In today’s dynamic food retail climate, many operators are wondering why they should retrofit their aging refrigeration supermarket refrigeration architecture. For most, this is a not an easy decision to make. While you’ll often find some form of a refrigerant regulation accelerating this process, a viable refrigeration retrofit should also include plans for ongoing energy optimization. In our most recent E360 webinar, I discussed how to merge these two considerations into a sustainable, long-term refrigeration strategy. Read the summary below and/or view the webinar in its entirety.
The transition to more environmentally friendly, future-ready refrigerants is underway, and as a result, many supermarket retailers are evaluating retrofit options on their existing systems. But for large enterprises or individual stores that consume a lot of energy, the rising costs of energy (especially in certain regions with high rates) are moving conversations toward energy management — not only in refrigeration systems, but also entire facility ecosystems and across the enterprise.
Ultimately, the goal of an effective approach to energy optimization is to minimize energy costs in every way possible. Doing so requires an understanding of the various factors that contribute to energy costs, including:
- Energy consumption profile of key store systems such as refrigeration, HVAC and lighting
- Peak electric consumption cycles and periods in each store
- Time of use rates as dictated by the electrical utility, including both on- and off-peak rates
- Seasonal changes and their impacts on consumption and electricity rates
This is particularly important in certain areas of the country where charges exceed $15 per kW during peak demand periods.
Why the focus on refrigeration?
A typical supermarket uses a centralized direct expansion refrigeration architecture which accounts for more than 50 percent of its total annual energy consumption, with HVAC systems the next largest consumer at 20 percent. At the same time, an average supermarket consumes three times more energy per square foot than other retail facilities. It’s no surprise then that these systems are becoming prime targets for energy optimization in the U.S. and around the globe.
The tendency for refrigerant leaks in traditional centralized systems — most of which are also charged with refrigerants that have a high global warming potential (GWP) — makes these systems ideal candidates for retrofits. Many of them can transition to lower-GWP refrigerants with relatively minimal retrofit requirements.
Six steps along the “Journey to Energy Excellence”
In the webinar, I cited a case study of a supermarket that went through a retrofit process in its centralized refrigeration system. The process followed a methodology that Emerson refers to as the Journey to Energy Excellence. By upgrading only the refrigeration system (i.e., the first three steps below), the supermarket reduced its energy costs by nearly $40 thousand per year.
The six steps along the journey to energy excellence include:
- Conduct a baseline energy audit of the existing system.
- Recommission the system to its original condition and setpoints.
- Make refrigeration technology upgrades, such as: digital compressors, variable frequency drives and floating the head/suction pressures.
- Change the lighting and other renewable upgrades such as adding doors, electronic expansion valves and electrically commutated motors on evaporators.
- Expand focus to HVAC technology upgrades, including rooftop units and demand control ventilation.
- Deploy a condition-based maintenance, internet of things (IoT) infrastructure to accurately monitor asset and system performance.
Each step enables progressive degrees of energy optimization, and as the case study demonstrates, implementing just the first three steps can provide significant financial gains. Collectively, this methodology can help supermarkets develop energy management strategies that consider entire facility ecosystems.
Regardless of where you are in this process, Emerson is providing solutions at every step to help retailers achieve energy excellence in stores and across the enterprise.