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Energy Conservation: Lighting
For the average retail property, lighting consumes 18 per cent of its energy use. Retail outlets could be missing out on savings of up to 30 per cent of lighting costs according to the Carbon Trust, with the potential for lighting efficiency initiatives to have a major effect on energy bills.
Not only have cost savings of 20 per cent to 40 per cent been achieved from improved lighting, dramatic increases in retail sales and improved employee productivity have been reported.
Breadth of Practice
In the Greening Retail best practices database, the most frequent method to reduce energy use from lighting is by changing lighting fixtures and bulbs with ones that are more energy-efficient. 24 out of 25 retailers in the database use this strategy. However, this option is best coupled with other practices to reduce lighting; for example, 5 of the case studies describe using more natural light (daylighting) to show off their merchandise. In five of the cases, retailers found that they could reduce the number of light fixtures; (4 out of 25) others use automatic controls to turn off lights (4) when the area is not in use.
The table below describes the types and frequency of fixture and bulb technologies that are found in the Greening Retail Best Practices Database.
One of the most effective ways for retailers to reduce energy use for lighting is to use natural sunlight as much as possible to light their stores. In a study prepared by the Heschong Mahone Group, published August 20, 1999, sales performance in 108 stores were compared. Two-thirds had daylighting, one third did not. Skylighting had the largest impact of five factors (skylighting, number of hours open per week, population of zip code, average income of zip code and number of years since store remodelled) boosting sales index by average of 40 per cent.
Among the stores to embrace skylights is Costco with more than 250 skylit stores in the United States. Costco's has been using skylights in all their new facilities since 1985. Every facility Wal-Mart builds today from the ground up includes a skylight/dimming system. As daylight increases, skylights allow Wal-Mart to dim the lights, or even turn them off, thereby reducing the demand for electricity during peak hours. HomeBase made a commitment to daylighting during a recent major remodelling campaign. Today, all 83 of this company's home improvement warehouse stores use extensive skylights and photocontrols.
Lighting sources impact the air conditioning load and the energy needed to operate the cooling system. Linking the luminaires to controls that respond to daylight sources is a recommended way to reduce operating hours for the lighting system and the cooling equipment needed to keep the indoor temperature at a comfortable level.
Another straightforward opportunity for energy savings comes from simply reducing the amount of lighting in an area. For example, the general sales-floor lighting in some of Calgary Co-op stores was so bright that track lighting over the produce was not highlighting the product properly. At the Richmond Road store, two fluorescent tubes were removed from each of the four-tube ceiling light fixtures, saving about $2,500 a year. Additional savings were found by grouping sales-floor lighting in zones and installing switches.
The reduced summer-lighting program was piloted in Wal-Mart stores throughout Ontario in the summers of 2005 and 2006, originally initiated in response to ongoing summer energy concerns in the province. Lighting throughout the 240 Wal-Mart stores was reduced to two-thirds. Costco also reduced indoor lighting by two-thirds during the day in response to the energy challenge
Motion Sensors: Motion sensors ensure that lighting is on only when rooms are occupied. At Calgary Co-op, motion sensors are replacing all light switches in washrooms, meeting rooms, offices, lunchrooms and walk-in freezers and coolers. The sensors are set to turn off lights after 10 minutes of inactivity. The sensors could save up to $3,000 per year in electricity costs at a single store. Office Depot is adding sensors in 476 stores for associate break rooms, restrooms and managers' offices. At H-E-B's corporate office, occupancy sensors were installed to automatically turn lights off 15 minutes after people leave a room. This has resulted in a savings of 4 per cent to 5 per cent.
Timed Lighting: In some areas, timed lighting is more appropriate than motion sensors. For example, at Calgary Co-op, in some locations, lights have been on 24 hours a day. They rezoned the circuits and connected them to a time clock. The result is a 50 percent reduction in lighting during off hours.
Energy Efficient Fixtures and Bulbs
Along with reducing the number of lighting fixtures and the amount of time they are left on, retailers are also changing to more energy-efficient fixtures.
Flourescent: Fluorescent lighting is a system involving both ballasts and lamps. A properly balanced fluorescent lamp/ballast system improves luminous effectiveness, improves colour characteristics, lengthens lamp life and increases energy efficiency. H-E-B's fluorescent high-bays are 40 per cent to 45 per cent more efficient and only lose 8 per cent of their light, declining to 92 per cent. The interior of the lighting fixture is highly reflective, which also increases the efficiency of the new units. H-E-B has three people in the area of lighting retrofits. Paybacks are generally under two years.
Electronic Ballast: Since 2000, all of Pic n' Pay's new stores are fitted with electronic ballast lighting. In addition to reducing the amount of electricity used in stores, the initiative is expected to enable a $1.5 million reduction in annual electricity expenses.
T8: Featuring a tube of only one inch in diameter, T8 lamps improve system efficiency. The smaller diameter of the T8 tube means that less of these costly materials are needed. In addition, T8 lamps provide optimum system efficiency when used with electronic ballasts.
T5: Fluorescent lamps are getting thinner. Although T8 lamps are still the choice for retrofitting most T12 installations and for new commercial construction, the new T5 suit some retailers better. World of Carpets improved energy efficiency by replacing its T12 fluorescent lamp and magnetic ballast lighting system with an ultra-energy efficient T5 fluorescent lamp and electronic ballast system. Office Depot ended 2006 with T5 coverage across the majority of North American footprint of over 1,110 stores.
Compact Fluorescent: Switching all of Ring Audio's existing light bulbs to compact fluorescents just made economic sense. With a small investment of approximately $60.00, Ring Audio is now saving 75 per cent on its lighting bill each month. For World of Carpets, savings were obtained by replacing highly inefficient incandescent flood lamps with ENERGY STAR qualified compact fluorescent lamps (CFLs).
LED: The Migros Supermarket in Eschenbach, Switzerland, sets an LED milestone by switching to 100 per cent LED lighting throughout the entire store-in the refrigerated compartments, overhead, and accenting the selection of products on offer.
Metal Halide: Bestway Supermarket is replacing standard fluorescent lighting with highly efficient metal-halide lamps.
Fiber Optics: Two features particularly applicable to food and jewelry merchandising are inherent to illumination by fiber optics: virtually no heat build-up, and no ultraviolet or infrared rays. This year, the EFO Fiber Optic Lighting System is being installed in more than a dozen Whole Foods supermarkets. First beta-tested in the Austin, Texas, flagship store, the patented system racked up a 72 percent savings over the existing lighting based on MR16 lamps.
This synopsis was compiled from case studies in the Greening Retail Best Practice Database. Sources for the information in the case studies are cited in the database.
This database contains links to case studies of environmental best practice from retailers around the world. You can search this database by the name of the company only, or you can find case studies that match one or several specific criteria, such as the type of retailer, the type of best practice, the company's country of origin, and/or project return on investment.
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