Among the financial rewards retailers can reap for implementing energy-saving initiatives are the substantial rebates available from utilities.
Save Mart, Modesto, Calif., accrued $2 million in energy rebates last year from utilities that serve its nearly 250 stores operating in Northern California and northern Nevada, according to Ray Agah, the chain's vice president of engineering. This year, the retailer has accumulated close to $1 million in rebates, including $46,000 from the Modesto Irrigation District (MID), a public power agency.
That $46,000 — the first rebate ever awarded by MID — was earned by a 55,000-square-foot store opened in Riverbank, Calif., in February that Save Mart has made its green store prototype. A similar store will open next year.
“We've done good stuff in the past to save energy and be a good citizen to the world and our cities,” said Agah. “But at this particular store, we put the pedal to the metal and did everything we could, considering you don't want to spend a lot of money if the ROI is not there.”
MID worked with Save Mart as it was building the store and “made recommendations on the design,” said Melissa Williams, public affairs specialist for MID.
The Riverbank store ended up costing “a little more” than a conventional Save Mart, Agah said. But with the rebate and energy savings, the new green technology will be able to bring a return on investment to the chain within its required payback period, about 1.5 years.
In the first 12 months of operation, the Riverbank store will lower its electric costs by an estimated $51,500 compared with a conventional store, Agah said. That represents a savings of more than 672,000 kilowatt-hours annually, enough to power 66 average homes.
An operation like this, in addition to exceeding California's energy-efficiency standards for new construction, prepares Save Mart for meeting the state's strict greenhouse gas limits, which must be met by 2020.
About three-quarters of the energy savings will be derived from the store's daylight harvesting system, which consists of one large skylight (20 feet by 30 feet) at the entrance plus 50 smaller skylights (3 feet by 6 feet) scattered across the roof. These fixed skylights do not use a tracking system to follow the position of the sun.
The interior lighting consists of a series of standard parallel T8 fluorescent light fixtures connected in two long rows across the top of the store. Because of the daylight harvesting, sensors usually keep only one of the two rows of fixtures lit at any time; the store determined that both rows are on together only 17% of the time, compared with 100% of the time at a conventional store. The fluorescent lighting accounts for slightly less than 50% of the overall lighting load during daylight hours.
High-efficiency LED lighting is used to illuminate outdoor signs and indoor exit signs.
Another energy-saver for the Riverbank store is a cold-air retrieval system that pulls cold air from underneath refrigerated cases through a cavity in the wall and back to air handlers, where it's used to supplement the store's air conditioning system. “So this means the HVAC system doesn't have to work as hard, and the frozen food aisles are not as cold,” said Agah.
In addition, an air curtain is used at the store entrance to ensure that outside air doesn't infiltrate the store as doors open and close. And a white roofing surface lowers the temperature of the roof. To warm the store (and to heat water), waste heat from the refrigeration systems is captured.
The store's design also incorporates a high-efficiency steamer, ice machine and air conditioning system. “We went out of our way to make sure every piece of equipment is high-efficiency,” said Agah.
The Riverbank store also attempts to minimize its material impact on the environment. For example, for medium-temperature cases, it employs a secondary-loop refrigeration system from Hill Phoenix that uses glycol as a coolant for cases and cooler rooms; the system minimizes the amount of refrigerant (R-404A, a non-ozone-depleting substance) used in the compressor room as well as the amount that can leak into the atmosphere. The low-temperature system is a standard DX version that employs R-22 refrigerant.
In another example of resource conservation, the store's floor surface is made of stained concrete rather than tile and glue. And the rest rooms save water by employing electric eyes in faucets and toilets to control usage.
When informed about Save Mart's green efforts in the Riverbank store, shoppers there react very favorably, said Agah. “We definitely believe that customers choose where to shop based on whether a store is a good citizen to the world or not.”