Seeking Sustainability in Supermarkets
Contractors promote savings via integrated controls, optimized compressor runtimes, and more
Sustainability and supermarkets might be the best fit since peanut butter and jelly (both may be found in aisle 4, across from the bread). Energy Star calculates that, on average, supermarkets in the U.S. use around 50 kilowatt-hours (kWh) of electricity and 50 cubic feet of natural gas per square foot per year — an average annual energy cost of more than $4 per square foot.
According to the National Action Plan for Energy Efficiency’s “Supermarket Energy Use Profile,” electricity accounts for 82 percent of the total energy consumption in supermarkets, and refrigeration alone accounts for more than 35 percent. The profile calculates that a 10 percent reduction in energy costs for the average supermarket is equivalent to increasing its net profit margins by 16 percent.
Fortunately, when it comes to helping supermarket owners and operators reach their sustainability goals, HVACR contractors have more tools available than ever before.
Jim Knudsen, manager, food retail segment marketing, and Richard Ruth, food retail services product manager, Danfoss, provided The NEWS with a look at some of the sustainability technologies contractors can provide.
• ‘Smart Store’ Integrated Controls — These controls are designed to provide benefits to individual stores and throughout entire supermarket chains, Knudsen said. It begins with integrating and connecting the store in the commissioning phase and ensuring that all parameters and functions are tested and operating in accordance with the specifications. The connected and monitored functions of these systems can then ensure that the conditions that exist during commissioning will be maintained throughout the life of the store. In addition, as the store changes, or as the outdoor environment fluctuates, these technologies allow for all operations to be optimized and adjusted as needed — often remotely.
Functions, such as predictive maintenance and alarm monitoring, can make certain that refrigeration temperature integrity is maintained and services are coordinated to minimize food waste, emergency service calls, and costs. Finally, smart store integrated controls allow a chain owner and contractor to compare operations at various sites and take advantage of learning from the performance at each location to optimize the entire portfolio.
“These technologies allow the tracking of actual results of upgrades and retrofits to help justify and advance energy- and cost-saving upgrades,” Knudsen said. “By partnering with the end user, HVACR contractors can provide leadership through this integration and support of the overall smart store strategy.”
• Optimizing Compressor Runtimes — By installing advanced controls and monitors, contractors can help a supermarket ensure optimum equipment performance regardless of operating or ambient conditions and customer shopping patterns, Ruth said.
“Optimizing and tracking compressor runtimes can help identify running conditions and possible faults in the compressors on the rack,” he said. “This allows for the graceful degradation of performance during failures and allows for correction and repair on a scheduled basis.”
Compressor tracking also allows for performance analysis to identify control or logic issues and provides data for predictive maintenance, Ruth added.
• Case Controllers — Knudsen said case controllers may be the most valuable upgrade to supermarkets for saving both energy and cost while improving operations.
“Not only do documented savings exceed 15 percent immediately, but the installation of case controllers can have a payback period well under three years, even for retrofit projects,” he said. “This can be accomplished with the existing equipment, the support of HVACR contractors, and without interfering with daily operations.”
In addition to the energy savings, these connected devices can support temperature monitoring and automatically adjust as seasons change. Case controllers also can provide for remote monitoring of case performance, which allows for more effective diagnostics and the ability to provide more effective service.
• Smart Grid Integration — Across the country, local utilities are faced with complex power demands that change throughout the day and year. To more efficiently utilize the energy infrastructure, they have established rate structures, demand charges, and incentives to allow large energy users to help them manage this complexity.
“This ‘help’ can bring savings and incentives that benefit the users greatly,” Knudsen noted. “This includes energy management, demand response, load shifting/shedding, and even the implementation of energy storage devices.”
• Data Analysis — Through connected devices and the data they provide, store personnel, owners, and managers are now able to make fast decisions to maximize energy efficiencies and cost savings, optimize food safety, and reduce their environmental footprints.
“Cloud-based service delivery platforms, such as Danfoss Enterprise Services, collect all types of data to provide real-time, powerful insight into a store’s operation from monitoring equipment alarms and food temperatures to detecting leaks and providing energy benchmarks,” Ruth said. “This service can help to ensure food temperatures meet safety standards, maximize equipment performance, reduce energy consumption, and prevent service calls when they’re not really needed.”
SUSTAINABILITY TAKES MANY FORMS
Abtar Singh, CEO, Singh 360 Inc., noted that sustainability in supermarkets can take many forms. In addition to reducing energy consumption, it can include switching to low-GWP (global warming potential) refrigerants and using cleaner sources of power. It can also include reducing trash and food waste going into landfills through recycling and/or composting and reducing water usage.
On the HVACR side of the equation, sustainability generally means using low-GWP refrigerants and helping store operators reduce energy consumption.
“Low-GWP refrigerants have really been picking up steam as EPA regulations get tougher and tougher,” Singh said. “When it comes to reducing power consumption, there are many things HVACR contractors can do, including installing LED lighting on cases, retrofitting to low- or no-heat doors, upgrading to ECMs [electronically commutated motors], signing up for demand-control programs, maximizing the efficiency of the condensers and compressors using variable-capacity control, and by using floating suction and head pressure control. All of these technologies are mature, and many qualify for utility company rebates, so there’s no reason not to implement them.”
According to Singh, the refrigeration systems that supermarket customers who are interested in sustainability decide to implement will largely be determined by whether the store is new or existing.
“New stores above the Mason-Dixon line really should be considering CO2 refrigeration systems if they have the team and the support staff to go in that direction,” he said. “Meanwhile, existing stores can achieve low-GWP sustainability and good energy efficiency by converting their existing HFC [hydrofluorocarbon] systems to an HFO [hydrofluoroolefin] refrigerant, such as R-448A or R-449A.”
He concluded that, as always, the biggest challenge most contractors will face when it comes to sustainability measures is convincing customers to invest in them.
“Customers tend to say they don’t have the money to make the upgrades, but contractors can show them they do have the money — they are just giving it to the utility company,” he said. “You have to speak financial language to the CFO and convey that the savings from the energy-efficiency investments they make will keep growing as the utility rates keep going up. That means the sooner they make the investment, the better.”
WORK WITH BOTH SIDES OF THE TEAM
Pete Savage, head of the controls division at AAA Refrigeration in New York City, said AAA is performing an increasing number of ECM motor upgrades, LED retrofits, “close-the-case” projects, installations of antisweat controls, and full controls upgrades to help maximize efficiencies in supermarkets.
According to Savage, the value of these and other sustainability measures differ depending on the point of view of the supermarket client’s personnel.
“An energy manager is fine with a measure that isn’t necessarily noticed by the customer, such as a controls upgrade or a variable frequency drive [VFD] retrofit, whereas the merchandising side prefers the lighting upgrades and close-the-case projects,” he said.
Savage noted this means contractors must explain the benefits of their sustainability offerings to both sides of the supermarket team.
“We try to present options that are helpful to sales along with additional options that are more focused on efficiency,” he said. “At that point, it’s up to them which ones they’d like to pursue.”
Savage added that great strides have been made in recent years in case controllers, and they are now important parts of the sustainability equation.
“The energy savings and greater visibility into the systems that case controllers provide allow supermarket operators to reduce their current energy use as well as identify any potential issues that may affect their energy use in the future,” he said.
In addition, Savage noted that VFDs have come down in cost and, with proper technician training, have become a more effective sustainability measure.
“Although VFDs have been utilized for years, it wasn’t uncommon to find a drive jumped out due to the technician not knowing how to work on it, thus eliminating the savings,” he said.
LOOK BEYOND THE FINANCIALS
Supermarket end users benefit in numerous ways from sustainability initiatives, according to Tristam Coffin, director of sustainability and facilities for the Northern California region of Whole Foods Market. Environmental stewardship has been a core value of Whole Foods Market since its inception, and that is evident today across its 467 stores. Coffin noted that when it comes to sustainability initiatives, the company looks not only at the financial aspects, but also the impact on stakeholders, such as customers, team members, the environment, and the community in which the store operates.
“Our goal is always to look for ways we can drive down our environmental footprint, but one of the beauties of sustainability today is that 99 percent of the time it also leads to profitability and a positive economic impact,” he said.
Whole Foods Market focuses on sustainability as it relates to the built environment and strives to find innovative ways to improve its performance and reduce its resource use across four pillars: energy, water, waste, and refrigerant. The company’s sustainability projects have evolved and expanded over the years thanks to new technologies. In the early days, sustainability might have meant using recycled materials in the construction of its stores; today, it can mean employing leading-edge, on-site generation and storage technologies, such as Axiom Energy’s refrigeration battery.
Refrigeration, Coffin noted, is a particularly important aspect of the sustainability puzzle.
“From a supermarket perspective, refrigeration can have a tremendous effect on the environment, depending on what type of system and refrigerant you’re using,” he said. “This applies both from a direct emissions perspective, due to leaks, as well as the indirect emissions associated with the energy use of refrigeration systems, which is typically the largest piece of energy use in a grocery store.”
Each Whole Foods Market store is unique, so although there are baseline architectural, engineering, and sustainability guidelines in place, one of the company’s goals is to not commit to any one type of refrigeration system or refrigerant but to always be open to the variety of technologies that are available. That may mean combining innovative refrigeration systems with on-site generation, renewable technologies, and other efficiency/sustainability measures to create high-performance grocery stores.
For example, the company’s Brooklyn, New York, store, which opened in the Gowanus neighborhood in 2013, incorporates a transcritical CO2 refrigeration system, a combined heat and power (CHP) system that provides on-site generation, solar PV over the parking lot, and even a 20,000-square-foot hydroponic greenhouse.
“That project allowed us to experiment, implement, learn, and then apply some of those strategies with a little different twist at some other stores,” Coffin said.
Given Whole Foods Market’s desire to always be willing to conduct a discovery process with new technologies, it’s not surprising that Coffin’s advice to the contractor community is to be open-minded and to get experience with as many new technologies as possible.
“Sustainability across the supermarket industry has become a cooperative approach rather than a competitive approach,” he said. “As innovative technologies become mainstream and the market begins to adopt them more readily, prices will be driven down, and the whole industry can move forward and adopt sustainability measures that will help the environment. Now, we need contractors to be a part of that. If we have great technologies but don’t have a solid contractor group to help us implement them, then that increases the challenges and holds the industry back.”
Publication date: 9/4/2017