Supermarket energy savings are top of mind for most Supermarket operators. If you are wondering how to allocate your energy management dollars for 2019 – 2020? If you are just embarking on your energy management program your biggest issue may be deciding what to implement first. If you are a veteran energy program manager, maybe you are wondering what’s next. In either case, read on for tried and true, new, or sometimes overlooked energy conservation strategies.
#1 – Upgrade Motors
Most of the electric motors in use today are based on 100-year-old technology, the induction motor. While there have been improvements to the induction motor over the past century, the basic operation and general efficiency can’t compare to new motor technology. Two motors worth looking at are the Software Motor Company’s (SMC) new Smart Motor System and QM Power’s Q Sync motor.
SMC Smart Motor System
Software Motor Company describes its innovative motor the “LED of Motors”. The SMC Smart Motor System combines the power of a switched reluctance motor with auto and phone computing technology. The result is a motor that is “smart” enough to only run when it is needed. The estimated payback period is less than 2 years. The system is designed to replace existing motors and is compatible with most control systems.
A recent SMC case study reports success for a large grocery retailer by installing 4 HP SMC Smart Motors. The smart motor system replaced two, single-speed, three-year-old supply fan motors rooftop HVAC units. This project resulted in a 48% overall decrease in fan energy consumption. Read the full case study here.
QM Power’s Q Sync
QM Power located in Lee’s Summit, Missouri, offers a synchronous motor. This motor synchronizes the rotation of the motor’s shaft with the frequency of the supplied current. To gain better market entry QM Power worked with Oak Ridge National Laboratory to install around 10,000 Q Sync fan motors in commercial refrigeration applications. This project was funded by the Department of Energy’s Building Technologies Office.
The results were astounding. Replacing shaded-pole motors with the Q Sync motor resulted in more than 78% fan energy savings. In applications where the Q sync replaced ECM motors the savings averaged 38%. Applications for this fan motor include reach-in display cases, walk-in coolers, and freezers, among a variety of others. Click here to learn more about the application of Q Sync motors in supermarkets.
#2 – DO sweat the small stuff
Some of the most cost-effective ways to improve supermarket energy efficiency revolve around routine maintenance. These simple items add up to big bucks and possible equipment failures when overlooked.
Most maintenance plans include the items below as routine PM. Sometimes if there are other things going on, and there are always other things going on, we skimp on the routine tasks. So, in this case, our number 2 tip is to get back to the basics – the small stuff matters.
- Tidy Up – Change HVAC filters at least monthly, more often if located in a high pollution area, near freeways, or ongoing construction. Clean filters mean the system does not have to work as hard to do its job. Wash the HVAC coils in the spring and fall. Clean the refrigeration condenser coils quarterly and perform a deep clean every six months.
- A-tisket a-tasket- Don’t forget the Gaskets! – Inspect all refrigerated-case doors and RTU gaskets quarterly. Replace broken or faulty seals.
- Climb the ladder – Get up on the rooftop and verify that your HVAC dampers are operating properly. Incorporate regular system examinations into your PM plan and make any necessary repairs. Check HVAC cabinet panels quarterly to combat chilled air leakages.
- Check your Plug Loads –Verify that plugged in devices are turned off when not being used. Review your closing SOP to add new process steps to ensure devices are turned off. Smart plug strips with occupancy sensors are also a great option.
- Calibrate Sensors – All temperature and humidity sensors should be tested and calibrated annually. If the sensor reading is off, your system is probably not performing at peak efficiency.
- Setpoint Review – Incorporate routine setpoint reviews into your PM plan. This keeps store comfort levels and cooler / freezers at optimal temperature settings and helps rectify any overrides or changes.
- Airflow Check – Have a licensed technician routinely check supply and return vents for both temperature and airflow. Airflow issues indicate that the register or ducts may be clogged. Check the supply and return temperatures to make sure they are within a 14 to a 22-degree differential. Temperature differences outside of this range mean there is a potential issue with the unit and should be investigated further.
#3 – Strategy Alignment
Review your energy-saving strategies to make sure they are in alignment with your preventative maintenance plan and consistent across your portfolio of managed locations. It is common for the maintenance team to be in the dark about the strategies planned and implemented during construction.
While great strides are made to bridge that gap, you may still have a few service vendors not fully aware of the strategies implemented. When this occurs, the system changes to fix one issue may inadvertently undermine one or more energy efficiency strategies. If you are running into this issue, consider a vendor workshop or conference between your Energy Management Service provider and your maintenance technicians.
Take time to know and understand the strategies deployed in your locations. If you aren’t sure what is in place from one location to the next, consider undertaking a portfolio alignment project. The more consistent you can be in deploying efficiency measures across multiple locations, the easier it will be to manage strategic energy conservation efforts.
A few examples of energy efficiency strategies include:
- Floating head pressure and Floating suction pressure controls. This strategy can save up to 150,000 kWh per year.
- Anti-sweat heater controls on refrigerated display cases. These controls monitor the temperature/humidity of the store and only run the heaters if there is a risk of condensation. Savings have been documented up to 265,000 kWh per year with the application of anti-sweat heaters.
- Night Covers for open refrigerated cases reduce the daily refrigeration load by approximately 8 percent. Placing the aluminum shields on the cases keeps product colder during the off hours and for a few hours after the shields are removed.
- Heat-Recovery Systems capture waste heat from refrigeration systems. This heat is used to make hot water for the store or for cold weather space heating (if ran through a heat exchanger). Some stores use heat reclaim to replace fossil fuels for space and water heating.
- Optimizing the number and duration of defrost cycles using Demand Defrost Controls can add up to significant annual savings.
Monitoring is an important aspect for getting the full value out of your energy management system. But all monitoring is not created equally. There is Predictive, Reactive, Performance-based and Energy monitoring. We recommend a hybrid of all the above. To maintain the greatest energy impact Performance based monitoring is recommended.
Performance-Based monitoring uses algorithms to evaluate system data and energy consumption to predict equipment failures before they occur, while also evaluating the alarm data. This is extremely valuable and can save a ton of money in preventing downtimes and loss of product. Performance-based monitoring programs establish energy use baselines. This allows real-time identification of any abnormal energy fluctuations, creating an avenue to maintain optimal efficiency.
Predictive monitoring is like performance-based monitoring because it is designed to predict needed maintenance and repairs before the equipment fails. The main difference is that predictive monitoring uses formulas based on system alarm data.
Reactive monitoring is rules-based monitoring that triggers a response based on alarms. This type of monitoring is the most basic and its success relies heavily on how well you define the rules for alarm triage.
Regardless of which type of monitoring you choose, it is important to establish a team to regularly review the data. Examine locations with high alarm volume, increased energy usage, or equipment failures not addressed through your monitoring program. The frequency of these reviews depends on how things are going and how long you have been using monitoring.
#5 Energy Tune-Up
An Energy Tune-Up is a wonderful way to improve efficiency in 2019. Energy Management Systems degrade over time due for several reasons. See our recent post, Sustainable Energy Efficiency to learn more about how and why systems degrade. An energy tune-up combines an energy audit with re-commissioning to ensure optimal energy conservation, O&M savings, space comfort and productivity, and improved performance.
An energy tune-up identifies and resolves issues – otherwise, it’s just a survey. A few standard items on most energy tune-ups include:
- Re-examine HVAC load requirements and often overlooked strategies including destratification, dehumidification, demand control ventilation, setback control strategy, and setpoints.
- Examine and make any needed changes to Control sequences.
- Verify board and point list accuracy and update as needed.
- Confirm accurate naming and appropriate setpoints for all units.
- Implement control strategies missing from the system, such as floating head pressure and floating suction.
- Bring any setpoint deviations back to established standards.
The return on investment for an Energy Tune-up averages $1.25 per square foot. Standard payback time averages one year or less in most cases.
If it’s been more than 2 years since your last energy tune-up, this may be your number one way to improve efficiency this year. Click to learn more about Energy Tune-Ups.
Energy conservation has never been more important than it is right now. It helps improve profitability, protect our natural resources and demonstrates a commitment to society and the future.