful refrigerants, we are confident that Australia really is leading the world. While there is still some way to go towards achieving HFC-free supermarkets that can deliver high levels of energy efficiency, the systems now being rolled out are a big step along this path,” Edwards said.
“With better acceptance of the natural refrigerants, further system refinement, more widespread training and up-skilling of commissioning engineers and service contractors, and greater component availability and production capacity from suppliers, we are confident the lead set by Coles will have far-reaching impacts across the industry,” he added.
“Using carbon dioxide, ammonia and hydrocarbon refrigerants makes sound economic and environmental good sense. Any additional incentive to move beyond HFCs provided by the carbon equivalent levy will only help to speed the transition that is well underway,” Edwards concluded.