Energy Savers

Apr 18, 2011 11:25 AM, By MICHAEL GARRY

Unlike other retail sectors, food retailers face the enormous challenge of running refrigeration systems, which account for more than half of the electricity costs in their stores.

While these systems are notably fragile and complex – and have a nasty tendency to spring refrigerant leaks – the good news is that advances in technology are helping retailers operate them more efficiently, with significant benefits to their bottom line. Over the past several years, a few pieces of technology — the electronically commutated (EC) motor and LED lighting — have enabled refrigerated and frozen cases to experience marked decreases in energy consumption. But in just the past year, several new refrigeration systems have emerged to drive a further dent in energy costs, including a “hybrid” condenser, a pressure controller and a device that mimics food temperatures in cold cases.

These new devices all have a direct impact on the guts of store refrigeration – the compressors that compress refrigerant gas to set the cooling cycle in motion.

Big Y Foods, a 56-store chain based in Springfield, Mass., has been involved in energy management and conservation for more than 30 years, installing its first energy management system in early 1975. “We’ve always been proactive in seeking out and evaluating new technologies to reduce our appetite for energy,” said Gary Kuchyt, the chain’s energy manager. “This has enabled Big Y to enhance the appearance of our stores and to contribute our part in reducing the release of pollutants into the atmosphere.”

Two of the chain’s most recent energy management efforts include the installation of EC motors in evaporator fans for refrigerated cases and walk-in coolers throughout the chain, and the implementation of a hybrid condenser in the refrigeration system of two stores.

Both projects were part of Big Y’s overall energy reduction plan, which includes installing LED lighting as frequently as possible and using case curtains when a store is closed. The plan has been paying dividends: Since 2004, Big Y has added more than 700,000 square feet of retail space, yet projected kilowatt consumption for 2011 has only increased by 3.5%, Kuchyt said.

With any new technology, noted Kuchyt, Big Y prefers to do a small pilot test “to see if the product performs as advertised.” The chain hired National Resource Management (NRM), Canton, Mass., to retrofit the walk-in coolers, freezers and refrigerated cases in two Connecticut stores with EC fan motors and monitor them for about nine months. The motors, which blow air across the evaporator coil to facilitate cooling, were supplied by Morrill Motors, Erwin, Tenn.

“We were very satisfied with the end results” of the pilot, said Kuchyt.
Big Y proceeded to roll out a retrofit program chainwide in 2009 to replace existing permanent-split-capacitor (PSC) fan motors in all cases and walk-in coolers with EC motors, completing the job last year. Each store took about 1-1⁄2 to two days to install an average of between 100 and 150 motors, “with minimal disruption to the customers,” he said. The average cost per store was $22,750.

The EC motors produced an energy savings of 55% in cases and 65% in walk-in coolers. Big Y was also able to secure incentive dollars from local utility companies covering 40% of the cost of the EC motor retrofits. The incentives, coupled with energy savings, enabled Big Y to see a payback for the motors in a little over two years, said Kuchyt.

“EC motors have evolved over the past several years to where they represent an energy-saving alternative to existing PSC and shaded pole motors, though EC motors are about twice as expensive,” said Jim Staley, chief operating officer, NRM. But whether retailers decide to retrofit existing cases with them depends on local energy rates and the availability of utility incentives, which will determine the ROI. Rates in Big Y’s New England market tend to be high – between 10 cents and 18 cents per kilowatt-hour – buttressing the argument for retrofits.

For the most part, EC motors have become a standard part of new cases, Staley noted. In fact, they have been a required part of all walk-in coolers installed since Jan. 1, 2009, per the federal Energy Savings and Independence Act of 2007.

Source: http://supermarketnews.com/technology/energy_savers_0418