A Challenge for Grocery Store Operators (Corporate and Independents)
Supermarket Controls and Commissioning:
Uncovering Hidden Opportunities
Diane Levin and Lawrence Paulsen,
Portland Energy Conservation, Inc.
Over the past 3 years, Portland Energy Conservation, Inc. (PECI) has investigated a full range of energy savings retrofit opportunities in over 900 grocery stores ranging from convenience stores to supermarkets. Research shows that there is tremendous potential for supermarket refrigeration controls. In one of the largest supermarket chains, a survey of 50 stores showed that the majority had control systems but that the control strategies were not implemented correctly, providing an opportunity for savings of up to 335,000 annual kWh per site. This opportunity was hidden because the building operators believed that they already had the full benefits of controls. By taking a programmatic approach to the technically complex arena of refrigeration controls, PECI identified and captured enormously cost-effective savings opportunities.
Refrigeration control technologies offer the opportunity to modulate energy use in response to fluctuating refrigeration loads. In addition, they offer built-in monitoring and remote management capabilities. New opportunities that combine supermarket control systems with demand response and management technologies are especially attractive. PECI has developed a pragmatic approach that tackles the technical complexity of control systems optimization within a simple program structure, ensuring high participation and long term energy savings. This paper describes the most popular controls and the savings potential for proper installation and commissioning. In addition, it will highlight practical program implementation strategies that have cost-effectively saved customers millions of dollars in this energy-intensive market sector.
Food stores in general present an attractive target for energy efficiency efforts because they are so energy intensive. At 48.7 kWh/square foot, they have the highest energy intensity of any of the building types in the 1999 CBECS survey.1 In addition, compared to many segments of the commercial market, ownership is relatively consolidated. Just 56 firms account for 80% of the groceries sold in the U.S. 2 With high energy intensity and consolidated ownership, targeted programs are feasible and cost-effective. For supermarkets in particular, cost-effective controls technologies to reduce energy usage are readily available. As the cost of controls systems has dropped, the capabilities have expanded, so that controls systems today are capable of implementing and monitoring multiple energy and demand management strategies.
This paper reviews the most promising supermarket refrigeration control technologies, discusses the current market conditions, and describes a resource acquisition program design that design that successfully saved almost 14 million kWh in San Diego, CA in 2005. For the purposes of this paper, “supermarkets” are loosely defined as grocery stores of 40,000 square feet or greater with multiplexed compressor systems. The majority of participants in the San Diego program were stores from a national chain with a centralized management; however, regional chains and independent supermarkets also participated and the program design described worked for them as well.
Because supermarkets have small profit margins, energy costs play a crucial role in their economic success. (Southern California Edison Refrigeration Technology and Test Center) While it is in their best interest to be energy efficient, several market conditions often prevent them from achieving that goal. Many supermarkets are missing opportunities to save energy because:
Refrigeration controls are technically complex, requiring site specific programming and customized installation. Few service technicians truly understand the underlying dynamics of the refrigeration cycle and so lack the information to understand how to properly optimize control systems for energy efficiency. Even in the largest national chains, the in-house maintenance staffs often lack the expertise to maintain, let alone program controls. Where programming is outsourced, it is often left to the refrigeration contractor in charge of equipment installation and repair. For this reason, the programming may minimize service calls, not maximize energy savings.
Supermarket owners believe they already have operational controls. Although large supermarket decision makers have embraced the concept of controls and will tell you that they in fact, have controls, audits in supermarkets have proven that controls implementation is patchy at best. In one chain claiming they were controlling head pressure, audits found fifteen out of 52 sites that were not programmed to float head pressure, wasting 2.1 million kWh a year. Although most national chains have “implemented controls”, they have failed to implement regular monitoring and recommissioning, missing out on enormous savings.
Key decision makers are faced with a host of issues that pre-empt energy efficiency. Supermarket decision makers grapple with multiple issues including Labor Relations, food safety and merchandising, all of which seem more pressing than efficiency. Even where they have energy managers designated to address efficiency, the Energy Manager must show that an investment in their efficiency project has a better ROI than an investment in their new merchandising program. Without solid information on project costs, utility incentives, and savings estimates, energy managers’ projects are at a disadvantage when competing with more familiar capital investments. As a result, most supermarkets – from the large chains to the independents - lack the time or information to implement efficiency projects. The conditions outlined above can be addressed with an appropriate, targeted program design. Each step is essential in facilitating part of the delivery chain and ensuring that the energy savings are realized.
Refrigeration is technically complex - deliver technical expertise and qualified contractors. It takes hands-on technical expertise to identify refrigeration system opportunities and implement effective control strategies. Skilled technical advisors who personally identify the opportunities and verify proper installations at each site are an essential element of a successful program offering. Relationships with knowledgeable contractors are also vital because the majority of refrigeration contractors lack the training to implement effective controls. Successful programs must tap the qualified controls contractors. Another program element that could be incorporated into a market transformation program is training for service and installation contractors so that customers can obtain energy optimization services from their existing contractors. In addition, customers should be encouraged to restructure their maintenance service contracts to require proper monitoring of specific controls, which would further motivate the service contractors to undertake controls training.
Supermarkets think they have energy efficient equipment – data shows the opportunity. To overcome owner misconceptions about their on-the-ground equipment, site specific surveys and Energy Savings Reports demonstrate the savings opportunities at each site. Although it may seem labor intensive to visit each and every site, it can be done cost-effectively by systematizing the site surveys to capture opportunities and produce compelling data quickly. By producing site specific results that attest to missing sensors or lack of programming, a program can convince decision makers to do more to improve efficiency. Rather than providing extensive detail and measured results for one site, the program design captures a snapshot of opportunities at all sites, allowing for concrete business planning and quick action on the identified opportunities.
Decision makers are hard to reach – offer objective expertise plus incentives. Because decision makers are wary of sales calls, having a utility-driven program with clearly defined incentives catalyzes results. The utility sponsorship overcomes nervousness regarding a black box solution and a concern that contractors are motivated by self-interest and not energy savings. Finally, although one might argue that incentives should be unnecessary, experience shows that access to rebate monies, especially where they are prescriptive rebates, provides internal advocates the ammunition they need to get corporate decision making to happen.
Perform audits. Site specific, streamlined audits scope the energy saving opportunity quickly and cost-effectively.
Require maintenance-related activities. All too often, adjustments in controls do not realize their full potential because the systems are poorly maintained. Anticipated energy savings are based on the assumption that all equipment is being properly maintained.
Coordinate contractors. It is risky to assume that the existing refrigeration service contractor will be able to program control systems effectively.
Build in data collection. Today’s controls offer the opportunity to garner extensive energy usage information. Before an installation is programmed, the contractor takes a “snapshot” of existing conditions. Post-installation points are tracked over time. Pre- and post- installation data can be compared to verify the controls are operational and optimized.
Issue rebates. Rebates serve to catalyze action. Without incentives, supermarkets are unwilling to spend the time investigating options and making control systems a priority. Change is difficult and requires incentives to push past the status quo.
Build in persistence. Once installed, post-installation checks are essential. These can be in-store, or via a modem if the supermarket has centralized data monitoring. Although properly installed controls generally function without fail, a re-inspection after six months will serve to ensure that the human side of the equation has not undone the careful work of the controls contractor. If there is evidence that the control settings have been altered, it is a good idea to renew efforts to educate all the involved parties.
Supermarket controls and commissioning offer strong opportunities for savings. An effective program must provide technical expertise, store specific information regarding the energy saving opportunities and project implementation support to get quick results. To ensure savings, there must be attention to all points of delivery from contractor training and coordination through post-installation verification of pre and post energy usage.
Singh, Abtar. 2006. Optimum Refrigeration Controls with E2™. Available online: http://www.cpcus.com/Library/Optimum%20Refrigeration%20Control%20with%20E2.pdf. Kennesaw, GA: Emerson Climate Technologies
Southern California Edison Refrigeration Technology and Test Center. Quantifying the Effects of FDA Food Code on Supermarket Energy Use Through Computer Simulation.
Zazzara, Jeffrey B. and D. Ward. 2004. “Supermarket Commissioning with an Emphasis on Energy Reduction.” In roceedings of the 2004 National Conference on Building Commissioning. Portland, OR: PECI.