Energy demands in U.S. supermarkets are massive, with refrigeration and lighting accounting for over 50% of total energy use. Each year, the average American supermarket consumes roughly 50 kilowatt-hours (kWh) of electricity, and 50 cubic feet of natural gas per square foot. This translates into average annual energy costs of $200,000, and the emission of 1,900 tons of CO2 into the atmosphere–the equivalent of 360 vehicles. Even small grocery stores have significant energy requirements as walk-in freezers experience severe heat infiltration during operating hours, necessitating the consumption of more power to keep foods at the desired temperature.
Grocery and supermarket chains are constantly seeking innovative yet proven methods to reduce energy spend and the carbon footprints of their stores. Profit margins in the grocery space are razor thin, and researchers at energystar.gov estimate that $1 in energy savings is equivalent to increasing sales by $59.
Proven Grocery Freezer Improvements
To tap into these potential energy savings, a large well-known international grocery chain invited Viking Cold Solutions™ to conduct a measurement and verification study of its thermal energy storage (TES) technology in a typical grocery store freezer.
Viking Cold’s TES systems optimize existing low-temperature refrigeration systems with groundbreaking technology to decrease energy consumption, lower operating expenses and reduce carbon footprint. The company’s patented solution uses food- safe, non-toxic phase change material (PCM), which absorbs 300 times more heat than food, to maintain stable temperatures and save up to 35% of energy costs (see how TES works).
Viking Cold’s patented TES solution was installed in the 320 ft2 main grocery walk-in freezer at a store in Fremont, CA. The data was collected during normal operating times including peak business hours when energy challenges, such as excessive cooling-loss due to continual freezer door openings, were most pressing. The study observed that even across multiple operating scenarios (running for overall energy reduction, running for load shift/peak period avoidance) and energy sources (grid and solar) the Viking Cold TES system produced significant results:
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Refrigeration equipment was able to be turned off for extended periods of time while maintaining stable temperatures, and overall electricity load was reduced by 70-85%.
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Temperature stability was improved by 38%
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Peak period equipment run time was reduced by 60.2%
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When paired with solar PV generation 55% of non-solar runtime (i.e. power from the grid) was eliminated
Integration of Viking Cold’s solutions proved to be effective at significantly lowering energy load, consumption, and costs while maintaining more stable temperatures and protecting food quality.
Supermarket Freezer Efficiency: Opportunities and Advantages
Because Viking Cold’s TES systems proved effective across so many energy scenarios, it is a cost-saving solution for grocery operators who experience high energy costs and peak period energy fees, and those who are already utilizing alternative energy sources like solar. This storage technology also allows grocery energy managers the flexibility to decide when to buy and use their energy across their portfolio of stores.
The global opportunity for improving energy efficiency in grocery freezers and reducing grocers’ costs is tremendous. And in the grocery and supermarket segment, where margins are so thin, the financial benefits alone can easily justify the investment in a TES system. For multi-store grocers especially, the payback period on their investment decreases as more of their stores include TES systems, and as they are able to exploit utility incentives, such as energy tax credits.
Thermal energy storage will soon be a standard technology in all cold-storage freezers. Those forward-looking supermarkets who already implement proven TES technology are gaining a competitive advantage through increased operating efficiencies, improved bottom lines, and the ability to demonstrate their commitment to the environment.
