GARDEN HOME, Ore. -- As far as its customers can see, the renovation of Lamb's Thriftway Marketplace here was a return to a small-town past, with vintage cast-iron street lamps inside the store contributing to the home-town atmosphere.
Behind the scenes, however, the renovation allowed the independent retailer to make the store's energy systems as up-to-date as possible. While the renovation nearly doubled the store's square footage, increasing it from 27,000 square feet to 50,000 square feet, its total energy costs rose only about 15%.
Owner Colin Lamb estimated that savings from energy efficiencies total more than $70,000 annually. These numbers are even more impressive considering the renovated store added a number of new services, including large energy users such as a home-meal replacement department with full ovens and a scratch bakery.
Energy-efficiency measures implemented during the renovation process included installation of two parallel rack compressor systems for low and medium temperature refrigeration; indoor and outdoor lights that automatically adjust based on available daylight; and increased use of doored refrigerator cases to showcase dairy and deli products.
In addition, a computerized energy-management system ties lighting, heating and refrigeration functions together, providing greater control and efficiency to the retailer.
"We worked with an energy consultant [during the renovation], who looked at each possible item to determine whether or not the payback on it was worthwhile," said Lamb. "For example, since it was an existing store, we could have used the existing lighting, which was already paid for.
"But even with the costs of ripping all the existing lighting out and putting in a brand-new system, the energy efficiency of the new lighting gave us a payback within 18 months, so we said 'do it,' " said Lamb.
Lighting improvements alone account for approximately $40,000 per year in energy savings, he noted. In total, the store is saving approximately 1.3 million kilowatt hours annually, according to a source familiar with the situation.
Electricity rates in Oregon are relatively low, at 5 cents per kilowatt-hour; implementing similar energy-saving measures in areas with higher rates would result in more substantial dollar savings, said the source.
Lamb's Thriftway uses T-8 fluorescent lamps in several areas of the store, and 175-watt metal halide lamps in its produce area. The metal halide lamps can be automatically dimmed when there is enough daylight shining through windows on the south side of the building.
"We hadn't planned to put windows in there, but the city of Portland had a requirement about them," said Lamb. "We put them in to humor the city, and then found out they were a good idea. The natural light is just great there; it adds a new feeling to the produce area."
The windows were designed so that direct sunlight would not affect the fresh produce, he noted. Lamb's Thriftway also makes use of natural light in its floral area, with both windows and skylights.
Another change that brought better results than expected was increased use of doored refrigerator cases for perishables. Lamb noted that the Garden Home store has more of these than the other four Lamb's Thriftway stores in the Portland area.
"Originally, we had thought we would go to an open deli case, because we didn't want a barrier between the customer and the product," said Lamb. "But it turned out the energy consumption would have been much higher in the remodeled store, and would require a whole new electrical panel, costing tens of thousands of dollars."
Customer reaction to the refrigerated cases, which include antisweat heaters and humidity monitors to keep the doors from fogging up, has been good, according to Lamb. "Everybody likes them, sales are fine and the product stays better as well," he said.
"The newer refrigerated cases all have prism lighting, which comes from vertical fluorescent lights located between the doors. It displays the product very well, maybe better than with older cases," he added.
The 15 compressor units that cool the refrigerated cases were also replaced during the renovation, which took place from December 1996 to August 1997. The new system is providing savings both in energy costs and maintenance, according to Lamb.
The new parallel compressor rack system has a total of six compressors cooling refrigeration units throughout the store. "We'll often have only two or three of them running the entire store," said Lamb.
Maintenance bills had been high with the old system, he noted, and Lamb wanted to avoid any refrigerant leaks. Rising refrigerant costs have made any type of leak very expensive, he said.
The old system used a reciprocating/piston compressor, "which [produced] a tremendous amount of vibration. It was contributing to the fatigue of the copper pipes," he said.
The new system uses a screw compressor with a variable-speed motor for even greater efficiency. Both screw and scroll compressors "reduce vibration and substantially reduce costs," Lamb noted.
The overall effect of the renovation was a change from "a conventional store to a marketplace store," said Lamb. New departments besides HMR, floral and bakery include video and pharmacy, as well as an in-store bank and post office. To service this variety of environments, Lamb's Thriftway maintains several different temperature zones with the help of its computerized energy-management system.
The system also provides savings by controlling the outdoor parking lot lights, which go on based on available daylight rather than operating on a timer. "As with the temperature controls, we just pick the lighting level we want," said Lamb.
The retailer received advice on the energy aspects of its renovation from its electric utility, Portland General Electric, Portland, Ore.