Shedding Light on C-store Energy Savings
It’s no secret. Any store that sells food uses a lot of energy — averaging 51.5 kilowatt-hours per square foot, more than any other commercial building.
Convenience stores use even more, consuming as much as 94 kilowatt-hours per square foot because of the added energy demands of outdoor canopy lighting, wall-to-wall refrigerators and even the always-on coffee pot.
Convenience stores open 24 hours can’t turn off the lights or coolers, but they can gain greater energy efficiency from both — which collectively account for about two-thirds of a c-store’s electricity usage.
A Minnesota Department of Commerce study of energy use in 50 convenience stores, all with gasoline sales, identified energy-saving measures that stores could act on to significantly reduce electricity consumption and improve profitability.
The big wins: converting to LED lighting systems and upgrading refrigeration technology. Here’s a short list of the findings:
Move past metal. Traditional metal halide lamps use about 450 watts each, compared to LED lamps that shed bright light using only about 150 watts each. The switch saves a c-store $120 to $150 per bulb per year based on a rate of 11 cents per kilowatt hour, the national average cost.
The biggest opportunities for energy savings lie in converting wall packs, parking lot luminaires and the canopy lights over gasoline pumps to LED.
Replace in-case lights. Swapping traditional lighting with LED lights cuts energy consumption in a standard refrigerated case by about 50 percent. The case also looks better because LED light doesn’t depreciate in cold temperatures the way fluorescent light does. That improves in-case merchandising and also creates a better-lit, safer environment for employees working in walk-in coolers and freezers.
The idea isn’t new: Grocery stores have benefited from the superior illumination and quick payback of in-case LEDs for several years. It’s time for c-stores to seize the opportunity.
Dial down in-store wattage. Swapping 32-watt bulbs for 25- or 28-watt bulbs for T8 lighting will keep a c-store’s interior bright while reducing energy use and cost.
Want to save even more? Convert those standard fluorescent fixtures to LED, which cuts 50 percent or more from energy consumption. LEDs also improve light quality; colorful packaging comes to life under LEDs.
Add light sensors — but with caution. The savings from occupancy-sensitive lights is certain: as much as 40-percent energy reduction per fixture. But the strategy may not be right for all areas of a convenience store.
A well-lit, always-on atmosphere is part of what sells a convenience store to shoppers. They won’t drive into a dark parking lot. And they’ll hesitate to walk into a dimly or partially lit store. Plus, when c-store shoppers see lights off in a refrigerated case or behind doors in a walk-in cooler — even if those sensor-enabled lights come on again when someone walks by — they read it as broken machinery. Their impression: products aren’t being kept at proper temperatures.
So, be strategic about where to use occupancy-prompted lighting in a convenience store. Restrooms and storage areas are smart spaces to save money by installing sensors.
Ramp up refrigeration efficiency. Refrigeration systems are designed for worst-case ambient temperatures based on climate data for a store’s location. Floating head and suction pressure controls respond to true ambient conditions, reducing the operational intensity required for a refrigeration system to maintain proper temperatures.
These controls reduce energy consumption by as much as 20 percent — savings that supermarkets across the country have realized for several years. Again, the time has come for c-stores to capitalize on this proven cost-cutting technology.
Upgrade to ECMs. Electronically commutated motors (ECMs) sound complex, but what they accomplish is pretty simple. They can be programmed to speed up or slow down based on cooling needs. ECMs are a major improvement on evaporator fans in walk-in coolers and split capacitor and shaded-pole motors in refrigerated cases.
Like floating head and suction pressure controls, ECMs boost efficiency and cut electricity use, shaving energy consumption by as much as two-thirds and yielding payback on the investment in a year or less.
Stop the sweat. Anti-sweat controls monitor temperature and humidity in the store and prompt heaters embedded in cooler and freezer doors to control condensation as needed. The potential energy savings can be as much as 50 percent. Adding this technology to freezer doors could save nearly $100 per door per year.
Now, for the grand total. The Minnesota Department of Commerce study indicated that the improvements listed above, combined with maintenance measures such as installing strip curtains and cleaning condenser and evaporator coils, reduced a convenience store’s electricity consumption by an average of 19 percent. At 11 cents per kilowatt hour, that adds up to energy savings of about $6,100 a year.
The effect on profitability is even greater. Recently revised figures from the U.S. Department of Energy indicate that every $1 a food retailer saves in energy costs equates to increasing sales by $18. That means if an average c-store takes advantage of these energy-efficient measures, the savings would equate to increasing sales by about $110,000 a year.
The bottom line: Boosting energy efficiency is a surefire way to improve c-store profit margins.
Editor’s note: The opinions expressed in this column are the author’s and do not necessarily reflect the views of Convenience Store News.