As these pie charts show, in a typical grocery store, just three energy users contribute about 95% of the electric use: Refrigeration at 60%, Lighting at 18%, and HVAC at 15%. Similarly, when it comes to gas use, there are really just three systems that consume 94%:Space heating at 56%, Water heating at 22%, and Bakery at 15%. The miscellaneous 6-7% attributed to "Other" is so small, it's hardly worth investigating.
One of the largest opportunities in grocery stores is often the refrigeration system. Simple, low-cost measures like checking door seals and closures to assure they are keeping the cooling in, and checking anti-sweat devices (door heaters that minimize moisture build-up) to assure they are not over-operating. And checking temperatures to be sure money isn't being wasted keeping anything too cold.
In stores with large glass exposures, be sure the windows are shaded or tinted to minimize solar heat gain. Many grocery stores have glass covering the entire front of the store.
Most grocery stores have some potential for savings by improving the building envelope since 15% of the electricity and 56% of natural gas usage is for space heating. Door openings can be wasting expensive heated or cooled air. Be sure automatic ones are timed to open and close briskly and not hanging open long after someone has passed through. Air curtains on public doorways and plastic strip in employee-only areas can reduce the vast amount of conditioned air that can escape through repeated door openings.
One tip for getting a feel for the facility energy use is based upon its square footage. As you can see in the table below, these are some ball park numbers for what annual energy costs might be for grocery stores of various sizes. Furthermore, the table gives a feel for how much savings potential might be in two systems if 20% savings were achieved.
Take a moment to think about the numbers. A 12,000 sq. ft. store might spend $52,000 annually on energy. If there were a project that could cut their refrigeration costs by 20%, they could save about $5,800 each year. A larger facility spending $156,000 annually on energy could have $17,500 savings from a similar measure.
In many cases, these measures have just a one or two year payback, so it's worth investigating. These savings keep on coming in future years and can be used to make the store more profitable and successful.
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